Derrick Wan

All Publications

• Clinical, mechanistic, and therapeutic landscape of cutaneous fibrosis. Science translational medicine Li, D. J., Berry, C. E., Wan, D. C., Longaker, M. T. 2024; 16 (766): eadn7871

  Abstract

  When dysregulated, skin fibrosis can lead to a multitude of pathologies. We provide a framework for understanding the wide clinical spectrum, mechanisms, and management of cutaneous fibrosis encompassing a variety of matrix disorders, fibrohistiocytic neoplasms, injury-induced scarring, and autoimmune scleroses. Underlying such entities are common mechanistic pathways that leverage morphogenic signaling, immune activation, and mechanotransduction to modulate fibroblast function. In light of the limited array of available treatments for cutaneous fibrosis, scientific insights have opened new therapeutic and investigative avenues for conditions that still lack effective interventions.

  View details for DOI 10.1126/scitranslmed.adn7871

  View details for PubMedID 39321265

• Comparing Cortiva Silhouette to AlloDerm for Use in Prepectoral Two-stage Prosthetic Breast Reconstruction. Plastic and reconstructive surgery. Global open Silverstein, M. L., Wan, D., Momeni, A. 2024; 12 (9): e6146

  Abstract

  The use of acellular dermal matrices (ADMs) in implant-based breast reconstruction has become increasingly routine during the past 20 years. ADMs improve soft-tissue support, facilitate greater tissue expander (TE) fill volumes, and reduce rates of capsular contracture. As the ADM market continues to grow, outcomes studies are necessary to assess the risks and benefits of each product. In this study, we compare the performance of Cortiva Silhouette, the thinnest ADM widely available, to AlloDerm, commonly considered the industry standard.We performed a retrospective review of 178 consecutive two-stage prosthetic breast reconstructions performed by the senior author. In every case, either Cortiva or AlloDerm was used to provide soft-tissue support during TE placement. Subjects were divided into Cortiva and AlloDerm cohorts and compared across patient characteristics and reconstructive outcomes variables.During the study period, AlloDerm was used in 116 reconstructions; Cortiva was used in 62. After propensity score matching (62 AlloDerm, 62 Cortiva), Cortiva was associated with greater intraoperative and final TE fill volumes, as well as larger silicone implants. Cortiva was also associated with fewer complications overall, and fewer instances of mastectomy skin necrosis, delayed wound healing, and seroma.Cortiva Silhouette is noninferior to AlloDerm in terms of safety and providing soft-tissue support in prepectoral two-stage implant-based breast reconstruction. In this study, Cortiva supported greater TE fill volumes and larger silicone implants relative to AlloDerm and was associated with fewer complications.

  View details for DOI 10.1097/GOX.0000000000006146

  View details for PubMedID 39247570

  View details for PubMedCentralID PMC11379484

• AI-based Cleft Lip and Palate Surgical Information is Preferred by Both Plastic Surgeons and Patients in a Blind Comparison. The Cleft palate-craniofacial journal : official publication of the American Cleft Palate-Craniofacial Association Fazilat, A. Z., Berry, C. E., Churukian, A., Lavin, C., Kameni, L., Brenac, C., Podda, S., Bruckman, K., Lorenz, H. P., Khosla, R. K., Wan, D. C. 2024: 10556656241266368

  Abstract

  INTRODUCTION: The application of artificial intelligence (AI) in healthcare has expanded in recent years, and these tools such as ChatGPT to generate patient-facing information have garnered particular interest. Online cleft lip and palate (CL/P) surgical information supplied by academic/professional (A/P) sources was therefore evaluated against ChatGPT regarding accuracy, comprehensiveness, and clarity.METHODS: 11 plastic and reconstructive surgeons and 29 non-medical individuals blindly compared responses written by ChatGPT or A/P sources to 30 frequently asked CL/P surgery questions. Surgeons indicated preference, determined accuracy, and scored comprehensiveness and clarity. Non-medical individuals indicated preference. Calculations of readability scores were determined using seven readability formulas. Statistical analysis of CL/P surgical online information was performed using paired t-tests.RESULTS: Surgeons, 60.88% of the time, blindly preferred material generated by ChatGPT over A/P sources. Additionally, surgeons consistently indicated that ChatGPT-generated material was more comprehensive and had greater clarity. No significant difference was found between ChatGPT and resources provided by professional organizations in terms of accuracy. Among individuals with no medical background, ChatGPT-generated materials were preferred 60.46% of the time. For materials from both ChatGPT and A/P sources, readability scores surpassed advised levels for patient proficiency across seven readability formulas.CONCLUSION: As the prominence of ChatGPT-based language tools rises in the healthcare space, potential applications of the tools should be assessed by experts against existing high-quality sources. Our results indicate that ChatGPT is capable of producing high-quality material in terms of accuracy, comprehensiveness, and clarity preferred by both plastic surgeons and individuals with no medical background.

  View details for DOI 10.1177/10556656241266368

  View details for PubMedID 39091088

• Understanding the Foreign Body Response via Single-Cell Meta-Analysis. Biology Liang, N. E., Parker, J. B., Lu, J. M., Januszyk, M., Wan, D. C., Griffin, M., Longaker, M. T. 2024; 13 (7)

  Abstract

  Foreign body response (FBR) is a universal reaction to implanted biomaterial that can affect the function and longevity of the implant. A few studies have attempted to identify targets for treating FBR through the use of single-cell RNA sequencing (scRNA-seq), though the generalizability of these findings from an individual study may be limited. In our study, we perform a meta-analysis of scRNA-seq data from all available FBR mouse studies and integrate these data to identify gene signatures specific to FBR across different models and anatomic locations. We identify subclusters of fibroblasts and macrophages that emerge in response to foreign bodies and characterize their signaling pathways, gene ontology terms, and downstream mediators. The fibroblast subpopulations enriched in the setting of FBR demonstrated significant signaling interactions in the transforming growth factor-beta (TGF-beta) signaling pathway, with known pro-fibrotic mediators identified as top expressed genes in these FBR-derived fibroblasts. In contrast, FBR-enriched macrophage subclusters highly expressed pro-fibrotic and pro-inflammatory mediators downstream of tumor necrosis factor (TNF) signaling. Cell-cell interactions were additionally interrogated using CellChat, with identification of key signaling interactions enriched between fibroblasts and macrophages in FBR. By combining multiple FBR datasets, our meta-analysis study identifies common cell-specific gene signatures enriched in foreign body reactions, providing potential therapeutic targets for patients requiring medical implants across a myriad of devices and indications.

  View details for DOI 10.3390/biology13070540

  View details for PubMedID 39056733

• Role of ferroptosis in radiation-induced soft tissue injury. Cell death discovery Berry, C. E., Kendig, C. B., An, N., Fazilat, A. Z., Churukian, A. A., Griffin, M., Pan, P. M., Longaker, M. T., Dixon, S. J., Wan, D. C. 2024; 10 (1): 313

  Abstract

  Ionizing radiation has been pivotal in cancer therapy since its discovery. Despite its therapeutic benefits, IR causes significant acute and chronic complications due to DNA damage and the generation of reactive oxygen species, which harm nucleic acids, lipids, and proteins. While cancer cells are more vulnerable to ionizing radiation due to their inefficiency in repairing damage, healthy cells in the irradiated area also suffer. Various types of cell death occur, including apoptosis, necrosis, pyroptosis, autophagy-dependent cell death, immunogenic cell death, and ferroptosis. Ferroptosis, driven by iron-dependent lipid peroxide accumulation, has been recognized as crucial in radiation therapy's therapeutic effects and complications, with extensive research across various tissues. This review aims to summarize the pathways involved in radiation-related ferroptosis, findings in different organs, and drugs targeting ferroptosis to mitigate its harmful effects.

  View details for DOI 10.1038/s41420-024-02003-5

  View details for PubMedID 38969638

  View details for PubMedCentralID PMC11226648

• Single-cell transcriptional analysis of irradiated skin reveals changes in fibroblast subpopulations and variability in caveolin expression. Radiation oncology (London, England) Kameni, L. E., Griffin, M., Berry, C. E., Shariatzadeh, S., Downer, M. A., Valencia, C., Fazilat, A. Z., Nazerali, R., Momeni, A., Januszyk, M., Longaker, M. T., Wan, D. C. 2024; 19 (1): 82

  Abstract

  Radiation-induced fibrosis (RIF) is an important late complication of radiation therapy, and the resulting damaging effects of RIF can significantly impact reconstructive outcomes. There is currently a paucity of effective treatment options available, likely due to the continuing knowledge gap surrounding the cellular mechanisms involved. In this study, detailed analyses of irradiated and non-irradiated human skin samples were performed incorporating histological and single-cell transcriptional analysis to identify novel features guiding development of skin fibrosis following radiation injury.Paired irradiated and contralateral non-irradiated skin samples were obtained from six female patients undergoing post-oncologic breast reconstruction. Skin samples underwent histological evaluation, immunohistochemistry, and biomechanical testing. Single-cell RNA sequencing was performed using the 10X single cell platform. Cells were separated into clusters using Seurat in R. The SingleR classifier was applied to ascribe cell type identities to each cluster. Differentially expressed genes characteristic to each cluster were then determined using non-parametric testing.Comparing irradiated and non-irradiated skin, epidermal atrophy, dermal thickening, and evidence of thick, disorganized collagen deposition within the extracellular matrix of irradiated skin were readily appreciated on histology. These histologic features were associated with stiffness that was higher in irradiated skin. Single-cell RNA sequencing revealed six predominant cell types. Focusing on fibroblasts/stromal lineage cells, five distinct transcriptional clusters (Clusters 0-4) were identified. Interestingly, while all clusters were noted to express Cav1, Cluster 2 was the only one to also express Cav2. Immunohistochemistry demonstrated increased expression of Cav2 in irradiated skin, whereas Cav1 was more readily identified in non-irradiated skin, suggesting Cav1 and Cav2 may act antagonistically to modulate fibrotic cellular responses.In response to radiation therapy, specific changes to fibroblast subpopulations and enhanced Cav2 expression may contribute to fibrosis. Altogether, this study introduces a novel pathway of caveolin involvement which may contribute to fibrotic development following radiation injury.

  View details for DOI 10.1186/s13014-024-02472-z

  View details for PubMedID 38926892

  View details for PubMedCentralID 6329848

• Microsurgical Breast Reconstruction can be Performed Safely in Patients with Obesity. Journal of reconstructive microsurgery Silverstein, M. L., Sorice-Virk, S., Wan, D. C., Momeni, A. 2024

  Abstract

   Numerous studies have shown that obesity is a risk factor for postoperative complications following breast reconstruction. Hence, obesity has traditionally been considered a relative contraindication to microsurgical breast reconstruction. In this study, we investigated the impact of obesity on outcomes following microsurgical breast reconstruction. A retrospective analysis of 200 consecutive patients who underwent microsurgical breast reconstruction with free abdominal flaps was performed. Subjects were divided into Nonobese (body mass index [BMI] < 30 kg/m2) and Obese (BMI ≥ 30 kg/m2) cohorts. Univariate and multivariate analyses were performed to evaluate differences in patient characteristics, complication rates, and efficiency metrics between the two groups. Of the 200 subjects included in the study, 128 were Nonobese, 72 were Obese. The prevalence of diabetes (3.9 vs. 16.9%, p = 0.002) and hypertension (14.7 vs. 39.4%, p < 0.001) were significantly greater in the Obese cohort. Among unilateral reconstructions, postoperative length of stay (LOS) was longer among Obese patients (3.1 vs. 3.6 days, p = 0.016). Seroma occurred more frequently in Obese patients following bilateral reconstruction (5.7 vs. 0.0%, p = 0.047). Otherwise, there were no significant differences in complication rates between the groups. On multivariate analysis, BMI was not independently associated with complications, LOS, or operative time. The improvements in clinical and patient-reported outcomes that have been associated with postmastectomy breast reconstruction do not exclude obese women. This study indicates that microsurgical breast reconstruction can be performed safely and efficiently in patients with obesity.

  View details for DOI 10.1055/s-0044-1787266

  View details for PubMedID 38815573

• Ferroptosis Inhibition with Deferoxamine Alleviates Radiation-Induced Fibrosis. Research square Berry, C. E., Kendig, C., Bs, T. L., Brenac, C., Griffin, M., Guo, J., Kameni, L., Dixon, S. J., Longaker, M. T., Wan, D. 2024

  Abstract

  Radiation-induced fibrosis (RIF) is a debilitating sequelae of radiation therapy that has been shown to improve with topical treatment with the iron chelator deferoxamine (DFO). We investigated whether DFO exerts this effect through attenuation of ferroptosis, a recently described iron-dependent pathway of cell death.Adult C57BL/6J mice were treated with topical DFO or ferrostastin-1 (Fer-1) and irradiated with 30 Grays of ionizing radiation to the dorsal skin to promote development of chronic RIF. Immunofluorescent staining with 4-hydroxynonenal (4-HNE) antibody was carried out directly following irradiation to assess ferroptosis activity. Perfusion testing with laser Doppler was performed throughout the healing interval. Eight weeks following radiation, dorsal skin was harvested and analyzed histologically and biomechanically.Immunohistochemical staining demonstrated lower presence of 4-HNE in non-irradiated skin, DFO-treated skin, and Fer-1-treated skin compared to irradiated, untreated skin. DFO resulted in histological measurements (dermal thickness and collagen content) that resembled normal skin, while Fer-1 treatment yielded less significant improvements. These results were mirrored by analysis of extracellular matrix ultrastructure and biomechanical testing, which recapitulated the ability of topical DFO treatment to alleviate RIF across these parameters while Fer-1 resulted in less notable improvement. Finally, perfusion levels in DFO treated irradiated skin were similar to measurements in normal skin, while Fer-1 treatment did not impact this feature.Ferroptosis contributes to the development of RIF and attenuation of this process leads to reduced skin injury. DFO further improves RIF through additional enhancement of perfusion not seen with Fer-1.

  View details for DOI 10.21203/rs.3.rs-4314380/v1

  View details for PubMedID 38853919

  View details for PubMedCentralID PMC11160928

• Deferoxamine topical cream superior to patch in rescuing radiation-induced fibrosis of unwounded and wounded skin. Journal of cellular and molecular medicine Berry, C. E., Abbas, D. B., Griffin, M., Lintel, H., Guo, J., Kameni, L., Churukian, A. A., Fazilat, A. Z., Chen, K., Gurtner, G. C., Longaker, M. T., Momeni, A., Wan, D. C. 2024; 28 (8): e18306

  Abstract

  Topical patch delivery of deferoxamine (DFO) has been studied as a treatment for this fibrotic transformation in irradiated tissue. Efficacy of a novel cream formulation of DFO was studied as a RIF therapeutic in unwounded and excisionally wounded irradiated skin. C57BL/6J mice underwent 30 Gy of radiation to the dorsum followed by 4 weeks of recovery. In a first experiment, mice were separated into six conditions: DFO 50 mg cream (D50), DFO 100 mg cream (D100), soluble DFO injections (DI), DFO 1 mg patch (DP), control cream (Vehicle), and irradiated untreated skin (IR). In a second experiment, excisional wounds were created on the irradiated dorsum of mice and then divided into four treatment groups: DFO 100 mg Cream (W-D100), DFO 1 mg patch (W-DP), control cream (W-Vehicle), and irradiated untreated wounds (W-IR). Laser Doppler perfusion scans, biomechanical testing, and histological analysis were performed. In irradiated skin, D100 improved perfusion compared to D50 or DP. Both D100 and DP enhanced dermal characteristics, including thickness, collagen density and 8-isoprostane staining compared to untreated irradiated skin. D100 outperformed DP in CD31 staining, indicating higher vascular density. Extracellular matrix features of D100 and DP resembled normal skin more closely than DI or control. In radiated excisional wounds, D100 facilitated faster wound healing and increased perfusion compared to DP. The 100 mg DFO cream formulation rescued RIF of unwounded irradiated skin and improved excisional wound healing in murine skin relative to patch delivery of DFO.

  View details for DOI 10.1111/jcmm.18306

  View details for PubMedID 38613357

• Modelling and targeting mechanical forces in organ fibrosis. Nature reviews bioengineering Mascharak, S., Guo, J. L., Griffin, M., Berry, C. E., Wan, D. C., Longaker, M. T. 2024; 2 (4): 305-323

  Abstract

  Few efficacious therapies exist for the treatment of fibrotic diseases, such as skin scarring, liver cirrhosis and pulmonary fibrosis, which is related to our limited understanding of the fundamental causes and mechanisms of fibrosis. Mechanical forces from cell-matrix interactions, cell-cell contact, fluid flow and other physical stimuli may play a central role in the initiation and propagation of fibrosis. In this Review, we highlight the mechanotransduction mechanisms by which various sources of physical force drive fibrotic disease processes, with an emphasis on central pathways that may be therapeutically targeted to prevent and reverse fibrosis. We then discuss engineered models of mechanotransduction in fibrosis, as well as molecular and biomaterials-based therapeutic approaches for limiting fibrosis and promoting regenerative healing phenotypes in various organs. Finally, we discuss challenges within fibrosis research that remain to be addressed and that may greatly benefit from next-generation bioengineered model systems.

  View details for DOI 10.1038/s44222-023-00144-3

  View details for PubMedID 39552705

• Understanding wound healing in obesity. World journal of experimental medicine Cotterell, A., Griffin, M., Downer, M. A., Parker, J. B., Wan, D., Longaker, M. T. 2024; 14 (1): 86898

  Abstract

  Obesity has become more prevalent in the global population. It is associated with the development of several diseases including diabetes mellitus, coronary heart disease, and metabolic syndrome. There are a multitude of factors impacted by obesity that may contribute to poor wound healing outcomes. With millions worldwide classified as obese, it is imperative to understand wound healing in these patients. Despite advances in the understanding of wound healing in both healthy and diabetic populations, much is unknown about wound healing in obese patients. This review examines the impact of obesity on wound healing and several animal models that may be used to broaden our understanding in this area. As a growing portion of the population identifies as obese, understanding the underlying mechanisms and how to overcome poor wound healing is of the utmost importance.

  View details for DOI 10.5493/wjem.v14.i1.86898

  View details for PubMedID 38590299

  View details for PubMedCentralID PMC10999071

• A tension offloading patch mitigates dermal fibrosis induced by pro-fibrotic skin injections. Research square Talbott, H. E., Griffin, M. F., Mascharak, S., Parker, J. B., Kuhnert, M. M., Guo, J. L., Diaz Deleon, N. M., Lavin, C., Abbas, D., Guardino, N., Morgan, A., Valencia, C., Cotterell, A., Longaker, M. T., Wan, D. C. 2024

  Abstract

  Skin fibrosis is a clinical problem with devastating impacts but limited treatment options. In the setting of diabetes, insulin administration often causes local dermal fibrosis, leading to a range of clinical sequelae including impeded insulin absorption. Mechanical forces are important drivers of fibrosis and, clinically, physical tension offloading at the skin level using an elastomeric patch significantly reduces wound scarring. However, it is not known whether tension offloading could similarly prevent skin fibrosis in the setting of pro-fibrotic injections. Here, we develop a porcine model using repeated local injections of bleomycin to recapitulate key features of insulin-induced skin fibrosis. Using histologic, tissue ultrastructural, and biomechanical analyses, we show that application of a tension-offloading patch both prevents and rescues existing skin fibrosis from bleomycin injections. By applying single-cell transcriptomic analysis, we find that the fibrotic response to bleomycin involves shifts in myeloid cell dynamics from favoring putatively pro-regenerative to pro-fibrotic myeloid subtypes; in a mechanomodulatory in vitro platform, we show that these shifts are mechanically driven and reversed by exogenous IL4. Finally, using a human foreskin xenograft model, we show that IL4 treatment mitigates bleomycin-induced dermal fibrosis. Overall, this study highlights that skin tension offloading, using an FDA cleared, commercially available patch, could have significant potential clinical benefit for the millions of patients dependent on insulin.

  View details for DOI 10.21203/rs.3.rs-3915097/v1

  View details for PubMedID 38464040

• Deferoxamine Intradermal Delivery Patch for Treatment of a Beta-Thalassemia Wound. Annals of surgery open : perspectives of surgical history, education, and clinical approaches Perrault, D., Chattopadhyay, A., Sivaraj, D., Wan, D., Chen, K., Gurtner, G., Sen, S. 2024; 5 (1): e372

  Abstract

  In this study, we present the first-in-human use of topical deferoxamine (DFO) in the treatment of a beta-thalassemia wound. We elected to use DFO on a patient that suffered from a chronic nonhealing wound in the setting of beta-thalassemia. Despite approximately 55 weeks of marginal improvement in healing, this patient's wound healed completely after 21 weeks of treatment with DFO. We believe that DFO has the potential to accelerate healing in beta-thalassemia wounds through iron chelation.

  View details for DOI 10.1097/AS9.0000000000000372

  View details for PubMedID 38883943

  View details for PubMedCentralID PMC11175915

• Both Patients and Plastic Surgeons prefer AI-Generated Microsurgical Information. Journal of reconstructive microsurgery Berry, C., Fazilat, A. Z., Lavin, C. V., Lintel, H., Cole, N. A., Stingl, C. S., Valencia, C., Morgan, A. G., Momeni, A., Wan, D. C. 2024

  Abstract

  BACKGROUND: With the growing relevance of AI-based patient-facing information, microsurgical-specific online information provided by professional organizations was compared to that of ChatGPT and assessed for accuracy, comprehensiveness, clarity, and readability.METHODS: Six plastic and reconstructive surgeons blindly assessed responses to ten microsurgery-related medical questions written either by American Society of Reconstructive Microsurgery (ASRM) or ChatGPT based on accuracy, comprehensiveness, and clarity. Surgeons were asked to choose which source provided the overall highest quality microsurgical patient-facing information. Additionally, 30 individuals with no medical background (ages 18-81, mu=49.8) were asked to determine a preference when blindly comparing materials. Readability scores were calculated, and all numerical scores were analyzed using the following six reliability formulas: Flesch-Kincaid Grade Level, Flesch-Kincaid Readability Ease, Gunning Fog Index, Simple Measure of Gobbledygook (SMOG) Index, Coleman-Liau Index, Linsear Write Formula (LWF), and Automated Readability Index. Statistical analysis of microsurgical-specific online sources was conducted utilizing paired t-tests.RESULTS: Statistically significant differences in comprehensiveness and clarity were seen in favor of ChatGPT. Surgeons, 70.7% of the time, blindly choose ChatGPT as the source that overall provided the highest quality microsurgical patient-facing information. Non-medical individuals 55.9% of the time selected AI-generated microsurgical materials as well. Neither ChatGPT nor ASRM-generated materials were found to contain inaccuracies. Readability scores for both ChatGPT and ASRM materials were found to exceed recommended levels for patient proficiency across six readability formulas, with AI-based material scored as more complex.CONCLUSION: AI-generated patient-facing materials were preferred by surgeons in terms of comprehensiveness and clarity when blindly compared to online material provided by ASRM. Studied AI-generated material was not found to contain inaccuracies. Additionally, surgeons and non-medical individuals consistently indicated an overall preference for AI-generated material. A readability analysis suggested that both materials sourced from ChatGPT and ASRM surpassed recommended reading levels across six readability scores.

  View details for DOI 10.1055/a-2273-4163

  View details for PubMedID 38382637

• Pharmacological and cell-based treatments to increase local skin flap viability in animal models. Journal of translational medicine Berry, C. E., Le, T., An, N., Griffin, M., Januszyk, M., Kendig, C. B., Fazilat, A. Z., Churukian, A. A., Pan, P. M., Wan, D. C. 2024; 22 (1): 68

  Abstract

  Local skin flaps are frequently employed for wound closure to address surgical, traumatic, congenital, or oncologic defects. (1) Despite their clinical utility, skin flaps may fail due to inadequate perfusion, ischemia/reperfusion injury (IRI), excessive cell death, and associated inflammatory response. (2) All of these factors contribute to skin flap necrosis in 10-15% of cases and represent a significant surgical challenge. (3, 4) Once flap necrosis occurs, it may require additional surgeries to remove the entire flap or repair the damage and secondary treatments for infection and disfiguration, which can be costly and painful. (5) In addition to employing appropriate surgical techniques and identifying healthy, well-vascularized tissue to mitigate the occurrence of these complications, there is growing interest in exploring cell-based and pharmacologic augmentation options. (6) These agents typically focus on preventing thrombosis and increasing vasodilation and angiogenesis while reducing inflammation and oxidative stress. Agents that modulate cell death pathways such as apoptosis and autophagy have also been investigated. (7) Implementation of drugs and cell lines with potentially beneficial properties have been proposed through various delivery techniques including systemic treatment, direct wound bed or flap injection, and topical application. This review summarizes pharmacologic- and cell-based interventions to augment skin flap viability in animal models, and discusses both translatability challenges facing these therapies and future directions in the field of skin flap augmentation.

  View details for DOI 10.1186/s12967-024-04882-9

  View details for PubMedID 38233920

  View details for PubMedCentralID 7791712

• US air pollution is associated with increased incidence of non-syndromic cleft lip/palate. Journal of plastic, reconstructive & aesthetic surgery : JPRAS Krakauer, K. N., Cevallos, P. C., Amakiri, U. O., Saldana, G. M., Lipman, K. J., Howell, L. K., Wan, D. C., Khosla, R. K., Nazerali, R., Sheckter, C. C. 2023; 88: 344-351

  Abstract

  Maternal cigarette use is associated with the fetal development of orofacial clefts. Air pollution should be investigated for similar causation. We hypothesize that the incidence of non-syndromic cleft lip with or without palate (NSCLP) and non-syndromic cleft palate (NSCP) would be positively correlated with air pollution concentration.The incidence of NSCLP and NSCP per 1000 live births from 2016 to 2020 was extracted from the Centers for Disease Control and Prevention Vital Statistics Database and merged with national reports on air pollution using the Environmental Protection Agency Air Quality Systems annual data. The most commonly reported pollutants were analyzed including benzene, sulfur dioxide (SO2), particulate matter (PM) 2.5, PM 10, ozone (O3), and carbon monoxide (CO). Multivariable negative binomial and Poisson log-linear regression models evaluated the incidence of NSCLP and NSCP as a function of the pollutants, adjusting for race. All p-values are reported with Bonferroni correction.The median NSCLP incidence was 0.22/1000 births, and isolated NSCP incidence was 0.18/1000 births. For NSCLP, SO2 had a coefficient estimate (CE) of 0.60 (95% CI [0.23, 0.98], p < 0.007) and PM 2.5 had a CE of 0.20 (95% CI [0.10, 0.31], p < 0.005). Among isolated NSCP, no pollutants were found to be significantly associated.SO2 and PM 2.5 were significantly correlated with increased incidence of NSCLP. The American people and perinatal practitioners should be aware of the connection to allow for risk reduction and in utero screening.

  View details for DOI 10.1016/j.bjps.2023.11.012

  View details for PubMedID 38064913

• Healing of Chronically Irradiated Excisional Wounds Improved by Topical Deferoxamine Treatment Berry, C., Griffin, M., Kameni, L., Abbas, D., Downer, M., Parker, J. B., Liang, N., Januszyk, M., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2023: S382-S383

  View details for Web of Science ID 001094086301234

• Single-Cell RNA-Seq Analysis Reveals Similar Fibroblasts in Irradiated Skin of Humans, Mice, and Pigs Kameni, L., Berry, C., Griffin, M., Januszyk, M., Downer, M., Huber, J. L., Parker, J., Momeni, A., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2023: S389

  View details for Web of Science ID 001094086301247

• Single-Cell RNA-Sequencing Identifies Modulator of Foreign Body Response with Use of Acellular Dermal Matrix in Breast Reconstruction Liang, N., Tevlin, R., Griffin, M., Parker, J. B., Henn, D., Navarro, R. S., Dung Nguyen, Momeni, A., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2023: S389-S390

  View details for Web of Science ID 001094086301248

• Tissue Microenvironment a Key Driver in Fibrotic Capsules Formed During Foreign Body Response Parker, J. B., Griffin, M., Downer, M., Morgan, A., Guo, J. L., Liang, N., Berry, C., Diiorio, S., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2023: S393

  View details for Web of Science ID 001094086301255

• Fat Grafting Treatment for Radiation-Induced Fibrosis Results in Downregulation of Inflammatory and Fibrotic Signaling Pathways Berry, C., Abbas, D., Kameni, L., Griffin, M., Downer, M., Parker, J. B., Guo, J. L., Januszyk, M., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2023: S381-S382

  View details for Web of Science ID 001094086301232

• Analysis of Collagen Extracellular Matrix Ultrastructure in Mouse Long Bone Distraction Osteogenesis Diiorio, S., Guo, J. L., Griffin, M., Huber, J. L., Downer, M., Berry, C., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2023: S378-S379

  View details for Web of Science ID 001094086301225

• Grafting of Human Foreskin onto Murine Dorsum Provides a Novel Model of Chronic Radiation-Induced Fibrosis Berry, C., Abbas, D., Griffin, M., Kameni, L., Downer, M., Parker, J. B., Liang, N., Dilorio, S., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2023: S398

  View details for Web of Science ID 001094086301270

• Meta-Analysis of Single-Cell Transcriptomics Data of Cardiac Fibroblasts Reveals Temporal Heterogeneity of Cardiac Fibroblast Response after MI Lu, J., Januszyk, M., Griffin, M., Guo, J. L., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2023: S68

  View details for Web of Science ID 001094086300124

• Novel Deferoxamine Cream Formulation Improves Perfusion, Elasticity, and Tissue Architecture in Chronically Irradiated Murine Skin Compared to Transdermal Patch Berry, C., Abbas, D., Kameni, L., Griffin, M., Downer, M., Parker, J. B., Liang, N., Guo, J. L., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2023: S386

  View details for Web of Science ID 001094086301241

• Pioglitazone Decreases Adipogenisis Leading to Melanoma Skin Tumor Suppression Downer, M., Griffin, M., Morgan, A., Parker, J. B., Berry, C., Li, D. J., Liang, N., Kameni, L., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2023: S387-S388

  View details for Web of Science ID 001094086301244

• Ferropotosis Levels Decrease in Response to Deferoxamine Treatment in Irradiated Murine Skin Berry, C., Kameni, L., Griffin, M., Downer, M., Parker, J. B., Guo, J. L., Liang, N., Januszyk, M., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2023: S382

  View details for Web of Science ID 001094086301233

• A Review of Radiation-Induced Vascular Injury and Clinical Impact. Annals of plastic surgery Kameni, L. E., Januszyk, M., Berry, C. E., Downer, M. A., Parker, J. B., Morgan, A. G., Valencia, C., Griffin, M., Li, D. J., Liang, N. E., Momeni, A., Longaker, M. T., Wan, D. C. 2023

  Abstract

  ABSTRACT: The number of cancer survivors continues to increase because of advances in therapeutic modalities. Along with surgery and chemotherapy, radiotherapy is a commonly used treatment modality in roughly half of all cancer patients. It is particularly helpful in the oncologic treatment of patients with breast, head and neck, and prostate malignancies. Unfortunately, among patients receiving radiation therapy, long-term sequalae are often unavoidable, and there is accumulating clinical evidence suggesting significant radiation-related damage to the vascular endothelium. Ionizing radiation has been known to cause obliterative fibrosis and increased wall thickness in irradiated blood vessels. Clinically, these vascular changes induced by ionizing radiation can pose unique surgical challenges when operating in radiated fields. Here, we review the relevant literature on radiation-induced vascular damage focusing on mechanisms and signaling pathways involved and highlight microsurgical anastomotic outcomes after radiotherapy. In addition, we briefly comment on potential therapeutic strategies, which may have the ability to mitigate radiation injury to the vascular endothelium.

  View details for DOI 10.1097/SAP.0000000000003723

  View details for PubMedID 37962260

• Quality Assessment of Online Resources for Gender-affirming Surgery. Plastic and reconstructive surgery. Global open Berry, C. E., Fazilat, A. Z., Churukian, A. A., Abbas, D. B., Griffin, M., Downer, M., Januszyk, M., Momeni, A., Morrison, S. D., Wan, D. C. 2023; 11 (10): e5306

  Abstract

  Background: As visibility of the transgender patient population and utilization of online resources increases, it is imperative that web-based gender-affirming surgery (GAS) materials for patients are readable, accessible, and of high quality.Methods: A search trends analysis was performed to determine frequency of GAS-related searches over time. The top 100 most common results for GAS-related terms were analyzed using six readability formulas. Accessibility of patient-facing GAS sources was determined by categorizing types of search results. Frequency of article types was compared in low- and high-population dense areas. Quality was assigned to GAS web-based sources using the DISCERN score.Results: Search engine trend data demonstrates increasing occurrence of searches related to GAS. Readability scores of the top 100 online sources for GAS were discovered to exceed recommended levels for patient proficiency. Availability of patient-facing online information related to GAS was found to be 60%, followed by information provided by insurance companies (17%). Differences in availability of online resources in varying dense cities were found to be minimal. The average quality of sources determined by the DISCERN score was found to be 3, indicating "potential important shortcomings."Conclusions: Despite increasing demand for web-based GAS information, the readability of online resources related to GAS was found to be significantly greater than the grade level of proficiency recommended for patients. A high number of nonpatient-facing search results appear in response to GAS search terms. Quality sources are still difficult for patients to find, as search results have a high incidence of low-quality resources.

  View details for DOI 10.1097/GOX.0000000000005306

  View details for PubMedID 37817924

• Allele-specific expression reveals genetic drivers of tissue regeneration in mice. Cell stem cell Mack, K. L., Talbott, H. E., Griffin, M. F., Parker, J. B., Guardino, N. J., Spielman, A. F., Davitt, M. F., Mascharak, S., Downer, M., Morgan, A., Valencia, C., Akras, D., Berger, M. J., Wan, D. C., Fraser, H. B., Longaker, M. T. 2023

  Abstract

  In adult mammals, skin wounds typically heal by scarring rather than through regeneration. In contrast, "super-healer" Murphy Roths Large (MRL) mice have the unusual ability to regenerate ear punch wounds; however, the molecular basis for this regeneration remains elusive. Here, in hybrid crosses between MRL and non-regenerating mice, we used allele-specific gene expression to identify cis-regulatory variation associated with ear regeneration. Analyzing three major cell populations (immune, fibroblast, and endothelial), we found that genes with cis-regulatory differences specifically in fibroblasts were associated with wound-healing pathways and also co-localized with quantitative trait loci for ear wound-healing. Ectopic treatment with one of these proteins, complement factor H (CFH), accelerated wound repair and induced regeneration in typically fibrotic wounds. Through single-cell RNA sequencing (RNA-seq), we observed that CFH treatment dramatically reduced immune cell recruitment to wounds, suggesting a potential mechanism for CFH's effect. Overall, our results provide insights into the molecular drivers of regeneration with potential clinical implications.

  View details for DOI 10.1016/j.stem.2023.08.010

  View details for PubMedID 37714154

• Technical Tips to Reduce Implant Rippling in Staged Pre-pectoral Breast Reconstruction. Aesthetic plastic surgery Tevlin, R., Sharma, A. D., Griffin, M., Wan, D., Momeni, A. 2023

  Abstract

  INTRODUCTION: Pre-pectoral implant-based breast reconstruction (IBR) is becoming increasingly popular, permitting optimal implant positioning on the chest wall, prevention of animation deformity, and reduced patient discomfort. There are, however, concerns related to increased rates of breast implant rippling in pre-pectoral (versus submuscular) IBR, which can prompt a patient to seek revisionary surgery. The aim of this study is to identify factors that can be implemented to reduce implant rippling in the setting of pre-pectoral IBR.METHODS: A literature review was conducted using the PubMed database to determine the rate of rippling in pre-pectoral IBR. Clinical studies in English were included. Further review was then performed to explore technical strategies associated with reduced rates of rippling in pre-pectoral two-stage breast reconstruction.RESULTS: Implant rippling has been reported with a rate varying from 0 to 53.8% in 25 studies of pre-pectoral IBR (including both direct-to-implant and two-stage IBR). The majority of studies reviewed did not demonstrate a significant association between BMI and rippling, suggesting that other factors, likely technical and device-related, contribute to the manifestation of implant rippling. Hence, we explored whether specific technical modifications could be implemented that would reduce the risk of rippling in patients undergoing pre-pectoral IBR. Specifically, we highlight the need for close attention to expansion protocol and pocket dimension, expander fill medium and implant characteristics, and the rationale behind adjunctive procedures to reduce implant rippling.CONCLUSION: Surgical modifications may reduce the incidence of rippling in pre-pectoral breast reconstruction.LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  View details for DOI 10.1007/s00266-023-03616-4

  View details for PubMedID 37704858

• Commentary on: Postoperative Mechanomodulation Decreases T-Junction Dehiscence After Reduction Mammaplasty: Early Scar Analysis From a Randomized Controlled Trial. Aesthetic surgery journal Berry, C. E., Longaker, M. T., Wan, D. C. 2023

  View details for DOI 10.1093/asj/sjad281

  View details for PubMedID 37625787

• Understanding Fibroblast Heterogeneity in Form and Function. Biomedicines Parker, J. B., Valencia, C., Akras, D., DiIorio, S. E., Griffin, M. F., Longaker, M. T., Wan, D. C. 2023; 11 (8)

  Abstract

  Historically believed to be a homogeneous cell type that is often overlooked, fibroblasts are more and more understood to be heterogeneous in nature. Though the mechanisms behind how fibroblasts participate in homeostasis and pathology are just beginning to be understood, these cells are believed to be highly dynamic and play key roles in fibrosis and remodeling. Focusing primarily on fibroblasts within the skin and during wound healing, we describe the field's current understanding of fibroblast heterogeneity in form and function. From differences due to embryonic origins to anatomical variations, we explore the diverse contributions that fibroblasts have in fibrosis and plasticity. Following this, we describe molecular techniques used in the field to provide deeper insights into subpopulations of fibroblasts and their varied roles in complex processes such as wound healing. Limitations to current work are also discussed, with a focus on future directions that investigators are recommended to take in order to gain a deeper understanding of fibroblast biology and to develop potential targets for translational applications in a clinical setting.

  View details for DOI 10.3390/biomedicines11082264

  View details for PubMedID 37626760

• Understanding the Role of Adipocytes and Fibroblasts in Cancer. Annals of plastic surgery Downer, M. A., Griffin, M. F., Morgan, A. G., Parker, J. B., Li, D. J., Berry, C. E., Liang, N. E., Kameni, L., Cotterell, A. C., Akras, D., Valencia, C., Longaker, M. T., Wan, D. C. 2023

  Abstract

  Cancer is currently the second leading cause of death in the United States. There is increasing evidence that the tumor microenvironment (TME) is pivotal for tumorigenesis and metastasis. Recently, adipocytes and cancer-associated fibroblasts (CAFs) in the TME have been shown to play a major role in tumorigenesis of different cancers, specifically melanoma. Animal studies have shown that CAFs and adipocytes within the TME help tumors evade the immune system, for example, by releasing chemokines to blunt the effectiveness of the host defense. Although studies have identified that adipocytes and CAFs play a role in tumorigenesis, adipocyte transition to fibroblast within the TME is fairly unknown. This review intends to elucidate the potential that adipocytes may have to transition to fibroblasts and, as part of the TME, a critical role that CAFs may play in affecting the growth and invasion of tumor cells. Future studies that illuminate the function of adipocytes and CAFs in the TME may pave way for new antitumor therapies.

  View details for DOI 10.1097/SAP.0000000000003658

  View details for PubMedID 37553786

• Complication Rates in Therapeutic Versus Prophylactic Bilateral Mastectomies: Insights From a National Database. Annals of plastic surgery Shaheen, M. S., Wan, D., Momeni, A. 2023

  Abstract

  The "Jolie effect" and other media focus on prophylactic treatments have resulted in unilateral breast cancer patients increasingly undergoing contralateral prophylactic mastectomy. Little is known, however, regarding outcomes following therapeutic versus prophylactic mastectomy. In this study, we compared complication rates of unilateral breast cancer patients undergoing contralateral prophylactic mastectomy (BM-TP) to patients undergoing bilateral prophylactic mastectomy (BM-P).The BM-TP and BM-P patients from 2015 to 2019 were identified in Optum Clinformatics DataMart. Six-month outcomes were assessed and included wound complications, infection, hematoma/seroma, breast pain, fat necrosis, flap failure, implant failure/removal, other flap/implant complications, and other complications. Multivariable regression models adjusted for age, residence, insurance, race, and Charlson Comorbidity Index score.Of 9319 women, 7114 (76.3%) underwent BM-TP, and 2205 (23.7%) underwent BM-P. In multivariable analysis, BM-TP had higher odds of overall complications (adjusted odds ratio [aOR], 1.35; P < 0.0001), but no difference was observed among patients who had autologous (P = 0.1448) or no breast reconstruction (P = 0.1530). Higher odds of overall complications persisted even after controlling for radiation therapy (aOR, 1.25; P = 0.0048) and chemotherapy (aOR, 1.28; P = 0.0047), but not after controlling for lymph node surgery (P = 0.7765).The BM-TP (vs BM-P) patients face higher odds of overall complications but without any difference in certain reconstructive modalities or after controlling for lymph node surgery.

  View details for DOI 10.1097/SAP.0000000000003648

  View details for PubMedID 37553890

• Medical Biology of Cancer-Associated Fibroblasts in Pancreatic Cancer. Biology Morgan, A., Griffin, M., Kameni, L., Wan, D. C., Longaker, M. T., Norton, J. A. 2023; 12 (8)

  Abstract

  Pancreatic cancer is one of the deadliest forms of cancer with one of the lowest 5-year survival rates of all cancer types. A defining characteristic of pancreatic cancer is the existence of dense desmoplastic stroma that, when exposed to stimuli such as cytokines, growth factors, and chemokines, generate a tumor-promoting environment. Cancer-associated fibroblasts (CAFs) are activated during the progression of pancreatic cancer and are a crucial component of the tumor microenvironment (TME). CAFs are primarily pro-tumorigenic in their activated state and function as promoters of cancer invasion, proliferation, metastasis, and immune modulation. Aided by many signaling pathways, cytokines, and chemokines in the tumor microenvironment, CAFs can originate from many cell types including resident fibroblasts, mesenchymal stem cells, pancreatic stellate cells, adipocytes, epithelial cells, endothelial cells, and other cell types. CAFs are a highly heterogeneous cell type expressing a variety of surface markers and performing a wide range of tumor promoting and inhibiting functions. Single-cell transcriptomic analyses have revealed a high degree of specialization among CAFs. Some examples of CAF subpopulations include myofibrotic CAFs (myCAFs), which exhibit a matrix-producing contractile phenotype; inflammatory CAFs (iCAF) that are classified by their immunomodulating, secretory phenotype; and antigen-presenting CAFs (apCAFs), which have antigen-presenting capabilities and express Major Histocompatibility Complex II (MHC II). Over the last several years, various attempts have been undertaken to describe the mechanisms of CAF-tumor cell interaction, as well as CAF-immune cell interaction, that contribute to tumor proliferation, invasion, and metastasis. Although our understanding of CAF biology in cancer has steadily increased, the extent of CAFs heterogeneity and their role in the pathobiology of pancreatic cancer remains elusive. In this regard, it becomes increasingly evident that further research on CAFs in pancreatic cancer is necessary.

  View details for DOI 10.3390/biology12081044

  View details for PubMedID 37626931

• Reduction of Tendon Fibrosis Using Galectin-3 Inhibitors. Plastic and reconstructive surgery Spielman, A. F., Griffin, M. F., Titan, A. L., Guardino, N., Cotterell, A. C., Akras, D., Wan, D. C., Longaker, M. T. 2023

  Abstract

  BACKGROUND: Fibrosis is a complication of both tendon injuries and repairs. We aim to develop a mouse model to assess tendon fibrosis and to identify an antifibrotic agent capable of overcoming tendon fibrosis.METHODS: Adult C57Bl/6 mice underwent a skin incision to expose the Achilles tendon, followed by 50% tendon injury and abrasion with sandpaper. Sham surgeries were conducted on contralateral hindlimbs. Histology and immunofluorescent staining for fibrotic markers (Col1, alpha-SMA) were used to confirm that the model induced tendon fibrosis. A second experiment was conducted to further examine the role of alpha-SMA in adhesion formation using alpha-SMA.mTmG mice (6-8 weeks old) (n=3) with the same injury model. The control group (tendon injury) was compared to the sham group, using the contralateral limb with skin incision only. A second experiment was conducted to further examine the role of alpha-SMA in adhesion formation using alpha-SMA.mTmG mice (6-8 weeks old) (n=3) with the same injury model. The control group (tendon injury) was compared to the sham group, using the contralateral limb with skin incision only. Lastly, alpha-SMA.mTmG mice were randomized to either condition 1. Tendon injury (control group) or 2. Tendon injury with Galectin-3 inhibitor (Gal3i) treatment at time of injury (treatment group).RESULTS: Histological analyses confirmed tendon thickening and collagen deposition after tendon injury and abrasion compared to control. Immunofluorescence showed higher levels of Col1 and alpha-SMA protein expression after injury compared to sham (*p<0.05). RT-qPCR also demonstrated increased gene expression of Col1 and alpha-SMA after injury compared to sham (*p<0.05). Gal3 protein expression also increased after injury and co-localized with alpha-SMA positive fibroblasts surrounding the fibrotic tendon. Gal3i treatment decreased collagen deposition and scarring observed in the treatment group (*p<0.05). Flow cytometry analysis further showed reduced numbers of profibrotic fibroblasts (CD26+) in the treatment compared to the control group (*p<0.05).CONCLUSIONS: Our study provides a reproducible and reliable model to investigate tendon fibrosis. Findings suggest the potential of Gal3i to overcome fibrosis resulting from tendon injuries.

  View details for DOI 10.1097/PRS.0000000000010880

  View details for PubMedID 37344932

• Attenuating Chronic Fibrosis: Decreasing Foreign Body Response with Acellular Dermal Matrix. Tissue engineering. Part B, Reviews Liang, N. E., Griffin, M., Berry, C. E., Parker, J. B., Downer, M. A., Wan, D. C., Longaker, M. T. 2023

  Abstract

  Surgical implants are increasingly used across multiple medical disciplines, with applications ranging from tissue reconstruction to improving compromised organ and limb function. Despite their significant potential for improving health and quality of life, biomaterial implant function is severely limited by the body's immune response to its presence: this is known as the foreign body response and is characterized by chronic inflammation and fibrotic capsule formation. This response can result in life-threatening sequelae such as implant malfunction, superimposed infection and associated vessel thrombosis, in addition to soft tissue disfigurement. Patients may require frequent medical visits, as well as repeated invasive procedures, increasing the burden on an already strained healthcare system. Currently, the foreign body response and the cells and molecular mechanisms that mediate it are poorly understood. With applications across a wide array of surgical specialties, acellular dermal matrix has emerged as a potential solution to the fibrotic reaction seen with FBR. Though the mechanisms by which acellular dermal matrix decreases chronic fibrosis remain to be clearly characterized, animal studies across diverse surgical models point to its biomimetic properties that facilitate decreased periprosthetic inflammation and improved host cell incorporation.

  View details for DOI 10.1089/ten.TEB.2023.0060

  View details for PubMedID 37212342

• Overcoming Radiation Induced Oral Fibrosis through the Down Regulation of Wnt Signaling Using Bmp-7 Inhibitors Cotterell, A. C., Griffin, M., Spielman, A., Guardino, N., Lintel, H., Abbas, D., Guo, J. L., Parker, J., Wan, D., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2023: S90

  View details for Web of Science ID 000989943300232

• Topical Vanadate Improves Excisional Wound Healing in Murine Model Lintel, H., Abbas, D., Mackay, D. D., Griffin, M., Spielman, A., Guardino, N., Churukian, A., Guo, J. L., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2023: S91

  View details for Web of Science ID 000989943300234

• Lineage Tracing Reveals Adipocytes Are Responsible for Muscle Fibrosis Following Nerve Injury Spielman, A., Griffin, M., Cotterell, A. C., Erich, K., Guo, B. L., Abbas, D., Parker, J. L., Lintel, H., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2023: S92

  View details for Web of Science ID 000989943300237

• Developing a Mouse Model to Evaluate Tibial Distraction Osteogenesis DiIorio, S., Tevlin, R., Shah, H. N., Salhotra, A., Griffin, M., Januszyk, M., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2023: S90

  View details for Web of Science ID 000989943300230

• Radiation Injury Genetically Alters Fibroblast Subpopulations to Induce Fibrosis Abbas, D., Griffin, M., Guo, J. L., Lavin, C. V., Fahy, E. J., Guardino, N. J., Lintel, H., Januszyk, M., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2023: S94

  View details for Web of Science ID 000989943300243

• Radiation Injury Therapy with Transdermal Deferoxamine Patch is Dose Dependent Abbas, D., Griffin, M., Lavin, C. V., Fahy, E. J., Lintel, H., Guardino, N. J., Guo, J. L., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2023: S91

  View details for Web of Science ID 000989943300233

• The effects of mechanical force on fibroblast behavior in cutaneous injury. Frontiers in surgery Berry, C. E., Downer, M., Morgan, A. G., Griffin, M., Liang, N. E., Kameni, L., Laufey Parker, J. B., Guo, J., Longaker, M. T., Wan, D. C. 2023; 10: 1167067

  Abstract

  Wound healing results in the formation of scar tissue which can be associated with functional impairment, psychological stress, and significant socioeconomic cost which exceeds 20 billion dollars annually in the United States alone. Pathologic scarring is often associated with exaggerated action of fibroblasts and subsequent excessive accumulation of extracellular matrix proteins which results in fibrotic thickening of the dermis. In skin wounds, fibroblasts transition to myofibroblasts which contract the wound and contribute to remodeling of the extracellular matrix. Mechanical stress on wounds has long been clinically observed to result in increased pathologic scar formation, and studies over the past decade have begun to uncover the cellular mechanisms that underly this phenomenon. In this article, we will review the investigations which have identified proteins involved in mechano-sensing, such as focal adhesion kinase, as well as other important pathway components that relay the transcriptional effects of mechanical forces, such as RhoA/ROCK, the hippo pathway, YAP/TAZ, and Piezo1. Additionally, we will discuss findings in animal models which show the inhibition of these pathways to promote wound healing, reduce contracture, mitigate scar formation, and restore normal extracellular matrix architecture. Recent advances in single cell RNA sequencing and spatial transcriptomics and the resulting ability to further characterize mechanoresponsive fibroblast subpopulations and the genes that define them will be summarized. Given the importance of mechanical signaling in scar formation, several clinical treatments focused on reducing tension on the wound have been developed and are described here. Finally, we will look toward future research which may reveal novel cellular pathways and deepen our understanding of the pathogenesis of pathologic scarring. The past decade of scientific inquiry has drawn many lines connecting these cellular mechanisms that may lead to a map for the development of transitional treatments for patients on the path to scarless healing.

  View details for DOI 10.3389/fsurg.2023.1167067

  View details for PubMedID 37143767

  View details for PubMedCentralID PMC10151708

• Combination of Distinct Vascular Stem/Progenitor Cells for Neovascularization and Ischemic Rescue. Arteriosclerosis, thrombosis, and vascular biology Zhao, L., Lee, A. S., Sasagawa, K., Sokol, J., Wang, Y., Ransom, R. C., Zhao, X., Ma, C., Steininger, H. M., Koepke, L. S., Borrelli, M. R., Brewer, R. E., Lee, L. L., Huang, X., Ambrosi, T. H., Sinha, R., Hoover, M. Y., Seita, J., Weissman, I. L., Wu, J. C., Wan, D. C., Xiao, J., Longaker, M. T., Nguyen, P. K., Chan, C. K. 2023

  Abstract

  Peripheral vascular disease remains a leading cause of vascular morbidity and mortality worldwide despite advances in medical and surgical therapy. Besides traditional approaches, which can only restore blood flow to native arteries, an alternative approach is to enhance the growth of new vessels, thereby facilitating the physiological response to ischemia.The ActinCreER/R26VT2/GK3 Rainbow reporter mouse was used for unbiased in vivo survey of injury-responsive vasculogenic clonal formation. Prospective isolation and transplantation were used to determine vessel-forming capacity of different populations. Single-cell RNA-sequencing was used to characterize distinct vessel-forming populations and their interactions.Two populations of distinct vascular stem/progenitor cells (VSPCs) were identified from adipose-derived mesenchymal stromal cells: VSPC1 is CD45-Ter119-Tie2+PDGFRa-CD31+CD105highSca1low, which gives rise to stunted vessels (incomplete tubular structures) in a transplant setting, and VSPC2 which is CD45-Ter119-Tie2+PDGFRa+CD31-CD105lowSca1high and forms stunted vessels and fat. Interestingly, cotransplantation of VSPC1 and VSPC2 is required to form functional vessels that improve perfusion in the mouse hindlimb ischemia model. Similarly, VSPC1 and VSPC2 populations isolated from human adipose tissue could rescue the ischemic condition in mice.These findings suggest that autologous cotransplantation of synergistic VSPCs from nonessential adipose tissue can promote neovascularization and represents a promising treatment for ischemic disease.

  View details for DOI 10.1161/ATVBAHA.122.317943

  View details for PubMedID 37051932

• Nipple-areola-complex preservation and obesity-Successful in stages. Microsurgery Daly, L., Tsai, J., Stone, K., Wapnir, I., Karin, M., Wan, D., Momeni, A. 2023

  Abstract

  The superiority of nipple-sparing mastectomy (NSM) on breast aesthetics and patient-reported outcomes has previously been demonstrated. Despite 42.4% of adults in the United States being considered obese, obesity has been considered a contraindication to NSM due to concerns for nipple areolar complex (NAC) malposition or ischemic complications. This report investigates the feasibility and safety of a staged surgical approach to NSM with immediate microsurgical breast reconstruction in the high-risk obese population.Only patients with a body mass index (BMI) of >30 kg/m2 who underwent bilateral mastopexy or breast reduction for correction of ptosis or macromastia (stage 1), respectively, followed by bilateral prophylactic NSM with immediate microsurgical breast reconstruction with free abdominal flaps (stage 2) were included in the analysis. Patient demographics and surgical outcomes were analyzed.Fifteen patients with high-risk genetic mutations for breast cancer with a mean age and BMI of 41.3 years and 35.0 kg/m2 , respectively, underwent bilateral staged NSM with immediate microsurgical breast reconstruction (30 breast reconstructions). At a mean follow-up of 15.7 months, complications were encountered following stage 2 only and included mastectomy skin necrosis (5 breasts [16.7%]), NAC necrosis (2 breasts [6.7%]), and abdominal seroma (1 patient [6.7%]) all of which were considered minor and neither required surgical intervention nor admission.Implementation of a staged approach permits NAC preservation in obese patients who present for prophylactic mastectomy and immediate microsurgical reconstruction.

  View details for DOI 10.1002/micr.31043

  View details for PubMedID 37013250

• Establishing a xenograft model with CD-1 nude mice to study human skin wound repair. Plastic and reconstructive surgery Abbas, D. B., Griffin, M., Fahy, E. J., Spielman, A. F., Guardino, N. J., Pu, A., Lintel, H., Lorenz, H. P., Longaker, M. T., Wan, D. C. 2023

  Abstract

  A significant gap exists in the translatability of small animal models to human subjects. One important factor is poor laboratory models involving human tissue. Thus, we have created a viable postnatal human skin xenograft model using athymic mice.Discarded human foreskins were collected following circumcision. All subcutaneous tissue was removed from these samples sterilely. Host CD-1 nude mice were then anesthetized, and dorsal skin was sterilized. A 1.2cm diameter, full-thickness section of dorsal skin was excised. The foreskin sample was then placed into the full-thickness defect in the host mice and sutured into place. Xenografts underwent dermal wounding using a 4 mm punch biopsy after engraftment. Xenografts were monitored for 14 days after wounding and then harvested.At 14 days postoperatively, all mice survived the procedure. Grossly, the xenograft wounds showed formation of a human scar at POD-14. H&E and Masson Trichome staining confirmed scar formation in the wounded human skin. Using a novel Artificial Intelligence (AI) algorithm using Picrosirius-Red staining, scar formation was confirmed in human wounded skin compared to the unwounded skin. Histologically, CD31 + immunostaining confirmed vascularization of the xenograft. The xenograft exclusively showed human collagen I, CD26 +, and human nuclear antigen in the human scar without any staining of these human markers in the murine skin.The proposed model demonstrates wound healing to be a local response from tissue resident human fibroblasts and allows for reproducible evaluation of human skin wound repair in a preclinical model.

  View details for DOI 10.1097/PRS.0000000000010465

  View details for PubMedID 36988644

• Denervation during mandibular distraction osteogenesis results in impaired bone formation. Scientific reports Tevlin, R., Griffin, M., Chen, K., Januszyk, M., Guardino, N., Spielman, A., Walters, S., Gold, G. E., Chan, C. K., Gurtner, G. C., Wan, D. C., Longaker, M. T. 2023; 13 (1): 2097

  Abstract

  Mandibular distraction osteogenesis (DO) is mediated by skeletal stem cells (SSCs) in mice, which enact bone regeneration via neural crest re-activation. As peripheral nerves are essential to progenitor function during development and in response to injury, we questioned if denervation impairs mandibular DO. C57Bl6 mice were divided into two groups: DO with a segmental defect in the inferior alveolar nerve (IAN) at the time of mandibular osteotomy ("DO Den") and DO with IAN intact ("DO Inn"). DO Den demonstrated significantly reduced histological and radiological osteogenesis relative to DO Inn. Denervation preceding DO results in reduced SSC amplification and osteogenic potential in mice. Single cell RNA sequencing analysis revealed that there was a predominance of innervated SSCs in clusters dominated by pathways related to bone formation. A rare human patient specimen was also analyzed and suggested that histological, radiological, and transcriptional alterations seen in mouse DO may be conserved in the setting of denervated human mandible distraction. Fibromodulin (FMOD) transcriptional and protein expression were reduced in denervated relative to innervated mouse and human mandible regenerate. Finally, when exogenous FMOD was added to DO-Den and DO-Inn SSCs undergoing in vitro osteogenic differentiation, the osteogenic potential of DO-Den SSCs was increased in comparison to control untreated DO-Den SSCs, modeling the superior osteogenic potential of DO-Inn SSCs.

  View details for DOI 10.1038/s41598-023-27921-9

  View details for PubMedID 36747028

• An Inexpensive 3D Printed Mouse Model of Successful, Complication-free Long Bone Distraction Osteogenesis. Plastic and reconstructive surgery. Global open Tevlin, R., Shah, H. N., Salhotra, A., Di Iorio, S. E., Griffin, M., Januszyk, M., Wan, D. C., Longaker, M. T. 2023; 11 (2): e4674

  Abstract

  Distraction osteogenesis (DO) is used for skeletal defects; however, up to 50% of cases exhibit complications. Previous mouse models of long bone DO have been anecdotally hampered by postoperative complications, expense, and availability. To improve clinical techniques, cost-effective, reliable animal models are needed. Our focus was to develop a new mouse tibial distractor, hypothesized to result in successful, complication-free DO.A lightweight tibial distractor was developed using CAD and 3D printing. The device was fixed to the tibia of C57Bl/6J mice prior to osteotomy. Postoperatively, mice underwent 5 days latency, 10 days distraction (0.15 mm every 12 hours), and 28 days consolidation. Bone regeneration was examined on postoperative day 43 using micro-computed tomography (μCT) and Movat's modified pentachrome staining on histology (mineralized volume fraction and pixels, respectively). Costs were recorded. We compared cohorts of 11 mice undergoing sham, DO, or acute lengthening (distractor acutely lengthened 3.0 mm).The histological bone regenerate was significantly increased in DO (1,879,257 ± 155,415 pixels) compared to acute lengthening (32847 ± 1589 pixels) (P < 0.0001). The mineralized volume fraction (bone/total tissue volume) of the regenerate was significantly increased in DO (0.9 ± 0.1) compared to acute lengthening (0.7 ± 0.1) (P < 0.001). There was no significant difference in bone regenerate between DO and sham. The distractor was relatively low cost ($11), with no complications.Histology and µCT analysis confirmed that the proposed tibial DO model resulted in successful bone formation. Our model is cost-effective and reproducible, enabling implementation in genetically dissectible transgenic mice.

  View details for DOI 10.1097/GOX.0000000000004674

  View details for PubMedID 36798717

  View details for PubMedCentralID PMC9925097

• Chelating the valley of death: Deferoxamine's path from bench to wound clinic. Frontiers in medicine Parker, J. B., Griffin, M. F., Downer, M. A., Akras, D., Berry, C. E., Cotterell, A. C., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2023; 10: 1015711

  Abstract

  There is undisputable benefit in translating basic science research concretely into clinical practice, and yet, the vast majority of therapies and treatments fail to achieve approval. The rift between basic research and approved treatment continues to grow, and in cases where a drug is granted approval, the average time from initiation of human trials to regulatory marketing authorization spans almost a decade. Albeit with these hurdles, recent research with deferoxamine (DFO) bodes significant promise as a potential treatment for chronic, radiation-induced soft tissue injury. DFO was originally approved by the Food and Drug Administration (FDA) in 1968 for the treatment of iron overload. However, investigators more recently have posited that its angiogenic and antioxidant properties could be beneficial in treating the hypovascular and reactive-oxygen species-rich tissues seen in chronic wounds and radiation-induced fibrosis (RIF). Small animal experiments of various chronic wound and RIF models confirmed that treatment with DFO improved blood flow and collagen ultrastructure. With a well-established safety profile, and now a strong foundation of basic scientific research that supports its potential use in chronic wounds and RIF, we believe that the next steps required for DFO to achieve FDA marketing approval will include large animal studies and, if those prove successful, human clinical trials. Though these milestones remain, the extensive research thus far leaves hope for DFO to bridge the gap between bench and wound clinic in the near future.

  View details for DOI 10.3389/fmed.2023.1015711

  View details for PubMedID 36873870

• Multiplexed evaluation of mouse wound tissue using oligonucleotide barcoding with single-cell RNA sequencing. STAR protocols Januszyk, M., Griffin, M., Mascharak, S., Talbott, H. E., Chen, K., Henn, D., Spielman, A. F., Parker, J. B., Liang, N. E., Cotterell, A., Guardino, N., Foster, D. S., Wagh, D., Coller, J., Gurtner, G. C., Wan, D. C., Longaker, M. T. 2022; 4 (1): 101946

  Abstract

  Despite its rapidly increased availability for the study of complex tissue, single-cell RNA sequencing remains prohibitively expensive for large studies. Here, we present a protocol using oligonucleotide barcoding for the tagging and pooling of multiple samples from healing wounds, which are among the most challenging tissue types for this application. We describe steps to generate skin wounds in mice, followed by tissue harvest and oligonucleotide barcoding. This protocol is also applicable to other species including rats, pigs, and humans. For complete details on the use and execution of this protocol, please refer to Stoeckius etal. (2018),1 Galiano etal. (2004),2 and Mascharak etal. (2022).3.

  View details for DOI 10.1016/j.xpro.2022.101946

  View details for PubMedID 36525348

• Topical vanadate improves tensile strength and alters collagen organization of excisional wounds in a mouse model. Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society Lintel, H., Abbas, D. B., Mackay, D. J., Griffin, M., Lavin, C. V., Berry, C. E., Guardino, N. J., Guo, J. L., Momeni, A., Mackay, D. R., Longaker, M. T., Wan, D. C. 2022

  Abstract

  Wound dehiscence, oftentimes a result of the poor tensile strength of early healing wounds, is a significant threat to the postoperative patient, potentially causing life-threatening complications. Vanadate, a protein tyrosine phosphatase inhibitor, has been shown to alter the organization of deposited collagen in healing wounds and significantly improve the tensile strength of incisional wounds in rats. In this study, we sought to explore the effects of locally administered vanadate on tensile strength and collagen organization in both the early and remodeling phases of excisional wound healing in a murine model. Wild-type mice underwent stented excisional wounding on their dorsal skin and were divided equally into three treatment conditions: vanadate injection, saline injection control, and an untreated control. Tensile strength testing, in vivo suction Cutometer analysis, gross wound measurements, and histologic analysis were performed during healing, immediately upon wound closure, and after four weeks of remodeling. We found that vanadate treatment significantly increased the tensile strength of wounds and their stiffness relative to control wounds, both immediately upon healing and into the remodeling phase. Histologic analysis revealed that these biomechanical changes were likely the result of increased collagen deposition and an altered collagen organization composed of thicker and distinctly organized collagen bundles. Given the risk that dehiscence poses to all operative patients, vanadate presents an interesting therapeutic avenue to improve the strength of post-operative wounds and unstable chronic wounds in order to reduce the risk of dehiscence.

  View details for DOI 10.1111/wrr.13062

  View details for PubMedID 36484112

• Investigating the Severity of Complications following Nipple-sparing Mastectomy and Immediate Prepectoral Implant-based vs. Autologous Reconstruction - A Single-Surgeon Experience. Plastic and reconstructive surgery Pedreira, R., Tevlin, R., Griffin, M., Wan, D., Momeni, A. 2022

  Abstract

  Several clinical studies have reported autologous breast reconstruction (ABR) to be associated with a higher postoperative complication rate; however, few have investigated the impact of reconstructive modality on complication severity. This study examines the impact of reconstructive modality on complication severity in a matched cohort of patients who underwent ABR versus implant-based breast reconstruction (IBR).A retrospective study of patients who underwent nipple-sparing mastectomy with immediate reconstruction was performed. Propensity score matching (PSM) ensured adequate matching of patients who underwent ABR and staged prepectoral IBR, respectively. Patient demographics, breast measurements and postoperative outcomes, including the incidence and severity of complications were analyzed. Multivariable logistic regression analysis was performed. A P-value of <0.05 was considered significant.128 patients (214 breast reconstructions) were included for analysis (ABR n = 64; IBR n = 64). No difference in overall complication rate was noted (p = 0.61). However, a significant association of IBR with major complications was noted (p = 0.02). In contrast, minor complications were significantly more frequent following ABR (p = 0.04).While the reconstructive modality did not appear to have an effect on the overall complication rate, it did significantly affect the severity of postoperative complications with major and minor complications being associated with IBR and ABR, respectively. These findings are relevant to patient-centered decision-making as they provide further granularity regarding postoperative complications and address the issue of complication severity.

  View details for DOI 10.1097/PRS.0000000000009827

  View details for PubMedID 36332003

• Adipose-Derived Stromal Cell-based Therapies for Radiation-Induced Fibrosis. Advances in wound care Berry, C., Abbas, D. B., Lintel, H., Churukian, A., Griffin, M., Guo, J., Cotterell, A. C., Parker, J., Downer, M. A., Longaker, M. T., Wan, D. C. 2022

  Abstract

  SIGNIFICANCE: Half of all cancer patients receive radiation therapy as a component of their treatment regimen, and the most common resulting complication is radiation-induced fibrosis of the skin and soft tissue. This thickening of the dermis paired with decreased vascularity results in functional limitations, aesthetic concerns, and poses unique challenges when considering surgical exploration or reconstruction. Existing therapeutic options for radiation-induced fibrosis of the skin are limited both in scope and efficacy. Cell-based therapies have emerged as a promising means of utilizing regenerative cell populations to improve both functional and aesthetic outcomes, and even as prophylaxis for radiation-induced fibrosis.RECENT ADVANCES: As one of the leading areas of cell-based therapy research, adipose-derived stromal cells (ADSCs) demonstrate significant therapeutic potential in the treatment of radiation-induced fibrosis (RIF). The introduction of the ADSC-augmented fat graft has shown clinical utility. Recent research dedicated to characterizing specific ADSC subpopulations points toward further granularity in understanding of the mechanisms driving the well-established clinical outcomes seen with fat grafting therapy.CRITICAL ISSUES: Various animal models of radiation-induced fibrosis demonstrated improved clinical outcomes following treatment with cell-based therapies, but the cellular and molecular basis underlying these effects remains poorly understood.FUTURE DIRECTIONS: Recent literature has focused on improving the efficacy of cell-based therapies, most notably through 1) augmentation of fat grafts with platelet-rich plasma and 2) the modification of expressed RNA through epitranscriptomics. For the latter, new and promising gene targets continue to be identified which have the potential to reverse the effects of fibrosis by increasing angiogenesis, decreasing inflammation, and promoting adipogenesis.

  View details for DOI 10.1089/wound.2022.0103

  View details for PubMedID 36345216

• Reversal of Senescence in Skin-derived Fibroblasts Using Exogenous Mechanical Stimulation Guo, J. L., Griffin, M., Guardino, N. J., Chen, K., Cotterell, A. C., Abbas, D., Spielman, A., Lintel, H., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2022: S70

  View details for Web of Science ID 000867877000176

• Inhibition of Yes-Associated Protein Promotes Skin Wound Regeneration in Large Animals Januszyk, M., Talbott, H. E., Griffin, M., Guardino, N., Spielman, A., Guo, J. L., Mascharak, S., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2022: S196

  View details for DOI 10.1097/01.XCS.0000894508.92389.a2

  View details for Web of Science ID 000867889300379

• Denervation During Mouse and Human Mandibular Distraction Osteogenesis Results in Impaired Osteogenesis Tevlin, R., Griffin, M., Chen, K., Januszyk, M., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2022: S202

  View details for DOI 10.1097/01.XCS.0000894560.64479.80

  View details for Web of Science ID 000867889300393

• Adipocytes the Forgotten Culprit in Skin Fibrosis: Exploring the Mechanism of Fat Driven Skin Fibrosis Griffin, M., Guardino, N., Spielman, A. F., Mascharak, S., Parker, J. L., Guo, J. L., Abbas, D., Wan, D. C., Bauer-Rowe, K. E., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2022: S199

  View details for DOI 10.1097/01.XCS.0000894536.38023.90

  View details for Web of Science ID 000867889300387

• Adipocyte Progenitor Cells Embedded in Collagen Gels Accelerate Bone Formation in a Murine Calvarial Critical Defect Model Cotterell, A. C., Griffin, M., Guardino, N., Spielman, A. F., Lintel, H., Abbas, D., Guo, J. L., Parker, J. L., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2022: S198-S199

  View details for DOI 10.1097/01.XCS.0000894532.90979.c9

  View details for Web of Science ID 000867889300386

• Transdermal Deferoxamine Improves Acute Wound Healing in Chronic Irradiated Skin in a Mouse Model Lintel, H., Abbas, D., Lavin, C., Griffin, M., Guo, J. L., Guardino, N., Churukian, A., Chen, K., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2022: S211-S212

  View details for DOI 10.1097/01.XCS.0000894656.51739.b7

  View details for Web of Science ID 000867889300416

• Fibroblast Subpopulations Are Modified with Fat Grafting to Treat Radiation-Induced Fibrosis Abbas, D. B., Guo, J. L., Griffin, M., Lintel, H., Guardino, N. J., Berry, C. E., Pu, A., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2022: S202-S203

  View details for DOI 10.1097/01.XCS.0000894568.35895.12

  View details for Web of Science ID 000867889300395

• Semantics Matter: Cheiloschisis Web-Based Information Differs from Cleft Lip Abbas, D. B., Lintel, H., Guardino, N. J., Griffin, M., Guo, J. L., Cotterell, A. C., Spielman, A. F., Parker, J. L., Longaker, M. T., Wan, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2022: S209

  View details for DOI 10.1097/01.XCS.0000894628.90579.08

  View details for Web of Science ID 000867889300410

• Multi-Modal Analysis of Cell Populations and Architectural States Mediating the Progression and Resolution of Pulmonary Fibrosis Guo, J. L., Griffin, M., Guardino, N. J., Abbas, D., Lu, J., Spielman, A., Lintel, H., Cotterell, A. C., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2022: S82

  View details for Web of Science ID 000867877000204

• Engrailed-Positive Fibroblasts: The Primary Cell Type Present in Fibrotic Capsules During Foreign Body Response Parker, J. B., Griffin, M., Mascharak, S., Spielman, A., Cotterell, A. C., Abbas, D., Lintel, H., Januszyk, M., Wan, D. C., Longaker, M. T. LIPPINCOTT WILLIAMS & WILKINS. 2022: S68

  View details for Web of Science ID 000867877000171

• Multiomic analysis reveals conservation of cancer-associated fibroblast phenotypes across species and tissue of origin. Cancer cell Foster, D. S., Januszyk, M., Delitto, D., Yost, K. E., Griffin, M., Guo, J., Guardino, N., Delitto, A. E., Chinta, M., Burcham, A. R., Nguyen, A. T., Bauer-Rowe, K. E., Titan, A. L., Salhotra, A., Jones, R. E., da Silva, O., Lindsay, H. G., Berry, C. E., Chen, K., Henn, D., Mascharak, S., Talbott, H. E., Kim, A., Nosrati, F., Sivaraj, D., Ransom, R. C., Matthews, M., Khan, A., Wagh, D., Coller, J., Gurtner, G. C., Wan, D. C., Wapnir, I. L., Chang, H. Y., Norton, J. A., Longaker, M. T. 2022

  Abstract

  Cancer-associated fibroblasts (CAFs) are integral to the solid tumor microenvironment. CAFs were once thought to be a relatively uniform population of matrix-producing cells, but single-cell RNA sequencing has revealed diverse CAF phenotypes. Here, we further probed CAF heterogeneity with a comprehensive multiomics approach. Using paired, same-cell chromatin accessibility and transcriptome analysis, we provided an integrated analysis of CAF subpopulations over a complex spatial transcriptomic and proteomic landscape to identify three superclusters: steady state-like (SSL), mechanoresponsive (MR), and immunomodulatory (IM) CAFs. These superclusters are recapitulated across multiple tissue types and species. Selective disruption of underlying mechanical force or immune checkpoint inhibition therapy results in shifts in CAF subpopulation distributions and affected tumor growth. As such, the balance among CAF superclusters may have considerable translational implications. Collectively, this research expands our understanding of CAF biology, identifying regulatory pathways in CAF differentiation and elucidating therapeutic targets in a species- and tumor-agnostic manner.

  View details for DOI 10.1016/j.ccell.2022.09.015

  View details for PubMedID 36270275

• Consensus on the Clinical Management of Chronic Radiation Dermatitis and Radiation Fibrosis: A Delphi Survey. The British journal of dermatology Wilson, B. N., Shah, R., Menzer, C., Aleisa, A., Sun, M. D., Kwong, B. Y., Kaffenberger, B. H., Seminario-Vidal, L., Barker, C. A., Stubblefield, M. D., Romesser, P. B., Fabbrocini, G., Alam, M., Abdulla, F., Dulmage, B., Sibaud, V., Anadkat, M., Mazer, J., Parikh, D., McLellan, B., Cartier, H., Pugliese, S., Wolkerstorfer, A., Laubach, H., LeBoeuf, N., Leventhal, J., Wan, D. C., Choi, J., Thanh Nga, T., Anderson, R. R., Markova, A., Rossi, A. 2022

  View details for DOI 10.1111/bjd.21852

  View details for PubMedID 36047980

• Wound healing, fibroblast heterogeneity, and fibrosis. Cell stem cell Talbott, H. E., Mascharak, S., Griffin, M., Wan, D. C., Longaker, M. T. 2022; 29 (8): 1161-1180

  Abstract

  Fibroblasts are highly dynamic cells that play a central role in tissue repair and fibrosis. However, the mechanisms by which they contribute to both physiologic and pathologic states of extracellular matrix deposition and remodeling are just starting to be understood. In this review article, we discuss the current state of knowledge in fibroblast biology and heterogeneity, with a primary focus on the role of fibroblasts in skin wound repair. We also consider emerging techniques in the field, which enable an increasingly nuanced and contextualized understanding of these complex systems, and evaluate limitations of existing methodologies and knowledge. Collectively, this review spotlights a diverse body of research examining an often-overlooked cell type-the fibroblast-and its critical functions in wound repair and beyond.

  View details for DOI 10.1016/j.stem.2022.07.006

  View details for PubMedID 35931028

• Exploring the Overlooked Roles and Mechanisms of Fibroblasts in the Foreign Body Response. Advances in wound care Parker, J., Griffin, M., Spielman, A. F., Wan, D. C., Longaker, M. T. 2022

  Abstract

  Significance Foreign body response (FBR), wherein a fibrotic capsule forms around an implanted structure, is a common surgical complication that often leads to pain, discomfort, and eventual revision surgeries. Though believed to have some mechanistic overlap with normal wound healing, much remains to be discovered about the specific mechanism by which this occurs. Recent Advances Current understanding of FBR has focused on the roles of the immune system and the biomaterial, both major contributors to FBR. However, another key player, the fibroblast, is often overlooked. This review summarizes key contributors of FBR, focusing on the roles of fibroblasts. As much remains to be discovered about fibroblasts' specific roles in FBR, we draw on current knowledge of fibroblast subpopulations and functions during wound healing. We also provide an overview on candidate biomaterials and signalling pathways involved in FBR. Critical Issues and Future Directions While the global implantable medical devices market is considerable and continues to appreciate in value, FBR remains one of the most common surgical implant complications. In parallel with the continued development of candidate biomaterials, further exploration of potential fibroblast subpopulations at a transcriptional level would provide key insights into further understanding the underlying mechanisms by which fibrous encapsulation occurs, and unveil novel directions for anti-fibrotic and regenerative therapies in the future.

  View details for DOI 10.1089/wound.2022.0066

  View details for PubMedID 35819293

• Transdermal deferoxamine administration improves excisional wound healing in chronically irradiated murine skin. Journal of translational medicine Lintel, H., Abbas, D. B., Lavin, C. V., Griffin, M., Guo, J. L., Guardino, N., Churukian, A., Gurtner, G. C., Momeni, A., Longaker, M. T., Wan, D. C. 2022; 20 (1): 274

  Abstract

  BACKGROUND: Radiation-induced skin injury is a well-known risk factor for impaired wound healing. Over time, the deleterious effects of radiation on skin produce a fibrotic, hypovascular dermis poorly suited to wound healing. Despite increasing understanding of the underlying pathophysiology, therapeutic options remain elusive. Deferoxamine (DFO), an iron-chelating drug, has been shown in prior murine studies to ameliorate radiation-induced skin injury as well as improve wound healing outcomes in various pathologic conditions when administered transdermally. In this preclinical study, we evaluated the effects of deferoxamine on wound healing outcomes in chronically irradiated murine skin.METHODS: Wild-type mice received 30Gy of irradiation to their dorsal skin and were left to develop chronic fibrosis. Stented excisional wounds were created on their dorsal skin. Wound healing outcomes were compared across 4 experimental conditions: DFO patch treatment, vehicle-only patch treatment, untreated irradiated wound, and untreated nonirradiated wounds. Gross closure rate, wound perfusion, scar elasticity, histology, and nitric oxide assays were compared across the conditions.RESULTS: Relative to vehicle and untreated irradiated wounds, DFO accelerated wound closure and reduced the frequency of healing failure in irradiated wounds. DFO augmented wound perfusion throughout healing and upregulated angiogenesis to levels observed in nonirradiated wounds. Histology revealed DFO increased wound thickness, collagen density, and improved collagen fiber organization to more closely resemble nonirradiated wounds, likely contributing to the observed improved scar elasticity. Lastly, DFO upregulated inducible nitric oxide synthase and increased nitric oxide production in early healing wounds.CONCLUSION: Deferoxamine treatment presents a potential therapeutic avenue through which to target impaired wound healing in patients following radiotherapy.

  View details for DOI 10.1186/s12967-022-03479-4

  View details for PubMedID 35715816

• Profibrotic Signaling Pathways and Surface Markers Are Upregulated in Fibroblasts of Human Striae Distensae and in a Mouse Model System. Plastic and reconstructive surgery Borrelli, M. R., Griffin, M., Chen, K., Diaz, N. M., Adem, S., Mascharak, S., Shen, A. H., Ngaage, L. M., Lewis, N., Longaker, M. T., Gurtner, G., Wan, D. C., Lorenz, H. P. 2022

  Abstract

  INTRODUCTION: Striae distensae (SD) are common disfiguring cutaneous lesions but lack effective treatments due to an incomplete understanding of their pathophysiology. Dermal fibroblasts likely play an important role. We investigate the cellular-molecular features distinguishing fibroblasts from human SD and normal skin (NS). We also develop a mouse model of SD.METHODS: Human SD and NS samples were compared for tensile strength and histological structure. Fibroblasts from SD and NS were isolated by fluorescence-activated cell sorting (FACS) for gene expression analysis. Immunofluorescence staining and FACS were used to confirm gene expression data at the protein level. A mouse model of SD formation was created by administering corticosteroids and mechanically loading the dorsal skin.RESULTS: Human SD exhibited reduced tensile strength, more disordered collagen fibers, and epidermal atrophy compared to human NS. There were 296 upregulated genes in SD fibroblasts, including the profibrotic lineage and surface marker CD26. Upregulated genes were involved in profibrotic and mechanoresponsive signaling pathways (TGFbeta and FAK-PI3-AKT-signaling). In contrast, 571 genes were downregulated, including CD74 and genes of the AMPK pathway. Increased CD26 and decreased CD74 expression was confirmed by FACS and immunofluorescence. Similar cutaneous histological and gene expression changes were induced in hypercortisolemic mice by mechanically loading the dorsal skin.CONCLUSIONS: Fibroblasts from human SD exhibit increased profibrotic and decreased antifibrotic signaling. CD26 and CD74 are promising surface markers that may be targeted therapeutically. Our mouse model of SD can be used as a platform to test the efficacy of potential therapeutic agents.

  View details for DOI 10.1097/PRS.0000000000009363

  View details for PubMedID 35666152

• Beyond the Scar: A Basic Science Review of Wound Remodeling. Advances in wound care Spielman, A. F., Griffin, M., Parker, J., Cotterell, A. C., Wan, D. C., Longaker, M. T. 2022

  Abstract

  SIGNIFICANCE: Increasing development of experimental animal models has allowed for the study of scar formation. However, many pathophysiological unknowns remain in the longest stage of healing, the remodeling stage, which may continue for a year or more. The wound healing process results in different types of scarring classified as normal or pathological depending on failures at each stage. Failures can also occur during wound remodeling, but the molecular mechanisms driving the wound remodeling process have yet to be investigated.RECENT ADVANCES: While current understanding of wound repair is based on investigations of acute healing, these experimental models have informed knowledge of key components of remodeling. This review examines the components that contribute to collagen organization and the final scar, including cell types, their regulation, and signaling pathways. Dysregulation in any one of these components causes pathologic healing.CRITICAL ISSUES AND FUTURE DIRECTIONS: As wounds continue to remodel months to years after re-epithelization, new models to better understand long-term remodeling will be critical for improving healing outcomes. Further investigation of the contributions of fibroblasts and cell signaling pathways involved during remodeling as well as their potential failures may inform new approaches in promoting regenerative healing beyond re-epithelization.

  View details for DOI 10.1089/wound.2022.0049

  View details for PubMedID 35658581

• Response to: Vitamin E Improves Volumetry and Regenerative Effects of Fat Grafting. Aesthetic surgery journal Abbas, D. B., Wan, D. C. 2022

  View details for DOI 10.1093/asj/sjac102

  View details for PubMedID 35468179

• Fat Grafts Augmented With Vitamin E Improve Volume Retention and Radiation-Induced Fibrosis. Aesthetic surgery journal Abbas, D. B., Lavin, C. V., Fahy, E. J., Griffin, M., Guardino, N. J., Nazerali, R. S., Nguyen, D. H., Momeni, A., Longaker, M. T., Wan, D. C. 2022

  Abstract

  Treatments for radiation-induced fibrosis range from vitamin E and pentoxifylline systemically to deferoxamine and fat grafting locally. Regarding fat grafting, volume retention hinders its long-term functionality and is affected by two factors: inflammation and necrosis secondary to hypovascularity.We aimed to simultaneously improve fat graft retention and radiation-induced fibrosis by integrating vitamin E and pentoxifylline into fat grafts locally.Forty adult CD-1 nude male mice at 6 weeks of age underwent scalp irradiation and recovered for four weeks to allow for the development of fibrosis. Mice received 200μL of donor human fat graft to the scalp. Mice were separated into 4 conditions: no grafting, fat graft without treatment, graft treated with pentoxifylline, and graft treated with vitamin E. Fat graft volume retention was monitored in-vivo using microCT scans at weeks 0, 1, 2, 4, 6, and 8 after grafting. Histological and cytokine analysis of the scalp skin and fat grafts were also performed.Vitamin E (VE) treated grafts had significant improvement in dermal thickness and collagen density of overlying skin compared to all other groups. VE decreased 8-isoprostane and increased CD31 + staining compared to the other grafted groups. Cytokine analysis revealed decreased inflammatory and increased angiogenic markers in both the fat graft and overlying skin of the vitamin E group. Fat graft volume retention was significantly improved in the vitamin E group starting at 1 week post grafting.Radiation-induced fibrosis and fat graft volume retention are both simultaneously improved with local administration of vitamin E.

  View details for DOI 10.1093/asj/sjac066

  View details for PubMedID 35350074

• Surgical Applications of Materials Engineered with Antimicrobial Properties. Bioengineering (Basel, Switzerland) Perrault, D. P., Sharma, A., Kim, J. F., Gurtner, G. C., Wan, D. C. 2022; 9 (4)

  Abstract

  The infection of surgically placed implants is a problem that is both large in magnitude and that broadly affects nearly all surgical specialties. Implant-associated infections deleteriously affect patient quality-of-life and can lead to greater morbidity, mortality, and cost to the health care system. The impact of this problem has prompted extensive pre-clinical and clinical investigation into decreasing implant infection rates. More recently, antimicrobial approaches that modify or treat the implant directly have been of great interest. These approaches include antibacterial implant coatings (antifouling materials, antibiotics, metal ions, and antimicrobial peptides), antibacterial nanostructured implant surfaces, and antibiotic-releasing implants. This review provides a compendium of these approaches and the clinical applications and outcomes. In general, implant-specific modalities for reducing infections have been effective; however, most applications remain in the preclinical or early clinical stages.

  View details for DOI 10.3390/bioengineering9040138

  View details for PubMedID 35447700

• Tension offloading improves cutaneous scar formation in Achilles tendon repair. Journal of surgical case reports Abbas, D. B., Lintel, H., Griffin, M., Guardino, N. J., Guo, J. L., Spielman, A. F., Cotterell, A. C., Parker, J. B., Januszyk, M., Wan, D. C. 2022; 2022 (3): rjac066

  Abstract

  Hypertrophic scar formation and non-healing wounds following Achilles tendon repair arise from poor vascularity to the incisional site or from excess mechanical stress/strain to the incision during the healing process. The embrace scar therapy dressing is a tension offloading device for incisional scars. This study explored the effects of tension offloading during Achilles scar formation. A healthy 30-year-old male without any medical co-morbidities developed an acute rupture of his left Achilles tendon. The patient underwent open repair 1 week after injury. At post-operative day (POD) 14, the patient started daily tension offloading treatment on the inferior portion of the incision through POD 120. By POD 120, the untreated portion of the Achilles incision appeared hypertrophic and hyperpigmented, while the treated portion of the scar appeared flat with minimal pigmentation changes. The 12-week treatment of tension offloading on an Achilles tendon repair incision significantly improved cosmesis compared to untreated incision.

  View details for DOI 10.1093/jscr/rjac066

  View details for PubMedID 35280050

• Overcoming Radiation Induced Oral Fibrosis Through The Down Regulation Of WNT Signaling Using BMP-7 Inhibitors Guardino, N., Griffin, M., Spielman, A. F., Abbas, D. B., King, M., Parker, J., Wan, D., Longaker, M. T. WILEY. 2022: A5

  View details for Web of Science ID 000763583000022

• Adipocytes Transition To Pro-Fibrotic Fibroblasts And Contribute To Muscle Fibrosis Following Nerve Injury Spielman, A. F., Griffin, M., Guardino, N., desJardins-Park, H. E., Bauer-Rowe, K. E., Guo, J. L., Parker, J., Abbas, D. B., Wan, D., Longaker, M. T. WILEY. 2022: A3-A4

  View details for Web of Science ID 000763583000018

• Vitamin E Treated Fat Grafts Demonstrate Improved Volume Retention And Decreased Radiation-Induced Fibrosis Abbas, D. B., Lavin, C. V., Fahy, E. J., Lintel, H., Griffin, M., Nazerali, R., Dung Nguyen, Momeni, A., Longaker, M. T., Wan, D. WILEY. 2022: A16

  View details for Web of Science ID 000763583000040

• Transdermal Deferoxamine Enhances Wound Healing In Chronically Irradiated Skin In Mice Lintel, H., Abbas, D. B., Lavin, C. V., Griffin, M., Guardino, N., Guo, J. L., Spielman, A. F., Gurtner, G. C., Longaker, M. T., Wan, D. WILEY. 2022: A29-A30

  View details for Web of Science ID 000763583000068

• Multi-omic analysis reveals divergent molecular events in scarring and regenerative wound healing. Cell stem cell Mascharak, S., Talbott, H. E., Januszyk, M., Griffin, M., Chen, K., Davitt, M. F., Demeter, J., Henn, D., Bonham, C. A., Foster, D. S., Mooney, N., Cheng, R., Jackson, P. K., Wan, D. C., Gurtner, G. C., Longaker, M. T. 1800

  Abstract

  Regeneration is the holy grail of tissue repair, but skin injury typically yields fibrotic, non-functional scars. Developing pro-regenerative therapies requires rigorous understanding of the molecular progression from injury to fibrosis or regeneration. Here, we report the divergent molecular events driving skin wound cells toward scarring or regenerative fates. We profile scarring versus YAP-inhibition-induced wound regeneration at the transcriptional (single-cell RNA sequencing), protein (timsTOF proteomics), and tissue (extracellular matrix ultrastructural analysis) levels. Using cell-surface barcoding, we integrate these data to reveal fibrotic and regenerative "molecular trajectories" of healing. We show that disrupting YAP mechanotransduction yields regenerative repair by fibroblasts with activated Trps1 and Wnt signaling. Finally, via invivo gene knockdown and overexpression in wounds, we identify Trps1 as a key regulatory gene that is necessary and partially sufficient for wound regeneration. Our findings serve as a multi-omic map of wound regeneration and could have therapeutic implications for pathologic fibroses.

  View details for DOI 10.1016/j.stem.2021.12.011

  View details for PubMedID 35077667

• Local Vitamin E Administration Improves Fat Graft Retention and Radiation-Induced Fibrosis in a Mouse Model Abbas, D. B., Lavin, C. V., Fahy, E. J., Griffin, M., King, M. E., Lee, D., Dung Nguyen, Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: S199

  View details for Web of Science ID 000718303100374

• The Impact of Reconstructive Modality on the Severity of Postoperative Complications in Breast Reconstruction Pedreira, R., Tevlin, R., Griffin, M., Wan, D., Momeni, A. ELSEVIER SCIENCE INC. 2021: S211-S212

  View details for Web of Science ID 000718303100399

• Analysis of Online Educational Materials Relating to Craniosynostosis Lavin, C. V., Fahy, E. J., Abbas, D. B., Deleon, N., Lee, D. K., Griffin, M., King, M. W., Guardino, N., Wan, D. C. ELSEVIER SCIENCE INC. 2021: S203-S204

  View details for Web of Science ID 000718303100383

• Transdermal Deferoxamine in a Porcine Model Is a Safe Treatment to Improve Elasticity Secondary to Radiation-induced Fibrosis Abbas, D. B., Fahy, E. J., Lavin, C. V., Griffin, M., Deleon, N., King, M. E., Gurtner, G. C., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: E164

  View details for Web of Science ID 000718306700398

• CD34+CD146+Adipose-derived Stromal Cells (ASCs) Enrichment of Fat Grafts Enhance Regeneration of Irradiated Skin and Graft Retention Deleon, N., Abbas, D. B., Borrelli, M. R., Adem, S., Lavin, C. V., Griffin, M., King, M. E., Lee, D., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: E198

  View details for Web of Science ID 000718306700482

• Dermal Iron Chelation Reduces Indirect Radiation Injury Lavin, C. V., Fahy, E. J., Abbas, D. B., Griffin, M., Lee, D. K., Deleon, N., Guardino, N., Gurtner, G. C., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: E155

  View details for Web of Science ID 000718306700375

• Dorsal Skin Fibrosis Secondary to Radiation Is Mitigated by Fat Grafting in Engrailed-1 Mice Abbas, D. B., Fahy, E. J., Griffin, M., Lavin, C. V., Deleon, N., King, M. E., Lee, D., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: E159-E160

  View details for Web of Science ID 000718306700387

• Suprazygomatic Maxillary Nerve Blocking Reduces Postoperative Pain and Opioid Use Following Bimaxillary Osteotomy Lavin, C. V., Lee, D. K., Fahy, E. J., Abbas, D. B., Griffin, M., King, M. E., Momeni, A., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: E157

  View details for Web of Science ID 000718306700380

• Optimizing Cutometer Mpa 580 Calculated Parameters to Determine In-vivo Elasticity of Human Skin Abbas, D. B., Lavin, C. V., Fahy, E., Griffin, M., Guardino, N., Lee, D., Gurtner, G. C., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: E162

  View details for Web of Science ID 000718306700394

• Temperature Influence on Scanning Laser Doppler Flowmetry in Anesthetized Mice Fahy, E. J., Lavin, C. V., Abbas, D., Griffin, M., King, M. E., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: E157

  View details for Web of Science ID 000718306700381

• Acellular Dermal Matrix Grafts Decrease Radiation-Induced Contracture and Dermal Thickening Deleon, N., Lavin, C. D., Abbas, D., Griffin, M., King, M. E., Fahy, E. J., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: E197

  View details for Web of Science ID 000718306700480

• Adipose-Derived Stromal Cell (ASC) Subpopulation with Adipogenic Capabilities Increase Fat Graft Quality in Irradiated Tissue Deleon, N., Adem, S., Borrelli, M. R., Abbas, D. B., Lavin, C. V., Griffin, M., King, M. E., Lee, D., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: E197-E198

  View details for Web of Science ID 000718306700481

• Acellular Dermal Matrix Modulation of the Peri-Prosthetic Breast Microenvironment During Breast Reconstruction Tevlin, R., Januszyk, M., Griffin, M., Shefren, K., Chan, C. F., Momeni, A., Wan, D. C., Longaker, M. T. ELSEVIER SCIENCE INC. 2021: S195-S196

  View details for Web of Science ID 000718303100367

• Fibroblast Sub-Populations Dynamically Change Composition to Heal Dorsal Skin Radiation Wounds in Wild-Type Mice Abbas, D. B., Griffin, M., Fahy, E. J., Lavin, C., Lee, D., Mascharak, S., King, M., Januszyk, M., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: S207-S208

  View details for Web of Science ID 000718303100389

• Adipose Precursor Cell-Embedded Collagen Gels Attenuate Inflammation and Improve Tissue Perfusion in Cutaneous Wounds Fahy, E. J., Griffin, M., Abbas, D., Lavin, C. V., King, M. E., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: S196

  View details for Web of Science ID 000718303100368

• Denervation During Mandibular Distraction Osteogenesis Results in Impaired Osteogenesis Tevlin, R., Januszyk, M., Griffin, M., Salhotra, A., Wan, D. C., Chan, C. F., Longaker, M. T. ELSEVIER SCIENCE INC. 2021: S196-S197

  View details for Web of Science ID 000718303100369

• Topical Deferoxamine Patch Is Superior to Direct Injection for the Treatment of Radiation-Induced Skin Fibrosis Lavin, C. V., Abbas, D. B., Fahy, E. J., Lee, D. K., Griffin, M., Deleon, N., Mascharak, S., Gurtner, G. C., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: S202-S203

  View details for Web of Science ID 000718303100381

• Effects of beta(3) Adrenergic Receptor Agonist Treatment in Murine Full Thickness Dorsal Cutaneous Wounds Fahy, E. J., Griffin, M., Abbas, D., Lavin, C. V., King, M. E., Lee, D., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2021: S197-S198

  View details for Web of Science ID 000718303100371

• Single-Cell RNA Sequencing Reveals Fibroblast Heterogeneity Across Mouse and Human Embryonic Origins Griffin, M., King, M. W., Guardino, N., Tevlin, R., Fahy, E. J., Mascharak, S., Abbas, D., Lavin, C. V., Wan, D., Longaker, M. ELSEVIER SCIENCE INC. 2021: S201-S202

  View details for Web of Science ID 000718303100378

• Integrated spatial multiomics reveals fibroblast fate during tissue repair. Proceedings of the National Academy of Sciences of the United States of America Foster, D. S., Januszyk, M., Yost, K. E., Chinta, M. S., Gulati, G. S., Nguyen, A. T., Burcham, A. R., Salhotra, A., Ransom, R. C., Henn, D., Chen, K., Mascharak, S., Tolentino, K., Titan, A. L., Jones, R. E., da Silva, O., Leavitt, W. T., Marshall, C. D., des Jardins-Park, H. E., Hu, M. S., Wan, D. C., Wernig, G., Wagh, D., Coller, J., Norton, J. A., Gurtner, G. C., Newman, A. M., Chang, H. Y., Longaker, M. T. 2021; 118 (41)

  Abstract

  In the skin, tissue injury results in fibrosis in the form of scars composed of dense extracellular matrix deposited by fibroblasts. The therapeutic goal of regenerative wound healing has remained elusive, in part because principles of fibroblast programming and adaptive response to injury remain incompletely understood. Here, we present a multimodal -omics platform for the comprehensive study of cell populations in complex tissue, which has allowed us to characterize the cells involved in wound healing across both time and space. We employ a stented wound model that recapitulates human tissue repair kinetics and multiple Rainbow transgenic lines to precisely track fibroblast fate during the physiologic response to skin injury. Through integrated analysis of single cell chromatin landscapes and gene expression states, coupled with spatial transcriptomic profiling, we are able to impute fibroblast epigenomes with temporospatial resolution. This has allowed us to reveal potential mechanisms controlling fibroblast fate during migration, proliferation, and differentiation following skin injury, and thereby reexamine the canonical phases of wound healing. These findings have broad implications for the study of tissue repair in complex organ systems.

  View details for DOI 10.1073/pnas.2110025118

  View details for PubMedID 34620713

• A comparative analysis of deferoxamine treatment modalities for dermal radiation-induced fibrosis. Journal of cellular and molecular medicine Lavin, C. V., Abbas, D. B., Fahy, E. J., Lee, D. K., Griffin, M., Diaz Deleon, N. M., Mascharak, S., Chen, K., Momeni, A., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2021

  Abstract

  The iron chelator, deferoxamine (DFO), has been shown to potentially improve dermal radiation-induced fibrosis (RIF) in mice through increased angiogenesis and reduced oxidative damage. This preclinical study evaluated the efficacy of two DFO administration modalities, transdermal delivery and direct injection, as well as temporal treatment strategies in relation to radiation therapy to address collateral soft tissue fibrosis. The dorsum of CD-1 nude mice received 30Gy radiation, and DFO (3mg) was administered daily via patch or injection. Treatment regimens were prophylactic, during acute recovery, post-recovery, or continuously throughout the experiment (n=5 per condition). Measures included ROS-detection, histology, biomechanics and vascularity changes. Compared with irradiated control skin, DFO treatment decreased oxidative damage, dermal thickness and collagen content, and increased skin elasticity and vascularity. Metrics of improvement in irradiated skin were most pronounced with continuous transdermal delivery of DFO. In summary, DFO administration reduces dermal fibrosis induced by radiation. Although both treatment modalities were efficacious, the transdermal delivery showed greater effect than injection for each temporal treatment strategy. Interestingly, the continuous patch group was more similar to normal skin than to irradiated control skin by most measures, highlighting a promising approach to address detrimental collateral soft tissue injury following radiation therapy.

  View details for DOI 10.1111/jcmm.16913

  View details for PubMedID 34612609

• Prevention and Management of Complications of Tissue Flaps. The Surgical clinics of North America Miller, T. J., Lavin, C. V., Momeni, A., Wan, D. C. 2021; 101 (5): 813-829

  Abstract

  In this article, we discuss 4 common free flaps performed in reconstructive surgery: the anterolateral thigh flap, the radial forearm flap, the fibula flap, and the transverse rectus abdominis myocutaneous/deep inferior epigastric perforator flap. Donor and recipient complications for each flap type and strategies on how to prevent and manage such complications are discussed.

  View details for DOI 10.1016/j.suc.2021.06.009

  View details for PubMedID 34537145

• Inhibiting Fibroblast Mechanotransduction Modulates Severity of Idiopathic Pulmonary Fibrosis. Advances in wound care Trotsyuk, A. A., Chen, K., Kwon, S. H., Ma, K. C., Henn, D., Mermin-Bunnell, A. M., Mittal, S., Padmanabhan, J., Larson, M. R., Steele, S. R., Sivaraj, D., Bonham, C. A., Noishiki, C., Rodrigues, M., Jiang, Y., Jing, S., Niu, S., Chattopadhyay, A., Perrault, D. P., Leeolou, M. C., Fischer, K., Gurusankar, G., Choi Kussie, H., Wan, D. C., Januszyk, M., Longaker, M. T., Gurtner, G. C. 2021

  Abstract

  OBJECTIVE: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease that affects 63 in every 100,000 Americans. Its etiology remains unknown, although inflammatory pathways appear to be important. Given the dynamic environment of the lung, we examined the significance of mechanotransduction on both inflammatory and fibrotic signaling during IPF.INNOVATION: Mechanotransduction pathways have not been thoroughly examined in the context of lung disease and pharmacologic approaches for IPF do not currently target these pathways. The interplay between mechanical strain and inflammation in pulmonary fibrosis remain incompletely understood.APPROACH: In this study, we used conditional KO mice to block mechanotransduction by knocking out FAK (Focal Adhesion Kinase) expression in fibroblasts, followed by induction of pulmonary fibrosis using bleomycin. We examined both normal human and human IPF fibroblasts and used immunohistochemistry, qRT-PCR, and Western Blot to evaluate the effects of FAK inhibition (FAKI) on modulating fibrotic and inflammatory genes.RESULTS: Our data indicate that deletion of FAK in mice reduces expression of fibrotic and inflammatory genes in lungs. Similarly, mechanical straining in normal human lung fibroblasts activates inflammatory and fibrotic pathways. FAK inhibition decreases these signals but has less effect on IPF fibroblasts as compared to normal human fibroblasts.CONCLUSION: Administering FAKI at early stages of fibrosis may attenuate the FAK-mediated fibrotic response pathway in IPF, potentially mediating disease progression.

  View details for DOI 10.1089/wound.2021.0077

  View details for PubMedID 34544267

• From Chronic Wounds to Scarring: The Growing Healthcare Burden of Under- and Over-healing Wounds. Advances in wound care desJardins-Park, H. E., Gurtner, G. C., Wan, D. C., Longaker, M. T. 2021

  Abstract

  SIGNIFICANCE: Wound healing is the largest medical market without an existing small molecule/drug treatment. Both "under-healing" (chronic wounds) and "over-healing" (scarring) cause a substantial biomedical burden and lifelong consequences for patients. These problems cost tens of billions of dollars per year in the United States alone, a number expected to grow as the population ages and the prevalence of common comorbidities (e.g., diabetes) rises. However, no therapies currently exist to produce the "ideal" healing outcome: efficient wound repair via regeneration of normal tissue. Recent Advances: Ongoing research continues to illuminate possible therapeutic avenues for wound healing. By identifying underlying mechanisms of wound repair - for instance, tissue mechanics' role in fibrosis, or cell populations that modulate wound healing and scarring - novel molecular targets may be defined. This Advances in Wound Care Forum issue includes reviews of scientific literature and original research from the Hagey Laboratory for Pediatric Regenerative Medicine at Stanford and its alumni, including developing approaches for encouraging wound healing, minimizing fibrosis, and coaxing regeneration.CRITICAL ISSUES: Wound healing problems reflect an enormous and rapidly expanding clinical burden. The issues of both under- and over-healing wound outcomes will continue to expand as their underlying causes (e.g., diabetes) grow. Targeted treatments are needed to enable wound repair with functional tissue restoration and decreased scarring.FUTURE DIRECTIONS: Basic scientists will continue to refine understanding of factors driving undesirable wound outcomes. These discoveries are beginning to be translated and, in the coming years, will hopefully form the foundation for anti-scarring drugs and other wound therapeutics.

  View details for DOI 10.1089/wound.2021.0039

  View details for PubMedID 34521257

• A Novel Xenograft Model Demonstrates Human Fibroblast Behavior During Skin Wound Repair and Fibrosis. Advances in wound care Borrelli, M., Shen, A. H., Griffin, M., Mascharak, S., Adem, S., Diaz Deleon, N. M., Ngaage, L. M., Longaker, M. T., Wan, D. C., Lorenz, H. P. 2021

  Abstract

  OBJECTIVE: Xenografts of human skin on immunodeficient mice provide a means of assessing human skin physiology and its response to wounding.APPROACH: We describe a novel xenograft model using full-thickness human neonatal foreskin to examine human skin wound repair and fibroblast heterogeneity. Full-thickness 8-mm human neonatal foreskin biopsies were sutured into the dorsum of NSG (NOD.Cg-Prkdc scidIl2rgtm1Wjl/SzJ) pups as subcutaneous grafts and exposed to cutaneous grafts at the time of weaning (postnatal day 21). To model fibrosis, xenografts were wounded with 5-mm linear incisions and monitored until post-wound day (PWD) 14. To explore whether our model can be used to test the efficacy of topical therapies, wounded xenografts were injected with fibroblast growth factor-2 (FGF2) for the first four consecutive PWDs. Xenografts were harvested for analysis by histology and fluorescence-activated cell sorting (FACS).RESULTS: Xenografts successfully engrafted with evidence of mouse-human anastomoses and resembled native neonatal foreskin at the gross and microscopic level. Wounded xenografted skin scarred with human collagen and an expansion of CD26-positive human fibroblasts. Collagen scar was quantitated by neural network analysis, which revealed distinct clustering of collagen fiber networks from unwounded skin and wounded skin at PWD7 and PWD14. Collagen fiber networks within FGF2-treated wounds at PWD14 resembled those in untreated wounded xenografts at PWD7, suggesting that FGF2 treatment at time of wounding can reduce fibrosis. Innovation and Conclusion: This novel xenograft model can be used to investigate acute fibrosis, fibroblast heterogeneity, and the efficacy of antifibrotic agents during wound repair in human skin.

  View details for DOI 10.1089/wound.2020.1392

  View details for PubMedID 34521222

• Perineal Reconstruction With the Profunda Artery Perforator Flap. Annals of plastic surgery Arquette, C., Wan, D., Momeni, A. 2021

  Abstract

  BACKGROUND: Abdominoperineal resection is used to treat a variety of colorectal pathologies. Traditionally, the vertical rectus abdominis myocutaneous flap has been most commonly used for reconstruction. Here, we explore the role of the profunda artery perforator (PAP) flap for perineal reconstruction.METHODS: A prospectively maintained database was retrospectively analyzed to identify patients who had undergone perineal reconstruction with a pedicled PAP flap. Parameters of interest included age, sex, body mass index, primary diagnosis, comorbidities, and history of radiation, and postoperative complications.RESULTS: Fifteen patients (5 men and 10 women) with a median age of 52 years (interquartile range, 48.5-61.5 years) were included in the study. Median body mass index was 26.3 kg/m2 (interquartile range, 24.0-29.3 kg/m2). Patients underwent abdominoperineal resection for treatment of rectal cancer (n = 9, 60.0%), recurrent anal squamous cell carcinoma (n = 3, 20.0%), and Crohn's disease (n = 3, 20.0%). Twelve patients (80.0%) underwent neoadjuvant radiotherapy. Eight patients (53.3%) experienced a total of 10 complications (2 major and 8 minor). The most common complication was donor (n = 3, 20.0%)/recipient (n = 3, 20.0%) site wound dehiscence. Stable soft tissue coverage was achieved in all patients.CONCLUSIONS: The PAP flap provides stable soft tissue coverage of perineal defects with a low donor-site morbidity. This flap should be strongly considered in the reconstructive algorithm when approaching perineal defects.

  View details for DOI 10.1097/SAP.0000000000002986

  View details for PubMedID 34510081

• Understanding Scarring in the Oral Mucosa. Advances in wound care Griffin, M., Fahy, E., King, M., Guardino, N., Chen, K., Abbas, D. B., Lavin, C., Diaz Deleon, N. M., Lorenz, H. P., Longaker, M. T., Wan, D. C. 2021

  Abstract

  SIGNIFICANCE: Skin inevitably heals with the formation of a fibrotic scar. Patients affected by skin fibrosis suffer from long-term psychological and physical burdens. Recent Advances: Since the discovery of fetal scarless skin-wound healing, research has hoped to identify and mimic scarless healing for adult skin. Oral mucosa healing in adults provides the closest example to fetal scarless healing. Injuries to the oral mucosa heal with very minimal scarring. Understanding the mechanisms through which this process occurs may bring us closer to achieving scarless healing in adults.CRITICAL ISSUES: In this review, we summarize the current evidence that illustrates distinct mechanisms involved in oral mucosal healing. We discuss the role of the oral niche in contributing to wound repair. The intrinsic properties of immune cells, fibroblasts, and keratinocytes within the oral mucosa that support regenerative repair are provided. We highlight the contribution of cytokines, growth factors, and chemokine secretion in permitting a scarless mucosal environment. Furthermore, we discuss the role of stem cell-like progenitor populations in the mucosa that may contribute to wound healing. We also provide suggestions for future studies that are needed to achieve scarless healing in adults.FUTURE DIRECTIONS: Many characteristics of the oral mucosa have been shown to contribute to decreased scarring, but the specific mechanism(s) is unclear. Advancing our understanding of oral healing may yield therapeutic therapies that can be used to overcome dermal fibrosis and scarring.

  View details for DOI 10.1089/wound.2021.0038

  View details for PubMedID 34470520

• Standardizing dimensionless cutometer parameters to determine in-vivo elasticity of human skin. Advances in wound care Abbas, D. B., Lavin, C., Fahy, E., Griffin, M., Guardino, N., King, M., Chen, K., Lorenz, H. P., Gurtner, G. C., Longaker, M. T., Momeni, A., Wan, D. C. 2021

  Abstract

  OBJECTIVE: Skin fibrosis places an enormous burden on patients and society, but disagreement exists over methods to quantify severity of skin scarring. A suction cutometer measures skin elasticity in-vivo, but it has not been widely adopted due to inconsistency in data produced. We investigated variability of several dimensionless parameters generated by the cutometer to improve their precision and accuracy.APPROACH: Twenty adult human subjects underwent suction cutometer measurement of normal skin and fibrotic scars. Using Mode 1, each subject underwent 5 trials with each trial containing 4 curves. R0/2/5/6/7 and Q1/2/3 data were collected. Analyses were performed on these calculated parameters.RESULTS: R0/2/5/6/7 and Q1/2 parameters from curves 1-4 demonstrated significant differences, while these same parameters were not significantly different when only using curves 2-4. Individual analysis of all parameters between curve 1 and every subsequent curve was statistically significant for R0, R2, R5, R6, R7, Q1, and Q2. No differences were appreciated for parameter Q3. Comparison between normal skin and fibrotic scars were significantly different for parameters R5, Q1, and Q3.INNOVATION: Our study is the first demonstration of accurate comparison between normal skin and fibrotic scars using the dimensionless parameters of a suction cutometer.CONCLUSION: Measured parameters from the first curve of each trial were significantly different from subsequent curves for both normal skin and fibrotic scars. Precision and reproducibility of data from dimensionless parameters can therefore be improved by removing the first curve. R5, Q1, and Q3 parameters differentiated normal skin as more elastic than fibrotic scars.

  View details for DOI 10.1089/wound.2021.0082

  View details for PubMedID 34470542

• JUN promotes hypertrophic skin scarring via CD36 in preclinical in vitro and in vivo models. Science translational medicine Griffin, M. F., Borrelli, M. R., Garcia, J. T., Januszyk, M., King, M., Lerbs, T., Cui, L., Moore, A. L., Shen, A. H., Mascharak, S., Diaz Deleon, N. M., Adem, S., Taylor, W. L., desJardins-Park, H. E., Gastou, M., Patel, R. A., Duoto, B. A., Sokol, J., Wei, Y., Foster, D., Chen, K., Wan, D. C., Gurtner, G. C., Lorenz, H. P., Chang, H. Y., Wernig, G., Longaker, M. T. 2021; 13 (609): eabb3312

  Abstract

  [Figure: see text].

  View details for DOI 10.1126/scitranslmed.abb3312

  View details for PubMedID 34516825

• Modulating cellular responses to mechanical forces to promote wound regeneration. Advances in wound care Mascharak, S., desJardins-Park, H. E., Davitt, M. F., Guardino, N. J., Gurtner, G. C., Wan, D. C., Longaker, M. T. 2021

  Abstract

  SIGNIFICANCE: Skin scarring poses a major biomedical burden for hundreds of millions of patients annually. However, this burden could be mitigated by therapies that promote wound regeneration, with full recovery of skin's normal adnexa, matrix ultrastructure, and mechanical strength. Recent Advances: The observation of wound regeneration in several mouse models suggests a retained capacity for postnatal mammalian skin to regenerate under the right conditions. Mechanical forces are a major contributor to skin fibrosis and a prime target for devices and therapeutics that could promote skin regeneration.CRITICAL ISSUES: Wound induced hair neogenesis, Acomys "spiny" mice, Murphy Roths Large (MRL) mice, and mice treated with mechanotransduction inhibitors all show various degrees of wound regeneration. Comparison of regenerating wounds in these models against scarring wounds reveals differences in ECM interactions and in mechanosensitive activation of key signaling pathways, including Wnt, Sonic hedgehog, Focal Adhesion Kinase, and Yes-associated protein. The advent of single cell "omics" technologies has deepened this understanding and revealed that regeneration may recapitulate development in certain contexts, though it is unknown whether these mechanisms are relevant to healing in tight-skinned animals such as humans.FUTURE DIRECTIONS: While early findings in mice are promising, comparison across model systems is needed to resolve conflicting mechanisms and to identify conserved master regulators of skin regeneration. There also remains a dire need for studies on mechanomodulation of wounds in large, tight-skinned animals such as red Duroc pigs, which better approximate human wound healing.

  View details for DOI 10.1089/wound.2021.0040

  View details for PubMedID 34465219

• Decellularized Adipose Matrices can Alleviate Radiation-induced Skin Fibrosis. Advances in wound care Adem, S., Abbas, D. B., Lavin, C., Fahy, E., Griffin, M., Diaz Deleon, N. M., Borrelli, M. R., Mascharak, S., Shen, A. H., Patel, R. A., Longaker, M. T., Nazerali, R. S., Wan, D. C. 2021

  Abstract

  OBJECTIVE: Radiation therapy is commonplace for cancer treatment but often results in fibrosis and atrophy of surrounding soft tissue. Decellularized adipose matrices (DAMs) have been reported to improve these soft tissue defects through the promotion of adipogenesis. These matrices are decellularized by a combination of physical, chemical, and enzymatic methods to minimize their immunologic effects while promoting their regenerative effects. In this study, we aimed to explore the regenerative ability of a DAM (Renuva, MTF Biologics, New Jersey, USA) in radiation-induced soft tissue injury.APPROACH: Fresh human lipoaspirate or DAM was injected into the irradiated scalp of CD-1 nude mice, and volume retention was monitored radiographically over 8 weeks. Explanted grafts were histologically assessed, and overlying skin was examined histologically and biomechanically. Irradiated human skin was also evaluated from patients following fat grafting or DAM injection. However, integrating data between murine and human skin in all cohorts is limited given the genetic variability between the two species.RESULTS: Volume retention was found to be greater with fat grafts, though DAM retention was nonetheless appreciated at irradiated sites. Improvement in both mouse and human irradiated skin overlying fat and DAM grafts was observed in terms of biomechanical stiffness, dermal thickness, collagen density, collagen fiber networks, and skin vascularity.INNOVATION: This is the first demonstration of the use of DAMs for augmenting the regenerative potential of irradiated mouse and human skin.CONCLUSIONS: These findings support use of DAMs to address soft tissue atrophy following radiation therapy. Morphological characteristics of the irradiated skin can also be improved with DAM grafting.

  View details for DOI 10.1089/wound.2021.0008

  View details for PubMedID 34346243

• Leveraging Mechanical Forces to Target Insulin Injection-Induced Lipohypertrophy and Fibrosis. Diabetes spectrum : a publication of the American Diabetes Association desJardins-Park, H. E., Wan, D. C. 2021; 34 (3): 308-312

  View details for DOI 10.2337/ds20-0048

  View details for PubMedID 34511858

• Skeletal stem and progenitor cells maintain cranial suture patency and prevent craniosynostosis. Nature communications Menon, S., Salhotra, A., Shailendra, S., Tevlin, R., Ransom, R. C., Januszyk, M., Chan, C. K., Behr, B., Wan, D. C., Longaker, M. T., Quarto, N. 2021; 12 (1): 4640

  Abstract

  Cranial sutures are major growth centers for the calvarial vault, and their premature fusion leads to a pathologic condition called craniosynostosis. This study investigates whether skeletal stem/progenitor cells are resident in the cranial sutures. Prospective isolation by FACS identifies this population with a significant difference in spatio-temporal representation between fusing versus patent sutures. Transcriptomic analysis highlights a distinct signature in cellsderived from the physiological closing PF suture, and scRNA sequencing identifies transcriptional heterogeneity among sutures. Wnt-signaling activation increases skeletal stem/progenitor cells in sutures, whereas its inhibition decreases. Crossing Axin2LacZ/+ mouse, endowing enhanced Wnt activation, to a Twist1+/- mouse model of coronal craniosynostosis enriches skeletal stem/progenitor cells in sutures restoring patency. Co-transplantation of these cells with Wnt3a prevents resynostosis following suturectomy in Twist1+/- mice. Our study reveals that decrease and/or imbalance of skeletal stem/progenitor cells representation within sutures may underlie craniosynostosis. These findings have translational implications toward therapeutic approaches for craniosynostosis.

  View details for DOI 10.1038/s41467-021-24801-6

  View details for PubMedID 34330896

• Mechanical Strain Drives Myeloid Cell Differentiation Toward Pro-Inflammatory Subpopulations. Advances in wound care Chen, K., Henn, D., Sivaraj, D., Bonham, C. A., Griffin, M., Choi Kussie, H., Padmanabhan, J., Trotsyuk, A. A., Wan, D. C., Januszyk, M., Longaker, M. T., Gurtner, G. C. 2021

  Abstract

  OBJECTIVE: After injury, humans and other mammals heal by forming fibrotic scar tissue with diminished function, and this healing process involves the dynamic interplay between resident cells within the skin and cells recruited from the circulation. Recent studies have provided mounting evidence that external mechanical forces stimulate intracellular signaling pathways to drive fibrotic processes.INNOVATION: While most studies have focused on studying mechanotransduction in fibroblasts, recent data suggest that mechanical stimulation may also shape the behavior of immune cells, referred to as "mechano-immunomodulation". However, the effect of mechanical strain on myeloid cell recruitment and differentiation remains poorly understood and has never been investigated at the single cell level.APPROACH: In this study, we utilized a three-dimensional (3D) in vitro culture system that permits the precise manipulation of mechanical strain applied to cells. We cultured myeloid cells and used single cell RNA-sequencing to interrogate the effects of strain on myeloid differentiation and transcriptional programming.RESULTS: Our data indicate that myeloid cells are indeed mechanoresponsive, with mechanical stress influencing myeloid differentiation. Mechanical strain also upregulated a cascade of inflammatory chemokines, most notably from the Ccl family.CONCLUSION: Further understanding of how mechanical stress affects myeloid cells in conjunction with other cell types in the complicated, multicellular milieu of wound healing may lead to novel insights and therapies for the treatment of fibrosis.

  View details for DOI 10.1089/wound.2021.0036

  View details for PubMedID 34278820

• Deferoxamine to minimize fibrosis during radiation therapy. Advances in wound care Tevlin, R., Longaker, M. T., Wan, D. 2021

  Abstract

  Significance By 2030, there will be over 4 million radiation-treated cancer survivors living in the US. Irradiation triggers inflammation, fibroblast activation, and extracellular matrix deposition in addition to reactive oxygen species (ROS) generation, leading to a chronic inflammatory response. Radiation-induced fibrosis (RIF) is a progressive pathology resulting in skin pigmentation, reduced elasticity, ulceration and dermal thickening, cosmetic deformity, pain, and the need for reconstructive surgery. Recent Advances Deferoxamine (DFO) is an FDA-approved iron chelator for blood dyscrasia management, which has been found to be pro-angiogenic, to decrease free radical formation, and reduce cell death. DFO has shown great promise in the treatment and prophylaxis of RIF in preclinical studies. Critical Issues Systemic DFO has a short half-life and is cumbersome to deliver to patients intravenously. Transdermal DFO delivery is complicated by its high atomic mass and hydrophilicity, preventing stratum corneum penetration. A transdermal drug delivery system was developed to address these challenges, in addition to a strategy for topical administration. Future Directions DFO has great potential to translate from bench to bedside. An important step in translation of DFO for RIF prophylaxis is to ensure that DFO treatment does not affect the efficacy of radiation therapy. Furthermore, following an initial plethora of studies reporting DFO treatment by intravenous and subcutaneous routes, a significant advantage of recent studies is the success of transdermal and topical delivery. Given the strong foundation of basic scientific research supporting the use of DFO treatment on RIF, clinicians will be closely following the results of the ongoing human studies.

  View details for DOI 10.1089/wound.2021.0021

  View details for PubMedID 34074152

• A Systematic Review of Mandibular Distraction Osteogenesis Versus Orthodontic Airway Plate for Airway Obstruction Treatment in Pierre Robin Sequence. The Cleft palate-craniofacial journal : official publication of the American Cleft Palate-Craniofacial Association Abbas, D. B., Lavin, C., Fahy, E. J., Choo, H., Truong, M. T., Bruckman, K. C., Khosla, R. K., Lorenz, H. P., Momeni, A., Wan, D. C. 2021: 10556656211011886

  Abstract

  OBJECTIVE: Mandibular distraction osteogenesis (MDO) is frequently performed to address airway obstruction in patients with Pierre Robin sequence (PRS), though more recently the technique of orthodontic airway plating (OAP) has gained traction. We aimed to evaluate OAP compared to MDO for airway obstruction in PRS.DESIGN: A systematic literature search across PubMed, Embase, and Google Scholar identified all studies published in English, which involved MDO or any form of OAP as treatments for PRS. All relevant articles were reviewed in detail and reported on, adhering to PRISMA guidelines.MAIN OUTCOME MEASURES: Airway (tracheostomy avoidance, decannulation rate), feeding (full oral feeding tolerance).RESULTS: Literature search identified 970 articles, of which 42 MDO studies and 9 OAP studies met criteria for review. A total of 1159 individuals were treated with MDO, and 322 individuals were treated with OAP. Primary outcomes appear similar for MDO and OAP at face value; however, this must be interpreted with different pretreatment contexts in mind.CONCLUSIONS: Orthodontic airway plating may be considered for airway obstruction in PRS, as some airway-related and feeding-related outcomes appear similar with MDO, per existing evidence in the literature. However, since PRS severity differed between studies, OAP cannot be uniformly considered a replacement for MDO. Further research is required to more comprehensively assess these treatment modalities inclusive of metrics that allow for direct comparison.

  View details for DOI 10.1177/10556656211011886

  View details for PubMedID 34075816

• The Impact of Coagulopathy on Clinical Outcomes following Microsurgical Breast Reconstruction. Plastic and reconstructive surgery Liu, F. C., Miller, T. J., Wan, D. C., Momeni, A. 2021

  Abstract

  SUMMARY: Autologous breast reconstruction has evolved considerably from pedicled muscle-based approaches to microsurgical perforator-based techniques. Patients with documented coagulopathy, however, remain a particularly challenging population. The authors present their experience in microsurgical breast reconstruction in patients with coagulopathy and discuss their treatment protocol. A prospectively maintained database was queried for patients with coagulopathy who underwent microsurgical breast reconstruction between 2016 and 2019. Information regarding patient demographics, type of coagulopathy, and anticoagulation regimen were retrieved, and clinical outcomes were investigated. Nineteen patients who underwent 34 microsurgical breast reconstructions with free abdominal flaps were included in the study. The most common coagulopathy was factor V Leiden [n = 7 (38.6 percent)]. Nine patients (47.4 percent) developed thrombotic complications (the majority occurring intraoperatively); notably, arterial and venous thrombosis in four (21.1 percent) and two patients (10.5 percent), respectively. Postoperative thrombotic complications included pulmonary embolism [n = 2 (10.5 percent)] and flap congestion secondary to venous thrombosis [two flaps (5.9 percent)]. Only one flap loss was observed secondary to delayed venous thrombosis on postoperative day 6 (2.9 percent). The anticoagulation regimen in the majority of patients consisted of intraoperative intravenous administration of heparin (2000 U [bolus]) followed by a 5-day heparin infusion at 500 U/hour [n = 10 (52.6 percent)]. The high rate of thrombotic complications in patients with coagulopathy who underwent microsurgical breast reconstruction is contrasted by a low flap loss rate. Although coagulopathy is a risk factor for thrombotic complications, successful microsurgical breast reconstruction is still possible in the majority of patients.

  View details for DOI 10.1097/PRS.0000000000008099

  View details for PubMedID 34003808

• Readability of Online Patient Information Relating to Cleft Palate Surgery. The Cleft palate-craniofacial journal : official publication of the American Cleft Palate-Craniofacial Association Lavin, C. V., Fahy, E. J., Abbas, D. B., Griffin, M., Deleon, N. M., Lee, D. K., Khosla, R. K., Bruckman, K., Lorenz, H. P., Wan, D. C. 2021: 10556656211013177

  Abstract

  OBJECTIVE: It is important for health care education materials to be easily understood by caretakers of children requiring craniofacial surgery. This study aimed to analyze the readability of Google search results as they pertain to "Cleft Palate Surgery" and "Palatoplasty." Additionally, the study included a search from several locations globally to identify possible geographic differences.DESIGN: Google searches of the terms "Cleft Palate Surgery" and "Palatoplasty" were performed. Additionally, searches of only "Cleft Palate Surgery" were run from several internet protocol addresses globally.MAIN OUTCOME MEASURES: Flesch-Kincaid Grade Level and Readability Ease, Gunning Fog Index, Simple Measure of Gobbledygook (SMOG) index, and Coleman-Liau Index.RESULTS: Search results for "Cleft Palate Surgery" were easier to read and comprehend compared to search results for "Palatoplasty." Mean Flesch-Kincaid Grade Level scores were 7.0 and 10.11, respectively (P = .0018). Mean Flesch-Kincaid Reading Ease scores were 61.29 and 40.71, respectively (P = .0003). Mean Gunning Fog Index scores were 8.370 and 10.34, respectively (P = .0458). Mean SMOG Index scores were 6.84 and 8.47, respectively (P = .0260). Mean Coleman-Liau Index scores were 12.95 and 15.33, respectively (P = .0281). No significant differences were found in any of the readability measures based on global location.CONCLUSIONS: Although some improvement can be made, craniofacial surgeons can be confident in the online information pertaining to cleft palate repair, regardless of where the search is performed from. The average readability of the top search results for "Cleft Palate Surgery" is around the seventh-grade reading level (US educational system) and compares favorably to other health care readability analyses.

  View details for DOI 10.1177/10556656211013177

  View details for PubMedID 33960204

• Wnt-active Engrailed-1 Lineage-negative Fibroblasts Mediate Postnatal Skin Regeneration Mascharak, S., desJardins-Park, H. E., Januszyk, M., Chen, K., Davitt, M. F., Demeter, J., Henn, D., Griffin, M., Bonham, C. A., Mooney, N., Cheng, R., Jackson, P. K., Wan, D. C., Gurtner, G. C., Longaker, M. T. WILEY. 2021: A30

  View details for Web of Science ID 000650720500076

• Single Cell RNA Sequencing Reveals Fibroblast Heterogeneity Across Embryonic Origins Of Skin Griffin, M., King, M., Chen, K., desJardins-Park, H., Mascharak, S., Fahy, E., Guardino, N., Lavin, C., Abbas, D., Januszyk, M., Wan, D., Longaker, M. WILEY. 2021: A11-A12

  View details for Web of Science ID 000650720500037

• Novel Genetic Analysis Of MRL Mice Reveals That Complement Inhibition By Factor H Reduces Scarring desJardins-Park, H. E., Mack, K. L., Guardino, N., Griffin, M., Davitt, M. F., Mascharak, S., Wan, D. C., Fraser, H. B., Longaker, M. T. WILEY. 2021: A13

  View details for Web of Science ID 000650720500040

• Transgenic Inhibition Of Engrailed-1 Results In Endogenous Postnatal Skin Regeneration Mascharak, S., desJardins-Park, H. E., Davitt, M. F., Chen, K., Griffin, M., Guardino, N., Lorenz, H., Wan, D. C., Gurtner, G. C., Longaker, M. T. WILEY. 2021: A14-A15

  View details for Web of Science ID 000650720500043

• Preventing Engrailed-1 activation in fibroblasts yields wound regeneration without scarring. Science (New York, N.Y.) Mascharak, S., desJardins-Park, H. E., Davitt, M. F., Griffin, M., Borrelli, M. R., Moore, A. L., Chen, K., Duoto, B., Chinta, M., Foster, D. S., Shen, A. H., Januszyk, M., Kwon, S. H., Wernig, G., Wan, D. C., Lorenz, H. P., Gurtner, G. C., Longaker, M. T. 2021; 372 (6540)

  Abstract

  Skin scarring, the end result of adult wound healing, is detrimental to tissue form and function. Engrailed-1 lineage-positive fibroblasts (EPFs) are known to function in scarring, but Engrailed-1 lineage-negative fibroblasts (ENFs) remain poorly characterized. Using cell transplantation and transgenic mouse models, we identified a dermal ENF subpopulation that gives rise to postnatally derived EPFs by activating Engrailed-1 expression during adult wound healing. By studying ENF responses to substrate mechanics, we found that mechanical tension drives Engrailed-1 activation via canonical mechanotransduction signaling. Finally, we showed that blocking mechanotransduction signaling with either verteporfin, an inhibitor of Yes-associated protein (YAP), or fibroblast-specific transgenic YAP knockout prevents Engrailed-1 activation and promotes wound regeneration by ENFs, with recovery of skin appendages, ultrastructure, and mechanical strength. This finding suggests that there are two possible outcomes to postnatal wound healing: a fibrotic response (EPF-mediated) and a regenerative response (ENF-mediated).

  View details for DOI 10.1126/science.aba2374

  View details for PubMedID 33888614

• Nonsurgical Orthodontic Airway Plate Treatment for Newborns With Robin Sequence. The Cleft palate-craniofacial journal : official publication of the American Cleft Palate-Craniofacial Association Choo, H., Khosla, R. K., Meister, K. D., Wan, D. C., Lin, H. C., Feczko, R., Bruckman, K., Hopkins, E., Truong, M. T., Lorenz, H. P. 2021: 10556656211007689

  Abstract

  Despite promising outcomes for >50 years, nonsurgical orthodontic airway plates (OAP) are only infrequently offered for babies with Robin sequence in a few parts of the world. This article demonstrates possibility of providing functional improvement using an OAP to help these babies overcome their functional and structural difficulties on their own. Two consecutively treated cases are presented exemplifying that OAP treatment that had originated from Europe is reproducible and effective in an institution in the United States.

  View details for DOI 10.1177/10556656211007689

  View details for PubMedID 33845627

• Craniofacial and Long Bone Development in the Context of Distraction Osteogenesis. Plastic and reconstructive surgery Shah, H. N., Jones, R. E., Borrelli, M. R., Robertson, K. n., Salhotra, A. n., Wan, D. C., Longaker, M. T. 2021; 147 (1): 54e–65e

  Abstract

  Bone retains regenerative potential into adulthood, and surgeons harness this plasticity during distraction osteogenesis. The underlying biology governing bone development, repair, and regeneration is divergent between the craniofacial and appendicular skeleton. Each type of bone formation is characterized by unique molecular signaling and cellular behavior. Recent discoveries have elucidated the cellular and genetic processes underlying skeletal development and regeneration, providing an opportunity to couple biological and clinical knowledge to improve patient care.A comprehensive literature review of basic and clinical literature regarding craniofacial and long bone development, regeneration, and distraction osteogenesis was performed.The current understanding in craniofacial and long bone development and regeneration is discussed, and clinical considerations for the respective distraction osteogenesis procedures are presented.Distraction osteogenesis is a powerful tool to regenerate bone and thus address a number of craniofacial and appendicular skeletal deficiencies. The molecular mechanisms underlying bone regeneration, however, remain elusive. Recent work has determined that embryologic morphogen gradients constitute important signals during regeneration. In addition, striking discoveries have illuminated the cellular processes underlying mandibular regeneration during distraction osteogenesis, showing that skeletal stem cells reactivate embryologic neural crest transcriptomic processes to carry out bone formation during regeneration. Furthermore, innovative adjuvant therapies to complement distraction osteogenesis use biological processes active in embryogenesis and regeneration. Additional research is needed to further characterize the underlying cellular mechanisms responsible for improved bone formation through adjuvant therapies and the role skeletal stem cells play during regeneration.

  View details for DOI 10.1097/PRS.0000000000007451

  View details for PubMedID 33370054

• AAPS Podium Presentations-Has the Level of Evidence Changed over the Past Decade? Plastic and reconstructive surgery. Global open Chattopadhyay, A., Wu, R., Wan, D., Momeni, A. 2021; 9 (5): e3588

  Abstract

  An increase in the number and quality of randomized controlled trials (RCTs) and trends toward higher levels of evidence (LOE) in the plastic surgery literature has been reported; however, there has not been a specific focus on the LOE of presentations at scientific meetings. The purpose of this study was to ascertain trends in the LOE of studies presented at the annual meeting of the American Association of Plastic Surgeons.A hand search was conducted identifying all abstracts of podium presentations from 2009 to 2019. LOE, using American Society of Plastic Surgeons guidelines, were ascribed to each presentation, along with identification of any corresponding journal publications. RCTs were further analyzed using the 12-item Modified Consolidated Standard of Reporting Trials checklist.Four hundred forty-one studies with a median LOE of 3 were included in the study. A non-significant improvement in the mean level of evidence was noted over time (P = 0.09) along with an increase in the number of level 2 studies (P = 0.589) and RCTs (P = 0.717). Level 1 studies were rare (0.91%) and of fair quality (median checklist score 8 out of 12). Seventy-two percent of abstracts resulted in publication, and the mean lag time to publication was 422 days.A favorable trend is observed with respect to the mean LOE as well as the number of level 2 studies and RCTs over time. The importance of research meeting attendance to maintain up-to-date information is noteworthy, given the long lag time from presentation to publication.

  View details for DOI 10.1097/GOX.0000000000003588

  View details for PubMedID 34046292

  View details for PubMedCentralID PMC8143775

• Xenogeneic skin transplantation promotes angiogenesis and tissue regeneration through activated Trem2+ macrophages. Science advances Henn, D., Chen, K., Fehlmann, T., Trotsyuk, A. A., Sivaraj, D., Maan, Z. N., Bonham, C. A., Barrera, J. A., Mays, C. J., Greco, A. H., Moortgat Illouz, S. E., Lin, J. Q., Steele, S. R., Foster, D. S., Padmanabhan, J., Momeni, A., Nguyen, D., Wan, D. C., Kneser, U., Januszyk, M., Keller, A., Longaker, M. T., Gurtner, G. C. 2021; 7 (49): eabi4528

  Abstract

  [Figure: see text].

  View details for DOI 10.1126/sciadv.abi4528

  View details for PubMedID 34851663

• Endogenous Mechanisms of Craniomaxillofacial Repair: Toward Novel Regenerative Therapies. Frontiers in oral health desJardins-Park, H. E., Mascharak, S., Longaker, M. T., Wan, D. C. 1800; 2: 676258

  Abstract

  In the fields of oral and craniomaxillofacial surgery, regeneration of multiple tissue types-including bone, skin, teeth, and mucosal soft tissue-is often a desired outcome. However, limited endogenous capacity for regeneration, as well as predisposition of many tissues to fibrotic healing, may prevent recovery of normal form and function for patients. Recent basic science research has advanced our understanding of molecular and cellular pathways of repair in the oral/craniofacial region and how these are influenced by local microenvironment and embryonic origin. Here, we review the current state of knowledge in oral and craniomaxillofacial tissue repair/regeneration in four key areas: bone (in the context of calvarial defects and mandibular regeneration during distraction osteogenesis); skin (in the context of cleft lip/palate surgery); oral mucosa (in the context of minimally scarring repair of mucosal injuries); and teeth (in the context of dental disease/decay). These represent four distinct healing processes and outcomes. We will discuss both divergent and conserved pathways of repair in these contexts, with an eye toward fundamental mechanisms of regeneration vs. fibrosis as well as translational research directions. Ultimately, this knowledge can be leveraged to develop new cell-based and molecular treatment strategies to encourage bone and soft tissue regeneration in oral and craniomaxillofacial surgery.

  View details for DOI 10.3389/froh.2021.676258

  View details for PubMedID 35048022

• Angiogenic CD34+CD146+ adipose-derived stromal cells augment recovery of soft tissue after radiotherapy. Journal of tissue engineering and regenerative medicine Diaz Deleon, N. M., Adem, S., Lavin, C. V., Abbas, D. B., Griffin, M., King, M. E., Borrelli, M. R., Patel, R. A., Fahy, E. J., Lee, D., Shen, A. H., Momeni, A., Longaker, M. T., Wan, D. C. 2021

  Abstract

  Radiation therapy is effective for cancer treatment but may also result in collateral soft tissue contracture, contour deformities, and non-healing wounds. Autologous fat transfer has been described to improve tissue architecture and function of radiation-induced fibrosis and these effects may be augmented by enrichment with specific adipose-derived stromal cells (ASCs) with enhanced angiogenic potential. CD34+CD146+, CD34+CD146-, or CD34+ unfractionated (UF) human ASCs were isolated by flow cytometry and used to supplement human lipoaspirate placed beneath the scalp of irradiated mice. Volume retention was followed radiographically and fat grafts as well as overlying soft tissue were harvested after eight weeks for histologic and biomechanical analyses. Radiographic evaluation revealed the highest volume retention in fat grafts supplemented with CD34+CD146+ ASCs, and these grafts were also found to have greater histologic integrity than other groups. Irradiated skin overlying CD34+CD146+ ASC-enriched grafts was significantly more vascularized than other treatment groups, had significantly less dermal thickness and collagen deposition, and the greatest improvement in fibrillin staining and return of elasticity. Radiation therapy obliterates vascularity and contributes to scarring and loss of tissue function. ASC-enrichment of fat grafts with CD34+CD146+ ASCs not only enhances fat graft vascularization and retention, but also significantly promotes improvement in overlying radiation-injured soft tissue. This regenerative effect on skin is highly promising for patients with impaired wound healing and deformities following radiotherapy. This article is protected by copyright. All rights reserved.

  View details for DOI 10.1002/term.3253

  View details for PubMedID 34582109

• Lymphatic regeneration after implantation of aligned nanofibrillar collagen scaffolds: Preliminary preclinical and clinical results. Journal of surgical oncology Nguyen, D., Zaitseva, T. S., Zhou, A., Rochlin, D., Sue, G., Deptula, P., Tabada, P., Wan, D., Loening, A., Paukshto, M., Dionyssiou, D. 2021

  Abstract

  We tested our hypothesis that implantation of aligned nanofibrillar collagen scaffolds (BioBridge™) can both prevent and reduce established lymphedema in the rat lymphedema model. Our authors report clinical cases that demonstrate new lymphatic formation guided by BioBridge™ as seen by near-infrared (NIR) fluoroscopy and magnetic resonance (MR) lymphography.A rat lymphedema model was utilized. A prevention group received implantation of BioBridge™ immediately after lymphadenectomy. A lymphedema group received implantation of BioBridge™ with autologous adipose-derived stem cells (ADSC; treatment group) or remained untreated (control group). All subjects were observed for 4 months after lymphadenectomy. The hindlimb change was evaluated using computed tomography-based volumetric analysis. Lymphagiogenesis was assessed by indocyanine green (ICG) lymphography.Animals in the treatment group showed a reduction in affected limb volume. Animals in the prevention group showed no increase in the affected limb volume. ICG fluoroscopy demonstrated lymph flow and formation of lymphatics toward healthy lymphatics.In the rat lymphedema model, implantation of BioBridge™ at the time of lymph node removal prevents the development of lymphedema. Treatment of established lymphedema with the BioBridge™ and ADSC reduces lymphedema. New lymphatic vessels are demonstrated by NIR fluoroscopy and MR lymphography. These findings have implications for the treatment of lymphedema in human subjects.

  View details for DOI 10.1002/jso.26679

  View details for PubMedID 34549427

• The Adrenergic System in Plastic and Reconstructive Surgery: Physiology and Clinical Considerations. Annals of plastic surgery Fahy, E. J., Griffin, M. n., Lavin, C. n., Abbas, D. n., Longaker, M. T., Wan, D. n. 2021

  Abstract

  The primary organ systems and tissues concerning plastic and reconstructive surgery include the integument, vasculature, subcutis, and peripheral nerves, because these may individually or collectively be injured requiring reconstruction, or indeed be used in reconstruction themselves through grafts, flaps, or anastomoses. Adrenergic receptors are present throughout these anatomic components on the vasculature, adipose, platelets, immune cells, keratinocytes, melanocytes, fibroblasts, peripheral nerves, and tendons. Herein, the influence of adrenergic signaling on the physiology of anatomic components related to plastic surgery is discussed, along with clinical considerations of this systems involvement in procedures, such as free flap reconstruction, skin grafting, fat grafting, and other areas relevant to plastic and reconstructive surgery. Current evidence as well as potential for further investigation is discussed.

  View details for DOI 10.1097/SAP.0000000000002706

  View details for PubMedID 33833152

• Prrx1 Fibroblasts Represent a Pro-fibrotic Lineage in the Mouse Ventral Dermis. Cell reports Leavitt, T., Hu, M. S., Borrelli, M. R., Januszyk, M., Garcia, J. T., Ransom, R. C., Mascharak, S., desJardins-Park, H. E., Litzenburger, U. M., Walmsley, G. G., Marshall, C. D., Moore, A. L., Duoto, B., Adem, S., Foster, D. S., Salhotra, A., Shen, A. H., Griffin, M., Shen, E. Z., Barnes, L. A., Zielins, E. R., Maan, Z. N., Wei, Y., Chan, C. K., Wan, D. C., Lorenz, H. P., Chang, H. Y., Gurtner, G. C., Longaker, M. T. 2020; 33 (6): 108356

  Abstract

  Fibroblast heterogeneity has been shown within the unwounded mouse dorsal dermis, with fibroblast subpopulations being identified according to anatomical location and embryonic lineage. Using lineage tracing, we demonstrate that paired related homeobox 1 (Prrx1)-expressing fibroblasts are responsible for acute and chronic fibroses in the ventral dermis. Single-cell transcriptomics further corroborated the inherent fibrotic characteristics of Prrx1 fibroblasts during wound repair. In summary, we identify and characterize a fibroblast subpopulation in the mouse ventral dermis with intrinsic scar-forming potential.

  View details for DOI 10.1016/j.celrep.2020.108356

  View details for PubMedID 33176144

• Skeletal Stem Cells-A Paradigm Shift in the Field of Craniofacial Bone Tissue Engineering. Frontiers in dental medicine Tevlin, R., Longaker, M. T., Wan, D. C. 2020; 1

  Abstract

  Defects of the craniofacial skeleton arise as a direct result of trauma, diseases, oncological resection, or congenital anomalies. Current treatment options are limited, highlighting the importance for developing new strategies to restore form, function, and aesthetics of missing or damaged bone in the face and the cranium. For optimal reconstruction, the goal is to replace "like with like." With the inherent challenges of existing options, there is a clear need to develop alternative strategies to reconstruct the craniofacial skeleton. The success of mesenchymal stem cell-based approaches has been hampered by high heterogeneity of transplanted cell populations with inconsistent preclinical and clinical trial outcomes. Here, we discuss the novel characterization and isolation of mouse skeletal stem cell (SSC) populations and their response to injury, systemic disease, and how their re-activation in vivo can contribute to tissue regeneration. These studies led to the characterization of human SSCs which are able to self-renew, give rise to increasingly fate restricted progenitors, and differentiate into bone, cartilage, and bone marrow stroma, all on the clonal level in vivo without prior in vitro culture. SSCs hold great potential for implementation in craniofacial bone tissue engineering and regenerative medicine. As we begin to better understand the diversity and the nature of skeletal stem and progenitor cells, there is a tangible future whereby a subset of human adult SSCs can be readily purified from bone or activated in situ with broad potential applications in craniofacial tissue engineering.

  View details for DOI 10.3389/fdmed.2020.596706

  View details for PubMedID 35664558

  View details for PubMedCentralID PMC9161996

• ALK-positive compound Spitz nevus with extensive perineural and intraneural neurotropism. Journal of cutaneous pathology Brown, R. A., Wang, J. Y., Raghavan, S. S., Zhang, J., Wan, D. C., Born, D., Koo, M., Hazard, F. K., Novoa, R. A., Rieger, K. E. 2020

  View details for DOI 10.1111/cup.13890

  View details for PubMedID 33034114

• Single-Cell RNA Sequencing Uncovers Antifibrotic Subpopulations of Macrophages in the Cellular Response to Skin Xenografts Henn, D., Chen, K., Maan, Z., Illouz, S., Bonham, C. A., Barrera, J. A., Momeni, A., Wan, D. C., Januszyk, M., Gurtner, G. C. ELSEVIER SCIENCE INC. 2020: S232

  View details for Web of Science ID 000582792300425

• Decellularized Adipose Tissue Extracellular Matrices Restore Volume Defects and Promote Regeneration of Irradiated Soft Tissue Borrelli, M. R., Adem, S., Deleon, N., Ngaage, L. M., Momeni, A., Nazerali, R., Wan, D. C. ELSEVIER SCIENCE INC. 2020: E184

  View details for Web of Science ID 000582798100415

• Skeletal Stem Cells Promote Regeneration in Long Bone Distraction Osteogenesis Salhotra, A., Shah, H. N., Wan, D. C. ELSEVIER SCIENCE INC. 2020: S232–S233

  View details for Web of Science ID 000582792300426

• Understanding Long Bone Regeneration through the Development of a Novel Murine Distraction Device Shah, H. N., Salhotra, A., Wan, D. C., Longaker, M. T. ELSEVIER SCIENCE INC. 2020: E173

  View details for Web of Science ID 000582798100387

• Detection, Scoring, and Classification of Solid Organ Fibroses with Machine Learning Analysis Mascharak, S., desJardins-Park, H. E., Davitt, M., Foster, D. S., Chinta, M., Wan, D. C., Wernig, G., Longaker, M. T. ELSEVIER SCIENCE INC. 2020: S222

  View details for Web of Science ID 000582792300403

• Adipose-Derived Stromal Cells within Transplanted Fat Hone to Blood Vessels and Assume a Pericyte Structure Borrelli, M. R., Adem, S., Deleon, N., Abbas, D., Momeni, A., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2020: E183

  View details for Web of Science ID 000582798100412

• Grafted Fat Depletes the Profibrotic Engrailed-1-Positive Fibroblast Subpopulation and Ameliorates Radiation-Induced Scalp Fibrosis Borrelli, M. R., Deleon, N., Adem, S., Abbas, D., Momeni, A., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2020: E186

  View details for Web of Science ID 000582798100420

• Radiation-Induced Soft Tissue Atrophy Impaired by Enhancement of Fat Grafts with CD146+Subpopulation of Adipose-Derived Stromal Cells Deleon, N., Borrelli, M. R., Adem, S., Shen, A., Abbas, D., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2020: E186

  View details for Web of Science ID 000582798100421

• Fat Grafting Depletes Profibrotic Prrx1-Positive Fibroblasts in Irradiated Skin and Mitigates Radiation-Induced Groin Contracture Borrelli, M. R., Adem, S., Deleon, N., Abbas, D., Chen, K., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2020: S225–S226

  View details for Web of Science ID 000582792300411

• Transdermal Deferoxamine Reduces Radiation-Induced Damage in Porcine Skin Adem, S., Deleon, N., Chen, K., Borrelli, M. R., Shen, A. H., Noishiki, C., Patel, R. A., Gurtner, G. C., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2020: E46–E47

  View details for Web of Science ID 000582798100088

• Transdermal Deferoxamine Treatment Mitigates Fibrosis in Irradiated Skin Shen, A. H., Borrelli, M. R., Deleon, N., Adem, S., Mascharak, S., Salhotra, A., Shah, H., Longaker, M. T., Gurtner, G. C., Wan, D. C. ELSEVIER SCIENCE INC. 2020: S235

  View details for Web of Science ID 000582792300431

• Characterization of Diabetic and Non-Diabetic Foot Ulcers Using Single-Cell RNA-Sequencing. Micromachines Januszyk, M., Chen, K., Henn, D., Foster, D. S., Borrelli, M. R., Bonham, C. A., Sivaraj, D., Wagh, D., Longaker, M. T., Wan, D. C., Gurtner, G. C. 2020; 11 (9)

  Abstract

  Background: Recent advances in high-throughput single-cell sequencing technologies have led to their increasingly widespread adoption for clinical applications. However, challenges associated with tissue viability, cell yield, and delayed time-to-capture have created unique obstacles for data processing. Chronic wounds, in particular, represent some of the most difficult target specimens, due to the significant amount of fibrinous debris, extracellular matrix components, and non-viable cells inherent in tissue routinely obtained from debridement. Methods: Here, we examined the feasibility of single cell RNA sequencing (scRNA-seq) analysis to evaluate human chronic wound samples acquired in the clinic, subjected to prolonged cold ischemia time, and processed without FACS sorting. Wound tissue from human diabetic and non-diabetic plantar foot ulcers were evaluated using an optimized 10X Genomics scRNA-seq platform and analyzed using a modified data pipeline designed for low-yield specimens. Cell subtypes were identified informatically and their distributions and transcriptional programs were compared between diabetic and non-diabetic tissue. Results: 139,000 diabetic and non-diabetic wound cells were delivered for 10X capture after either 90 or 180 min of cold ischemia time. cDNA library concentrations were 858.7 and 364.7 pg/L, respectively, prior to sequencing. Among all barcoded fragments, we found that 83.5% successfully aligned to the human transcriptome and 68% met the minimum cell viability threshold. The average mitochondrial mRNA fraction was 8.5% for diabetic cells and 6.6% for non-diabetic cells, correlating with differences in cold ischemia time. A total of 384 individual cells were of sufficient quality for subsequent analyses; from this cell pool, we identified transcriptionally-distinct cell clusters whose gene expression profiles corresponded to fibroblasts, keratinocytes, neutrophils, monocytes, and endothelial cells. Fibroblast subpopulations with differing fibrotic potentials were identified, and their distributions were found to be altered in diabetic vs. non-diabetic cells. Conclusions: scRNA-seq of clinical wound samples can be achieved using minor modifications to standard processing protocols and data analysis methods. This simple approach can capture widespread transcriptional differences between diabetic and non-diabetic tissue obtained from matched wound locations.

  View details for DOI 10.3390/mi11090815

  View details for PubMedID 32872278

• Articular cartilage regeneration by activated skeletal stem cells. Nature medicine Murphy, M. P., Koepke, L. S., Lopez, M. T., Tong, X., Ambrosi, T. H., Gulati, G. S., Marecic, O., Wang, Y., Ransom, R. C., Hoover, M. Y., Steininger, H., Zhao, L., Walkiewicz, M. P., Quarto, N., Levi, B., Wan, D. C., Weissman, I. L., Goodman, S. B., Yang, F., Longaker, M. T., Chan, C. K. 2020

  Abstract

  Osteoarthritis (OA) is a degenerative disease resulting in irreversible, progressive destruction of articular cartilage1. The etiology of OA is complex and involves a variety of factors, including genetic predisposition, acute injury and chronic inflammation2-4. Here we investigate the ability of resident skeletal stem-cell (SSC) populations to regenerate cartilage in relation to age, a possible contributor to the development of osteoarthritis5-7. We demonstrate that aging is associated with progressive loss of SSCs and diminished chondrogenesis in the joints of both mice and humans. However, a local expansion of SSCs could still be triggered in the chondral surface of adult limb joints in mice by stimulating a regenerative response using microfracture (MF) surgery. Although MF-activated SSCs tended to form fibrous tissues, localized co-delivery of BMP2 and soluble VEGFR1 (sVEGFR1), a VEGF receptor antagonist, in a hydrogel skewed differentiation of MF-activated SSCs toward articular cartilage. These data indicate that following MF, a resident stem-cell population can be induced to generate cartilage for treatment of localized chondral disease in OA.

  View details for DOI 10.1038/s41591-020-1013-2

  View details for PubMedID 32807933

• Rewriting the Future: Promises and Limits of Germline Gene Editing in Craniofacial Surgery. The Journal of craniofacial surgery Davitt, M., Mascharak, S., desJardins-Park, H., Chinta, M., Wan, D. C., Longaker, M. T. 2020

  View details for DOI 10.1097/SCS.0000000000006602

  View details for PubMedID 32796298

• Prophylactic treatment with transdermal deferoxamine mitigates radiation-induced skin fibrosis. Scientific reports Shen, A. H., Borrelli, M. R., Adem, S., Deleon, N. M., Patel, R. A., Mascharak, S., Yen, S. J., Sun, B. Y., Taylor, W. L., Januszyk, M., Nguyen, D. H., Momeni, A., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2020; 10 (1): 12346

  Abstract

  Radiation therapy can result in pathological fibrosis of healthy soft tissue. The iron chelator deferoxamine (DFO) has been shown to improve skin vascularization when injected into radiated tissue prior to fat grafting. Here, we evaluated whether topical DFO administration using a transdermal drug delivery system prior to and immediately following irradiation (IR) can mitigate the chronic effects of radiation damage to the skin. CD-1 nude immunodeficient mice were split into four experimental groups: (1) IR alone (IR only), (2) DFO treatment for two weeks after recovery from IR (DFO post-IR), (3) DFO prophylaxis with treatment through and post-IR (DFO ppx), or (4) no irradiation or DFO (No IR). Immediately following IR, reactive oxygen species and apoptotic markers were significantly decreased and laser doppler analysis revealed significantly improved skin perfusion in mice receiving prophylactic DFO. Six weeks following IR, mice in the DFO post-IR and DFO ppx groups had improved skin perfusion and increased vascularization. DFO-treated groups also had evidence of reduced dermal thickness and collagen fiber network organization akin to non-irradiated skin. Thus, transdermal delivery of DFO improves tissue perfusion and mitigates chronic radiation-induced skin fibrosis, highlighting a potential role for DFO in the treatment of oncological patients.

  View details for DOI 10.1038/s41598-020-69293-4

  View details for PubMedID 32704071

• Human cryopreserved skingrafts recruit M2-macrophages and induce angiogenesis in a murine xenograft model Henn, D., Chen, K., Maan, Z. N., Illouz, S., Bonham, C. A., Fischer, K. S., Padmanabhan, J., Barrera, J. A., Wan, D. C., Januszyk, M., Gurtner, G. C. WILEY. 2020: S62–S63

  View details for Web of Science ID 000548418300144

• Supplementing fat grafts with Renuva (R) promotes regeneration of irradiated soft tissue Borrelli, M. R., Diaz, N., Adem, S., Spargo, T., Sen, A., Dung Nguyen, Momeni, A., Nazerali, R., Wan, D. C. WILEY. 2020: S62

  View details for Web of Science ID 000548418300143

• Radiation-induced skin fibrosis is reversed by transdermal delivery of deferoxamine Borrelli, M. R., Adem, S., Diaz, N., Mascharak, S., Sen, A., Januszyk, M., Nguyen, D., Momeni, A., Gurtner, G. C., Longaker, M. T., Wan, D. C. WILEY. 2020: S51–S52

  View details for Web of Science ID 000548418300116

• Reactive oxygen species and apoptotic proteins in irradiated murine skin decrease with deferoxamine treatment Shen, A. H., Deleon, N., Adem, S., Borrelli, M. R., Salhotra, A., Shah, H., Gurtner, G. C., Longaker, M. T., Wan, D. C. WILEY. 2020: S32–S33

  View details for Web of Science ID 000548418300070

• Activation of skeletal stems cells in response to long bone distraction osteogenesis Salhotra, A., Shah, H. N., Lopez, M. T., Wan, D. C., Longaker, M. T. WILEY. 2020: S25–S26

  View details for Web of Science ID 000548418300053

• Stretch marks are abundant in CD26-positive human dermal fibroblasts and exhibit increased profibrotic mechanosensitive signaling Borrelli, M. R., Griffin, M., Ngaage, L. M., Mascharak, S., Lewis, N., Januszyk, M., Wan, D. C., Longaker, M. T., Lorenz, H. P. WILEY. 2020: S32

  View details for Web of Science ID 000548418300069

• A novel murine distraction device investigating long bone regeneration Shah, H. N., Salhotra, A., Lopez, M. T., Wan, D. C., Longaker, M. T. WILEY. 2020: S16

  View details for Web of Science ID 000548418300032

• Radiation-induced fibrosis in porcine skin improves with transdermal deferoxamine treatment Adem, S., Borrelli, M. R., Deleon, N., Shen, A. H., Chen, K., Noishiki, C., Gurtner, G. C., Longaker, M. T., Wan, D. C. WILEY. 2020: S31–S32

  View details for Web of Science ID 000548418300068

• Fibroblast Heterogeneity in and Its Implications for Plastic and Reconstructive Surgery: A Basic Science Review PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN desJardins-Park, H. E., Chinta, M. S., Foster, D. S., Borrelli, M. R., Shen, A. H., Wan, D. C., Longaker, M. T. 2020; 8 (6)

  View details for DOI 10.1097/GOX.0000000000002927

  View details for Web of Science ID 000552760800046

• Fibroblast Heterogeneity in and Its Implications for Plastic and Reconstructive Surgery: A Basic Science Review. Plastic and reconstructive surgery. Global open desJardins-Park, H. E., Chinta, M. S., Foster, D. S., Borrelli, M. R., Shen, A. H., Wan, D. C., Longaker, M. T. 2020; 8 (6): e2927

  Abstract

  Fibroblasts' integral role in tissue development, maintenance, and disease represents a fast-growing field of basic science research. Although fibroblasts were long thought to be a homogeneous cell population, recent research has illuminated the unforeseen complexity of these cells, giving rise to the rapidly expanding research field of "fibroblast heterogeneity." Fibroblasts play a critical role in states of tissue fibrosis such as skin scarring, which affects hundreds of millions of patients annually and causes severe aesthetic, developmental, and functional morbidity. Beyond scarring, major organ fibrosis is an enormous public health concern responsible for nearly half of all deaths in the United States. Because fibrosis is a conserved response to tissue damage in all organs, the study of fibroblasts throughout the body may help us to understand their role in the conditions most relevant to plastic and reconstructive surgery-for instance, skin scarring (eg, from burns, traumatic lacerations, or surgical incisions), "pathological" scarring (hypertrophic scars, keloids), and capsular contracture. Here, we present a basic science review of fibroblast heterogeneity in wound healing, cancer, organ fibrosis, and human dermal architecture. The field of fibroblast heterogeneity is young, and many of the insights discussed have yet to be translated clinically. However, plastic surgeons stand in a unique position to bridge these discoveries into clinical realities. We hope this information can spur readers to consider both what questions in plastic surgery can be studied from the lens of fibroblast heterogeneity, and how these preclinical insights can be translated to improving care of our patients.

  View details for DOI 10.1097/GOX.0000000000002927

  View details for PubMedID 32766071

  View details for PubMedCentralID PMC7339369

• Saethre-Chotzen Syndrome: A Report of 7 Patients and Review of the Literature. Annals of plastic surgery Abulezz, T. A., Allam, K. A., Wan, D. C., Lee, J. C., Kawamoto, H. K. 2020

  Abstract

  INTRODUCTION: Saethre-Chotzen syndrome is a genetic condition characterized by craniofacial and limb anomalies, with craniosynostosis (mainly coronal) being the most frequent craniofacial finding. Cranial and facial deformities can be extremely variable requiring individualization of treatment strategies. We present our case series to highlight clinical findings, treatment philosophy, and challenges facing Saethre-Chotzen patients.METHODS: A retrospective review was performed on records of patients given a diagnosis of Saethre-Chotzen syndrome at the University of California Los Angeles (UCLA) Craniofacial Clinic (n = 7) between 1980 and 2010. Patients with complete records were included in this study, and review of demographic data, clinical findings, surgical interventions and postoperative follow-up, and stability were performed.RESULTS: Seven patients (1 male and 6 female) were included in this study. The average age at which the patients were first seen was 6.5 years. Suture involvement was bicoronal (n = 6) and unicoronal (n = 1). There was 1 patient having superimposed metopic synostosis, and there was another patient having Kleeblattschadel deformity. Previous procedures performed for patients before establishing care at UCLA were strip craniectomy (n = 2) and fronto-orbital advancement (n = 2). All patients (n = 7) had fronto-orbital advancements at UCLA. Other skeletal operations included the following: redo forehead advancement and contouring (n = 3), monobloc advancement (n = 1), and LeFort III distraction (n = 1). Five patients reached skeletal maturity, and 2 patients received LeFort I advancement for class III malocclusion, one of which also required a bilateral sagittal split osteotomy of the mandible.CONCLUSION: Clinical presentation and severity of deformity in Saethre-Chotzen syndrome are variable. Our current report reviews our treatment strategies and illustrates the predominance of cranial and upper face deformities and frequent need for redo surgeries to address forehead asymmetry in this group of syndromic craniosynostosis patients.

  View details for DOI 10.1097/SAP.0000000000002391

  View details for PubMedID 32487807

• Compounding Benefits of Sentinel Lymph Node Biopsy for Perineal Melanoma: A Population-Based Retrospective Cohort Analysis. Annals of plastic surgery Patel, R. A., Patel, P. D., Ashack, K., Borrelli, M. R., Trickey, A., Wan, D. C. 2020; 84 (5S Suppl 4): S257–S263

  Abstract

  INTRODUCTION: Sentinel lymph node biopsy (SLNB) in the treatment of melanoma is known to provide valuable prognostic information. However, there is no literature describing an overall or disease-specific survival (DDS) benefit of SLNB. In the perineum, melanoma is often more advanced at presentation with current treatment guidelines translated from nonanatomic specific melanoma. As a result, there is little understanding surrounding the role of SLNB in melanoma of the perineum. Our objective is to better understand the therapeutic benefits of SLNB in perineal melanoma.METHODS: The Surveillance, Epidemiology, and End Results program is a large population-based cancer registry including survival data from millions of patients in the United States. The registry was used to generate patient data for analysis from 2004 to 2016. Inclusion criteria included melanoma of the perineum; Breslow depth of 0.80 mm or greater and less than 0.80 mm with ulceration; SLNB or no intervention; clinically negative nodal disease; and available overall survival data.RESULTS: For 879 patients from 2004 to 2016 with perineal melanoma, significant predictors of reduced survival include older than 75 years, Clark level IV-V, Breslow depth of greater than 4.00 mm, positive ulceration status, regional and distant nodal micrometastases, and clinically positive nodes on presentation. Aggregates for overall survival (OS) and disease-specific survival (DSS) were improved with implementation of SLNB. The 5-year survival rates with SLNB versus no SLNB were 54.0% and 43.0% for OS (P = 0.001) and 57.8% and 53.1% for DSS (P = 0.044). Stratification by Breslow depth yielded significant OS and DSS advantage for greater than 1.00 to 2.00 mm (21.3% benefit, P =0.021, and 16.8% benefit, P = 0.044) and greater than 4.00 mm (30.3% benefit, P = 0.005, and 21.0% benefit, P = 0.007) Breslow depths.CONCLUSIONS AND RELEVANCE: Sentinel lymph node biopsy may provide therapeutic benefits in addition to prognostic information for melanoma of the perineum through an increase in 5-year OS.

  View details for DOI 10.1097/SAP.0000000000002388

  View details for PubMedID 32282396

• Pro-Fibrotic CD26-Positive Fibroblasts Are Present in Greater Abundance in Breast Capsule Tissue of Irradiated Breasts AESTHETIC SURGERY JOURNAL Borrelli, M. R., Irizzary, D., Patel, R. A., Dung Nguyen, Momeni, A., Longaker, M. T., Wan, D. C. 2020; 40 (4): 369–79

  View details for DOI 10.1093/asj/sjz109

  View details for Web of Science ID 000558971600024

• Commentary on: Accelerated chronic skin changes without allograft vasculopathy: A 10-year outcome report after face transplantation. Surgery Wan, D. C., Yang, G. P. 2020

  View details for DOI 10.1016/j.surg.2020.02.011

  View details for PubMedID 32200975

• The antifibrotic adipose-derived stromal cell: Grafted fat enriched with CD74+ adipose-derived stromal cells reduces chronic radiation-induced skin fibrosis. Stem cells translational medicine Borrelli, M. R., Patel, R. A., Adem, S. n., Diaz Deleon, N. M., Shen, A. H., Sokol, J. n., Yen, S. n., Chang, E. Y., Nazerali, R. n., Nguyen, D. n., Momeni, A. n., Wang, K. C., Longaker, M. T., Wan, D. C. 2020

  Abstract

  Fat grafting can reduce radiation-induced fibrosis. Improved outcomes are found when fat grafts are enriched with adipose-derived stromal cells (ASCs), implicating ASCs as key drivers of soft tissue regeneration. We have identified a subpopulation of ASCs positive for CD74 with enhanced antifibrotic effects. Compared to CD74- and unsorted (US) ASCs, CD74+ ASCs have increased expression of hepatocyte growth factor, fibroblast growth factor 2, and transforming growth factor β3 (TGF-β3) and decreased levels of TGF-β1. Dermal fibroblasts incubated with conditioned media from CD74+ ASCs produced less collagen upon stimulation, compared to fibroblasts incubated with media from CD74- or US ASCs. Upon transplantation, fat grafts enriched with CD74+ ASCs reduced the stiffness, dermal thickness, and collagen content of overlying skin, and decreased the relative proportions of more fibrotic dermal fibroblasts. Improvements in several extracellular matrix components were also appreciated on immunofluorescent staining. Together these findings indicate CD74+ ASCs have antifibrotic qualities and may play an important role in future strategies to address fibrotic remodeling following radiation-induced fibrosis.

  View details for DOI 10.1002/sctm.19-0317

  View details for PubMedID 32563212

• CD34+CD146+ adipose-derived stromal cells enhance engraftment of transplanted fat. Stem cells translational medicine Borrelli, M. R., Patel, R. A., Blackshear, C. n., Vistnes, S. n., Diaz Deleon, N. M., Adem, S. n., Shen, A. H., Sokol, J. n., Momeni, A. n., Nguyen, D. n., Longaker, M. T., Wan, D. C. 2020

  Abstract

  Fat grafting is a surgical technique able to reconstruct and regenerate soft tissue. The adipose-derived stromal cells (ASCs) within the stromal vascular fraction are believed to drive these beneficial effects. ASCs are increasingly recognized to be a heterogeneous group, comprised of multiple stem and progenitor subpopulations with distinct functions. We hypothesized the existence of an ASC subpopulation with enhanced angiogenic potential. Human ASCs that were CD34+CD146+, CD34+CD146-, or CD34+ unfractionated (UF) were isolated by flow cytometry for comparison of expression of proangiogenic factors and endothelial tube-forming potential. Next, lipoaspirate was enriched with either CD34+CD146+, CD34+CD146-, CD34+ UF ASCs, or was not enriched, and grafted beneath the scalp skin of immunodeficient CD-1 Nude mice (10 000 cells/200 μL/graft). Fat retention was monitored radiographically more than 8 weeks and fat grafts were harvested for histological assessment of quality and vascularization. The CD34+CD146+ subpopulation comprised ~30% of ASCs, and exhibited increased expression of vascular endothelial growth factor and angiopoietin-1 compared to CD34+CD146- and CD34+ UF ASCs, and increased expression of fibroblast growth factor-2 compared to CD34+CD146- ASCs. The CD34+CD146+ subpopulation exhibited enhanced induction of tube-formation compared to CD34+CD146- ASCs. Upon transplantation, fat enriched CD34+CD146+ ASCs underwent less resorption and had improved histologic quality and vascularization. We have identified a subpopulation of CD34+ ASCs with enhanced angiogenic effects in vitro and in vivo, likely mediated by increased expression of potent proangiogenic factors. These findings suggest that enriching lipoaspirate with CD34+CD146+ ASCs may enhance fat graft vascularization and retention in the clinical setting.

  View details for DOI 10.1002/sctm.19-0195

  View details for PubMedID 32543083

• "Tissues in a Dish": A Review of Organoids in Plastic Surgery. Plastic and reconstructive surgery. Global open Chinta, M. S., desJardins-Park, H. E., Wan, D. C., Longaker, M. T. 2020; 8 (4): e2787

  Abstract

  Organoids are in vitro miniaturized organ models-or, colloquially, "organs in a dish." These 3-dimensional, multicellular structures are classically derived from pluripotent or multipotent stem cells. When guided by tissue-specific molecular factors, these cells exhibit self-organizing abilities that allow them to accurately recapitulate the architecture and function of the organ of interest. Organoid technology is a rapidly expanding field that endows researchers with an unprecedented ability to recreate, study, and manipulate complex biologic processes in vitro. When compared with standard 2- and 3-dimensional culture systems, which rely on co-culturing pre-established cell types, organoids provide a more biomimetic model with which to study the intercellular interactions necessary for in vivo organ function and architecture. Organoids have the potential to impact all avenues of medicine, including those fields most relevant to plastic and reconstructive surgery such as wound healing, oncology, craniofacial reconstruction, and burn care. In addition to their ability to serve as a novel tool for studying human-specific disease, organoids may be used for tissue engineering with the goal of developing biomimetic soft-tissue substitutes, which would be especially valuable to the plastic surgeon. Although organoids hold great promise for the field of plastic surgery, technical challenges in creating vascularized, multilineage organoids must be overcome to allow for the integration of this technology in clinical practice. This review provides a brief history of the organoid, highlights its potential clinical applications, discusses certain limitations, and examines the impact that this technology may have on the field of plastic and reconstructive surgery.

  View details for DOI 10.1097/GOX.0000000000002787

  View details for PubMedID 32440447

  View details for PubMedCentralID PMC7209840

• Delivery of Human Stromal Vascular Fraction Cells on Nanofibrillar Scaffolds for Treatment of Peripheral Arterial Disease. Frontiers in bioengineering and biotechnology Hu, C. n., Zaitseva, T. S., Alcazar, C. n., Tabada, P. n., Sawamura, S. n., Yang, G. n., Borrelli, M. R., Wan, D. C., Nguyen, D. H., Paukshto, M. V., Huang, N. F. 2020; 8: 689

  Abstract

  Cell therapy for treatment of peripheral arterial disease (PAD) is a promising approach but is limited by poor cell survival when cells are delivered using saline. The objective of this study was to examine the feasibility of aligned nanofibrillar scaffolds as a vehicle for the delivery of human stromal vascular fraction (SVF), and then to assess the efficacy of the cell-seeded scaffolds in a murine model of PAD. Flow cytometric analysis was performed to characterize the phenotype of SVF cells from freshly isolated lipoaspirate, as well as after attachment onto aligned nanofibrillar scaffolds. Flow cytometry results demonstrated that the SVF consisted of 33.1 ± 9.6% CD45+ cells, a small fraction of CD45-/CD31+ (4.5 ± 3.1%) and 45.4 ± 20.0% of CD45-/CD31-/CD34+ cells. Although the subpopulations of SVF did not change significantly after attachment to the aligned nanofibrillar scaffolds, protein secretion of vascular endothelial growth factor (VEGF) significantly increased by six-fold, compared to SVF cultured in suspension. Importantly, when SVF-seeded scaffolds were transplanted into immunodeficient mice with induced hindlimb ischemia, the cell-seeded scaffolds induced a significant higher mean perfusion ratio after 14 days, compared to cells delivered using saline. Together, these results show that aligned nanofibrillar scaffolds promoted cellular attachment, enhanced the secretion of VEGF from attached SVF cells, and their implantation with attached SVF cells stimulated blood perfusion recovery. These findings have important therapeutic implications for the treatment of PAD using SVF.

  View details for DOI 10.3389/fbioe.2020.00689

  View details for PubMedID 32766213

  View details for PubMedCentralID PMC7380169

• Pelvic/Perineal Reconstruction: Time to Consider the Anterolateral Thigh Flap as a First-line Option? Plastic and reconstructive surgery. Global open Perrault, D. n., Kin, C. n., Wan, D. C., Kirilcuk, N. n., Shelton, A. n., Momeni, A. n. 2020; 8 (4): e2733

  Abstract

  Abdominoperineal resection (APR) and pelvic exenteration continue to be common procedures for the treatment of colorectal malignancy. The workhorse flap for reconstruction in these instances has been the vertical rectus abdominis myocutaneous flap. The associated donor site morbidity, however, cannot be ignored. Here, we provide a review of the literature and present the senior author's (A.M.) experience using the pedicled anterolateral thigh (ALT) flap for reconstruction of soft tissue defects following APR and pelvic exenteration.Patients who underwent pelvic/perineal reconstruction with pedicled ALT flaps between 2017 and 2019 were included in the study. Parameters of interest included age, gender, body mass index, comorbidities, history of radiation, extent of ablative surgery, and postoperative complication rate.A total of 23 patients (16 men and 7 women) with a median age and body mass index of 66 years (inter-quartile range [IQR]: 49-71 years) and 24.9 kg/m2 (IQR: 24.2-26.7 kg/m2) were included in the study, respectively. Thirteen (56.5%) patients presented with rectal cancer, 5 (21.7%) with anal squamous cell carcinoma (SCC), 4 (17.4%) with Crohn's disease, and 1 (4.3%) with Paget's disease. Nineteen patients (82.6%) received neoadjuvant radiation. Nine (39.1%) patients experienced 11 complications (2 major and 9 minor). The most common complication was partial perineal wound dehiscence (N = 6 [26.1%]). Stable soft tissue coverage was achieved in all but one patient.The ALT flap allows for stable soft tissue coverage following APR and pelvic exenteration without being associated with abdominal donor site morbidity. Consideration to its use as a first-line reconstructive option should be given in pelvic/perineal reconstruction.

  View details for DOI 10.1097/GOX.0000000000002733

  View details for PubMedID 32440406

  View details for PubMedCentralID PMC7209827

• Cryopreserved human skin allografts promote angiogenesis and dermal regeneration in a murine model. International wound journal Henn, D. n., Chen, K. n., Maan, Z. N., Greco, A. H., Moortgat Illouz, S. E., Bonham, C. A., Barrera, J. A., Trotsyuk, A. A., Padmanabhan, J. n., Momeni, A. n., Wan, D. C., Nguyen, D. n., Januszyk, M. n., Gurtner, G. C. 2020

  Abstract

  Cryopreserved human skin allografts (CHSAs) are used for the coverage of major burns when donor sites for autografts are insufficiently available and have clinically shown beneficial effects on chronic non-healing wounds. However, the biologic mechanisms behind the regenerative properties of CHSA remain elusive. Furthermore, the impact of cryopreservation on the immunogenicity of CHSA has not been thoroughly investigated and raised concerns with regard to their clinical application. To investigate the importance and fate of living cells, we compared cryopreserved CHSA with human acellular dermal matrix (ADM) grafts in which living cells had been removed by chemical processing. Both grafts were subcutaneously implanted into C57BL/6 mice and explanted after 1, 3, 7, and 28 days (n = 5 per group). A sham surgery where no graft was implanted served as a control. Transmission electron microscopy (TEM) and flow cytometry were used to characterise the ultrastructure and cells within CHSA before implantation. Immunofluorescent staining of tissue sections was used to determine the immune reaction against the implanted grafts, the rate of apoptotic cells, and vascularisation as well as collagen content of the overlaying murine dermis. Digital quantification of collagen fibre alignment on tissue sections was used to quantify the degree of fibrosis within the murine dermis. A substantial population of live human cells with intact organelles was identified in CHSA prior to implantation. Subcutaneous pockets with implanted xenografts or ADMs healed without clinically apparent rejection and with a similar cellular immune response. CHSA implantation largely preserved the cellularity of the overlying murine dermis, whereas ADM was associated with a significantly higher rate of cellular apoptosis, identified by cleaved caspase-3 staining, and a stronger dendritic cell infiltration of the murine dermis. CHSA was found to induce a local angiogenic response, leading to significantly more vascularisation of the murine dermis compared with ADM and sham surgery on day 7. By day 28, aggregate collagen-1 content within the murine dermis was greater following CHSA implantation compared with ADM. Collagen fibre alignment of the murine dermis, correlating with the degree of fibrosis, was significantly greater in the ADM group, whereas CHSA maintained the characteristic basket weave pattern of the native murine dermis. Our data indicate that CHSAs promote angiogenesis and collagen-1 production without eliciting a significant fibrotic response in a xenograft model. These findings may provide insight into the beneficial effects clinically observed after treatment of chronic wounds and burns with CHSA.

  View details for DOI 10.1111/iwj.13349

  View details for PubMedID 32227459

• Fat Grafting Rescues Radiation-Induced Joint Contracture. Stem cells (Dayton, Ohio) Borrelli, M. R., Diaz Deleon, N. M., Adem, S., Patel, R. A., Mascharak, S., Shen, A. H., Irizarry, D., Nguyen, D., Momeni, A., Longaker, M. T., Wan, D. C. 2019

  Abstract

  The aim of this study was to explore the therapeutic effects of fat grafting on radiation-induced hind limb contracture. Radiation therapy (RT) is used to palliate and/or cure a range of malignancies but causes inevitable and progressive fibrosis of surrounding soft tissue. Pathological fibrosis may lead to painful contractures which limit movement and negatively impact quality of life. Fat grafting is able to reduce and/or reverse radiation-induced soft tissue fibrosis. We explored whether fat grafting could improve extensibility in irradiated and contracted hind limbs of mice. Right hind limbs of female 60-day-old CD-1 nude mice were irradiated. Chronic skin fibrosis and limb contracture developed. After 4weeks, irradiated hind limbs were then injected with (a) fat enriched with stromal vascular cells (SVCs); (b) fat only; (c) saline; or (d) nothing (n = 10/group). Limb extension was measured at baseline and every 2weeks for 12weeks. Hind limb skin then underwent histological analysis and biomechanical strength testing. Irradiation significantly reduced limb extension but was progressively rescued by fat grafting. Fat grafting also reduced skin stiffness and reversed the radiation-induced histological changes in the skin. The greatest benefits were found in mice injected with fat enriched with SVCs. Hind limb radiation induces contracture in our mouse model which can be improved with fat grafting. Enriching fat with SVCs enhances these beneficial effects. These results underscore an attractive approach to address challenging soft tissue fibrosis in patients following RT.

  View details for DOI 10.1002/stem.3115

  View details for PubMedID 31793745

• The Impact of Device Innovation on Clinical Outcomes in Expander-based Breast Reconstruction PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN Momeni, A., Li, A. Y., Tsai, J., Wan, D., Karin, M. R., Wapnir, I. L. 2019; 7 (12)

  View details for DOI 10.1097/GOX.0000000000002524

  View details for Web of Science ID 000512700800009

• The Impact of Device Innovation on Clinical Outcomes in Expander-based Breast Reconstruction. Plastic and reconstructive surgery. Global open Momeni, A., Li, A. Y., Tsai, J., Wan, D., Karin, M. R., Wapnir, I. L. 2019; 7 (12): e2524

  Abstract

  Staged expander-based breast reconstruction represents the most common reconstructive modality in the United States. The introduction of a novel tissue expander with an integrated drain (Sientra AlloX2) holds promise to further improve clinical outcomes.Patients who underwent immediate expander-based pre-pectoral breast reconstruction were identified. Two cohorts were created, that is, patients who underwent placement of a conventional tissue expander [133MX (Allergan)] (Group 1) versus AlloX2 (Sientra) (Group 2). The study endpoint was successful completion of expansion with the objective being to investigate differences in outcome following expander placement.Fifty-eight patients underwent 99 breast reconstructions [Group 1: N = 24 (40 breasts) versus Group 2: N = 34 (59 breast)]. No differences were noted for age (P = 0.586), BMI (P = 0.109), history of radiation (P = 0.377), adjuvant radiotherapy (P = 1.00), and overall complication rate (P = 0.141). A significantly longer time to drain removal was noted in Group 1 (P < 0.001). All patients with postoperative infection in Group 1 required surgical treatment versus successful washout of the peri-prosthetic space via the AlloX2 drain port in 3 of 5 patients in Group 2 (P = 0.196). Furthermore, both cases of seroma in Group 1 required image-guided drainage versus in-office drainage via the AlloX2 drain port in 1 patient in Group 2 (P =0.333).The unique feature of the AlloX2 provides surgeons easy access to the peri-prosthetic space without altering any of the other characteristics of a tissue expander. This resulted in a reduced time to drain removal and facilitated management of postoperative seroma and infection.

  View details for DOI 10.1097/GOX.0000000000002524

  View details for PubMedID 32537287

  View details for PubMedCentralID PMC7288893

• Retrospective cohort-based comparison of intraoperative liposomal bupivacaine versus bupivacaine for donor site iliac crest analgesia during alveolar bone grafting. Journal of plastic, reconstructive & aesthetic surgery : JPRAS Patel, R. A., Jablonka, E. M., Rustad, K. C., Pridgen, B. C., Sorice-Virk, S. S., Borrelli, M. R., Khosla, R. K., Lorenz, H. P., Momeni, A., Wan, D. C. 2019

  Abstract

  INTRODUCTION: Bone grafting of alveolar clefts is routinely performed with cancellous bone harvested from the iliac crest. Graft site morbidity is frequently seen, with early postoperative pain being one of the most common complaints. Liposomal bupivacaine (LB) has been demonstrated to provide improvement in postoperative pain for patients undergoing bunionectomy or hemorrhoidectomy, which may translate to patients requiring iliac crest bone graft harvest.METHODS: Thirty-eight patients undergoing iliac crest bone harvest were included in the study. Twenty-one patients underwent open iliac crest bone graft harvest with administration of 0.25% bupivacaine at the hip donor site, while 17 patients received local infiltration of 1.3% liposomal bupivacaine. Patient-reported pain scores, total narcotic use, length of stay, and postoperative steps were monitored.RESULTS: There were no significant differences in age, weight, distribution of clefts, or choice of donor hip between the two groups. There were no significant differences in length of hospitalization stay. However, differences were noted in average postoperative pain scores at five of six time points in the first 24h, total oral morphine equivalents administered (4.7 ± 5.3 vs. 14.3 ± 12.0), and steps at postoperative days one to three (p<0.001, for all three days) for patients receiving 1.3% LB versus 0.25% bupivacaine, respectively.CONCLUSION: Reduced pain scores and increased postoperative activity highlight the potential of LB to improve postoperative pain management in children undergoing iliac crest bone harvest for alveolar bone grafting.

  View details for DOI 10.1016/j.bjps.2019.09.026

  View details for PubMedID 31648962

• Much-Needed Clarification and Guidance on Cell-Based Therapies for Musculoskeletal Disorders - Secondary Publication. Journal of orthopaedic research : official publication of the Orthopaedic Research Society Murphy, M. P., Wan, D. C., Longaker, M. T. 2019

  View details for DOI 10.1002/jor.24486

  View details for PubMedID 31573106

• JUN Drives Pathologic Scarring by Activating Key Fibroproliferative Pathways in Fibroblast Subpopulations Borrelli, M. R., Garcia, J. T., Moore, A. L., Patel, R. A., Mascharak, S., Duoto, B., Cui, L., Wan, D. C., Wernig, G., Longaker, M. T. ELSEVIER SCIENCE INC. 2019: E215–E216

  View details for Web of Science ID 000492749600516

• CD74+Adipose-Derived Stromal Cells Have Anti-Fibrotic Effects in Grafted Fat in the Irradiated and Non-Irradiated Setting Borrelli, M. R., Patel, R. A., Sokol, J., Dung Nguyen, Momeni, A., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2019: E214

  View details for Web of Science ID 000492749600512

• CD26(+) Fibroblasts Increase in Abundance in Breast Capsule Tissue Surrounding Irradiated Breasts Borrelli, M. R., Patel, R. A., Dung Nguyen, Momeni, A., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2019: S220

  View details for Web of Science ID 000492740900421

• Outcomes of Fat Grafting in Irradiated Tissue Are Improved by Pre-Treatment with Transdermal Deferoxamine Borrelli, M. R., Patel, R. A., Sokol, J., Momeni, A., Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2019: E216

  View details for Web of Science ID 000492749600518

• CD146(+) Adipose-Derived Stromal Cells Have Proangiogenic Qualities and Enhance the Regenerative Potential of Grafted Fat Borrelli, M. R., Patel, R. A., Blackshear, C., Vistnes, S., Deleon, N., Nazerali, R., Momeni, A., Dung Nguyen, Longaker, M. T., Wan, D. C. ELSEVIER SCIENCE INC. 2019: S284

  View details for Web of Science ID 000492740900554

• Should free deep inferior epigastric artery perforator flaps be considered a quality indicator in breast reconstruction? Journal of plastic, reconstructive & aesthetic surgery : JPRAS Tevlin, R., Wan, D. C., Momeni, A. 2019

  Abstract

  Over the past several decades, technical advances in breast reconstruction have resulted in the development of flaps that are aimed at progressively decreasing abdominal wall morbidity. There is, however, ongoing controversy related to the superiority of deep inferior epigastric perforator (DIEP) flaps over muscle-sparing TRAM (MS-TRAM) flaps. Hence, the question remains unanswered as to which approach should be considered the standard of care, and more importantly, whether the rate of DIEP flap utilization should be considered a quality metric in breast reconstruction. In this review article, we examine the literature pertaining to abdominal free tissue transfer in breast reconstruction from both donor site and flap characteristics as well as the resultant complications and morbidity. The impact on the donor site remains a prevailing principle for autologous breast reconstruction; thus, must be adequately respected when classifying what is left behind following flap harvest. The most commonly used nomenclature is too simplistic. This, in turn, leads to inadequate incorporation of critical variables, such as degree of muscular preservation, fascial involvement, mesh implantation, and segmental nerve anatomy. Currently, there is insufficient evidence to support DIEP flap harvest as a quality indicator in breast reconstruction, as DIEP flap outcomes are not clearly superior when compared with MS-TRAM flaps.

  View details for DOI 10.1016/j.bjps.2019.08.005

  View details for PubMedID 31570216

• Identifying risk factors for postoperative major complications in staged implant-based breast reconstruction with AlloDerm BREAST JOURNAL Remington, A. C., Gurtner, G. C., Wan, D. C., Nguyen, D., Momeni, A. 2019; 25 (4): 597–603

  View details for DOI 10.1111/tbj.13299

  View details for Web of Science ID 000474305600005

• Postoperative analgesia after microsurgical breast reconstruction using liposomal bupivacaine (Exparel). The breast journal Momeni, A., Ramesh, N. K., Wan, D., Nguyen, D., Sorice, S. C. 2019

  Abstract

  Conventional opioid-based regimen for postoperative analgesia after autologous breast reconstruction can be associated with significant side effects. The purpose of this study was to assess the efficacy of an intraoperatively administered transversus abdominis plane (TAP) block with liposomal bupivacaine on postoperative narcotic use in patients undergoing microsurgical breast reconstruction with free abdominal flaps. Patients treated between December 2016 and June 2017 were included in the study. Parameters of interest were patient-reported pain score, total narcotic use (in oral morphine equivalent [OME]) during the hospitalization, length of stay (LOS), and the need for patient-controlled analgesia (PCA). Eighty-two free abdominal flaps were transferred in 46 patients with a mean age of 47.6years and a mean body mass index (BMI) of 28.1kg/m2 . The average LOS was 3.5days (range, 3-5). Postoperatively, 42 patients (91.3%) did not require patient-controlled analgesia (PCA). The mean time to first narcotic use after arrival on the nursing unit was 6hours (range, 0-19hours). The mean total postoperative OME use was 123.2mg (range, 0-285mg). However, analysis of OME use excluding the four patients requiring PCA revealed a mean OME use of 90.3mg (range, 0-167.5mg). Liposomal bupivacaine provides for reliable, safe, and long-acting postoperative analgesia and contributes to a reduction in postoperative narcotic intake. The use of liposomal bupivacaine shows great promise in improving the standard of care in postoperative analgesia in microsurgical breast reconstruction.

  View details for DOI 10.1111/tbj.13349

  View details for PubMedID 31131501

• Identifying risk factors for postoperative major complications in staged implant-based breast reconstruction with AlloDerm. The breast journal Remington, A. C., Gurtner, G. C., Wan, D. C., Nguyen, D., Momeni, A. 2019

  Abstract

  Acellular dermal matrices (ADM) have reportedly been associated with postoperative complications following breast reconstruction. The purpose of this study was to identify risk factors predictive of major postoperative complications after staged implant-based breast reconstruction with ADM. A retrospective study of all patients who underwent implant-based breast reconstruction with AlloDerm between 2013 and 2017 was conducted. Demographic information, procedural data, and postoperative complications were retrieved. The main objective was to analyze patient and procedural factors associated with the occurrence of major complications, including postoperative readmission and loss of reconstruction. A total of 166 patients (288 breasts) were included. Major complications were noted in 19.9%. The overall rate of infection and mastectomy skin necrosis was 16.9% and 6.6%, respectively. Readmission occurred in 16.3% and loss of reconstruction occurred in 8.4% of patients. Risk factors for major complications included body mass index (BMI) >27.0 kg/m2 (OR 2.46; p = 0.041), higher tissue expander volume (p = 0.049), history of chemotherapy (OR 2.20; p = 0.047) and radiotherapy (OR 2.22; p = 0.040). Loss of reconstruction was associated with a BMI >27.0 kg/m2 (OR 4.00; p = 0.012), tobacco use (OR 6.64, p = 0.006), and higher tissue expander volume (p = 0.035). Similarly, readmission was associated with higher tissue expander volume (p = 0.042). In conclusion, a variety of factors were identified to be associated with major complications, including higher BMI, increased tissue expander volume, as well as history of chemotherapy and radiation. This information is valuable for pre-operative counseling and for future comparative studies between different ADM types.

  View details for PubMedID 31087378

• Acellular Dermal Matrix Reduces Myofibroblast Presence in the Breast Capsule. Plastic and reconstructive surgery. Global open Tevlin, R., Borrelli, M. R., Irizarry, D., Nguyen, D., Wan, D. C., Momeni, A. 2019; 7 (5): e2213

  Abstract

  Background: Capsular contracture remains a common complication after implant-based breast reconstruction. Previous work has suggested that the use of acellular dermal matrix (ADM) reduces the rate of capsular contracture, though little is understood about the underlying mechanism. As myofibroblasts are believed to be the key cells implicated in contracture formation, we hypothesized that ADM would result in a reduction in periprosthetic myofibroblast concentration.Methods: Five patients who underwent immediate prepectoral tissue expander placement with anterior ADM coverage and an inferior cuff were included. At the second stage, tissue samples were obtained of both ADM and capsule from each reconstructed breast. Samples were then prepared for hematoxylin and eosin staining and immunohistochemistry for myofibroblast identification (alpha smooth muscle actin and vimentin positive and desmin negative) and analysis. Experimental values are presented as mean ± SD unless otherwise stated. Statistical significance was determined using unpaired t test.Results: Successful incorporation of ADM was noted in all cases. A significant reduction in myofibroblast concentration was noted in the ADM versus the capsule (P = 0.0018). This was paralleled by significantly thicker periprosthetic capsule formation overlying the formerly raw pectoralis major muscle, that is, not covered by ADM (P < 0.0001).Conclusions: In the presence of ADM, there are significantly fewer myofibroblasts in breast capsules and thinner capsules on histology. Given the central role of myofibroblasts in the development of clinically significant capsular contracture, this study unmasks a possible mechanism for the protective effect of ADM with respect to capsular contracture development.

  View details for DOI 10.1097/GOX.0000000000002213

  View details for PubMedID 31333946

• Pro-Fibrotic CD26-Positive Fibroblasts are Present in Greater Abundance in Breast Capsule Tissue of Irradiated Breasts. Aesthetic surgery journal Borrelli, M. R., Irizzary, D., Patel, R. A., Nguyen, D., Momeni, A., Longaker, M. T., Wan, D. C. 2019

  Abstract

  BACKGROUND: Breast capsular contracture is a major problem following implant-based breast reconstruction, particularly in the setting of radiation therapy. Recent work has identified a fibrogenic fibroblast subpopulation characterized by CD26 surface marker expression.OBJECTIVE: This work aimed to investigate the role of CD26-positive fibroblasts in the formation of breast implant capsules following radiation therapy.METHODS: Breast capsule specimens were obtained from irradiated and non-irradiated breasts of 10 patients following bilateral mastectomy and unilateral irradiation at the time of expander-implant exchange, under institutional review board approval. Specimens were processed for Hematoxylin and Eosin staining, as well as for immunohistochemistry and fluorescence activated cell sorting (FACS) for CD26-positive fibroblasts. Expression of fibrotic genes and production of collagen was compared between CD26-positive, CD26-negative, and unsorted fibroblasts.RESULTS: Capsule specimens from irradiated breast tissue were thicker and had greater CD26-postive cells on immunofluorescence imaging and on FACS analysis, than did capsule specimens from the non-irradiated breast. Compared to CD26-negative fibroblasts, CD26-positive fibroblasts produced more collagen and had increased expression of the profibrotic genes IL8, TGF-beta1, COL1A1, and TIMP4.CONCLUSIONS: CD26-positive fibroblasts were found in a significantly greater abundance in capsules of irradiated compared to non-irradiated breasts and demonstrated greater fibrotic potential. This fibrogenic fibroblast subpopulation may play an important role in the development of capsular contracture following irradiation, and its targeted depletion or moderation may represent a potential therapeutic option.

  View details for PubMedID 30972420

• Fat Grafting into Younger Recipients Improves Volume Retention in an Animal Model PLASTIC AND RECONSTRUCTIVE SURGERY Chung, N. N., Ransom, R. C., Blackshear, C. P., Irizarry, D. M., Yen, D., Momeni, A., Lee, G. K., Nguyen, D. H., Longaker, M. T., Wan, D. C. 2019; 143 (4): 1067–75

  View details for DOI 10.1097/PRS.0000000000005483

  View details for Web of Science ID 000474582600052

• Beneath the Surface: A Review of Laser Remodeling of Hypertrophic Scars and Burns. Advances in wound care Kuehlmann, B., Stern-Buchbinder, Z., Wan, D. C., Friedstat, J. S., Gurtner, G. C. 2019; 8 (4): 168-176

  Abstract

  Significance: Hypertrophic scars, keloids, and burn injuries of the skin have a significant impact on patients' lives and impact the health care system tremendously. Treating skin wounds and lesions can be challenging, with a variety of choices available for treatment. Scar and burn managements range from invasive, surgical options such as scar excision to less invasive, nonsurgical alternatives such as laser therapy or topical drug application. Recent Advances: Laser treatment has become increasingly popular, with a growing body of research supporting its use for scars and burns. Numerous methods are available for the treatment of these skin diseases, including different nonsurgical laser therapies. Critical Issues: To date, the optimal treatment method for scars, keloids, and burn injuries of the skin has not yet been established, although it is an area of increasing clinical concern. Future Directions: This review provides an updated summary of the treatment of scars and burn wounds of the skin using different laser treatments, including the most recent technologies. It addresses their indications, mechanisms of action, differences, efficacies, and complications.

  View details for DOI 10.1089/wound.2018.0857

  View details for PubMedID 31832273

  View details for PubMedCentralID PMC6906753

• Beneath the Surface: A Review of Laser Remodeling of Hypertrophic Scars and Burns ADVANCES IN WOUND CARE Kuehlmann, B., Stern-Buchbinder, Z., Wan, D. C., Friedstat, J. S., Gurtner, G. C. 2019; 8 (4): 168–76

  View details for DOI 10.1089/wound.2018.0857

  View details for Web of Science ID 000463604100005

• The Spectrum of Scarring in Craniofacial Wound Repair. Frontiers in physiology desJardins-Park, H. E., Mascharak, S., Chinta, M. S., Wan, D. C., Longaker, M. T. 2019; 10: 322

  Abstract

  Fibrosis is intimately linked to wound healing and is one of the largest causes of wound-related morbidity. While scar formation is the normal and inevitable outcome of adult mammalian cutaneous wound healing, scarring varies widely between different anatomical sites. The spectrum of craniofacial wound healing spans a particularly diverse range of outcomes. While most craniofacial wounds heal by scarring, which can be functionally and aesthetically devastating, healing of the oral mucosa represents a rare example of nearly scarless postnatal healing in humans. In this review, we describe the typical wound healing process in both skin and the oral cavity. We present clinical correlates and current therapies and discuss the current state of research into mechanisms of scarless healing, toward the ultimate goal of achieving scarless adult skin healing.

  View details for DOI 10.3389/fphys.2019.00322

  View details for PubMedID 30984020

  View details for PubMedCentralID PMC6450464

• The Spectrum of Scarring in Craniofacial Wound Repair FRONTIERS IN PHYSIOLOGY desJardins-Park, H. E., Mascharak, S., Chinta, M. S., Wan, D. C., Longaker, M. T. 2019; 10

  View details for DOI 10.3389/fphys.2019.00322

  View details for Web of Science ID 000462815300002

• Fat Chance: The Rejuvenation of Irradiated Skin PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN Borrelli, M. R., Patel, R. A., Sokol, J., Dung Nguyen, Momeni, A., Longaker, M. T., Wan, D. C. 2019; 7 (2): e2092

  Abstract

  Radiotherapy (RT) helps cure and palliate thousands of patients with a range of malignant diseases. A major drawback, however, is the collateral damage done to tissues surrounding the tumor in the radiation field. The skin and subcutaneous tissue are among the most severely affected regions. Immediately following RT, the skin may be inflamed, hyperemic, and can form ulcers. With time, the dermis becomes progressively indurated. These acute and chronic changes cause substantial patient morbidity, yet there are few effective treatment modalities able to reduce radiodermatitis. Fat grafting is increasingly recognized as a tool able to reverse the fibrotic skin changes and rejuvenate the irradiated skin. This review outlines the current progress toward describing and understanding the cellular and molecular effects of fat grafting in irradiated skin. Identification of the key factors involved in the pathophysiology of fibrosis following RT will inform therapeutic interventions to enhance its beneficial effects.

  View details for PubMedID 30881833

• Fat Grafting into Younger Recipients Improves Volume Retention in an Animal Model. Plastic and reconstructive surgery Chung, N. N., Ransom, R. C., Blackshear, C. P., Irizarry, D. M., Yen, D., Momeni, A., Lee, G. K., Nguyen, D. H., Longaker, M. T., Wan, D. C. 2019

  Abstract

  BACKGROUND: Soft tissue deficits associated with various craniofacial anomalies can be addressed by fat grafting, although outcomes remain unpredictable. Furthermore, consensus does not exist for timing of these procedures. While some advocate approaching soft tissue reconstruction after the underlying skeletal foundation has been corrected, other studies have suggested earlier grafting may exploit a younger recipient niche that is more conducive for fat graft survival. As there is a dearth of research investigating effects of recipient age on fat graft volume retention, this study compared the effectiveness of fat grafting in younger versus older animals through a longitudinal, in vivo analysis.METHODS: Human lipoaspirate from three healthy female donors was grafted subcutaneously over the calvarium of immunocompromised mice. Volume retention over 8 weeks was evaluated using micro-computed tomography in three experimental ages - 3-weeks old, 6-months old, and 1-year old. Histology was performed on explanted grafts to evaluate graft health and vascularity. Recipient site vascularity was also evaluated by confocal microscopy.RESULTS: Greatest retention of fat graft volume was noted in the youngest group compared to both older groups (*p < 0.05) at 6 and 8 weeks following grafting. Histological and immunohistochemical analyses revealed that improved retention in younger groups was associated with greater fat graft integrity and more robust vascularization.CONCLUSION: Our study provides evidence that grafting fat into a younger recipient site correlates with improved volume retention over time, suggesting that beginning soft tissue reconstruction with fat grafting in patients at an earlier age may be preferable to late correction.

  View details for PubMedID 30730498

• In Vitro and In Vivo Osteogenic Differentiation of Human Adipose-Derived Stromal Cells. Methods in molecular biology (Clifton, N.J.) Marshall, C. D., Brett, E. A., Moore, A. L., Wan, D. C., Longaker, M. T. 2019; 1891: 9–18

  Abstract

  Adipose-derived stromal cells (ASCs) are a promising population of cells that may be useful for the regeneration of human tissue defects. ASCs are capable of forming bone tissue in vitro and in vivo. Further work is required to determine the optimal conditions that will allow human ASCs to regenerate tissue in clinically significant tissue defects. Here we present three experimental protocols that are indispensable for the study of ASC osteogenic activity.

  View details for PubMedID 30414122

• Skeletal Stem Cell-Schwann Cell Circuitry in Mandibular Repair. Cell reports Jones, R. E., Salhotra, A. n., Robertson, K. S., Ransom, R. C., Foster, D. S., Shah, H. N., Quarto, N. n., Wan, D. C., Longaker, M. T. 2019; 28 (11): 2757–66.e5

  Abstract

  Regenerative paradigms exhibit nerve dependency, including regeneration of the mouse digit tip and salamander limb. Denervation impairs regeneration and produces morphological aberrancy in these contexts, but the direct effect of innervation on the stem and progenitor cells enacting these processes is unknown. We devised a model to examine nerve dependency of the mouse skeletal stem cell (mSSC), the progenitor responsible for skeletal development and repair. We show that after inferior alveolar denervation, mandibular bone repair is compromised because of functional defects in mSSCs. We present mSSC reliance on paracrine factors secreted by Schwann cells as the underlying mechanism, with partial rescue of the denervated phenotype by Schwann cell transplantation and by Schwann-derived growth factors. This work sheds light on the nerve dependency of mSSCs and has implications for clinical treatment of mandibular defects.

  View details for DOI 10.1016/j.celrep.2019.08.021

  View details for PubMedID 31509739

• Radiation-Induced Skin Fibrosis: Pathogenesis, Current Treatment Options, and Emerging Therapeutics. Annals of plastic surgery Borrelli, M. R., Shen, A. H., Lee, G. K., Momeni, A. n., Longaker, M. T., Wan, D. C. 2019; 83 (4S Suppl 1): S59–S64

  Abstract

  Radiotherapy (RT) has become an indispensable part of oncologic treatment protocols for a range of malignancies. However, a serious adverse effect of RT is radiodermatitis; almost 95% of patients develop moderate to severe skin reactions following radiation treatment. In the acute setting, these can be erythema, desquamation, ulceration, and pain. Chronically, soft tissue atrophy, alopecia, and stiffness can be noted. Radiodermatitis can delay oncologic treatment protocols and significantly impair quality of life. There is currently a paucity of effective treatment options and prevention strategies for radiodermatitis. Importantly, recent preclinical and clinical studies have suggested that fat grafting may be of therapeutic benefit, reversing detrimental changes to soft tissue following RT. This review outlines the damaging effects of RT on the skin and soft tissue as well as discusses available treatment options for radiodermatitis. Emerging strategies to mitigate detrimental, chronic radiation-induced changes are also presented.

  View details for DOI 10.1097/SAP.0000000000002098

  View details for PubMedID 31513068

• Discussion: Adipose-Derived Stem Cells and Ceiling Culture-Derived Preadipocytes Cultured from Subcutaneous Fat Tissue Differ in Their Epigenetic Characteristics and Osteogenic Potential. Plastic and reconstructive surgery Borrelli, M. R., Longaker, M. T., Wan, D. C. 2019; 144 (3): 656–57

  View details for DOI 10.1097/PRS.0000000000005914

  View details for PubMedID 31461021

• A Matched-Pair Analysis of Prepectoral with Subpectoral Breast Reconstruction: Is There a Difference in Postoperative Complication Rate? Plastic and reconstructive surgery Momeni, A. n., Remington, A. C., Wan, D. C., Nguyen, D. n., Gurtner, G. C. 2019; 144 (4): 801–7

  Abstract

  The development of acellular dermal matrices has revolutionized implant-based breast reconstruction. The most recent development has been the introduction of prepectoral breast reconstruction. However, concerns have been expressed related to the quality of soft-tissue coverage and infectious complications. Thus, the authors felt it prudent to perform a matched-pair analysis of clinical outcomes following prepectoral and subpectoral tissue expander placement.A retrospective study of patients who underwent immediate breast reconstruction by means of prepectoral (group 1) and dual-plane subpectoral (group 2) tissue expander placement was performed. Patients in each group were matched for age, body mass index, history of radiotherapy, and type of acellular dermal matrix. Of note, patients in group 1 received perioperative antibiotic prophylaxis for less than 24 hours, whereas patients in group 2 received antibiotic prophylaxis for at least 1 week.A total of 80 patients (138 breast reconstructions) were included in the study (group 1, n = 40; group 2, n = 40). No difference in total postoperative complication rate (p = 0.356) and mastectomy skin necrosis rate (p = 1.0) was noted. Observed differences in major complications (p = 0.06), major infection (p = 0.09), and loss of reconstruction (p = 0.09) were not found to be significant.Immediate prepectoral tissue expander insertion with anterior acellular dermal matrix coverage and less than 24 hours of antibiotic prophylaxis is safe and compares favorably to subpectoral tissue expander placement with an inferior acellular dermal matrix sling and a prolonged course of antibiotics.Therapeutic, III.

  View details for DOI 10.1097/PRS.0000000000006008

  View details for PubMedID 31568276

• Discussion: Recipient-Site Preconditioning with Deferoxamine Increases Fat-Graft Survival by Inducing VEGF and Neovascularization in a Rat Model. Plastic and reconstructive surgery Kuehlmann, B. n., Wan, D. C., Gurtner, G. C. 2019; 144 (4): 630e–631e

  View details for DOI 10.1097/PRS.0000000000006037

  View details for PubMedID 31568299

• Much-Needed Clarification and Guidance on Cell-Based Therapies for Musculoskeletal Disorders. Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research Murphy, M. P., Wan, D. C., Longaker, M. T. 2019

  View details for DOI 10.1002/jbmr.3841

  View details for PubMedID 31545871

• Honey bee Royalactin unlocks conserved pluripotency pathway in mammals. Nature communications Wan, D. C., Morgan, S. L., Spencley, A. L., Mariano, N., Chang, E. Y., Shankar, G., Luo, Y., Li, T. H., Huh, D., Huynh, S. K., Garcia, J. M., Dovey, C. M., Lumb, J., Liu, L., Brown, K. V., Bermudez, A., Luong, R., Zeng, H., Mascetti, V. L., Pitteri, S. J., Wang, J., Tu, H., Quarta, M., Sebastiano, V., Nusse, R., Rando, T. A., Carette, J. E., Bazan, J. F., Wang, K. C. 2018; 9 (1): 5078

  Abstract

  Royal jelly is the queen-maker for the honey bee Apis mellifera, and has cross-species effects on longevity, fertility, and regeneration in mammals. Despite this knowledge, how royal jelly or its components exert their myriad effects has remained poorly understood. Using mouse embryonic stem cells as a platform, here we report that through its major protein component Royalactin, royal jelly can maintain pluripotency by activating a ground-state pluripotency-like gene network. We further identify Regina, a mammalian structural analog of Royalactin that also induces a naive-like state in mouse embryonic stem cells. This reveals an important innate program for stem cell self-renewal with broad implications in understanding the molecular regulation of stem cell fate across species.

  View details for PubMedID 30510260

• Reply: Deferoxamine Preconditioning of Irradiated Tissue Improves Perfusion and Fat Graft Retention. Plastic and reconstructive surgery Wan, D. C. 2018; 142 (6): 978e

  View details for PubMedID 30496150

• Discussion: CRISPR Craft: DNA Editing the Reconstructive Ladder. Plastic and reconstructive surgery Hu, M. S., Longaker, M. T., Wan, D. C. 2018; 142 (5): 1365-1366

  View details for DOI 10.1097/PRS.0000000000004949

  View details for PubMedID 30511993

• Discussion: CRISPR Craft: DNA Editing the Reconstructive Ladder PLASTIC AND RECONSTRUCTIVE SURGERY Hu, M. S., Longaker, M. T., Wan, D. C. 2018; 142 (5): 1365–66

  View details for DOI 10.1097/PRS.0000000000004949

  View details for Web of Science ID 000448330200083

• Mechanoresponsive stem cells acquire neural crest fate in jaw regeneration. Nature Ransom, R. C., Carter, A. C., Salhotra, A., Leavitt, T., Marecic, O., Murphy, M. P., Lopez, M. L., Wei, Y., Marshall, C. D., Shen, E. Z., Jones, R. E., Sharir, A., Klein, O. D., Chan, C. K., Wan, D. C., Chang, H. Y., Longaker, M. T. 2018

  Abstract

  During both embryonic development and adult tissue regeneration, changes in chromatin structure driven by master transcription factors lead to stimulus-responsive transcriptional programs. A thorough understanding of how stem cells in the skeleton interpret mechanical stimuli and enact regeneration would shed light on how forces are transduced to the nucleus in regenerative processes. Here we develop a genetically dissectible mouse model of mandibular distraction osteogenesis-which isa process that is used in humans to correct an undersized lower jawthat involves surgically separating the jaw bone, whichelicits new bone growth in the gap. We use this model to show that regions of newly formed bone are clonally derived from stem cells that reside in the skeleton. Using chromatin and transcriptional profiling, we show that these stem-cell populations gain activity within the focal adhesion kinase (FAK) signalling pathway, and that inhibiting FAK abolishes new bone formation. Mechanotransduction via FAK in skeletal stem cells during distraction activates a gene-regulatory program and retrotransposons that are normally active in primitive neural crest cells, from which skeletal stem cells arise during development. This reversion to a developmental state underlies the robust tissue growth that facilitates stem-cell-based regeneration of adult skeletal tissue.

  View details for PubMedID 30356216

• Author Correction: Genetic dissection of clonal lineage relationships with hydroxytamoxifen liposomes. Nature communications Ransom, R. C., Foster, D. S., Salhotra, A., Jones, R. E., Marshall, C. D., Leavitt, T., Murphy, M. P., Moore, A. L., Blackshear, C. P., Brett, E. A., Wan, D. C., Longaker, M. T. 2018; 9 (1): 4411

  Abstract

  In the original version of this Article, the authors inadvertently omitted Elizabeth A. Brett, who contributed to the generation of the histology figures, from the author list.This has now been corrected in both the PDF and HTML versions of the Article.

  View details for PubMedID 30341306

• Nerve-Dependent Mandibular Regeneration by Skeletal Stem Cells in Fracture Repair Jones, R., Ransom, R. C., Salhotra, A., Foster, D. S., Wan, D. C., Longaker, M. T. ELSEVIER SCIENCE INC. 2018: S197

  View details for DOI 10.1016/j.jamcollsurg.2018.07.434

  View details for Web of Science ID 000447760600388

• Identification of the Human Skeletal Stem Cell. Cell Chan, C. K., Gulati, G. S., Sinha, R., Tompkins, J. V., Lopez, M., Carter, A. C., Ransom, R. C., Reinisch, A., Wearda, T., Murphy, M., Brewer, R. E., Koepke, L. S., Marecic, O., Manjunath, A., Seo, E. Y., Leavitt, T., Lu, W., Nguyen, A., Conley, S. D., Salhotra, A., Ambrosi, T. H., Borrelli, M. R., Siebel, T., Chan, K., Schallmoser, K., Seita, J., Sahoo, D., Goodnough, H., Bishop, J., Gardner, M., Majeti, R., Wan, D. C., Goodman, S., Weissman, I. L., Chang, H. Y., Longaker, M. T. 2018; 175 (1): 43

  Abstract

  Stem cell regulation and hierarchical organization ofhuman skeletal progenitors remain largely unexplored. Here, we report the isolation of a self-renewing and multipotent human skeletal stem cell (hSSC) that generates progenitors of bone, cartilage, and stroma, but not fat. Self-renewing and multipotent hSSCs are present in fetal and adult bones and can also be derived from BMP2-treated human adipose stroma (B-HAS) and induced pluripotent stem cells (iPSCs). Gene expression analysis of individual hSSCs reveals overall similarity between hSSCs obtained from different sources and partially explains skewed differentiation toward cartilage in fetal and iPSC-derived hSSCs. hSSCs undergo local expansion in response to acute skeletal injury. In addition, hSSC-derived stroma can maintain human hematopoietic stem cells (hHSCs) in serum-free culture conditions. Finally, we combine gene expression and epigenetic data of mouse skeletal stem cells (mSSCs) and hSSCs to identify evolutionarily conserved and divergent pathways driving SSC-mediated skeletogenesis. VIDEO ABSTRACT.

  View details for PubMedID 30241615

• Utilizing Confocal Microscopy to Characterize Human and Mouse Adipose Tissue. Tissue engineering. Part C, Methods Blackshear, C., Borrelli, M. R., Shen, E. Z., Ransom, R. C., Chung, N. N., Vistnes, S., Irizarry, D., Nazerali, R., Momeni, A., Longaker, M. T., Wan, D. C. 2018

  Abstract

  Significant advances in our understanding of human obesity, endocrinology, and metabolism have been made possible by murine comparative models, in which anatomically analogous fat depots are utilized; however, current research has questioned how truly analogous these depots are. In this study, we assess the validity of the analogy from the perspective of cellular architecture. Whole tissue mounting, confocal microscopy, and image reconstruction software were employed to characterize the three-dimensional structure of the inguinal fat pad in mice, gluteofemoral fat in humans, and subcutaneous adipose tissue of the human abdominal wall. Abdominal and gluteofemoral adipose tissue specimens from 12 human patients and bilateral inguinal fat pads from 12 mice were stained for adipocytes, blood vessels, and a putative marker for adipose-derived multipotent progenitor cells, CD34. Samples were whole-mounted and imaged with laser scanning confocal microscopy. Expectedly, human adipocytes were larger and demonstrated greater size heterogeneity. Mouse fat displayed significantly higher vascular density compared to human fat when normalized to adipocyte count. There was no significant difference in the concentration of CD34+ stromal cells from either species. However, the mean distance between CD34+ stromal cells and blood vessels was significantly greater in human fat. Finally, mouse inguinal fat contained larger numbers of brown adipocytes than did human gluteofemoral or human abdominal fat. Overall, the basic architecture of human adipose tissue differs significantly from that of mice. Insofar as human gluteofemoral fat differs from human abdominal adipose tissue, it was closer to mouse inguinal fat, being its comparative developmental analogue. These differences likely confer variance in functional properties between the two sources, and thus must be considered when designing murine models of human disease.

  View details for PubMedID 30215305

• Determining the impact of sarcopenia on postoperative complications after ventral hernia repair. Journal of plastic, reconstructive & aesthetic surgery : JPRAS Barnes, L. A., Li, A. Y., Wan, D. C., Momeni, A. 2018; 71 (9): 1260–68

  Abstract

  BACKGROUND: Postoperative complication following ventral hernia repair (VHR) is a major clinical and financial burden. Preoperative risk assessment is necessary to minimize adverse outcomes following VHR. This study examines the ability of an independent parameter to predict postoperative morbidity following VHR.METHODS: A retrospective analysis of 58 patients who underwent VHR by component separation between January 2009 and December 2013 was performed. Preoperative abdominal CT scans were analyzed to assess sarcopenia. Sarcopenia was determined using the Hounsfield unit average calculation (HUAC), a measure of psoas muscle size and density. Sarcopenia was defined as an HUAC score of less than 19.6HU calculated using receiver operating characteristic (ROC) analysis and the Youden index. Multivariate analysis was performed to analyze the association of sarcopenia and postoperative complications.RESULTS: Preoperative sarcopenia was associated with an increased risk for postoperative complications (odds ratio [OR] = 5.3; p = 0.04). Preexisting gastrointestinal conditions such as ulcerative colitis or colon cancer were associated with an increased risk for postoperative complications (OR = 5.7; p = 0.05). A significantly higher rate of hernia recurrence (33.3% vs. 10.8% [p = 0.04]) and renal failure (19% vs. 2.7% [p = 0.03]) was noted in patients with sarcopenia when compared to patients without sarcopenia.CONCLUSIONS: Sarcopenia is an independent risk factor for postoperative complications in patients who underwent VHR. Assessment of sarcopenia using the HUAC score provides an opportunity for the adjustment of perioperative care plans to minimize postoperative complication rates.

  View details for PubMedID 30173713

• Pathway Analysis of Gene Expression in Murine Fetal and Adult Wounds. Advances in wound care Hu, M. S., Hong, W. X., Januszyk, M., Walmsley, G. G., Luan, A., Maan, Z. N., Moshrefi, S., Tevlin, R., Wan, D. C., Gurtner, G. C., Longaker, M. T., Lorenz, H. P. 2018; 7 (8): 262-275

  Abstract

  Objective: In early gestation, fetal wounds heal without fibrosis in a process resembling regeneration. Elucidating this remarkable mechanism can result in tremendous benefits to prevent scarring. Fetal mouse cutaneous wounds before embryonic day (E)18 heal without scar. Herein, we analyze expression profiles of fetal and postnatal wounds utilizing updated gene annotations and pathway analysis to further delineate between repair and regeneration. Approach: Dorsal wounds from time-dated pregnant BALB/c mouse fetuses and adult mice at various time points were collected. Total RNA was isolated and microarray analysis was performed using chips with 42,000 genes. Significance analysis of microarrays was utilized to select genes with >2-fold expression differences with a false discovery rate of <2. Enrichment analysis was performed on significant genes to identify differentially expressed pathways. Results: Our analysis identified 471 differentially expressed genes in fetal versus adult wounds following injury. Utilizing enrichment analysis of significant genes, we identified the top 20 signaling pathways that were upregulated and downregulated at 1 and 12 h after injury. At 24 h after injury, we discovered 18 signaling pathways upregulated in adult wounds and 11 pathways upregulated in fetal wounds. Innovation: These novel target genes and pathways may reveal repair mechanisms of the early fetus that promote regeneration over fibrosis. Conclusion: Our microarray analysis recognizes hundreds of possible genes as candidates for regulators of scarless versus scarring wound repair. Enrichment analysis reveals 109 signaling pathways related to fetal scarless wound healing.

  View details for DOI 10.1089/wound.2017.0779

  View details for PubMedID 30087802

  View details for PubMedCentralID PMC6080120

• Genetic dissection of clonal lineage relationships with hydroxytamoxifen liposomes. Nature communications Ransom, R. C., Foster, D. S., Salhotra, A., Jones, R. E., Marshall, C. D., Leavitt, T., Murphy, M. P., Moore, A. L., Blackshear, C. P., Wan, D. C., Longaker, M. T. 2018; 9 (1): 2971

  Abstract

  Targeted genetic dissection of tissues to identify precise cell populations has vast biological and therapeutic applications. Here we develop an approach, through thepackaging and delivery of 4-hydroxytamoxifen liposomes (LiTMX), that enables localized induction of CreERT2 recombinase in mice. Our method permits precise, in vivo, tissue-specific clonal analysis with both spatial and temporal control. This technology is effective using mice with both specific and ubiquitous Cre drivers in a variety of tissue types, under conditions of homeostasis and post-injury repair, and is highly efficient for lineage tracing and genetic analysis. This methodology is directly and immediately applicable to the developmental biology, stem cell biology and regenerative medicine, and cancer biology fields.

  View details for PubMedID 30061668

• Opinions on Authorship: A Survey of Plastic Surgery Residents and Fellows ANNALS OF PLASTIC SURGERY Momeni, A., Hunter, C., Li, A. Y., Safa, B., Wan, D. C., Kneser, U. 2018; 80 (6): 660–63

  Abstract

  Scientific publications are the cornerstone of scholarly activities. The importance of appropriately assigned authorship cannot be overstated. Hence, we felt it prudent to examine the perception of plastic surgery trainees regarding authorship. We hypothesized that plastic surgery trainees would not be in compliance with International Committee of Medical Journal Editors guidelines when determining what constitutes an authorship justifying contribution.An online survey describing 4 distinct scenarios was distributed to plastic surgery trainees at 2 academic institutions using the Qualtrics research software (Provo, UT). Additional parameters queried included level of training and number of publications. Linear regression models were used to test correlation between responses and level of training and number of publications.Thirty-three of 48 trainees responded (response rate, 68.8%). All respondents had previously authored publications, with the majority (54.5%) having at least 10 publications. Although none of the scenarios presented justified authorship based on international guidelines, 33.3% of respondents believed that authorship was warranted in at least 3 of the 4 presented scenarios. Linear regression comparing for demographic variables to number of perceived authorship scenarios found a mild-moderate positive correlation with level of training (R = 0.34, P = 0.05) and number of publications (R = 0.32, P = 0.07).Plastic surgery trainees do not seem to be familiar with guidelines regarding authorship justifying contributions. It is important to raise awareness regarding criteria that warrant authorship and to educate our residents and fellows in matters of appropriate scholarly conduct because nothing short of the credibility of our scientific endeavors is otherwise in question.

  View details for DOI 10.1097/SAP.0000000000001396

  View details for Web of Science ID 000432679800014

  View details for PubMedID 29489531

• Pathway Analysis of Gene Expression in Murine Fetal and Adult Wounds ADVANCES IN WOUND CARE Hu, M. S., Hong, W., Januszyk, M., Walmsley, G. G., Luan, A., Maan, Z. N., Moshrefi, S., Tevlin, R., Wan, D. C., Gurtner, G. C., Longaker, M. T., Lorenz, H. 2018

  View details for DOI 10.1089/wound.2017.0779

  View details for Web of Science ID 000429548900001

• Three-Dimensional Ultrasound Versus Computerized Tomography in Fat Graft Volumetric Analysis ANNALS OF PLASTIC SURGERY Blackshear, C., Rector, M., Chung, N., Irizarry, D., Flacco, J., Brett, E., Momeni, A., Lee, G., Longaker, M. T., Wan, D. C. 2018; 80 (3): 293–96

  Abstract

  Studies evaluating fat grafting in mice have frequently used micro-computed tomography (micro-CT) as an accurate radiographic tool to measure longitudinal volume retention without killing the animal. Over the past decade, however, microultrasonography has emerged as an equally powerful preclinical imaging tool. Given their respective strengths in 3-dimensional reconstruction, there is no study to our knowledge that directly compares micro-CT with microultrasound in volumetric analysis. In this study, we compared the performance of micro-CT with microultrasound in the evaluation of adipose tissue graft volume in a murine model. Fifteen immunodeficient mice were given 200 μL of adipose tissue grafts. In vivo volumetric analysis of the grafts by micro-CT and microultrasound was conducted at discrete time points up to postoperative day 105. Three mice were killed at multiple time points, and explanted grafts were reimaged by CT and ultrasound, as mentioned previously. Analysis revealed that in vivo graft volumes measured by micro-CT do not differ significantly from those of microultrasound. Furthermore, both micro-CT and microultrasound were capable of accurately measuring fat grafts as in vivo volumes closely correlated with explanted volumes. Finally, ultrasound was found to yield improved soft tissue contrast compared with micro-CT. Therefore, either modality may be used, depending on experimental needs.

  View details for DOI 10.1097/SAP.0000000000001183

  View details for Web of Science ID 000425352000021

  View details for PubMedID 28678028

  View details for PubMedCentralID PMC5752634

• Deferoxamine Preconditioning of Irradiated Tissue Improves Perfusion and Fat Graft Retention PLASTIC AND RECONSTRUCTIVE SURGERY Flacco, J., Chung, N., Blackshear, C. P., Irizarry, D., Momeni, A., Lee, G. K., Dung Nguyen, Gurtner, G. C., Longaker, M. T., Wan, D. C. 2018; 141 (3): 655–65

  Abstract

  Radiation therapy is a mainstay in the treatment of many malignancies, but collateral damage to surrounding tissue, with resultant hypovascularity, fibrosis, and atrophy, can be difficult to reconstruct. Fat grafting has been shown to improve the quality of irradiated skin, but volume retention of the graft is significantly decreased. Deferoxamine is a U.S. Food and Drug Administration-approved iron-chelating medication for acute iron intoxication and chronic iron overload that has also been shown to increase angiogenesis. The present study evaluates the effects of deferoxamine treatment on irradiated skin and subsequent fat graft volume retention.Mice underwent irradiation to the scalp followed by treatment with deferoxamine or saline and perfusion and were analyzed using laser Doppler analysis. Human fat grafts were then placed beneath the scalp and retention was also followed up to 8 weeks radiographically. Finally, histologic evaluation of overlying skin was performed to evaluate the effects of deferoxamine preconditioning.Treatment with deferoxamine resulted in significantly increased perfusion, as demonstrated by laser Doppler analysis and CD31 immunofluorescent staining (p < 0.05). Increased dermal thickness and collagen content secondary to irradiation, however, were not affected by deferoxamine (p > 0.05). Importantly, fat graft volume retention was significantly increased when the irradiated recipient site was preconditioned with deferoxamine (p < 0.05).The authors' results demonstrated increased perfusion with deferoxamine treatment, which was also associated with improved fat graft volume retention. Preconditioning with deferoxamine may thus enhance fat graft outcomes for soft-tissue reconstruction following radiation therapy.

  View details for PubMedID 29135894

  View details for PubMedCentralID PMC5826842

• Mesenchymal Stromal Cells and Cutaneous Wound Healing: A Comprehensive Review of the Background, Role, and Therapeutic Potential STEM CELLS INTERNATIONAL Hu, M. S., Borrelli, M. R., Lorenz, H., Longaker, M. T., Wan, D. C. 2018: 6901983

  Abstract

  Cutaneous wound repair is a highly coordinated cascade of cellular responses to injury which restores the epidermal integrity and its barrier functions. Even under optimal healing conditions, normal wound repair of adult human skin is imperfect and delayed healing and scarring are frequent occurrences. Dysregulated wound healing is a major concern for global healthcare, and, given the rise in diabetic and aging populations, this medicoeconomic disease burden will continue to rise. Therapies to reliably improve nonhealing wounds and reduce scarring are currently unavailable. Mesenchymal stromal cells (MSCs) have emerged as a powerful technique to improve skin wound healing. Their differentiation potential, ease of harvest, low immunogenicity, and integral role in native wound healing physiology make MSCs an attractive therapeutic remedy. MSCs promote cell migration, angiogenesis, epithelialization, and granulation tissue formation, which result in accelerated wound closure. MSCs encourage a regenerative, rather than fibrotic, wound healing microenvironment. Recent translational research efforts using modern bioengineering approaches have made progress in creating novel techniques for stromal cell delivery into healing wounds. This paper discusses experimental applications of various stromal cells to promote wound healing and discusses the novel methods used to increase MSC delivery and efficacy.

  View details for PubMedID 29887893

  View details for PubMedCentralID PMC5985130

• An Improved Humanized Mouse Model for Excisional Wound Healing Using Double Transgenic Mice ADVANCES IN WOUND CARE Hu, M. S., Cheng, J., Borrelli, M. R., Leavitt, T., Walmsley, G. G., Zielins, E. R., Hong, W., Cheung, A. M., Duscher, D., Maan, Z. N., Irizarry, D. M., Stephan, B., Parsa, F., Wan, D. C., Gurtner, G. C., Lorenz, H., Longaker, M. T. 2018; 7 (1): 11–17

  Abstract

  Objective: Splinting full-thickness cutaneous wounds in mice has allowed for a humanized model of wound healing. Delineating the epithelial edge and assessing time to closure of these healing wounds via macroscopic visualization have remained a challenge. Approach: Double transgenic mice were created by crossbreeding K14-Cre and ROSAmT/mG reporter mice. Full-thickness excisional wounds were created in K14-Cre/ROSAmT/mG mice (n = 5) and imaged using both normal and fluorescent light on the day of surgery, and every other postoperative day (POD) until wound healing was complete. Ten blinded observers analyzed a series of images from a single representative healing wound, taken using normal or fluorescent light, to decide the POD when healing was complete. K14-Cre/ROSAmT/mG mice (n = 4) were subsequently sacrificed at the four potential days of rated wound closure to accurately determine the histological point of wound closure using microscopic fluorescence imaging. Results: Average time to wound closure was rated significantly longer in the wound series images taken using normal light, compared with fluorescent light (mean POD 13.6 vs. 11.6, *p = 0.008). Fluorescence imaging of histological samples indicated that reepithelialization was complete at 12 days postwounding. Innovation: We describe a novel technique, using double transgenic mice K14-Cre/ROSAmT/mG and fluorescence imaging, to more accurately determine the healing time of wounds in mice upon macroscopic evaluation. Conclusion: The accuracy by which wound healing can be macroscopically determined in vivo in mouse models of wound healing is significantly enhanced using K14-Cre/ROSAmT/mG double transgenic mice and fluorescence imaging.

  View details for PubMedID 29344430

• Prrx1 Labels the Fibrogenic Fibroblast in the Ventral Dermis Hu, M., Leavitt, T., Garcia, J., Ransom, R., Litzenburger, U., Walmsley, G., Marshall, C., Moore, A., Mascharak, S., Chan, C., Wan, D., Lorenz, P., Chang, H., Longaker, M. WILEY. 2018: A4

  View details for Web of Science ID 000430308600009

• Noncoding RNAs in Wound Healing: A New and Vast Frontier ADVANCES IN WOUND CARE Luan, A., Hu, M. S., Leavitt, T., Brett, E. A., Wang, K. C., Longaker, M. T., Wan, D. C. 2018; 7 (1): 19–27

  Abstract

  Significance: Wound healing requires a highly orchestrated coordination of processes that are not yet fully understood. Therefore, available clinical therapies are thus far limited in their efficacy in preventing and treating both chronic wounds and scars. Current gene-based therapeutics is largely based on our understanding of the protein-coding genome and proteins involved in known wound healing pathways. Recent Advances: Noncoding RNAs such as microRNAs and long noncoding RNAs have recently been found to be significant modulators of gene expression in diverse cellular pathways. Research has now implicated noncoding RNAs in nearly every stage of the wound healing process, suggesting that they may serve as clinical therapeutic targets. Noncoding RNAs are critical regulators in processes such as angiogenesis and cutaneous cell migration and proliferation, including classically described biological pathways previously attributed to mostly protein constituents. Critical Issues: The complexity and diversity of the interactions of noncoding RNAs with their targets and other binding partners require thorough characterization and understanding of their functions before they may be altered to modulate human wound healing pathways. Future Directions: Research in the area of noncoding RNAs continues to rapidly expand our understanding of their potential roles in physiological and pathological wound healing. Coupled with improving technologies to enhance or suppress target noncoding RNA in vivo, these advances hold great promise in the development of new therapies for wound healing.

  View details for PubMedID 29344431

  View details for PubMedCentralID PMC5770091

• Ultrasound-assisted liposuction provides a source for functional adipose-derived stromal cells CYTOTHERAPY Duscher, D., Maan, Z. N., Luan, A., Aitzetmueller, M. M., Brett, E. A., Atashroo, D., Whittam, A. J., Hu, M. S., Walmsley, G. G., Houschyar, K. S., Schilling, A. F., Machens, H., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2017; 19 (12): 1491–1500

  Abstract

  Regenerative medicine employs human mesenchymal stromal cells (MSCs) for their multi-lineage plasticity and their pro-regenerative cytokine secretome. Adipose-derived mesenchymal stromal cells (ASCs) are concentrated in fat tissue, and the ease of harvest via liposuction makes them a particularly interesting cell source. However, there are various liposuction methods, and few have been assessed regarding their impact on ASC functionality. Here we study the impact of the two most popular ultrasound-assisted liposuction (UAL) devices currently in clinical use, VASER (Solta Medical) and Lysonix 3000 (Mentor) on ASCs.After lipoaspirate harvest and processing, we sorted for ASCs using fluorescent-assisted cell sorting based on an established surface marker profile (CD34+CD31-CD45-). ASC yield, viability, osteogenic and adipogenic differentiation capacity and in vivo regenerative performance were assessed.Both UAL samples demonstrated equivalent ASC yield and viability. VASER UAL ASCs showed higher osteogenic and adipogenic marker expression, but a comparable differentiation capacity was observed. Soft tissue healing and neovascularization were significantly enhanced via both UAL-derived ASCs in vivo, and there was no significant difference between the cell therapy groups.Taken together, our data suggest that UAL allows safe and efficient harvesting of the mesenchymal stromal cellular fraction of adipose tissue and that cells harvested via this approach are suitable for cell therapy and tissue engineering applications.

  View details for PubMedID 28917626

  View details for PubMedCentralID PMC5723208

• Cell-Based Soft Tissue Reconstruction in a Hydrogel Scaffold ANNALS OF PLASTIC SURGERY Blackshear, C. P., Flacco, J. S., Vistnes, S. M., Chung, N. N., Irizarry, D., Brett, E. A., Yen, D. J., Momeni, A., Longaker, M. T., Wan, D. C. 2017; 79 (6): 618–22

  Abstract

  Renevia is a hyaluronin-gelatin crosslinked matrix scaffold that has been studied as an alternative to adipose transfer in soft tissue reconstruction. It is designed to emulate the native extracellular matrix environment by supporting stromal vascular fraction (SVF) cell attachment, survival, and proliferation, thus promoting cell-based volume restoration. However, the concentration of incorporated cells for a clinically relevant result has yet to be determined.Five experimental groups of seven CD-1 nude immunodeficient mice were given 250 μL grafts of the following composition: 1 million human SVF cells per mL of Renevia scaffold, 6 million human SVF cells per mL scaffold, 12 million human SVF cells per mL scaffold, Renevia scaffold-alone or human adipose tissue-alone. Volumetric analysis was conducted at discrete time points over 16 weeks using 3-dimensional ultrasound, after which time the grafts were explanted for histologic analysis.At the conclusion of the study at week 16, the Renevia scaffold group incorporating the highest concentration of human SVF cells (12 million cells per mL scaffold) had significantly greater volume retention compared with the 2 lower concentrations, scaffold-alone and fat-alone groups. Histology of the 12 million scaffold group revealed abundant adipocyte formation within the scaffold, exceeding that observed in the 6 million, 1 million, and scaffold-alone groups. The 12 million group also demonstrated significantly increased vascularity per CD31 staining.Stromal vascular fraction cells coupled with Renevia hydrogel scaffold can enhance soft tissue volume reconstruction. In this study, we observed the greatest effect with 12 million cells per mL. From the perspective of volume retention, incorporation of higher concentrations of SVF cells with Renevia may be an alternative to conventional adipose tissue grafting.

  View details for PubMedID 28671889

  View details for PubMedCentralID PMC5677558

• Calvarial Defects: Cell-Based Reconstructive Strategies in the Murine Model TISSUE ENGINEERING PART C-METHODS Murphy, M. P., Quarto, N., Longaker, M. T., Wan, D. C. 2017; 23 (12): 971–81

  Abstract

  Calvarial defects pose a continued clinical dilemma for reconstruction. Advancements within the fields of stem cell biology and tissue engineering have enabled researchers to develop reconstructive strategies using animal models. We review the utility of various animal models and focus on the mouse, which has aided investigators in understanding cranial development and calvarial bone healing. The murine model has also been used to study regenerative approaches to critical-sized calvarial defects, and we discuss the application of stem cells such as bone marrow-derived mesenchymal stromal cells, adipose-derived stromal cells, muscle-derived stem cells, and pluripotent stem cells to address deficient bone in this animal. Finally, we highlight strategies to manipulate stem cells using various growth factors and inhibitors and ultimately how these factors may prove crucial in future advancements within calvarial reconstruction using native skeletal stem cells.

  View details for PubMedID 28825366

  View details for PubMedCentralID PMC5734144

• Impact of a Cleft and Craniofacial Center on an Academic Health System. Plastic and reconstructive surgery Pourtaheri, N., Kearney, A., Wan, D. C., Lakin, G. E. 2017; 140 (4): 587e-597e

  Abstract

  The contributions of all physician specialties and ancillary services involved in cleft and craniofacial center care must be evaluated to fairly assess the financial impact of a cleft and craniofacial center. The authors hypothesized that the cleft and craniofacial center generates profitable downstream productivity for the academic health system.This was a retrospective cohort study of all patients who presented to a cleft and craniofacial center in the first quarter of 2011. Analysis included all health system encounters for each patient over a 2-year period using the electronic medical record and health system financial database.Sixty-two patients were seen (mean age, 11.4 years; 38 boys and 24 girls; 18 new and 44 established patients). Over 2 years, there were 618 health system encounters (599 outpatient and 19 inpatient encounters), 68 hospital days, and 110 procedures. The most common physician specialty was plastic surgery [312 encounters (50.5 percent)] and the most common ancillary service was speech therapy [256 encounters (41.4 percent)]. The overall reimbursement rate was 39.9 percent, with a majority payor-mix of government payors (62.1 percent). The total profit margin percentage from all encounters was 13.7 percent, which was greater for managed care compared with government payor (38.9 percent versus -10.8 percent; p = 0.022), inpatient compared to outpatient (24.5 percent versus -2.8 percent; p < 0.001), and plastic surgery compared to other specialty encounters (19.7 percent versus 8.7 percent; p = 0.003).The cleft and craniofacial center generated profitable downstream productivity for the academic health system with referrals to 39 different physician and nonphysician specialties. Health system providers and the business team should align to analyze the center, enhance patient outcomes, and improve specialty care access for patients.

  View details for DOI 10.1097/PRS.0000000000003822

  View details for PubMedID 28953731

• Is Distraction Osteogenesis of the Irradiated Craniofacial Skeleton Contraindicated? JOURNAL OF CRANIOFACIAL SURGERY Momeni, A., Januszyk, M., Wan, D. C. 2017; 28 (5): 1236–41

  Abstract

  Craniofacial distraction osteogenesis (DO) is a common treatment modality today. Despite its numerous advantages, however, concerns have been expressed regarding the use of DO in the irradiated setting.A systematic review was performed to identify all published reports of patients who underwent DO of the irradiated craniofacial skeleton. The following parameters were of particular interest: postoperative complications, specifically, insufficient bone formation, fracture, and hardware exposure (intraoral and cutaneous), as well as the need for additional bone grafting.The initial search retrieved a total of 183 articles of which 20 articles (38 patients) met predetermined inclusion criteria. The most common site of distraction was the mandible (76.3%). The median radiation dose was 50.7 Gy (range, 30-70 Gy). Bone defects ranged from 30 to 80 mm (median, 42.5 mm). Complications were encountered in 19 patients (50%), with insufficient bone formation being most common (9 patients; 23%). The overall incidence of complications was not significantly associated with radiation dosage (P = 0.79). The remaining procedural and demographic variables also failed to meet statistical significance when compared against the overall complication rate (P = 0.27-0.97).The complication rate associated with craniofacial DO of the irradiated skeleton does not appear to be substantially higher than what is reported for DO in the nonirradiated setting. As such, patients should be offered this treatment modality, particularly in light of the fact, that it offers the option to decrease patient morbidity as well as treatment complexity.

  View details for PubMedID 28665865

• Dynamic Rheology for the Prediction of Surgical Outcomes in Autologous Fat Grafting. Plastic and reconstructive surgery Luan, A., Zielins, E. R., Wearda, T., Atashroo, D. A., Blackshear, C. P., Raphel, J., Brett, E. A., Flacco, J., Alyono, M. C., Momeni, A., Heilshorn, S., Longaker, M. T., Wan, D. C. 2017

  Abstract

  Due to the abundance and biocompatibility of fat, lipotransfer has become an attractive method for treating soft tissue deficits. However, it is limited by unpredictable graft survival and retention. Currently, little is known about the viscoelastic properties of fat after various injection methods. Here, we assess the effects of cannula diameter, length, and shape on the viscoelastic properties, structure, and retention of fat.Human lipoaspirate was harvested using suction-assisted liposuction and prepared for grafting. A syringe pump was used to inject fat at a controlled flow rate through cannulas of varying gauge, length, and shape. Processed samples were tested in triplicate on an oscillatory rheometer to measure their viscoelastic properties. Fat grafts from each group were placed into the scalps of immunocompromised mice. After 8 weeks, graft retention was measured using micro-CT and grafts were explanted for histological analysis.Lipoaspirate injected through narrower, longer, and bent cannulas exhibited more shear thinning with diminished quality. The storage modulus (G') of fat processed with 18-gauge cannulas was significantly lower than when processed with 14-gauge or larger cannulas, which also corresponded with inferior in vivo histological structure. Similarly, the longer cannula group had a significantly lower G' than the shorter cannula, and was associated with decreased graft retention.Discrete modifications in the methods used for fat placement can have a significant impact on immediate graft integrity, and ultimately on graft survival and quality. Respecting these biomechanical influences during the placement phase of lipotransfer may allow surgeons to optimize outcomes.

  View details for DOI 10.1097/PRS.0000000000003578

  View details for PubMedID 28574947

• Isolation of CD248-expressing stromal vascular fraction for targeted improvement of wound healing. Wound repair and regeneration Brett, E., Zielins, E. R., Chin, M., Januszyk, M., Blackshear, C. P., Findlay, M., Momeni, A., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2017

  Abstract

  Wound healing remains a global issue of disability, cost, and health. Addition of cells from the stromal vascular fraction (SVF) of adipose tissue has been shown to increase the rate of full thickness wound closure. This study aimed to investigate the angiogenic mechanisms of CD248+ SVF cells in the context of full thickness excisional wounds. Single cell transcriptional analysis was used to identify and cluster angiogenic gene-expressing cells, which was then correlated with surface marker expression. SVF cells isolated from human lipoaspirate were FACS sorted based on the presence of CD248. Cells were analyzed for angiogenic gene expression and ability to promote microvascular tubule formation in vitro. Following this, 6mm full thickness dermal wounds were created on the dorsa of immunocompromised mice and then treated with CD248+, CD248-, or unsorted SVF cells delivered in a pullalan-collagen hydrogel or the hydrogel alone. Wounds were measured every other day photometrically until closure. Wounds were also evaluated histologically at 7 and 14 days post-wounding and when fully healed to assess for reepithelialization and development of neovasculature. Wounds treated with CD248+ cells healed significantly faster than other treatment groups, and at 7 days, had quantitatively more reepithelialization. Concurrently, immunohistochemistry of CD31 revealed a much higher presence of vascularity in the CD248+ SVF cells treated group at the time of healing and at 14 days post-op, consistent with a pro-angiogenic effect of CD248+ cells in vivo. Therefore, using CD248+ pro-angiogenic cells obtained from SVF presents a viable strategy in wound healing by promoting increased vessel growth in the wound.

  View details for DOI 10.1111/wrr.12542

  View details for PubMedID 28464475

• A Review of Cell-Based Strategies for Soft Tissue Reconstruction. Tissue engineering. Part B, Reviews Brett, E., Chung, N., Leavitt, W. T., Momeni, A., Longaker, M. T., Wan, D. C. 2017

  Abstract

  Soft tissue reconstruction to restore volume to damaged or deficient tissue beneath the skin remains a challenging endeavor. Current techniques are centered around autologous fat transfer, or the use of synthetic substitutes, however, a great deal of scientific inquiry has been made into both the molecular mechanisms involved in, and limitations of, de novo adipogenesis, that is, the formation of new adipose tissue from precursor cells. To best comprehend these mechanisms, an understanding of defined markers for adipogenic differentiation, and knowledge of both commercially available and primary cell lines that enable in vitro and in vivo studies is necessary. We review the growth factors, proteins, cytokines, drugs, and molecular pathways that have shown promise in enhancing adipogenesis and vasculogenesis, in addition to the multitude of scaffolds that act as delivery vehicles to support these processes. While progress continues on these fronts, equally important is how researchers are optimizing clinically employed strategies such as autologous fat transfer through cell-based intervention, and the potential to augment this approach through isolation of preferentially adipogenic or angiogenic precursor subpopulations, which exists on the horizon. This review will highlight the novel molecular and synthetic modifications currently being studied for inducing adipose tissue regeneration on a cellular level, which will expand our arsenal of techniques for approaching soft tissue reconstruction.

  View details for DOI 10.1089/ten.TEB.2016.0455

  View details for PubMedID 28372485

• Discussion: Regeneration of Vascularized Corticocancellous Bone and Diploic Space Using Muscle-Derived Stem Cells: A Translational Biologic Alternative for Healing Critical Bone Defects PLASTIC AND RECONSTRUCTIVE SURGERY Irizarry, D. M., Wan, D. C. 2017; 139 (4): 908–9

  View details for PubMedID 28350670

• Purified Adipose-Derived Stromal Cells Provide Superior Fat Graft Retention Compared with Unenriched Stromal Vascular Fraction PLASTIC AND RECONSTRUCTIVE SURGERY Zielins, E. R., Brett, E. A., Blackshear, C. P., Flacco, J., Ransom, R. C., Longaker, M. T., Wan, D. C. 2017; 139 (4): 911–14

  Abstract

  Cell-assisted lipotransfer has shown much promise as a technique to improve fat graft retention in both mouse and human studies. However, the literature varies as to whether fresh stromal vascular fraction or culture-expanded adipose-derived stromal cells are used to augment volume retention. The authors' study sought to determine whether there was a significant advantage to using adipose-derived stromal cells over unpurified stromal vascular fraction cells in a mouse model of cell-assisted lipotransfer.

  View details for PubMedID 28350672

  View details for PubMedCentralID PMC5398091

• Excess Dermal Tissue Remodeling In Vivo: Does It Settle? Plastic and reconstructive surgery Leavitt, T., Hu, M. S., Zielins, E. R., Barnes, L. A., Marshall, C. D., Wan, D. C., Lorenz, H. P., Gurtner, G. C., Longaker, M. T. 2017; 139 (2): 415e-424e

  Abstract

  Surgical manipulation of skin may result in undesired puckering of excess tissue, which is generally assumed to settle over time. In this article, the authors address the novel question of how this excess tissue remodels.Purse-string sutures (6-0 nylon) were placed at the midline dorsum of 22 wild-type BALB/c mice in a circular pattern marked with tattoo ink. Sutures were cinched and tied under tension in the treatment group, creating an excess tissue deformity, whereas control group sutures were tied without tension. After 2 or 4 weeks, sutures were removed. The area of tattooed skin was measured up to 56 days after suture removal. Histologic analysis was performed on samples harvested 14 days after suture removal.The majority of excess tissue deformities flattened within 2 days after suture removal. However, the sutured skin in the treatment group decreased in area by an average of 18 percent from baseline (n = 9), compared to a 1 percent increase in the control group (n = 10) at 14 days after suture removal (p < 0.05). This was similarly observed at 28 days (treatment, -11.7 percent; control, 4.5 percent; n = 5; p = 0.0243). Despite flattening, deformation with purse-string suture correlated with increased collagen content of skin, in addition to increased numbers of myofibroblasts. Change in area did not correlate with duration of suture placement.Excess dermal tissue deformities demonstrate the ability to remodel with gross flattening of the skin, increased collagen deposition, and incomplete reexpansion to baseline area. Further studies will reveal whether our findings in this mouse model translate to humans.

  View details for DOI 10.1097/PRS.0000000000003026

  View details for PubMedID 28121870

• Rapid Isolation of BMPR-IB plus Adipose-Derived Stromal Cells for Use in a Calvarial Defect Healing Model JOVE-JOURNAL OF VISUALIZED EXPERIMENTS Marshall, C. D., Zielins, E. R., Brett, E. A., Blackshear, C. P., Hu, M. S., Leavitt, T., Barnes, L. A., Lorenz, H. P., Longaker, M. T., Wan, D. C. 2017

  Abstract

  Invasive cancers, major injuries, and infection can cause bone defects that are too large to be reconstructed with preexisting bone from the patient's own body. The ability to grow bone de novo using a patient's own cells would allow bony defects to be filled with adequate tissue without the morbidity of harvesting native bone. There is interest in the use of adipose-derived stromal cells (ASCs) as a source for tissue engineering because these are obtained from an abundant source: the patient's own adipose tissue. However, ASCs are a heterogeneous population and some subpopulations may be more effective in this application than others. Isolation of the most osteogenic population of ASCs could improve the efficiency and effectiveness of a bone engineering process. In this protocol, ASCs are obtained from subcutaneous fat tissue from a human donor. The subpopulation of ASCs expressing the marker BMPR-IB is isolated using FACS. These cells are then applied to an in vivo calvarial defect healing assay and are found to have improved osteogenic regenerative potential compared with unsorted cells.

  View details for DOI 10.3791/55120

  View details for Web of Science ID 000397847700048

  View details for PubMedID 28287559

• Rapid Isolation of BMPR-IB plus Adipose-Derived Stromal Cells for Use in a Calvarial Defect Healing Model JOVE-JOURNAL OF VISUALIZED EXPERIMENTS Marshall, C. D., Zielins, E. R., Brett, E. A., Blackshear, C. P., Hu, M. S., Leavitt, T., Barnes, L. A., Lorenz, H. P., Longaker, M. T., Wan, D. C. 2017

  Abstract

  Invasive cancers, major injuries, and infection can cause bone defects that are too large to be reconstructed with preexisting bone from the patient's own body. The ability to grow bone de novo using a patient's own cells would allow bony defects to be filled with adequate tissue without the morbidity of harvesting native bone. There is interest in the use of adipose-derived stromal cells (ASCs) as a source for tissue engineering because these are obtained from an abundant source: the patient's own adipose tissue. However, ASCs are a heterogeneous population and some subpopulations may be more effective in this application than others. Isolation of the most osteogenic population of ASCs could improve the efficiency and effectiveness of a bone engineering process. In this protocol, ASCs are obtained from subcutaneous fat tissue from a human donor. The subpopulation of ASCs expressing the marker BMPR-IB is isolated using FACS. These cells are then applied to an in vivo calvarial defect healing assay and are found to have improved osteogenic regenerative potential compared with unsorted cells.

  View details for DOI 10.3791/55120

  View details for Web of Science ID 000397847700048

  View details for PubMedID 28287559

• Pharmacological rescue of diabetic skeletal stem cell niches. Science translational medicine Tevlin, R., Seo, E. Y., Marecic, O., McArdle, A., Tong, X., Zimdahl, B., Malkovskiy, A., Sinha, R., Gulati, G., Li, X., Wearda, T., Morganti, R., Lopez, M., Ransom, R. C., Duldulao, C. R., Rodrigues, M., Nguyen, A., Januszyk, M., Maan, Z., Paik, K., Yapa, K., Rajadas, J., Wan, D. C., Gurtner, G. C., Snyder, M., Beachy, P. A., Yang, F., Goodman, S. B., Weissman, I. L., Chan, C. K., Longaker, M. T. 2017; 9 (372)

  Abstract

  Diabetes mellitus (DM) is a metabolic disease frequently associated with impaired bone healing. Despite its increasing prevalence worldwide, the molecular etiology of DM-linked skeletal complications remains poorly defined. Using advanced stem cell characterization techniques, we analyzed intrinsic and extrinsic determinants of mouse skeletal stem cell (mSSC) function to identify specific mSSC niche-related abnormalities that could impair skeletal repair in diabetic (Db) mice. We discovered that high serum concentrations of tumor necrosis factor-α directly repressed the expression of Indian hedgehog (Ihh) in mSSCs and in their downstream skeletogenic progenitors in Db mice. When hedgehog signaling was inhibited during fracture repair, injury-induced mSSC expansion was suppressed, resulting in impaired healing. We reversed this deficiency by precise delivery of purified Ihh to the fracture site via a specially formulated, slow-release hydrogel. In the presence of exogenous Ihh, the injury-induced expansion and osteogenic potential of mSSCs were restored, culminating in the rescue of Db bone healing. Our results present a feasible strategy for precise treatment of molecular aberrations in stem and progenitor cell populations to correct skeletal manifestations of systemic disease.

  View details for DOI 10.1126/scitranslmed.aag2809

  View details for PubMedID 28077677

• Biomimetics of Bone Implants: The Regenerative Road. BioResearch open access Brett, E., Flacco, J., Blackshear, C., Longaker, M. T., Wan, D. C. 2017; 6 (1): 1-6

  Abstract

  The current strategies for healing bone defects are numerous and varied. At the core of each bone healing therapy is a biomimetic mechanism, which works to enhance bone growth. These range from porous scaffolds, bone mineral usage, collagen, and glycosaminoglycan substitutes to transplanted cell populations. Bone defects face a range of difficulty in their healing, given the composite of dense outer compact bone and blood-rich inner trabecular bone. As such, the tissue possesses a number of inherent characteristics, which may be clinically harnessed as promoters of bone healing. These include mechanical characteristics, mineral composition, native collagen content, and cellular fraction of bone. This review charts multiple biomimetic strategies to help heal bony defects in large and small osseous injury sites, with a special focus on cell transplantation.

  View details for DOI 10.1089/biores.2016.0044

  View details for PubMedID 28163982

• Human Adipose-Derived Stromal Cell Isolation Methods and Use in Osteogenic and Adipogenic In Vivo Applications. Current protocols in stem cell biology Brett, E., Tevlin, R., McArdle, A., Seo, E. Y., Chan, C. K., Wan, D. C., Longaker, M. T. 2017; 43

  Abstract

  Adipose tissue represents an abundant and easily accessible source of multipotent cells, which may serve as excellent building blocks for tissue engineering. This article presents a newly described protocol for isolating adipose-derived stromal cells (ASCs) from human lipoaspirate, compared to the standard protocol for harvesting ASCs established in 2001. Human ASC isolation is performed using two methods, and resultant cells are compared through cell yield, cell viability, cell proliferation and regenerative potential. The osteogenic and adipogenic potential of ASCs isolated using both protocols are assessed invitro and gene expression analysis is performed. The focus of this series of protocols is the regenerative potential of both cell populations in vivo. As such, the two in vivo animal models described are fat graft retention (soft tissue reconstruction) and calvarial defect healing (bone regeneration). The techniques described comprise fat grafting with cell assisted lipotransfer, and calvarial defect creation healed with cell-seeded scaffolds. © 2017 by John Wiley & Sons, Inc.

  View details for PubMedID 29140567

• Magnetic Nanoparticle-Based Upregulation of B-Cell Lymphoma 2 Enhances Bone Regeneration. Stem cells translational medicine Brett, E., Zielins, E. R., Luan, A., Ooi, C. C., Shailendra, S., Atashroo, D., Menon, S., Blackshear, C., Flacco, J., Quarto, N., Wang, S. X., Longaker, M. T., Wan, D. C. 2017; 6 (1): 151-160

  Abstract

  Clinical translation of cell-based strategies for tissue regeneration remains challenging because survival of implanted cells within hostile, hypoxic wound environments is uncertain. Overexpression of B-cell lymphoma 2 (Bcl-2) has been shown to inhibit apoptosis in implanted cells. The present study describes an "off the shelf" prefabricated scaffold integrated with magnetic nanoparticles (MNPs) used to upregulate Bcl-2 expression in implanted adipose-derived stromal cells for bone regeneration. Iron oxide cores were sequentially coated with branched polyethyleneimine, minicircle plasmid encoding green fluorescent protein and Bcl-2, and poly-β-amino ester. Through in vitro assays, increased osteogenic potential and biological resilience were demonstrated in the magnetofected group over control and nucleofected groups. Similarly, our in vivo calvarial defect study showed that magnetofection had an efficiency rate of 30%, which in turn resulted in significantly more healing compared with control group and nucleofected group. Our novel, prefabricated MNP-integrated scaffold allows for in situ postimplant temporospatial control of cell transfection to augment bone regeneration. Stem Cells Translational Medicine 2017;6:151-160.

  View details for DOI 10.5966/sctm.2016-0051

  View details for PubMedID 28170185

• Commentary on: Adipose Stem Cell Function Maintained with Age: An Intra-Subject Study of Long-Term Cryopreserved Cells. Aesthetic surgery journal Irizarry, D., Longaker, M. T., Wan, D. C. 2016

  View details for DOI 10.1093/asj/sjw224

  View details for PubMedID 28039122

• A Novel Method of Human Adipose-Derived Stem Cell Isolation with Resultant Increased Cell Yield PLASTIC AND RECONSTRUCTIVE SURGERY Tevlin, R., McArdle, A., Brett, E., Chung, M. T., Paik, K., Seo, E. Y., Walmsley, G. G., Duldulao, C. R., Atashroo, D., Zielins, E., Vistnes, S., Chan, C. K., Wan, D. C., Longaker, M. T. 2016; 138 (6): 983E-996E

  Abstract

  The authors have developed a novel protocol for isolating adipose-derived stem cells from human lipoaspirate. In this study, they compare their new method to a previously published standard protocol.Human adipose-derived stem cell isolation was performed using two methods to compare cell yield, cell viability, cell proliferation, and regenerative potential. The new and conventional isolation methods differ in two key areas: the collagenase digestion buffer constituents and the use of an orbital shaker. The osteogenic and adipogenic potential of adipose-derived stem cells isolated using both protocols was assessed in vitro, and gene expression analysis was performed. To assess the ability of the isolated cells to generate bone in vivo, the authors created critical-size calvarial defects in mice, which were treated with adipose-derived stem cells loaded onto hydroxyapatite-coated poly(lactic-co-glycolic acid) scaffolds. To test the ability of the isolated cells to enhance adipogenesis, the cells were added to lipoaspirate and placed beneath the scalp of immunocompromised mice. Fat graft volume retention was subsequently assessed by serial computed tomographic volumetric scanning.The new method resulted in a 10-fold increased yield of adipose-derived stem cells compared with the conventional method. Cells harvested using the new method demonstrated significantly increased cell viability and proliferation in vitro (p < 0.05). New method cells also demonstrated significantly enhanced osteogenic and adipogenic differentiation capacity in vitro (p < 0.05) in comparison with the conventional method cells. Both cell groups demonstrated equivalent osteogenic and adipogenic regenerative potential in mice.The authors have developed a protocol that maximizes the yield of adipose-derived stem cells derived from lipoaspirate. The new method cells have increased osteogenic and adipogenic potential in vitro and are not inferior to conventional method cells in terms of their ability to generate bone and fat in vivo.Therapeutic, V.

  View details for DOI 10.1097/PRS.0000000000002790

  View details for PubMedID 27537222

• Commentary on: The Effects of Fat Harvesting and Preparation, Air Exposure, Obesity, and Stem Cell Enrichment on Adipocyte Viability Prior to Graft Transplantation. Aesthetic surgery journal Blackshear, C. P., Longaker, M. T., Wan, D. C. 2016; 36 (10): 1174-1175

  View details for PubMedID 27474768

• Stem Cells in Bone Regeneration STEM CELL REVIEWS AND REPORTS Walmsley, G. G., Ransom, R. C., Zielins, E. R., Leavitt, T., Flacco, J. S., Hu, M. S., Lee, A. S., Longaker, M. T., Wan, D. C. 2016; 12 (5): 524-529

  Abstract

  Bone has the capacity to regenerate and repair itself. However, this capacity may be impaired or lost depending on the size of the defect or the presence of certain disease states. In this review, we discuss the key principles underlying bone healing, efforts to characterize bone stem and progenitor cell populations, and the current status of translational and clinical studies in cell-based bone tissue engineering. Though barriers to clinical implementation still exist, the application of stem and progenitor cell populations to bone engineering strategies has the potential to profoundly impact regenerative medicine.

  View details for DOI 10.1007/s12015-016-9665-5

  View details for Web of Science ID 000385138500003

  View details for PubMedID 27250635

  View details for PubMedCentralID PMC5053855

• Systematic Reviews in Craniofacial Trauma-Strengths and Weaknesses. Annals of plastic surgery Hunter, C., Januszyk, M., Wan, D. C., Momeni, A. 2016; 77 (3): 363-368

  Abstract

  Despite substantial advances in the management of craniofacial trauma, numerous clinical questions remain. These are increasingly being answered using systematic reviews (SRs). However, caution is warranted as their validity and role in influencing clinical practice has been called into question.A PubMed search was performed in October 2014 to identify SRs published up to and including September 2014 in 35 scientific journals. Two authors independently reviewed the literature and extracted data from included studies. Discrepancies were resolved by consensus. Assessment of multiple systematic reviews (AMSTAR) was used to determine the quality of SRs.The initial search retrieved 3080 articles of which 3051 articles were excluded after screening title and abstract. After full-text review of the remaining 29 articles, 3 additional articles were excluded, thus, leaving 26 SRs for final analysis. Regression analysis demonstrated that the overall number of published SRs increased significantly throughout the period analyzed (P = 0.022). The median AMSTAR score of all SRs was 4.5, consistent with a "poor-to-fair" quality. The interobserver agreement was high, as evidenced by a mean κ of 0.91. Although there appeared to be a trend toward an increase in AMSTAR score by year over the period analyzed, this failed to reach statistical significance in terms of median (P = 0.36) or absolute (P = 0.26) counts.A tremendous opportunity exists for improvements in the quality of SRs focusing on craniofacial trauma. In addition to familiarizing authors with quality criteria for SRs, adoption of strict reporting criteria by scientific journals may result in long-term improvements in the quality of reporting.

  View details for DOI 10.1097/SAP.0000000000000633

  View details for PubMedID 26418794

• Magnetic Nanoparticle-Based Upregulation of B-Cell Lymphoma 2 Enhances Bone Regeneration. Stem cells translational medicine Brett, E., Zielins, E. R., Luan, A., Ooi, C. C., Shailendra, S., Atashroo, D., Menon, S., Blackshear, C., Flacco, J., Quarto, N., Wang, S. X., Longaker, M. T., Wan, D. C. 2016

  Abstract

  : Clinical translation of cell-based strategies for tissue regeneration remains challenging because survival of implanted cells within hostile, hypoxic wound environments is uncertain. Overexpression of B-cell lymphoma 2 (Bcl-2) has been shown to inhibit apoptosis in implanted cells. The present study describes an "off the shelf" prefabricated scaffold integrated with magnetic nanoparticles (MNPs) used to upregulate Bcl-2 expression in implanted adipose-derived stromal cells for bone regeneration. Iron oxide cores were sequentially coated with branched polyethyleneimine, minicircle plasmid encoding green fluorescent protein and Bcl-2, and poly-β-amino ester. Through in vitro assays, increased osteogenic potential and biological resilience were demonstrated in the magnetofected group over control and nucleofected groups. Similarly, our in vivo calvarial defect study showed that magnetofection had an efficiency rate of 30%, which in turn resulted in significantly more healing compared with control group and nucleofected group. Our novel, prefabricated MNP-integrated scaffold allows for in situ postimplant temporospatial control of cell transfection to augment bone regeneration.The use of adipose-derived stem cells as transplanted cells in wounded areas is desirable for their regenerative potential, but they are difficult to use owing to their fragility. Enhancing their survival in the context of a calvarial defect can be achieved by stimulating antiapoptotic protein expression in the cells themselves, through a plasmid expression vector. The present study used a nonintegrating minicircle plasmid encoding B-cell lymphoma 2 attached to a magnetic nanoparticle to facilitate in vivo transfection with temporospatial control (external magnetic field). This in situ system stimulates cell survival through gene expression and knock-on bone regeneration through cell survival.

  View details for PubMedID 27484867

• Scaffold-mediated BMP-2 minicircle DNA delivery accelerated bone repair in a mouse critical-size calvarial defect model JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A Keeney, M., Chung, M. T., Zielins, E. R., Paik, K. J., McArdle, A., Morrison, S. D., Ransom, R. C., Barbhaiya, N., Atashroo, D., Jacobson, G., Zare, R. N., Longaker, M. T., Wan, D. C., Yang, F. 2016; 104 (8): 2099-2107

  Abstract

  Scaffold-mediated gene delivery holds great promise for tissue regeneration. However, previous attempts to induce bone regeneration using scaffold-mediated non-viral gene delivery rarely resulted in satisfactory healing. We report a novel platform with sustained release of minicircle DNA (MC) from PLGA scaffolds to accelerate bone repair. MC was encapsulated inside PLGA scaffolds using supercritical CO2 , which showed prolonged release of MC. Skull-derived osteoblasts transfected with BMP-2 MC in vitro result in higher osteocalcin gene expression and mineralized bone formation. When implanted in a critical-size mouse calvarial defect, scaffolds containing luciferase MC lead to robust in situ protein production up to at least 60 days. Scaffold-mediated BMP-2 MC delivery leads to substantially accelerated bone repair as early as two weeks, which continues to progress over 12 weeks. This platform represents an efficient, long-term nonviral gene delivery system, and may be applicable for enhancing repair of a broad range of tissues types. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2099-2107, 2016.

  View details for DOI 10.1002/jbm.a.35735

  View details for Web of Science ID 000379736500025

  View details for PubMedID 27059085

• Clinical Use of Deferoxamine in Distraction Osteogenesis of Irradiated Bone JOURNAL OF CRANIOFACIAL SURGERY Momeni, A., Rapp, S., Donneys, A., Buchman, S. R., Wan, D. C. 2016; 27 (4): 880-882

  Abstract

  The deleterious effects of radiotherapy, including hypovascularity and hypocellularity, have made distraction of irradiated bones challenging. Animal studies, however, have demonstrated adjunctive measures such as the administration of deferoxamine to significantly improve bone regeneration across irradiated distraction gaps. In this report, the authors demonstrate, for the first time, enhanced bone formation following deferoxamine application in a patient following distraction of a previously irradiated maxilla. Computed tomography imaging of the pterygomaxillary buttress on the side of administration revealed significantly increased bone area and density relative to the contralateral buttress. This is the first presentation of clinical deferoxamine use to promote bone formation following irradiated bone distraction and highlights the promise for this adjunctive measure to make outcomes after distraction of irradiated bone more reliable.

  View details for DOI 10.1097/SCS.0000000000002633

  View details for Web of Science ID 000378088800052

  View details for PubMedID 27171947

  View details for PubMedCentralID PMC4902756

• Winner of the Young Investigator Award of the Society for Biomaterials at the 10th World Biomaterials Congress, May 17-22, 2016, Montreal QC, Canada: Microribbon-based hydrogels accelerate stem cell-based bone regeneration in a mouse critical-size cranial defect model JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A Han, L., Conrad, B., Chung, M. T., Deveza, L., Jiang, X., Wang, A., Butte, M. J., Longaker, M. T., Wan, D., Yang, F. 2016; 104 (6): 1321-1331

  Abstract

  Stem cell-based therapies hold great promise for enhancing tissue regeneration. However, the majority of cells die shortly after transplantation, which greatly diminishes the efficacy of stem cell-based therapies. Poor cell engraftment and survival remain a major bottleneck to fully exploiting the power of stem cells for regenerative medicine. Biomaterials such as hydrogels can serve as artificial matrices to protect cells during delivery and guide desirable cell fates. However, conventional hydrogels often lack macroporosity, which restricts cell proliferation and delays matrix deposition. Here we report the use of injectable, macroporous microribbon (μRB) hydrogels as stem cell carriers for bone repair, which supports direct cell encapsulation into a macroporous scaffold with rapid spreading. When transplanted in a critical-sized, mouse cranial defect model, μRB-based hydrogels significantly enhanced the survival of transplanted adipose-derived stromal cells (ADSCs) (81%) and enabled up to three-fold cell proliferation after 7 days. In contrast, conventional hydrogels only led to 27% cell survival, which continued to decrease over time. MicroCT imaging showed μRBs enhanced and accelerated mineralized bone repair compared to hydrogels (61% vs. 34% by week 6), and stem cells were required for bone repair to occur. These results suggest that paracrine signaling of transplanted stem cells are responsible for the observed bone repair, and enhancing cell survival and proliferation using μRBs further promoted the paracrine-signaling effects of ADSCs for stimulating endogenous bone repair. We envision μRB-based scaffolds can be broadly useful as a novel scaffold for enhancing stem cell survival and regeneration of other tissue types. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1321-1331, 2016.

  View details for DOI 10.1002/jbm.a.35715

  View details for Web of Science ID 000375117200001

  View details for PubMedID 26991141

  View details for PubMedCentralID PMC5142823

• Suction assisted liposuction does not impair the regenerative potential of adipose derived stem cells JOURNAL OF TRANSLATIONAL MEDICINE Duscher, D., Luan, A., Rennert, R. C., Atashroo, D., Maan, Z. N., Brett, E. A., Whittam, A. J., Ho, N., Lin, M., Hu, M. S., Walmsley, G. G., Wenny, R., Schmidt, M., Schilling, A. F., Machens, H., Huemer, G. M., Wan, D. C., Longaker, M. T., Gurtner, G. C. 2016; 14

  Abstract

  Adipose-derived stem cells (ASCs) have been identified as a population of multipotent cells with promising applications in tissue engineering and regenerative medicine. ASCs are abundant in fat tissue, which can be safely harvested through the minimally invasive procedure of liposuction. However, there exist a variety of different harvesting methods, with unclear impact on ASC regenerative potential. The aim of this study was thus to compare the functionality of ASCs derived from the common technique of suction-assisted lipoaspiration (SAL) versus resection.Human adipose tissue was obtained from paired abdominoplasty and SAL samples from three female donors, and was processed to isolate the stromal vascular fraction. Fluorescence-activated cell sorting was used to determine ASC yield, and cell viability was assayed. Adipogenic and osteogenic differentiation capacity were assessed in vitro using phenotypic staining and quantification of gene expression. Finally, ASCs were applied in an in vivo model of tissue repair to evaluate their regenerative potential.SAL specimens provided significantly fewer ASCs when compared to excised fat tissue, however, with equivalent viability. SAL-derived ASCs demonstrated greater expression of the adipogenic markers FABP-4 and LPL, although this did not result in a difference in adipogenic differentiation. There were no differences detected in osteogenic differentiation capacity as measured by alkaline phosphatase, mineralization or osteogenic gene expression. Both SAL- and resection-derived ASCs enhanced significantly cutaneous healing and vascularization in vivo, with no significant difference between the two groups.SAL provides viable ASCs with full capacity for multi-lineage differentiation and tissue regeneration, and is an effective method of obtaining ASCs for cell-based therapies.

  View details for DOI 10.1186/s12967-016-0881-1

  View details for Web of Science ID 000375475200004

  View details for PubMedID 27153799

  View details for PubMedCentralID PMC4859988

• Mandibular Distraction in a Patient With Type II Collagenopathy. journal of craniofacial surgery Garza, R. M., Alyono, J. C., Dorfman, D. W., Wan, D. C. 2016: -?

  Abstract

  Kniest dysplasia is an extremely rare form of type II collagenopathy associated with cleft palate, micrognathia, shortened trunk, arms and legs, and club foot. The authors present a case of an infant with this disorder who also had micrognathia and respiratory distress for which mandibular distraction was performed. Although abnormal collagen and impaired endochondral ossification is noted with Kniest dysplasia, adequate bone formation was observed across the distraction gap. Nonetheless, despite stable mandibular advancement, failure to consider concomitant restrictive lung disease resulted in tracheostomy dependence. The authors demonstrate that while successful bone regeneration can be achieved through distraction of intramembranous facial bones, discretion must still be employed in patients with collagenopathies.

  View details for PubMedID 27152560

• Microsurgical ear replantation is venous repair necessary? A systematic review MICROSURGERY Momeni, A., Liu, X., Januszyk, M., Wan, D. C., Buncke, G. M., Buntic, R. F., Parrett, B. M. 2016; 36 (4): 345-350

  Abstract

  A common postoperative observation after microsurgical ear replantation has been venous congestion necessitating alternate modes of decongestion, frequently in conjunction with blood transfusion. A comprehensive literature search was performed to assess the relationship between mode of vascular reconstruction and postoperative outcome as well as postoperative transfusion requirement after microsurgical ear replantation.The search was limited to cases of microsurgical ear replantation following complete amputation. Only articles published in English and indexed in PubMed were included.The initial search retrieved 285 articles, which was narrowed down to 40 articles reporting on 60 cases that matched the aforementioned criteria. Reconstruction of the arterial and venous limb (Group 1) was performed in 63.3% of patients and artery-only anastomosis (Group 2) was performed in 31.7%. Among measurable outcomes, only the duration of surgery was significantly different between groups (2.6 hours longer in Group 1 than Group 2; P = 0.0042).In light of contemporary data demonstrating successful artery-only ear replantation, replantation should not be abandoned when unable to establish venous outflow microsurgically. © 2015 Wiley Periodicals, Inc. Microsurgery 36:345-350, 2016.

  View details for DOI 10.1002/micr.22411

  View details for Web of Science ID 000377114900013

  View details for PubMedID 25847853

• Small Molecule Inhibition of Transforming Growth Factor Beta Signaling Enables the Endogenous Regenerative Potential of the Mammalian Calvarium TISSUE ENGINEERING PART A Senarath-Yapa, K., Li, S., Walmsley, G. G., Zielins, E., Paik, K., Britto, J. A., Grigoriadis, A. E., Wan, D. C., Liu, K. J., Longaker, M. T., Quarto, N. 2016; 22 (9-10): 707-720

  Abstract

  Current approaches for the treatment of skeletal defects are suboptimal, principally because the ability of bone to repair and regenerate is poor. Although the promise of effective cellular therapies for skeletal repair is encouraging, these approaches are limited by the risks of infection, cellular contamination, and tumorigenicity. Development of a pharmacological approach would therefore help avoid some of these potential risks. This study identifies transforming growth factor beta (TGFβ) signaling as a potential pathway for pharmacological modulation in vivo. We demonstrate that inhibition of TGFβ signaling by the small molecule SB431542 potentiates calvarial skeletal repair through activation of bone morphogenetic protein (BMP) signaling on osteoblasts and dura mater cells participating in healing of calvarial defects. Cells respond to inhibition of TGFβ signaling by producing higher levels of BMP2 that upregulates inhibitory Smad6 expression, thus providing a negative feedback loop to contain excessive BMP signaling. Importantly, study on human osteoblasts indicates that molecular mechanism(s) triggered by SB431542 are conserved. Collectively, these data provide insights into the use of small molecules to modulate key signaling pathways for repairing skeletal defects.

  View details for DOI 10.1089/ten.tea.2015.0527

  View details for Web of Science ID 000377380600001

  View details for PubMedID 27036931

  View details for PubMedCentralID PMC4876548

• Autologous Fat Grafting: The Science Behind the Surgery. Aesthetic surgery journal Zielins, E. R., Brett, E. A., Longaker, M. T., Wan, D. C. 2016; 36 (4): 488-496

  Abstract

  An invaluable part of the plastic surgeon's technical arsenal for soft tissue contouring, fat grafting continues to be plagued by unpredictable outcomes, resulting in either reoperation and/or patient dissatisfaction. Thus, extensive research has been conducted into the effects of adipose tissue procurement, processing, and placement on fat graft quality at both the cellular level and in terms of overall volume retention. Herein, we present an overview of the vast body of literature in these areas, with additional discussion of cell-assisted lipotransfer as a therapy to improve volume retention, and on the controversial use of autologous fat in the setting of prior irradiation.

  View details for DOI 10.1093/asj/sjw004

  View details for PubMedID 26961989

• Discussion: In Vitro Validation of a Closed Device Enabling the Purification of the Fluid Portion of Liposuction Aspirates. Plastic and reconstructive surgery Zielins, E. R., Longaker, M. T., Wan, D. C. 2016; 137 (4): 1168-1170

  View details for DOI 10.1097/PRS.0000000000002035

  View details for PubMedID 27018671

• Stem and progenitor cells: advancing bone tissue engineering. Drug delivery and translational research Tevlin, R., Walmsley, G. G., Marecic, O., Hu, M. S., Wan, D. C., Longaker, M. T. 2016; 6 (2): 159-173

  Abstract

  Unlike many other postnatal tissues, bone can regenerate and repair itself; nevertheless, this capacity can be overcome. Traditionally, surgical reconstructive strategies have implemented autologous, allogeneic, and prosthetic materials. Autologous bone-the best option-is limited in supply and also mandates an additional surgical procedure. In regenerative tissue engineering, there are myriad issues to consider in the creation of a functional, implantable replacement tissue. Importantly, there must exist an easily accessible, abundant cell source with the capacity to express the phenotype of the desired tissue, and a biocompatible scaffold to deliver the cells to the damaged region. A literature review was performed using PubMed; peer-reviewed publications were screened for relevance in order to identify key advances in stem and progenitor cell contribution to the field of bone tissue engineering. In this review, we briefly introduce various adult stem cells implemented in bone tissue engineering such as mesenchymal stem cells (including bone marrow- and adipose-derived stem cells), endothelial progenitor cells, and induced pluripotent stem cells. We then discuss numerous advances associated with their application and subsequently focus on technological advances in the field, before addressing key regenerative strategies currently used in clinical practice. Stem and progenitor cell implementation in bone tissue engineering strategies have the ability to make a major impact on regenerative medicine and reduce patient morbidity. As the field of regenerative medicine endeavors to harness the body's own cells for treatment, scientific innovation has led to great advances in stem cell-based therapies in the past decade.

  View details for DOI 10.1007/s13346-015-0235-1

  View details for PubMedID 25990836

  View details for PubMedCentralID PMC4654714

• Cell-Assisted Lipotransfer Improves Volume Retention in Irradiated Recipient Sites and Rescues Radiation-Induced Skin Changes STEM CELLS Luan, A., Duscher, D., Whittam, A. J., Paik, K. J., Zielins, E. R., Brett, E. A., Atashroo, D. A., Hu, M. S., Lee, G. K., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2016; 34 (3): 668-673

  Abstract

  Radiation therapy is not only a mainstay in the treatment of many malignancies but also results in collateral obliteration of microvasculature and dermal/subcutaneous fibrosis. Soft tissue reconstruction of hypovascular, irradiated recipient sites through fat grafting remains challenging; however, a coincident improvement in surrounding skin quality has been noted. Cell-assisted lipotransfer (CAL), the enrichment of fat with additional adipose-derived stem cells (ASCs) from the stromal vascular fraction, has been shown to improve fat volume retention, and enhanced outcomes may also be achieved with CAL at irradiated sites. Supplementing fat grafts with additional ASCs may also augment the regenerative effect on radiation-damaged skin. In this study, we demonstrate the ability for CAL to enhance fat graft volume retention when placed beneath the irradiated scalps of immunocompromised mice. Histologic metrics of fat graft survival were also appreciated, with improved structural qualities and vascularity. Finally, rehabilitation of radiation-induced soft tissue changes were also noted, as enhanced amelioration of dermal thickness, collagen content, skin vascularity, and biomechanical measures were all observed with CAL compared to unsupplemented fat grafts. Supplementation of fat grafts with ASCs therefore shows promise for reconstruction of complex soft tissue defects following adjuvant radiotherapy. Stem Cells 2016;34:668-673.

  View details for DOI 10.1002/stem.2256

  View details for Web of Science ID 000372552600013

• Cell-Assisted Lipotransfer Improves Volume Retention in Irradiated Recipient Sites and Rescues Radiation-Induced Skin Changes. Stem cells Luan, A., Duscher, D., Whittam, A. J., Paik, K. J., Zielins, E. R., Brett, E. A., Atashroo, D. A., Hu, M. S., Lee, G. K., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2016; 34 (3): 668-673

  Abstract

  Radiation therapy is not only a mainstay in the treatment of many malignancies but also results in collateral obliteration of microvasculature and dermal/subcutaneous fibrosis. Soft tissue reconstruction of hypovascular, irradiated recipient sites through fat grafting remains challenging; however, a coincident improvement in surrounding skin quality has been noted. Cell-assisted lipotransfer (CAL), the enrichment of fat with additional adipose-derived stem cells (ASCs) from the stromal vascular fraction, has been shown to improve fat volume retention, and enhanced outcomes may also be achieved with CAL at irradiated sites. Supplementing fat grafts with additional ASCs may also augment the regenerative effect on radiation-damaged skin. In this study, we demonstrate the ability for CAL to enhance fat graft volume retention when placed beneath the irradiated scalps of immunocompromised mice. Histologic metrics of fat graft survival were also appreciated, with improved structural qualities and vascularity. Finally, rehabilitation of radiation-induced soft tissue changes were also noted, as enhanced amelioration of dermal thickness, collagen content, skin vascularity, and biomechanical measures were all observed with CAL compared to unsupplemented fat grafts. Supplementation of fat grafts with ASCs therefore shows promise for reconstruction of complex soft tissue defects following adjuvant radiotherapy. Stem Cells 2016;34:668-673.

  View details for DOI 10.1002/stem.2256

  View details for PubMedID 26661694

• Ultrasound-Assisted Liposuction Does Not Compromise the Regenerative Potential of Adipose-Derived Stem Cells. Stem cells translational medicine Duscher, D., Atashroo, D., Maan, Z. N., Luan, A., Brett, E. A., Barrera, J., Khong, S. M., Zielins, E. R., Whittam, A. J., Hu, M. S., Walmsley, G. G., Pollhammer, M. S., Schmidt, M., Schilling, A. F., Machens, H., Huemer, G. M., Wan, D. C., Longaker, M. T., Gurtner, G. C. 2016; 5 (2): 248-257

  Abstract

  Human mesenchymal stem cells (MSCs) have recently become a focus of regenerative medicine, both for their multilineage differentiation capacity and their excretion of proregenerative cytokines. Adipose-derived mesenchymal stem cells (ASCs) are of particular interest because of their abundance in fat tissue and the ease of harvest via liposuction. However, little is known about the impact of different liposuction methods on the functionality of ASCs. Here we evaluate the regenerative abilities of ASCs harvested via a third-generation ultrasound-assisted liposuction (UAL) device versus ASCs obtained via standard suction-assisted lipoaspiration (SAL). Lipoaspirates were sorted using fluorescent assisted cell sorting based on an established surface-marker profile (CD34+/CD31-/CD45-), to obtain viable ASCs. Yield and viability were compared and the differentiation capacities of the ASCs were assessed. Finally, the regenerative potential of ASCs was examined using an in vivo model of tissue regeneration. UAL- and SAL-derived samples demonstrated equivalent ASC yield and viability, and UAL ASCs were not impaired in their osteogenic, adipogenic, or chondrogenic differentiation capacity. Equally, quantitative real-time polymerase chain reaction showed comparable expression of most osteogenic, adipogenic, and key regenerative genes between both ASC groups. Cutaneous regeneration and neovascularization were significantly enhanced in mice treated with ASCs obtained by either UAL or SAL compared with controls, but there were no significant differences in healing between cell-therapy groups. We conclude that UAL is a successful method of obtaining fully functional ASCs for regenerative medicine purposes. Cells harvested with this alternative approach to liposuction are suitable for cell therapy and tissue engineering applications. Significance: Adipose-derived mesenchymal stem cells (ASCs) are an appealing source of therapeutic progenitor cells because of their multipotency, diverse cytokine profile, and ease of harvest via liposuction. Alternative approaches to classical suction-assisted liposuction are gaining popularity; however, little evidence exists regarding the impact of different liposuction methods on the regenerative functionality of ASCs. Human ASC characteristics and regenerative capacity were assessed when harvested via ultrasound-assisted (UAL) versus standard suction-assisted liposuction. ASCs obtained via UAL were of equal quality when directly compared with the current gold standard harvest method. UAL is an adjunctive source of fully functional mesenchymal stem cells for applications in basic research and clinical therapy.

  View details for DOI 10.5966/sctm.2015-0064

  View details for PubMedID 26702129

  View details for PubMedCentralID PMC4729547

• Enrichment of Adipose-Derived Stromal Cells for BMPR1A Facilitates Enhanced Adipogenesis TISSUE ENGINEERING PART A Zielins, E. R., Paik, K., Ransom, R. C., Brett, E. A., Blackshear, C. P., Luan, A., Walmsley, G. G., Atashroo, D. A., Senarath-Yapa, K., Momeni, A., Rennert, R., Sorkin, M., Seo, E. Y., Chan, C. K., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2016; 22 (3-4): 214-221

  Abstract

  Reconstruction of soft tissue defects has traditionally relied on the use of grafts and flaps, which may be associated with variable resorption and/or significant donor site morbidity. Cell-based strategies employing adipose-derived stromal cells (ASCs), found within the stromal vascular fraction (SVF) of adipose tissue, may offer an alternative strategy for soft tissue reconstruction. In this study, we investigated the potential of a bone morphogenetic protein receptor type 1A (BMPR1A)(+) subpopulation of ASCs to enhance de novo adipogenesis.Human lipoaspirate was enzymatically digested to isolate SVF and magnetic-activated cell separation was utilized to obtain BMPR1A(+) and BMPR1A(-) cells. These cells, along with unenriched cells, were expanded in culture and evaluated for adipogenic gene expression and in vitro adipocyte formation. Cells from each group were also labeled with a green fluorescent protein (GFP) lentivirus and transplanted into the inguinal fat pads, an adipogenic niche, of immunocompromised mice to determine their potential for de novo adipogenesis. Confocal microscopy along with staining of lipid droplets and vasculature was performed to evaluate the formation of mature adipocytes by transplanted cells.In comparison to BMPR1A(-) and unenriched ASCs, BMPR1A(+) cells demonstrated significantly enhanced adipogenesis when cultured in an adipogenic differentiation medium, as evidenced by increased staining with Oil Red O and increased expression of peroxisome proliferator-activating receptor gamma (PPAR-γ) and fatty acid-binding protein 4 (FABP4). BMPR1A(+) cells also formed significantly more adipocytes in vivo, as demonstrated by quantification of GFP+ adipocytes. Minimal formation of mature adipocytes was appreciated by BMPR1A(-) cells.BMPR1A(+) ASCs show an enhanced ability for adipogenesis in vitro, as shown by gene expression and histological staining. Furthermore, within an adipogenic niche, BMPR1A(+) cells possessed an increased capacity to generate de novo fat compared to BMPR1A(-) and unenriched cells. This suggests utility for the BMPR1A(+) subpopulation in cell-based strategies for soft tissue reconstruction.

  View details for DOI 10.1089/ten.tea.2015.0278

  View details for PubMedID 26585335

• Short Hairpin RNA Silencing of PHD-2 Improves Neovascularization and Functional Outcomes in Diabetic Wounds and Ischemic Limbs. PloS one Paik, K. J., Maan, Z. N., Zielins, E. R., Duscher, D., Whittam, A. J., Morrison, S. D., Brett, E. A., Ransom, R. C., Hu, M. S., Wu, J. C., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2016; 11 (3)

  Abstract

  The transcription factor hypoxia-inducible factor 1-alpha (HIF-1α) is responsible for the downstream expression of over 60 genes that regulate cell survival and metabolism in hypoxic conditions as well as those that enhance angiogenesis to alleviate hypoxia. However, under normoxic conditions, HIF-1α is hydroxylated by prolyl hydroxylase 2, and subsequently degraded, with a biological half-life of less than five minutes. Here we investigated the therapeutic potential of inhibiting HIF-1α degradation through short hairpin RNA silencing of PHD-2 in the setting of diabetic wounds and limb ischemia. Treatment of diabetic mouse fibroblasts with shPHD-2 in vitro resulted in decreased levels of PHD-2 transcript demonstrated by qRT-PCR, higher levels of HIF-1α as measured by western blot, and higher expression of the downstream angiogenic genes SDF-1 and VEGFα, as measured by qRT-PCR. In vivo, shPHD-2 accelerated healing of full thickness excisional wounds in diabetic mice compared to shScr control, (14.33 ± 0.45 days vs. 19 ± 0.33 days) and was associated with an increased vascular density. Delivery of shPHD-2 also resulted in improved perfusion of ischemic hind limbs compared to shScr, prevention of distal digit tip necrosis, and increased survival of muscle tissue. Knockdown of PHD-2 through shRNA treatment has the potential to stimulate angiogenesis through overexpression of HIF-1α and upregulation of pro-angiogenic genes downstream of HIF-1α, and may represent a viable, non-viral approach to gene therapy for ischemia related applications.

  View details for DOI 10.1371/journal.pone.0150927

  View details for PubMedID 26967994

  View details for PubMedCentralID PMC4788284

• The role of stem cells in limb regeneration ORGANOGENESIS Zielins, E. R., Ransom, R. C., Leavitt, T. E., Longaker, M. T., Wan, D. C. 2016; 12 (1): 16-27

  Abstract

  Limb regeneration is a complex yet fascinating process observed to some extent in many animal species, though seen in its entirety in urodele amphibians. Accomplished by formation of a morphologically uniform intermediate, the blastema, scientists have long attempted to define the cellular constituents that enable regrowth of a functional appendage. Today, we know that the blastema consists of a variety of multipotent progenitor cells originating from a variety of tissues, and which contribute to limb tissue regeneration in a lineage-restricted manner. By continuing to dissect the role of stem cells in limb regeneration, we can hope to one day modulate the human response to limb amputation and facilitate regrowth of a working replacement.

  View details for DOI 10.1080/15476278.2016.1163463

  View details for Web of Science ID 000377930900002

  View details for PubMedID 27008101

  View details for PubMedCentralID PMC4882123

• Reply: Studies in Fat Grafting: Part V. Cell-Assisted Lipotransfer to Enhance Fat Graft Retention Is Dose Dependent PLASTIC AND RECONSTRUCTIVE SURGERY Zielins, E. R., Longaker, M. T., Wan, D. C. 2015; 136 (6): 850E–851E

  View details for PubMedID 26322809

• RNA Sequencing for Identification of Differentially Expressed Noncoding Transcripts during Adipogenic Differentiation of Adipose-Derived Stromal Cells. Plastic and reconstructive surgery Luan, A., Paik, K. J., Li, J., Zielins, E. R., Atashroo, D. A., Spencley, A., Momeni, A., Longaker, M. T., Wang, K. C., Wan, D. C. 2015; 136 (4): 752-763

  Abstract

  Adipose-derived stromal cells represent a relatively abundant source of multipotent cells, with many potential applications in regenerative medicine. The present study sought to demonstrate the use of RNA sequencing in identifying differentially expressed transcripts, particularly long noncoding RNAs, associated with adipogenic differentiation to gain a clearer picture of the mechanisms responsible for directing adipose-derived stromal cell fate toward the adipogenic lineage.Human adipose-derived stromal cells were cultured in adipogenic differentiation media, and RNA was harvested at days 0, 1, 3, 5, and 7. Directional RNA sequencing libraries were prepared and sequenced. Paired-end reads were mapped to the human genome reference sequence hg19. Transcriptome assembly was performed and significantly differentially expressed transcripts were identified. Gene ontology term analysis was then performed to identify coding and noncoding transcripts of interest. Differential expression was verified by quantitative real-time polymerase chain reaction.Of 2868 significantly differentially expressed transcripts identified, 207 were noncoding. Enriched gene ontology terms among up-regulated coding transcripts notably reflected differentiation toward the adipogenic lineage. Enriched gene ontology terms among down-regulated coding transcripts reflected growth arrest. Guilt-by-association analysis revealed noncoding RNA candidates with potential roles in the process of adipogenic differentiation.The precise mechanisms that guide lineage-specific differentiation in multipotent cells are not yet fully understood. Defining long noncoding RNAs associated with adipogenic differentiation allows for potential manipulation of regulatory pathways in novel ways. The authors present RNA sequencing as a powerful tool for expanding the understanding of adipose-derived stromal cells and developing novel applications within regenerative medicine.

  View details for DOI 10.1097/PRS.0000000000001582

  View details for PubMedID 26090763

• How "Low-Level" Evidence Has Changed Plastic Surgery: Time to Appreciate the Value of Case Reports and Case Series. Annals of plastic surgery Momeni, A., Wan, D. C. 2015; 75 (4): 361-363

  View details for DOI 10.1097/SAP.0000000000000596

  View details for PubMedID 26207557

• High-Throughput Screening of Surface Marker Expression on Undifferentiated and Differentiated Human Adipose-Derived Stromal Cells TISSUE ENGINEERING PART A Walmsley, G. G., Atashroo, D. A., Maan, Z. N., Hu, M. S., Zielins, E. R., Tsai, J. M., Duscher, D., Paik, K., Tevlin, R., Marecic, O., Wan, D. C., Gurtner, G. C., Longaker, M. T. 2015; 21 (15-16): 2281-2291

  Abstract

  Adipose tissue contains an abundant source of multipotent mesenchymal cells termed "adipose-derived stromal cells" (ASCs) that hold potential for regenerative medicine. However, the heterogeneity inherent to ASCs harvested using standard methodologies remains largely undefined, particularly in regards to differences across donors. Identifying the subpopulations of ASCs predisposed toward differentiation along distinct lineages holds value for improving graft survival, predictability, and efficiency. Human ASCs (hASCs) from three different donors were independently isolated by density-based centrifugation from adipose tissue and maintained in culture or differentiated along either adipogenic or osteogenic lineages using differentiation media. Undifferentiated and differentiated hASCs were then analyzed for the presence of 242 human surface markers by flow cytometry analysis. By comprehensively characterizing the surface marker profile of undifferentiated hASCs using flow cytometry, we gained novel insights into the heterogeneity underlying protein expression on the surface of cultured undifferentiated hASCs across different donors. Comparison of the surface marker profile of undifferentiated hASCs with hASCs that have undergone osteogenic or adipogenic differentiation allowed for the identification of surface markers that were upregulated and downregulated by osteogenic or adipogenic differentiation. Osteogenic differentiation induced upregulation of CD164 and downregulation of CD49a, CD49b, CD49c, CD49d, CD55, CD58, CD105, and CD166 while adipogenic differentiation induced upregulation of CD36, CD40, CD146, CD164, and CD271 and downregulation of CD49b, CD49c, CD49d, CD71, CD105, and CD166. These results lend support to the notion that hASCs isolated using standard methodologies represent a heterogeneous population and serve as a foundation for future studies seeking to maximize their regenerative potential through fluorescence-activated cell sorting-based selection before therapy.

  View details for DOI 10.1089/ten.tea.2015.0039

  View details for Web of Science ID 000359812700014

  View details for PubMedID 26020286

  View details for PubMedCentralID PMC4529076

• What Makes a Plastic Surgery Residency Program Attractive? An Applicant's Perspective PLASTIC AND RECONSTRUCTIVE SURGERY Atashroo, D. A., Luan, A., Vyas, K. S., Zielins, E. R., Maan, Z., Duscher, D., Walmsley, G. G., Lynch, M. P., Davenport, D. L., Wan, D. C., Longaker, M. T., Vasconez, H. C. 2015; 136 (1): 189-196

  Abstract

  Plastic surgery is among the most competitive specialties in medicine, but little is known about the attributes of programs that are most attractive to successful applicants. This study aimed to understand and provide insights regarding program characteristics that are most influential to students when ranking plastic surgery programs.An anonymous online survey was conducted with newly matched plastic surgery residents for the integrated and combined Match in 2012 and 2013. Subjects were queried regarding their demographics, qualifications, application experiences, and motivations for residency program selection.A total of 92 of 245 matched plastic surgery residents (38 percent) responded to the survey. The perception of resident happiness was the most positive factor influencing program ranking, followed by high operative volume, faculty mentorship, and strong research infrastructure. Perception of a program as "malignant" was the most negative attribute. Applicants with Step 1 scores greater than 245 received significantly more interviews (p =0.001) and considered resident benefits less important (p < 0.05), but geographic location more important (p =0.005). Applicants who published more than two articles also received more interviews (p =0.001) and ranked a strong research infrastructure and program reputation as significantly more important (p < 0.05). Forty-two percent of applicants completed an away rotation at the program with which they matched, and these applicants were more likely to match at their number one ranked program (p = 0.001).Plastic surgery applicants have differing preferences regarding the ideal training program, but some attributes resonate. These trends can guide programs for improvement in attracting the best applicants.

  View details for DOI 10.1097/PRS.0000000000001365

  View details for Web of Science ID 000357097900001

  View details for PubMedID 26111321

• Nanotechnology in bone tissue engineering NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE Walmsley, G. G., McArdle, A., Tevlin, R., Momeni, A., Atashroo, D., Hu, M. S., Feroze, A. H., Wong, V. W., Lorenz, P. H., Longaker, M. T., Wan, D. C. 2015; 11 (5): 1253-1263

  Abstract

  Nanotechnology represents a major frontier with potential to significantly advance the field of bone tissue engineering. Current limitations in regenerative strategies include impaired cellular proliferation and differentiation, insufficient mechanical strength of scaffolds, and inadequate production of extrinsic factors necessary for efficient osteogenesis. Here we review several major areas of research in nanotechnology with potential implications in bone regeneration: 1) nanoparticle-based methods for delivery of bioactive molecules, growth factors, and genetic material, 2) nanoparticle-mediated cell labeling and targeting, and 3) nano-based scaffold construction and modification to enhance physicochemical interactions, biocompatibility, mechanical stability, and cellular attachment/survival. As these technologies continue to evolve, ultimate translation to the clinical environment may allow for improved therapeutic outcomes in patients with large bone deficits and osteodegenerative diseases.Traditionally, the reconstruction of bony defects has relied on the use of bone grafts. With advances in nanotechnology, there has been significant development of synthetic biomaterials. In this article, the authors provided a comprehensive review on current research in nanoparticle-based therapies for bone tissue engineering, which should be useful reading for clinicians as well as researchers in this field.

  View details for DOI 10.1016/j.nano.2015.02.013

  View details for Web of Science ID 000363967100022

  View details for PubMedID 25791811

  View details for PubMedCentralID PMC4476906

• Studies in Fat Grafting: Part V. Cell-Assisted Lipotransfer to Enhance Fat Graft Retention Is Dose Dependent PLASTIC AND RECONSTRUCTIVE SURGERY Paik, K. J., Zielins, E. R., Atashroo, D. A., Maan, Z. N., Duscher, D., Luan, A., Walmsley, G. G., Momeni, A., Vistnes, S., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2015; 136 (1): 67-75

  Abstract

  Cell-assisted lipotransfer has shown much promise as a technique for improving fat graft take. However, the concentration of stromal vascular fraction cells required to optimally enhance fat graft retention remains unknown.Human lipoaspirate was processed for both fat transfer and harvest of stromal vascular fraction cells. Cells were then mixed back with fat at varying concentrations ranging from 10,000 to 10 million cells per 200 μl of fat. Fat graft volume retention was assessed by means of computed tomographic scanning over 8 weeks, and then fat grafts were explanted and compared histologically for overall architecture and vascularity.Maximum fat graft retention was seen at a concentration of 10,000 cells per 200 μl of fat. The addition of higher number of cells negatively impacted fat graft retention, with supplementation of 10 million cells producing the lowest final volumes, lower than fat alone. Interestingly, fat grafts supplemented with 10,000 cells showed significantly increased vascularity and decreased inflammation, whereas fat grafts supplemented with 10 million cells showed significant lipodegeneration compared with fat alone: The authors' study demonstrates dose dependence in the number of stromal vascular fraction cells that can be added to a fat graft to enhance retention. Although cell-assisted lipotransfer may help promote graft survival, this effect may need to be balanced with the increased metabolic load of added cells that may compete with adipocytes for nutrients during the postgraft period.

  View details for DOI 10.1097/PRS.0000000000001367

  View details for Web of Science ID 000357096300002

  View details for PubMedID 25829158

  View details for PubMedCentralID PMC4483157

• Emerging drugs for the treatment of wound healing EXPERT OPINION ON EMERGING DRUGS Zielins, E. R., Brett, E. A., Luan, A., Hu, M. S., Walmsley, G. G., Paik, K., Senarath-Yapa, K., Atashroo, D. A., Wearda, T., Lorenz, H. P., Wan, D. C., Longaker, M. T. 2015; 20 (2): 235-246

  Abstract

  Wound healing can be characterized as underhealing, as in the setting of chronic wounds, or overhealing, occurring with hypertrophic scar formation after burn injury. Topical therapies targeting specific biochemical and molecular pathways represent a promising avenue for improving and, in some cases normalizing, the healing process.A brief overview of both normal and pathological wound healing has been provided, along with a review of the current clinical guidelines and treatment modalities for chronic wounds, burn wounds and scar formation. Next, the major avenues for wound healing drugs, along with drugs currently in development, are discussed. Finally, potential challenges to further drug development, and future research directions are discussed.The large body of research concerning wound healing pathophysiology has provided multiple targets for topical therapies. Growth factor therapies with the ability to be targeted for localized release in the wound microenvironment are most promising, particularly when they modulate processes in the proliferative phase of wound healing.

  View details for DOI 10.1517/14728214.2015.1018176

  View details for Web of Science ID 000356118400007

  View details for PubMedID 25704608

• Studies in Fat Grafting: Part IV. Adipose-Derived Stromal Cell Gene Expression in Cell-Assisted Lipotransfer PLASTIC AND RECONSTRUCTIVE SURGERY Garza, R. M., Rennert, R. C., Paik, K. J., Atashroo, D., Chung, M. T., Duscher, D., Januszyk, M., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2015; 135 (4): 1045-1055

  Abstract

  Fat graft volume retention remains highly unpredictable, but addition of adipose-derived stromal cells to fat grafts has been shown to improve retention. The present study aimed to investigate the mechanisms involved in adipose-derived stromal cell enhancement of fat grafting.Adipose-derived stromal cells isolated from human lipoaspirate were labeled with green fluorescent protein and luciferase. Fat grafts enhanced with adipose-derived stromal cells were injected into the scalp and bioluminescent imaging was performed to follow retention of adipose-derived stromal cells within the fat graft. Fat grafts were also explanted at days 1, 5, and 10 after grafting for adipose-derived stromal cell extraction and single-cell gene analysis. Finally, CD31 immunohistochemical staining was performed on fat grafts enriched with adipose-derived stromal cells.Bioluminescent imaging demonstrated significant reduction in luciferase-positive adipose-derived stromal cells within fat grafts at 5 days after grafting. A similar reduction in viable green fluorescent protein-positive adipose-derived stromal cells retrieved from explanted grafts was also noted. Single-cell analysis revealed expression of multiple genes/markers related to cell survival and angiogenesis, including BMPR2, CD90, CD105, FGF2, CD248, TGFß1, and VEGFA. Genes involved in adipogenesis were not expressed by adipose-derived stromal cells. Finally, CD31 staining revealed significantly higher vascular density in fat grafts explanted at day 10 after grafting.Although adipose-derived stromal cell survival in the hypoxic graft environment decreases significantly over time, these cells provide multiple angiogenic growth factors. Therefore, improved fat graft volume retention with adipose-derived stromal cell enrichment may be attributable to improved graft vascularization.

  View details for DOI 10.1097/PRS.0000000000001104

  View details for Web of Science ID 000351910200043

  View details for PubMedID 25502860

  View details for PubMedCentralID PMC4376612

• Therapeutic applications of human adipose-derived stromal cells for soft tissue reconstruction. Discovery medicine Zielins, E. R., Luan, A., Brett, E. A., Longaker, M. T., Wan, D. C. 2015; 19 (105): 245-253

  Abstract

  Adipose derived stromal cells (ASCs) are a multipotent cell population derived from the stromal vascular fraction of lipoaspirate. Given their relatively broad differentiation potential and paracrine capabilities, ASCs represent a readily accessible, endogenous resource for novel reconstructive strategies. In particular, augmentation of autologous fat grafts with ASCs has already been employed clinically for restoration of soft tissue defects. While fat grafting alone remains highly unpredictable, enrichment of fat with supplemental ASCs, also known as cell-assisted lipotransfer (CAL), has been shown to significantly enhance volume retention. How addition of these cells to fat grafts results in improved outcomes, however, remains poorly understood. Furthermore, the safety of CAL in the setting of prior malignancy and post-radiation wound beds has yet to be fully determined, an important consideration for its use in cancer reconstruction. Thus, further studies to determine the how and why behind the efficacy of CAL are necessary before it can be widely adopted as a safe and reliable surgical technique.

  View details for PubMedID 25977187

• Therapeutic Applications of Human Adipose-Derived Stromal Cells for Soft Tissue Reconstruction DISCOVERY MEDICINE Zielins, E. R., Luan, A., Brett, E. A., Longaker, M. T., Wan, D. C. 2015; 105: 245-253

  Abstract

  Adipose derived stromal cells (ASCs) are a multipotent cell population derived from the stromal vascular fraction of lipoaspirate. Given their relatively broad differentiation potential and paracrine capabilities, ASCs represent a readily accessible, endogenous resource for novel reconstructive strategies. In particular, augmentation of autologous fat grafts with ASCs has already been employed clinically for restoration of soft tissue defects. While fat grafting alone remains highly unpredictable, enrichment of fat with supplemental ASCs, also known as cell-assisted lipotransfer (CAL), has been shown to significantly enhance volume retention. How addition of these cells to fat grafts results in improved outcomes, however, remains poorly understood. Furthermore, the safety of CAL in the setting of prior malignancy and post-radiation wound beds has yet to be fully determined, an important consideration for its use in cancer reconstruction. Thus, further studies to determine the how and why behind the efficacy of CAL are necessary before it can be widely adopted as a safe and reliable surgical technique.

  View details for Web of Science ID 000356922200001

• The role and regulation of osteoclasts in normal bone homeostasis and in response to injury. Plastic and reconstructive surgery McArdle, A., Marecic, O., Tevlin, R., Walmsley, G. G., Chan, C. K., Longaker, M. T., Wan, D. C. 2015; 135 (3): 808-816

  Abstract

  Bone is a dynamic tissue, with a range of diverse functions, including locomotion, protection of internal organs, and hematopoiesis. Optimum treatment of fractures and/or bone defects requires knowledge of the complex cellular interactions involved with bone healing and remodeling. Emerging data have underscored the importance of osteoclasts in this process, playing a key role both in normal bone turnover and in facilitating bone regeneration. In this review, the authors discuss the basic principles of osteoclast biology, including its cellular origins, its function, and key regulatory mechanisms, in addition to conditions that arise when osteoclast function is altered.

  View details for DOI 10.1097/PRS.0000000000000963

  View details for PubMedID 25719699

• Reply: Studies in fat grafting: part I. Effects of injection technique on in vitro fat viability and in vivo volume retention; and studies in fat grafting: part II. Effects of injection mechanics on material properties of fat. Plastic and reconstructive surgery Wan, D. C., Gurtner, G. C., Longaker, M. T. 2015; 135 (2): 448e-9e

  View details for DOI 10.1097/PRS.0000000000000978

  View details for PubMedID 25626833

• Isolation and Enrichment of Human Adipose-derived Stromal Cells for Enhanced Osteogenesis. Journal of visualized experiments : JoVE Zielins, E. R., Tevlin, R., Hu, M. S., Chung, M. T., McArdle, A., Paik, K. J., Atashroo, D., Duldulao, C. R., Luan, A., Senarath-Yapa, K., Walmsley, G. G., Wearda, T., Longaker, M. T., Wan, D. C. 2015

  View details for DOI 10.3791/52181

  View details for PubMedID 25650785

• Assessment of viability of human fat injection into nude mice with micro-computed tomography. Journal of visualized experiments : JoVE Atashroo, D. A., Paik, K. J., Chung, M. T., McArdle, A., Senarath-Yapa, K., Zielins, E. R., Tevlin, R., Duldulao, C. R., Walmsley, G. G., Wearda, T., Marecic, O., Longaker, M. T., Wan, D. C. 2015

  View details for DOI 10.3791/52217

  View details for PubMedID 25590561

• Impact of surgical innovation on tissue repair in the surgical patient. British journal of surgery Tevlin, R., Atashroo, D., Duscher, D., Mc Ardle, A., Gurtner, G. C., Wan, D. C., Longaker, M. T. 2015; 102 (2): e41-55

  View details for DOI 10.1002/bjs.9672

  View details for PubMedID 25627135

• Impact of surgical innovation on tissue repair in the surgical patient. British journal of surgery Tevlin, R., Atashroo, D., Duscher, D., Mc Ardle, A., Gurtner, G. C., Wan, D. C., Longaker, M. T. 2015; 102 (2): e41-55

  Abstract

  Throughout history, surgeons have been prolific innovators, which is hardly surprising as most surgeons innovate daily, tailoring their intervention to the intrinsic uniqueness of each operation, each patient and each disease. Innovation can be defined as the application of better solutions that meet new requirements, unarticulated needs or existing market needs. In the past two decades, surgical innovation has significantly improved patient outcomes, complication rates and length of hospital stay. There is one key area that has great potential to change the face of surgical practice and which is still in its infancy: the realm of regenerative medicine and tissue engineering.A literature review was performed using PubMed; peer-reviewed publications were screened for relevance in order to identify key surgical innovations influencing regenerative medicine, with a focus on osseous, cutaneous and soft tissue reconstruction.This review describes recent advances in regenerative medicine, documenting key innovations in osseous, cutaneous and soft tissue regeneration that have brought regenerative medicine to the forefront of the surgical imagination.Surgical innovation in the emerging field of regenerative medicine has the ability to make a major impact on surgery on a daily basis.

  View details for DOI 10.1002/bjs.9672

  View details for PubMedID 25627135

• Isolation and enrichment of human adipose-derived stromal cells for enhanced osteogenesis. Journal of visualized experiments : JoVE Zielins, E. R., Tevlin, R., Hu, M. S., Chung, M. T., McArdle, A., Paik, K. J., Atashroo, D., Duldulao, C. R., Luan, A., Senarath-Yapa, K., Walmsley, G. G., Wearda, T., Longaker, M. T., Wan, D. C. 2015: 52181-?

  Abstract

  Bone marrow-derived mesenchymal stromal cells (BM-MSCs) are considered the gold standard for stem cell-based tissue engineering applications. However, the process by which they must be harvested can be associated with significant donor site morbidity. In contrast, adipose-derived stromal cells (ASCs) are more readily abundant and more easily harvested, making them an appealing alternative to BM-MSCs. Like BM-MSCs, ASCs can differentiate into osteogenic lineage cells and can be used in tissue engineering applications, such as seeding onto scaffolds for use in craniofacial skeletal defects. ASCs are obtained from the stromal vascular fraction (SVF) of digested adipose tissue, which is a heterogeneous mixture of ASCs, vascular endothelial and mural cells, smooth muscle cells, pericytes, fibroblasts, and circulating cells. Flow cytometric analysis has shown that the surface marker profile for ASCs is similar to that for BM-MSCs. Despite several published reports establishing markers for the ASC phenotype, there is still a lack of consensus over profiles identifying osteoprogenitor cells in this heterogeneous population. This protocol describes how to isolate and use a subpopulation of ASCs with enhanced osteogenic capacity to repair critical-sized calvarial defects.

  View details for DOI 10.3791/52181

  View details for PubMedID 25650785

• Assessment of viability of human fat injection into nude mice with micro-computed tomography. Journal of visualized experiments : JoVE Atashroo, D. A., Paik, K. J., Chung, M. T., McArdle, A., Senarath-Yapa, K., Zielins, E. R., Tevlin, R., Duldulao, C. R., Walmsley, G. G., Wearda, T., Marecic, O., Longaker, M. T., Wan, D. C. 2015

  Abstract

  Lipotransfer is a vital tool in the surgeon's armamentarium for the treatment of soft tissue deficits of throughout the body. Fat is the ideal soft tissue filler as it is readily available, easily obtained, inexpensive, and inherently biocompatible.(1) However, despite its burgeoning popularity, fat grafting is hampered by unpredictable results and variable graft survival, with published retention rates ranging anywhere from 10-80%. (1-3) To facilitate investigations on fat grafting, we have therefore developed an animal model that allows for real-time analysis of injected fat volume retention. Briefly, a small cut is made in the scalp of a CD-1 nude mouse and 200-400 µl of processed lipoaspirate is placed over the skull. The scalp is chosen as the recipient site because of its absence of native subcutaneous fat, and because of the excellent background contrast provided by the calvarium, which aids in the analysis process. Micro-computed tomography (micro-CT) is used to scan the graft at baseline and every two weeks thereafter. The CT images are reconstructed, and an imaging software is used to quantify graft volumes. Traditionally, techniques to assess fat graft volume have necessitated euthanizing the study animal to provide just a single assessment of graft weight and volume by physical measurement ex vivo. Biochemical and histological comparisons have likewise required the study animal to be euthanized. This described imaging technique offers the advantage of visualizing and objectively quantifying volume at multiple time points after initial grafting without having to sacrifice the study animal. The technique is limited by the size of the graft able to be injected as larger grafts risk skin and fat necrosis. This method has utility for all studies evaluating fat graft viability and volume retention. It is particularly well-suited to providing a visual representation of fat grafts and following changes in volume over time.

  View details for DOI 10.3791/52217

  View details for PubMedID 25590561

• Biomaterials for Craniofacial Bone Engineering JOURNAL OF DENTAL RESEARCH Tevlin, R., Mcardle, A., Atashroo, D., Walmsley, G. G., Senarath-Yapa, K., Zielins, E. R., Paik, K. J., Longaker, M. T., Wan, D. C. 2014; 93 (12): 1187-1195

  View details for DOI 10.1177/0022034514547271

  View details for Web of Science ID 000345340400002

• Positive Selection for Bone Morphogenetic Protein Receptor Type-IB Promotes Differentiation and Specification of Human Adipose-Derived Stromal Cells Toward an Osteogenic Lineage TISSUE ENGINEERING PART A McArdle, A., Chung, M. T., Paik, K. J., Duldulao, C., Chan, C., Rennert, R., Walmsley, G. G., Senarath-Yapa, K., Hu, M., Seo, E., Lee, M., Wan, D. C., Longaker, M. T. 2014; 20 (21-22): 3031-3040

  Abstract

  Adipose tissue represents an abundant and easily accessible source of multipotent cells that may serve as an excellent building block for tissue engineering. However, adipose-derived stromal cells (ASCs) are a heterogeneous group and subpopulations may be identified with enhanced osteogenic potential.Human ASC subpopulations were prospectively isolated based on expression of bone morphogenetic protein receptor type-IB (BMPR-IB). Unsorted, BMPR-IB(+), and BMPR-IB(-) cells were analyzed for their osteogenic capacity through histological staining and gene expression. To evaluate their in vivo osteogenic potential, critical-sized calvarial defects were created in immunocompromised mice and treated with unsorted, BMPR-IB(+), or BMPR-IB(-) cells. Healing was assessed using microcomputed tomography and pentachrome staining of specimens at 8 weeks.Increased osteogenic differentiation was noted in the BMPR-IB(+) subpopulation, as demonstrated by alkaline phosphatase staining at day 7 and extracellular matrix mineralization with Alizarin red staining at day 14. This was also associated with increased expression for osteocalcin, a late marker of osteogenesis. Radiographic analysis demonstrated significantly enhanced healing of critical-sized calvarial defects treated with BMPR-IB(+) ASCs compared with unsorted or BMPR-IB(-) cells. This was confirmed through pentachrome staining, which revealed more robust bone regeneration in the BMPR-IB(+) group.BMPR-IB(+) human ASCs have an enhanced ability to form bone both in vitro and in vivo. These data suggest that positive selection for BMPR-IB(+) and manipulation of the BMP pathway in these cells may yield a highly osteogenic subpopulation of cells for bone tissue engineering.

  View details for DOI 10.1089/ten.tea.2014.0101

  View details for Web of Science ID 000344592600021

  View details for PubMedCentralID PMC4229710

• Positive selection for bone morphogenetic protein receptor type-IB promotes differentiation and specification of human adipose-derived stromal cells toward an osteogenic lineage. Tissue engineering. Part A McArdle, A., Chung, M. T., Paik, K. J., Duldulao, C., Chan, C., Rennert, R., Walmsley, G. G., Senarath-Yapa, K., Hu, M., Seo, E., Lee, M., Wan, D. C., Longaker, M. T. 2014; 20 (21-22): 3031-3040

  Abstract

  Adipose tissue represents an abundant and easily accessible source of multipotent cells that may serve as an excellent building block for tissue engineering. However, adipose-derived stromal cells (ASCs) are a heterogeneous group and subpopulations may be identified with enhanced osteogenic potential.Human ASC subpopulations were prospectively isolated based on expression of bone morphogenetic protein receptor type-IB (BMPR-IB). Unsorted, BMPR-IB(+), and BMPR-IB(-) cells were analyzed for their osteogenic capacity through histological staining and gene expression. To evaluate their in vivo osteogenic potential, critical-sized calvarial defects were created in immunocompromised mice and treated with unsorted, BMPR-IB(+), or BMPR-IB(-) cells. Healing was assessed using microcomputed tomography and pentachrome staining of specimens at 8 weeks.Increased osteogenic differentiation was noted in the BMPR-IB(+) subpopulation, as demonstrated by alkaline phosphatase staining at day 7 and extracellular matrix mineralization with Alizarin red staining at day 14. This was also associated with increased expression for osteocalcin, a late marker of osteogenesis. Radiographic analysis demonstrated significantly enhanced healing of critical-sized calvarial defects treated with BMPR-IB(+) ASCs compared with unsorted or BMPR-IB(-) cells. This was confirmed through pentachrome staining, which revealed more robust bone regeneration in the BMPR-IB(+) group.BMPR-IB(+) human ASCs have an enhanced ability to form bone both in vitro and in vivo. These data suggest that positive selection for BMPR-IB(+) and manipulation of the BMP pathway in these cells may yield a highly osteogenic subpopulation of cells for bone tissue engineering.

  View details for DOI 10.1089/ten.TEA.2014.0101

  View details for PubMedID 24854876

• Adipose derived stromal cells obtained by ultrasound assisted liposuction versus suction assisted liposuction: a comparison of their regenerative capacity. Plastic and reconstructive surgery Atashroo, D., Duscher, D., Maan, Z. N., Zielins, E. R., Paik, K., Whittam, A., Lin, M., McArdle, A., Duldulao, C., Walmsley, G. G., Hu, M. S., Tevlin, R., Wan, D. C., Gurtner, G. C., Longaker, M. T. 2014; 134 (4): 56-57

  View details for DOI 10.1097/01.prs.0000455397.91552.50

  View details for PubMedID 25254755

• The role of stem cells in aesthetic surgery: fact or fiction? Plastic and reconstructive surgery McArdle, A., Senarath-Yapa, K., Walmsley, G. G., Hu, M., Atashroo, D. A., Tevlin, R., Zielins, E., Gurtner, G. C., Wan, D. C., Longaker, M. T. 2014; 134 (2): 193-200

  Abstract

  Stem cells are attractive candidates for the development of novel therapies, targeting indications that involve functional restoration of defective tissue. Although most stem cell therapies are new and highly experimental, there are clinics around the world that exploit vulnerable patients with the hope of offering supposed stem cell therapies, many of which operate without credible scientific merit, oversight, or other patient protection.We review the potential, as well as drawbacks, for incorporation of stem cells in cosmetic procedures. A review of FDA-approved indications and ongoing clinical trials with adipose stem cells is provided. Furthermore, a "snapshot" analysis of websites using the search terms "stem cell therapy" or "stem cell treatment" or "stem cell facelift" was performed.Despite the protective net cast by regulatory agencies such as the FDA and professional societies such as the American Society of Plastic Surgeons, we are witnessing worrying advertisements for procedures such as stem cell facelifts, stem cell breast augmentations, and even stem cell vaginal rejuvenation. The marketing and promotion of stem cell procedures in aesthetic surgery is not adequately supported by clinical evidence in the majority of cases.Stem cells offer tremendous potential, but the marketplace is saturated with unsubstantiated and sometimes fraudulent claims that may place patients at risk. With plastic surgeons at the forefront of stem cell-based regenerative medicine, it is critically important that we provide an example of a rigorous approach to research, data collection, and advertising of stem cell therapies.

  View details for DOI 10.1097/PRS.0000000000000404

  View details for PubMedID 24732654

• Studies in Fat Grafting: Part III. Fat Grafting Irradiated Tissue-Improved Skin Quality and Decreased Fat Graft Retention. Plastic and reconstructive surgery Garza, R. M., Paik, K. J., Chung, M. T., Duscher, D., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2014; 134 (2): 249-257

  Abstract

  Following radiation therapy, skin becomes fibrotic and can present a difficult problem for reconstructive surgeons. There is an increasing belief that fat grafting under irradiated skin can reverse the damage caused by radiation. The present study evaluated the effect of fat grafting on irradiated skin, along with fat graft quality and retention rates in irradiated tissue.Nine adult Crl:NU-Foxn1 CD-1 mice underwent 30-Gy external beam irradiation of the scalp. Four weeks after irradiation, scalp skin from irradiated and nonirradiated mice was harvested and compared histologically for dermal thickness, collagen content, and vascular density. Human fat grafts were then injected in the subcutaneous plane of the scalp. Skin assessment was performed in the irradiated group at 2 and 8 weeks after grafting, and fat graft retention was measured at baseline and every 2 weeks up to 8 weeks after grafting using micro-computed tomography. Finally, fat graft samples were explanted at 8 weeks, and quality scoring was performed.Fat grafting resulted in decreased dermal thickness, decreased collagen content, and increased vascular density in irradiated skin. Computed tomographic analysis revealed significantly decreased fat graft survival in the irradiated group compared with the nonirradiated group. Histologic scoring of explanted fat grafts demonstrated no difference in quality between the irradiated and nonirradiated groups.Fat grafting attenuates dermal collagen deposition and vessel depletion characteristic of radiation fibrosis. Although fat graft retention rates are significantly lower in irradiated than in nonirradiated tissue, the quality of retained fat between the groups is similar.

  View details for DOI 10.1097/PRS.0000000000000326

  View details for PubMedID 25068325

  View details for PubMedCentralID PMC4116637

• Studies in fat grafting: Part I. Effects of injection technique on in vitro fat viability and in vivo volume retention. Plastic and reconstructive surgery Chung, M. T., Paik, K. J., Atashroo, D. A., Hyun, J. S., McArdle, A., Senarath-Yapa, K., Zielins, E. R., Tevlin, R., Duldulao, C., Hu, M. S., Walmsley, G. G., Parisi-Amon, A., Momeni, A., Rimsa, J. R., Commons, G. W., Gurtner, G. C., Wan, D. C., Longaker, M. T. 2014; 134 (1): 29-38

  Abstract

  Fat grafting has become increasingly popular for the correction of soft tissue deficits at many sites throughout the body. Long-term outcomes, however, depend on delivery of fat in the least traumatic fashion to optimize viability of the transplanted tissue. In this study, we compare the biologic properties of fat following injection using two methods.Lipoaspiration samples were obtained from five female donors and cellular viability, proliferation, and lipolysis were evaluated following injection using either a modified Coleman technique or an automated, low shear device. Comparisons were made to minimally processed, uninjected fat. Volume retention was also measured over twelve weeks following injection of fat under the scalp of immunodeficient mice using either the modified Coleman technique or the Adipose Tissue Injector. Finally, fat grafts were analyzed histologically.Fat viability and cellular proliferation were both significantly greater with the Adipose Tissue Injector relative to injection with the modified Coleman technique. In contrast, significantly less lipolysis was noted using the automated device. In vivo fat volume retention was significantly greater than with the modified Coleman technique at 4, 6, 8, and 12 week time points. This corresponded with significantly greater histological scores for healthy fat and lower scores for injury following injection with the device.Biological properties of injected tissues reflect how disruptive and harmful techniques for placement of fat may be, and our in vitro and in vivo data both support the use of the automated, low shear devices compared to the modified Coleman technique.

  View details for DOI 10.1097/PRS.0000000000000290

  View details for PubMedID 24622574

• Studies in fat grafting: Part II. Effects of injection mechanics on material properties of fat. Plastic and reconstructive surgery Atashroo, D., Raphel, J., Chung, M. T., Paik, K. J., Parisi-Amon, A., McArdle, A., Senarath-Yapa, K., Zielins, E. R., Tevlin, R., Duldulao, C., Walmsley, G. G., Hu, M. S., Momeni, A., Domecus, B., Rimsa, J. R., Greenberg, L., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2014; 134 (1): 39-46

  Abstract

  Although fat grafting can address many soft-tissue deficits, results remain inconsistent. In this study, the authors compared physical properties of fat following injection using an automated, low-shear device or the modified Coleman technique.Lipoaspirate was obtained from nine patients and processed for injection using either a modified Coleman technique or an automated, low-shear device. Fat was passed through a 2-mm cannula and compared with minimally processed fat. A rheometer was used to measure the storage modulus and shear rate at which tissues began to lose their solid-like properties. Viscosity was also measured, and gross properties of treatment groups were evaluated qualitatively with a glass slide test.Fat injected through an automated, low-shear device closely matched physical properties of minimally processed fat. The storage modulus (G') of fat for the device group was greater than for the modified Coleman group, and the onset of breakdown was delayed. Similarly, viscosity measurement of fat from the automated device closely matched minimally processed fat and was greater than that of othe modified Coleman group.The physical properties of lipoaspirate processed using an automated, low-shear device with a 2-mm cannula preserved the intactness of fat more than the modified Coleman technique. The authors' rheologic data demonstrate less damage using an automated device compared with the modified Coleman technique and potentially support its use for improved fat graft integrity.

  View details for DOI 10.1097/PRS.0000000000000289

  View details for PubMedID 25028817

• Studies in Fat Grafting: Part I. Effects of Injection Technique on In Vitro Fat Viability and In Vivo Volume Retention PLASTIC AND RECONSTRUCTIVE SURGERY Chung, M. T., Paik, K. J., Atashroo, D. A., Hyun, J. S., McArdle, A., Senarath-Yapa, K., Zielins, E. R., Tevlin, R., Duldulao, C., Hu, M. S., Walmsley, G. G., Parisi-Amon, A., Momeni, A., Rimsa, J. R., Commons, G. W., Gurtner, G. C., Wan, D. C., Longaker, M. T. 2014; 134 (1): 29-38

  Abstract

  Fat grafting has become increasingly popular for the correction of soft tissue deficits at many sites throughout the body. Long-term outcomes, however, depend on delivery of fat in the least traumatic fashion to optimize viability of the transplanted tissue. In this study, we compare the biologic properties of fat following injection using two methods.Lipoaspiration samples were obtained from five female donors and cellular viability, proliferation, and lipolysis were evaluated following injection using either a modified Coleman technique or an automated, low shear device. Comparisons were made to minimally processed, uninjected fat. Volume retention was also measured over twelve weeks following injection of fat under the scalp of immunodeficient mice using either the modified Coleman technique or the Adipose Tissue Injector. Finally, fat grafts were analyzed histologically.Fat viability and cellular proliferation were both significantly greater with the Adipose Tissue Injector relative to injection with the modified Coleman technique. In contrast, significantly less lipolysis was noted using the automated device. In vivo fat volume retention was significantly greater than with the modified Coleman technique at 4, 6, 8, and 12 week time points. This corresponded with significantly greater histological scores for healthy fat and lower scores for injury following injection with the device.Biological properties of injected tissues reflect how disruptive and harmful techniques for placement of fat may be, and our in vitro and in vivo data both support the use of the automated, low shear devices compared to the modified Coleman technique.

  View details for DOI 10.1097/PRS.0000000000000290

  View details for Web of Science ID 000338116400042

• Studies in Fat Grafting: Part II. Effects of Injection Mechanics on Material Properties of Fat PLASTIC AND RECONSTRUCTIVE SURGERY Atashroo, D., Raphel, J., Chung, M. T., Paik, K. J., Parisi-Amon, A., McArdle, A., Senarath-Yapa, K., Zielins, E. R., Tevlin, R., Duldulao, C., Walmsley, G. G., Hu, M. S., Momeni, A., Domecus, B., Rimsa, J. R., Greenberg, L., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2014; 134 (1): 39-46

  Abstract

  Although fat grafting can address many soft-tissue deficits, results remain inconsistent. In this study, the authors compared physical properties of fat following injection using an automated, low-shear device or the modified Coleman technique.Lipoaspirate was obtained from nine patients and processed for injection using either a modified Coleman technique or an automated, low-shear device. Fat was passed through a 2-mm cannula and compared with minimally processed fat. A rheometer was used to measure the storage modulus and shear rate at which tissues began to lose their solid-like properties. Viscosity was also measured, and gross properties of treatment groups were evaluated qualitatively with a glass slide test.Fat injected through an automated, low-shear device closely matched physical properties of minimally processed fat. The storage modulus (G') of fat for the device group was greater than for the modified Coleman group, and the onset of breakdown was delayed. Similarly, viscosity measurement of fat from the automated device closely matched minimally processed fat and was greater than that of othe modified Coleman group.The physical properties of lipoaspirate processed using an automated, low-shear device with a 2-mm cannula preserved the intactness of fat more than the modified Coleman technique. The authors' rheologic data demonstrate less damage using an automated device compared with the modified Coleman technique and potentially support its use for improved fat graft integrity.

  View details for DOI 10.1097/PRS.0000000000000289

  View details for Web of Science ID 000338116400043

  View details for PubMedCentralID PMC4101917

• Fat or fiction: origins matter. Cell metabolism Wan, D. C., Longaker, M. T. 2014; 19 (6): 900-901

  Abstract

  Cell-lineage tracing has revealed a complex heterogeneity present in postnatal tissue and adult progenitors. Chau et al. (2014) and Long et al. (2014) provide further evidence for this among adipocytes, and their findings underscore the importance of cellular ontogeny not just for development but also for potential treatment of disease.

  View details for DOI 10.1016/j.cmet.2014.05.007

  View details for PubMedID 24896537

• Moisturizing different racial skin types. The Journal of clinical and aesthetic dermatology Wan, D. C., Wong, V. W., Longaker, M. T., Yang, G. P., Wei, F. 2014; 7 (6): 25-32

  Abstract

  The skin is a complex organ involved in thermoregulation, gas exchange, protection against pathogens, and barrier function to maintain proper hydration. When dry, the ability for skin to execute these tasks becomes impaired. Dry skin affects almost everyone as we age, but it is also dependent on external factors, such as dry climate, colder temperatures, and repeated washing. In addition, increasing evidence has shown racial variability in the physiological properties of skin, which directly impacts water content of the stratum corneum and sensitivity to exogenously applied agents. A multitude of products have been developed to treat dry skin, and as a group, moisturizers have been designed to either impart or restore hydration in the stratum corneum. Given the large number of moisturizers presently available, depending on individual components, several different mechanisms may be employed to promote skin hydration. As there exists dramatic racial variability in skin properties, certain moisturizers may thus be more effective in some and less effective in others to treat the common condition of dry skin.

  View details for PubMedID 25013536

• Long noncoding RNA: significance and potential in skin biology. Cold Spring Harbor perspectives in medicine Wan, D. C., Wang, K. C. 2014; 4 (5)

  Abstract

  Over the past few years, advances in genome analyses have identified an emerging class of noncoding RNAs that play critical roles in the regulation of gene expression and epigenetic reprogramming. Given their transcriptional pervasiveness, the potential for these intriguing macromolecules to integrate a myriad of external cellular cues with nuclear responses has become increasingly apparent. Recent studies have implicated noncoding RNAs in epidermal development and keratinocyte differentiation, but the complexity of multilevel regulation of transcriptional programs involved in these processes remains ill defined. In this review, we discuss the relevance of noncoding RNA in normal skin development, their involvement in cutaneous malignancies, and their role in the regulation of adult stem-cell maintenance in stratified epithelial tissues. Furthermore, we provide additional examples highlighting the ubiquity of noncoding RNAs in diverse human diseases.

  View details for DOI 10.1101/cshperspect.a015404

  View details for PubMedID 24789873

• Induced pluripotent stem cells in regenerative medicine and disease modeling. Current stem cell research & therapy Walmsley, G. G., Hyun, J., McArdle, A., Senarath-Yapa, K., Hu, M. S., Chung, M. T., Wong, V. W., Longaker, M. T., Wan, D. C. 2014; 9 (2): 73-81

  Abstract

  In 2006, Dr. Yamanaka created the induced pluripotent stem cell (iPSC) by reprogramming adult fibroblasts back to an immature, pluripotent state. Effectively bypassing the ethical constraints of human embryonic stem cells, iPSCs have expanded the horizons of regenerative medicine by offering a means to derive autologous patient-matched cells and tissues for clinical transplantation. However, persisting safety concerns must be addressed prior to their widespread clinical application. In this review, we discuss the history of iPSCs, derivation strategies, and current research involving gene therapy and disease modeling. We review the potential of iPSCs for improving a range of cell-based therapies and obstacles to their clinical implementation.

  View details for PubMedID 24359141

• Abstract 165: Enhanced Adipose-Derived Stromal Cell Osteogenesis through Surface Marker Enrichment and BMP Modulation using Magnet-assisted Transfection. Plastic and reconstructive surgery Chung, M. T., Morrison, S. D., Paik, K. J., McArdle, A., Walmsley, G., Senarath-Yapa, K., Hu, M. S., Tevlin, R., Zielins, E., Atashroo, D., Hong, W. X., Duldulao, C., Wearda, T., Garza, R. M., Momeni, A., Longaker, M. T., Wan, D. C. 2014; 133 (3): 181-182

  View details for DOI 10.1097/01.prs.0000444994.28797.34

  View details for PubMedID 25942275

• Abstract 151: short hairpin RNA interference therapy for diabetic murine wound closure and hindlimb ischemia. Plastic and reconstructive surgery Paik, K. J., Rennert, R., Chung, M. T., Sorkin, M., Duscher, D., Atashroo, D., Chen, H., Morrison, S. D., Zimmermann, A., Nauta, A., Ko, S., Tevlin, R., Zielins, E., Hu, M. S., McArdle, A., Walmsley, G., Senarath-Yapa, K., Hong, W. X., Garza, R. M., Duldulao, C., Wearda, T., Momeni, A., Wu, J. C., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2014; 133 (3): 167-168

  View details for DOI 10.1097/01.prs.0000444979.14443.08

  View details for PubMedID 25942261

• Abstract 158: Identification of BMP-Responsive Long Noncoding RNAs in Pluripotent Cells. Plastic and reconstructive surgery Paik, K. J., Qu, K., Hsueh, B., Torre, E. A., Flynn, R. A., Chung, M. T., Spencley, A., Wang, K. C., Wu, J. C., Longaker, M. T., Chang, H. Y., Wan, D. C. 2014; 133 (3): 174-?

  View details for DOI 10.1097/01.prs.0000444987.90678.b2

  View details for PubMedID 25942268

• Osteoclast derivation from mouse bone marrow. Journal of visualized experiments : JoVE Tevlin, R., McArdle, A., Chan, C. K., Pluvinage, J., Walmsley, G. G., Wearda, T., Marecic, O., Hu, M. S., Paik, K. J., Senarath-Yapa, K., Atashroo, D. A., Zielins, E. R., Wan, D. C., Weissman, I. L., Longaker, M. T. 2014

  Abstract

  Osteoclasts are highly specialized cells that are derived from the monocyte/macrophage lineage of the bone marrow. Their unique ability to resorb both the organic and inorganic matrices of bone means that they play a key role in regulating skeletal remodeling. Together, osteoblasts and osteoclasts are responsible for the dynamic coupling process that involves both bone resorption and bone formation acting together to maintain the normal skeleton during health and disease. As the principal bone-resorbing cell in the body, changes in osteoclast differentiation or function can result in profound effects in the body. Diseases associated with altered osteoclast function can range in severity from lethal neonatal disease due to failure to form a marrow space for hematopoiesis, to more commonly observed pathologies such as osteoporosis, in which excessive osteoclastic bone resorption predisposes to fracture formation. An ability to isolate osteoclasts in high numbers in vitro has allowed for significant advances in the understanding of the bone remodeling cycle and has paved the way for the discovery of novel therapeutic strategies that combat these diseases. Here, we describe a protocol to isolate and cultivate osteoclasts from mouse bone marrow that will yield large numbers of osteoclasts.

  View details for DOI 10.3791/52056

  View details for PubMedID 25407120

• Long Noncoding RNA: Significance and Potential in Skin Biology. Cold Spring Harbor perspectives in medicine Wan, D. C., Wang, K. C. 2014; 4 (5)

  View details for DOI 10.1101/cshperspect.a015404

  View details for PubMedID 24789873

• Osteoclast derivation from mouse bone marrow. Journal of visualized experiments : JoVE Tevlin, R., McArdle, A., Chan, C. K., Pluvinage, J., Walmsley, G. G., Wearda, T., Marecic, O., Hu, M. S., Paik, K. J., Senarath-Yapa, K., Atashroo, D. A., Zielins, E. R., Wan, D. C., Weissman, I. L., Longaker, M. T. 2014

  View details for DOI 10.3791/52056

  View details for PubMedID 25407120

• Aesthetic Surgery Training during Residency in the United States: A Comparison of the Integrated, Combined, and Independent Training Models. Plastic surgery international Momeni, A., Kim, R. Y., Wan, D. C., Izadpanah, A., Lee, G. K. 2014; 2014: 281923-?

  Abstract

  Background. Three educational models for plastic surgery training exist in the United States, the integrated, combined, and independent model. The present study is a comparative analysis of aesthetic surgery training, to assess whether one model is particularly suitable to provide for high-quality training in aesthetic surgery. Methods. An 18-item online survey was developed to assess residents' perceptions regarding the quality of training in aesthetic surgery in the US. The survey had three distinct sections: demographic information, current state of aesthetic surgery training, and residents' perception regarding the quality of aesthetic surgery training. Results. A total of 86 senior plastic surgery residents completed the survey. Twenty-three, 24, and 39 residents were in integrated, combined, and independent residency programs, respectively. No statistically significant differences were seen with respect to number of aesthetic surgery procedures performed, additional training received in minimal-invasive cosmetic procedures, median level of confidence with index cosmetic surgery procedures, or perceived quality of aesthetic surgery training. Facial aesthetic procedures were felt to be the most challenging procedures. Exposure to minimally invasive aesthetic procedures was limited. Conclusion. While the educational experience in aesthetic surgery appears to be similar, weaknesses still exist with respect to training in minimally invasive/nonsurgical aesthetic procedures.

  View details for DOI 10.1155/2014/281923

  View details for PubMedID 25225615

• Isolation of human adipose-derived stromal cells using laser-assisted liposuction and their therapeutic potential in regenerative medicine. Stem cells translational medicine Chung, M. T., Zimmermann, A. S., Paik, K. J., Morrison, S. D., Hyun, J. S., Lo, D. D., McArdle, A., Montoro, D. T., Walmsley, G. G., Senarath-Yapa, K., Sorkin, M., Rennert, R., Chen, H., Chung, A. S., Vistnes, D., Gurtner, G. C., Longaker, M. T., Wan, D. C. 2013; 2 (10): 808-817

  Abstract

  Harvesting adipose-derived stromal cells (ASCs) for tissue engineering is frequently done through liposuction. However, several different techniques exist. Although third-generation ultrasound-assisted liposuction has been shown to not have a negative effect on ASCs, the impact of laser-assisted liposuction on the quality and differentiation potential of ASCs has not been studied. Therefore, ASCs were harvested from laser-assisted lipoaspirate and suction-assisted lipoaspirate. Next, in vitro parameters of cell yield, cell viability and proliferation, surface marker phenotype, osteogenic differentiation, and adipogenic differentiation were performed. Finally, in vivo bone formation was assessed using a critical-sized cranial defect in athymic nude mice. Although ASCs isolated from suction-assisted lipoaspirate and laser-assisted lipoaspirate both successfully underwent osteogenic and adipogenic differentiation, the cell yield, viability, proliferation, and frequency of ASCs (CD34(+)CD31(-)CD45(-)) in the stromal vascular fraction were all significantly less with laser-assisted liposuction in vitro (p < .05). In vivo, quantification of osseous healing by micro-computed tomography revealed significantly more healing with ASCs isolated from suction-assisted lipoaspirate relative to laser-assisted lipoaspirate at the 4-, 6-, and 8-week time points (p < .05). Therefore, as laser-assisted liposuction appears to negatively impact the biology of ASCs, cell harvest using suction-assisted liposuction is preferable for tissue-engineering purposes.

  View details for DOI 10.5966/sctm.2012-0183

  View details for PubMedID 24018794

  View details for PubMedCentralID PMC3785265

• Enhancing stem cell survival in vivo for tissue repair BIOTECHNOLOGY ADVANCES Hyun, J. S., Tran, M. C., Wong, V. W., Chung, M. T., Lo, D. D., Montoro, D. T., Wan, D. C., Longaker, M. T. 2013; 31 (5): 736-743

  Abstract

  The ability to use progenitor cells for regenerative medicine remains an evolving but elusive clinical goal. A serious obstacle towards widespread use of stem cells for tissue regeneration is the challenges that face these cells when they are placed in vivo into a wound for therapy. These environments are hypoxic, acidic, and have an upregulation of inflammatory mediators creating a region that is hostile towards cellular survival. Within this environment, the majority of progenitor cells undergo apoptosis prior to participating in lineage differentiation and cellular integration. In order to maximize the clinical utility of stem cells, strategies must be employed to increase the cell's ability to survive in vivo through manipulation of both the stem cell and the surrounding environment. This review focuses on current advances and techniques being used to increase in vivo stem cell survival for the purpose of tissue regeneration.

  View details for DOI 10.1016/j.biotechadv.2012.11.003

  View details for Web of Science ID 000322058900019

  View details for PubMedID 23153460

• Molecular analysis and differentiation capacity of adipose-derived stem cells from lymphedema tissue. Plastic and reconstructive surgery Levi, B., Glotzbach, J. P., Sorkin, M., Hyun, J., Januszyk, M., Wan, D. C., Li, S., Nelson, E. R., Longaker, M. T., Gurtner, G. C. 2013; 132 (3): 580-589

  Abstract

  Many breast cancer patients are plagued by the disabling complication of upper limb lymphedema after axillary surgery. Conservative treatments using massage and compression therapy do not offer a lasting relief, as they fail to address the chronic transformation of edema into excess adipose tissue. Liposuction to address the adipose nature of the lymphedema has provided an opportunity for a detailed analysis of the stromal fraction of lymphedema-associated fat to clarify the molecular mechanisms for this adipogenic transformation.Adipose-derived stem cells were harvested from human lipoaspirate of the upper extremity from age-matched patients with lymphedema (n = 3) or subcutaneous adipose tissue from control patients undergoing cosmetic procedures (n = 3). Immediately after harvest, adipose-derived stem cells were analyzed using single-cell transcriptional profiling techniques. Osteogenic, adipogenic, and vasculogenic gene expression and differentiation were assessed by quantitative real-time polymerase chain reaction and standard in vitro differentiation assays.Differential transcriptional clusters of adipose-derived stem cells were found between lymphedema and subcutaneous fat. Interestingly, lymphedema-associated stem cells had a much higher adipogenic gene expression and enhanced ability to undergo adipogenic differentiation. Conversely, they had lower vasculogenic gene expression and diminished capability to form tubules in vitro, whereas the osteogenic differentiation capacity was not significantly altered.Adipose-derived stem cells from extremities affected by lymphedema appear to exhibit transcriptional profiles similar to those of abdominal adipose-derived stem cells; however, their adipogenic differentiation potential is strongly increased and their vasculogenic capacity is compromised. These results suggest that the underlying pathophysiology of lymphedema drives adipose-derived stem cells toward adipogenic differentiation.

  View details for DOI 10.1097/PRS.0b013e31829ace13

  View details for PubMedID 23985633

• Enhancing in vivo survival of adipose-derived stromal cells through bcl-2 overexpression using a minicircle vector. Stem cells translational medicine Hyun, J., Grova, M., Nejadnik, H., Lo, D., Morrison, S., Montoro, D., Chung, M., Zimmermann, A., Walmsley, G. G., Lee, M., Daldrup-Link, H., Wan, D. C., Longaker, M. T. 2013; 2 (9): 690-702

  Abstract

  Tissue regeneration using progenitor cell-based therapy has the potential to aid in the healing of a diverse range of pathologies, ranging from short-gut syndrome to spinal cord lesions. However, there are numerous hurdles to be overcome prior to the widespread application of these cells in the clinical setting. One of the primary barriers to effective stem cell therapy is the hostile environment that progenitor cells encounter in the clinical injury wound setting. In order to promote cellular survival, stem cell differentiation, and participation in tissue regeneration, relevant cells and delivery scaffolds must be paired with strategies to prevent cell death to ensure that these cells can survive to form de novo tissue. The Bcl-2 protein is a prosurvival member of a family of proteins that regulate the mitochondrial pathway of apoptosis. Using several strategies to overexpress the Bcl-2 protein, we demonstrated a decrease in the mediators of apoptosis in vitro and in vivo. This was shown through the use of two different clinical tissue repair models. Cells overexpressing Bcl-2 not only survived within the wound environment at a statistically significantly higher rate than control cells, but also increased tissue regeneration. Finally, we used a nonintegrating minicircle technology to achieve this in a potentially clinically applicable strategy for stem cell therapy.

  View details for DOI 10.5966/sctm.2013-0035

  View details for PubMedID 23934910

• Molecular analysis and differentiation capacity of adipose-derived stem cells from lymphedema tissue. Plastic and reconstructive surgery Levi, B., Glotzbach, J. P., Sorkin, M., Hyun, J., Januszyk, M., Wan, D. C., Li, S., Nelson, E. R., Longaker, M. T., Gurtner, G. C. 2013; 132 (3): 580-589

  Abstract

  Many breast cancer patients are plagued by the disabling complication of upper limb lymphedema after axillary surgery. Conservative treatments using massage and compression therapy do not offer a lasting relief, as they fail to address the chronic transformation of edema into excess adipose tissue. Liposuction to address the adipose nature of the lymphedema has provided an opportunity for a detailed analysis of the stromal fraction of lymphedema-associated fat to clarify the molecular mechanisms for this adipogenic transformation.Adipose-derived stem cells were harvested from human lipoaspirate of the upper extremity from age-matched patients with lymphedema (n = 3) or subcutaneous adipose tissue from control patients undergoing cosmetic procedures (n = 3). Immediately after harvest, adipose-derived stem cells were analyzed using single-cell transcriptional profiling techniques. Osteogenic, adipogenic, and vasculogenic gene expression and differentiation were assessed by quantitative real-time polymerase chain reaction and standard in vitro differentiation assays.Differential transcriptional clusters of adipose-derived stem cells were found between lymphedema and subcutaneous fat. Interestingly, lymphedema-associated stem cells had a much higher adipogenic gene expression and enhanced ability to undergo adipogenic differentiation. Conversely, they had lower vasculogenic gene expression and diminished capability to form tubules in vitro, whereas the osteogenic differentiation capacity was not significantly altered.Adipose-derived stem cells from extremities affected by lymphedema appear to exhibit transcriptional profiles similar to those of abdominal adipose-derived stem cells; however, their adipogenic differentiation potential is strongly increased and their vasculogenic capacity is compromised. These results suggest that the underlying pathophysiology of lymphedema drives adipose-derived stem cells toward adipogenic differentiation.

  View details for DOI 10.1097/PRS.0b013e31829ace13

  View details for PubMedID 23985633

• Clonal precursor of bone, cartilage, and hematopoietic niche stromal cells PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Chan, C. K., Lindau, P., Jiang, W., Chen, J. Y., Zhang, L. F., Chen, C., Seita, J., Sahoo, D., Kim, J., Lee, A., Park, S., Nag, D., Gong, Y., Kulkarni, S., Luppen, C. A., Theologis, A. A., Wan, D. C., DeBoer, A., Seo, E. Y., Vincent-Tompkins, J. D., Loh, K., Walmsley, G. G., Kraft, D. L., Wu, J. C., Longaker, M. T., Weissman, I. L. 2013; 110 (31): 12643-12648

  Abstract

  Organs are composites of tissue types with diverse developmental origins, and they rely on distinct stem and progenitor cells to meet physiological demands for cellular production and homeostasis. How diverse stem cell activity is coordinated within organs is not well understood. Here we describe a lineage-restricted, self-renewing common skeletal progenitor (bone, cartilage, stromal progenitor; BCSP) isolated from limb bones and bone marrow tissue of fetal, neonatal, and adult mice. The BCSP clonally produces chondrocytes (cartilage-forming) and osteogenic (bone-forming) cells and at least three subsets of stromal cells that exhibit differential expression of cell surface markers, including CD105 (or endoglin), Thy1 [or CD90 (cluster of differentiation 90)], and 6C3 [ENPEP glutamyl aminopeptidase (aminopeptidase A)]. These three stromal subsets exhibit differential capacities to support hematopoietic (blood-forming) stem and progenitor cells. Although the 6C3-expressing subset demonstrates functional stem cell niche activity by maintaining primitive hematopoietic stem cell (HSC) renewal in vitro, the other stromal populations promote HSC differentiation to more committed lines of hematopoiesis, such as the B-cell lineage. Gene expression analysis and microscopic studies further reveal a microenvironment in which CD105-, Thy1-, and 6C3-expressing marrow stroma collaborate to provide cytokine signaling to HSCs and more committed hematopoietic progenitors. As a result, within the context of bone as a blood-forming organ, the BCSP plays a critical role in supporting hematopoiesis through its generation of diverse osteogenic and hematopoietic-promoting stroma, including HSC supportive 6C3(+) niche cells.

  View details for DOI 10.1073/pnas.1310212110

  View details for PubMedID 23858471

• CD90 (Thy-1)-Positive Selection Enhances Osteogenic Capacity of Human Adipose-Derived Stromal Cells TISSUE ENGINEERING PART A Chung, M. T., Liu, C., Hyun, J. S., Lo, D. D., Montoro, D. T., Hasegawa, M., Li, S., Sorkin, M., Rennert, R., Keeney, M., Yang, F., Quarto, N., Longaker, M. T., Wan, D. C. 2013; 19 (7-8): 989-997

  Abstract

  Stem cell-based bone tissue engineering with adipose-derived stromal cells (ASCs) has shown great promise for revolutionizing treatment of large bone deficits. However, there is still a lack of consensus on cell surface markers identifying osteoprogenitors. Fluorescence-activated cell sorting has identified a subpopulation of CD105(low) cells with enhanced osteogenic differentiation. The purpose of the present study was to compare the ability of CD90 (Thy-1) to identify osteoprogenitors relative to CD(105).Unsorted cells, CD90(+), CD90(-), CD105(high), and CD105(low) cells were treated with an osteogenic differentiation medium. For evaluation of in vitro osteogenesis, alkaline phosphatase (ALP) staining and alizarin red staining were performed at 7 days and 14 days, respectively. RNA was harvested after 7 and 14 days of differentiation, and osteogenic gene expression was examined by quantitative real-time polymerase chain reaction. For evaluation of in vivo osteogenesis, critical-sized (4-mm) calvarial defects in nude mice were treated with the hydroxyapatite-poly(lactic-co-glycolic acid) scaffold seeded with the above-mentioned subpopulations. Healing was followed using micro-CT scans for 8 weeks. Calvaria were harvested at 8 weeks postoperatively, and sections were stained with Movat's Pentachrome.Transcriptional analysis revealed that the CD90(+) subpopulation was enriched for a more osteogenic subtype relative to the CD105(low) subpopulation. Staining at day 7 for ALP was greatest in the CD90(+) cells, followed by the CD105(low) cells. Staining at day 14 for alizarin red demonstrated the greatest amount of mineralized extracellular matrix in the CD90(+) cells, again followed by the CD105(low) cells. Quantification of in vivo healing at 2, 4, 6, and 8weeks postoperatively demonstrated increased bone formation in defects treated with CD90(+) ASCs relative to all other groups. On Movat's Pentachrome-stained sections, defects treated with CD90(+) cells showed the most robust bony regeneration. Defects treated with CD90(-) cells, CD105(high) cells, and CD105(low) cells demonstrated some bone formation, but to a lesser degree when compared with the CD90(+) group.While CD105(low) cells have previously been shown to possess an enhanced osteogenic potential, we found that CD90(+) cells are more capable of forming bone both in vitro and in vivo. These data therefore suggest that CD90 may be a more effective marker than CD105 to isolate a highly osteogenic subpopulation for bone tissue engineering.

  View details for DOI 10.1089/ten.tea.2012.0370

  View details for PubMedID 23216074

• Simultaneous reconstruction of extensor mechanism in the free transfer of vascularized proximal interphalangeal joint. Techniques in hand & upper extremity surgery Lin, Y., Kao, D. S., Wan, D. C., Lien, S., Lin, C., Wei, F. 2013; 17 (1): 20-24

  Abstract

  From a recent systemic review, vascularized toe proximal interphalangeal joint (PIPJ) transfer achieved an average arc of motion (AOM) of merely 37 degrees for finger PIPJ reconstruction. Despite the technical refinement over the past 3 decades, the resulting active motion of the reconstructed joint remains unpredictable and often fraught with extension lag. The technique for vascularized toe PIPJ transfer at our institute has evolved over the years to its current state, with simultaneous extensor mechanism reconstruction being a major component. During the transfer, the quality of extensor tendons on the recipient finger and donor toe are carefully evaluated. If the central slip of finger extensor is destroyed but the quality of lateral bands is adequate, centralization of lateral bands overlying the transferred PIPJ is performed. If there is acceptable central slip remnant at the proximal phalanx level, modified Stack procedure is performed for central slip reconstruction while leaving the lateral bands in continuity. If both lateral bands are poor, modified Stack procedure is performed unless the central tendon of the toe is strong enough to extend the PIPJ. From November 2008 to October 2010, 7 joints were transferred with this modified technique. The average follow-up was 18.2 months. The average active AOM of the transferred PIPJ was 56.4 degrees. The average extension lag of the toe PIPJ was 10.7 and 16.4 degrees before and after the transfer, respectively. Simultaneous reconstruction of extensor mechanism decreases the extension lag without sacrificing AOM of the transferred PIPJ.

  View details for DOI 10.1097/BTH.0b013e318272f918

  View details for PubMedID 23423230

• Micro-Computed Tomography Evaluation of Human Fat Grafts in Nude Mice TISSUE ENGINEERING PART C-METHODS Chung, M. T., Hyun, J. S., Lo, D. D., Montoro, D. T., Hasegawa, M., Levi, B., Januszyk, M., Longaker, M. T., Wan, D. C. 2013; 19 (3): 227-232

  Abstract

  Although autologous fat grafting has revolutionized the field of soft tissue reconstruction and augmentation, long-term maintenance of fat grafts is unpredictable. Recent studies have reported survival rates of fat grafts to vary anywhere between 10% and 80% over time. The present study evaluated the long-term viability of human fat grafts in a murine model using a novel imaging technique allowing for in vivo volumetric analysis.Human fat grafts were prepared from lipoaspirate samples using the Coleman technique. Fat was injected subcutaneously into the scalp of 10 adult Crl:NU-Foxn1(nu) CD-1 male mice. Micro-computed tomography (CT) was performed immediately following injection and then weekly thereafter. Fat volume was rendered by reconstructing a three-dimensional (3D) surface through cubic-spline interpolation. Specimens were also harvested at various time points and sections were prepared and stained with hematoxylin and eosin (H&E), for macrophages using CD68 and for the cannabinoid receptor 1 (CB1). Finally, samples were explanted at 8- and 12-week time points to validate calculated micro-CT volumes.Weekly CT scanning demonstrated progressive volume loss over the time course. However, volumetric analysis at the 8- and 12-week time points stabilized, showing an average of 62.2% and 60.9% survival, respectively. Gross analysis showed the fat graft to be healthy and vascularized. H&E analysis and staining for CD68 showed minimal inflammatory reaction with viable adipocytes. Immunohistochemical staining with anti-human CB1 antibodies confirmed human origin of the adipocytes.Studies assessing the fate of autologous fat grafts in animals have focused on nonimaging modalities, including histological and biochemical analyses, which require euthanasia of the animals. In this study, we have demonstrated the ability to employ micro-CT for 3D reconstruction and volumetric analysis of human fat grafts in a mouse model. Importantly, this model provides a platform for subsequent study of fat manipulation and soft tissue engineering.

  View details for DOI 10.1089/ten.tec.2012.0371

  View details for Web of Science ID 000314179900006

  View details for PubMedID 22916732

  View details for PubMedCentralID PMC3557441

• Discussion: A report of the ASPS Task Force on regenerative medicine: opportunities for plastic surgery. Plastic and reconstructive surgery McArdle, A., Lo, D. D., Hyun, J. S., Senarath-Yapa, K., Chung, M. T., Wan, D. C., Longaker, M. T. 2013; 131 (2): 400-403

  View details for DOI 10.1097/PRS.0b013e318278d88c

  View details for PubMedID 23358002

• The Seed and the Soil Optimizing Stem Cells and Their Environment for Tissue Regeneration ANNALS OF PLASTIC SURGERY Hyun, J. S., Montoro, D. T., Lo, D. D., Flynn, R. A., Wong, V., Chung, M. T., Longaker, M. T., Wan, D. C. 2013; 70 (2): 235-239

  Abstract

  The potential for stem cells to serve as cellular building blocks for reconstruction of complex defects has prompted significant enthusiasm in the field of regenerative medicine. Clinical application, however, is still limited, as implantation of cells into hostile wound environments may greatly hinder their tissue forming capacity. To circumvent this obstacle, novel approaches have been developed to manipulate both the stem cell itself and its surrounding environmental niche. By understanding this paradigm of seed and soil optimization, innovative strategies may thus be developed to harness the true promise of stem cells for tissue regeneration.

  View details for DOI 10.1097/SAP.0b013e31826a18fb

  View details for Web of Science ID 000313964300024

  View details for PubMedID 23295233

• Novel Application of Human Morphomics to Quantify Temporal Soft Tissues in Pierre Robin and Treacher Collins JOURNAL OF CRANIOFACIAL SURGERY Lisiecki, J., Wan, D. C., Wang, L., Zhang, P., Enchakalody, B., Zhang, X., Kasten, S. J., Wang, S. C., Buchman, S. R., Levi, B. 2013; 24 (1): 158-162

  Abstract

  Pierre Robin sequence (PR) and Treacher Collins syndrome (TC) are congenital disorders associated with multiple craniofacial abnormalities. The mandibular malformations linked with these maladies are closely associated with the form and function of the temporalis muscle. Despite these associations, a paucity of research has been directed at quantifying how these malformations affect the tissues of the temporal region. In this paper, we seek to quantify differences in the temporalis muscle and the temporal fat pad using a novel CT-derived analytic program to examine craniofacial morphomic indices within these patient groups in comparison to normal age-matched controls. We posit that the temporalis muscle and temporal fat pad, like other derivatives of the first branchial arch, are hypoplastic in patients with TC and PR compared to age-matched controls.High-throughput image analysis was used to reconstruct the 3-dimensional (3D) anatomy and quantify morphomic measures of the temporalis muscle and temporal fat pad in children with PR, TC, and age-matched controls. These steps were completed in a semi-automated method using algorithms programmed in MATLAB v13.0. The 3D reconstructions were analyzed in 3 children with PR (6 temporal regions), 3 children with TC (6 temporal regions), and a control group of 19 children (38 temporal regions). We also quantified the same measurements in a localized "core" sample in the area of greatest thickness, providing a more consistent sample of the tissue position. Relationships between the temporal muscle and fat pad values and craniofacial abnormality type were assessed using Wilcoxon nonparametric test using exact distribution, with a P value of less than 0.05 being deemed significant.The mean age of our patients was 6.0 years in PR and 4.5 years in TC cohorts. We were able to establish an automated methodology to quantify the temporalis muscle and temporal fat pad based on CT characteristics. Localized temporalis volume and localized temporalis area were significantly smaller in children with PR than in the control group. Total temporalis fat volume and localized temporalis area were significantly less in children with TC than in the control group. When compared to each other, the PR group had small morphomic values compared to TC group.There are significant morphomic differences in the temporalis muscle and the temporal fat pad in children with either PR or TC when compared to age-matched control group which can be measured from pre-existing CT scans. Specifically, both of these test groups show decreases in the morphomic measures of the temporalis region. The quantification of these changes corroborates and objectifies the clinical findings associated with these congenital deformities while simultaneously allowing for preoperative planning. Furthermore, this finding confirms that the hypoplasia seen in these patient populations is not only hypoplasia of the mandible but also of the surrounding functional matrix, which includes the temporalis muscle and temporal fat pad.

  View details for DOI 10.1097/SCS.0b013e3182646411

  View details for Web of Science ID 000314853300079

  View details for PubMedID 23348276

• In vivo directed differentiation of pluripotent stem cells for skeletal regeneration PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Levi, B., Hyun, J. S., Montoro, D. T., Lo, D. D., Chan, C. K., Hu, S., Sun, N., Lee, M., Grova, M., Connolly, A. J., Wu, J. C., Gurtner, G. C., Weissman, I. L., Wan, D. C., Longaker, M. T. 2012; 109 (50): 20379-20384

  Abstract

  Pluripotent cells represent a powerful tool for tissue regeneration, but their clinical utility is limited by their propensity to form teratomas. Little is known about their interaction with the surrounding niche following implantation and how this may be applied to promote survival and functional engraftment. In this study, we evaluated the ability of an osteogenic microniche consisting of a hydroxyapatite-coated, bone morphogenetic protein-2-releasing poly-L-lactic acid scaffold placed within the context of a macroenvironmental skeletal defect to guide in vivo differentiation of both embryonic and induced pluripotent stem cells. In this setting, we found de novo bone formation and participation by implanted cells in skeletal regeneration without the formation of a teratoma. This finding suggests that local cues from both the implanted scaffold/cell micro- and surrounding macroniche may act in concert to promote cellular survival and the in vivo acquisition of a terminal cell fate, thereby allowing for functional engraftment of pluripotent cells into regenerating tissue.

  View details for DOI 10.1073/pnas.1218052109

  View details for PubMedID 23169671

• Femtosecond plasma mediated laser ablation has advantages over mechanical osteotomy of cranial bone LASERS IN SURGERY AND MEDICINE Lo, D. D., Mackanos, M. A., Chung, M. T., Hyun, J. S., Montoro, D. T., Grova, M., Liu, C., Wang, J., Palanker, D., Connolly, A. J., Longaker, M. T., Contag, C. H., Wan, D. C. 2012; 44 (10): 805-814

  Abstract

  Although mechanical osteotomies are frequently made on the craniofacial skeleton, collateral thermal, and mechanical trauma to adjacent bone tissue causes cell death and may delay healing. The present study evaluated the use of plasma-mediated laser ablation using a femtosecond laser to circumvent thermal damage and improve bone regeneration.Critical-size circular calvarial defects were created with a trephine drill bit or with a Ti:Sapphire femtosecond pulsed laser. Healing was followed using micro-CT scans for 8 weeks. Calvaria were also harvested at various time points for histological analysis. Finally, scanning electron microscopy was used to analyze the microstructure of bone tissue treated with the Ti:Sapphire laser, and compared to that treated with the trephine bur.Laser-created defects healed significantly faster than those created mechanically at 2, 4, and 6 weeks post-surgery. However, at 8 weeks post-surgery, there was no significant difference. In the drill osteotomy treatment group, empty osteocyte lacunae were seen to extend 699 ± 27 µm away from the edge of the defect. In marked contrast, empty osteocyte lacunae were seen to extend only 182 ± 22 µm away from the edge of the laser-created craters. Significantly less ossification and formation of irregular woven bone was noted on histological analysis for drill defects.We demonstrate accelerated bone healing after femtosecond laser ablation in a calvarial defect model compared to traditional mechanical drilling techniques. Improved rates of early regeneration make plasma-mediated ablation of the craniofacial skeleton advantageous for applications to osteotomy.

  View details for DOI 10.1002/lsm.22098

  View details for Web of Science ID 000312941600004

  View details for PubMedID 23184427

• Pierre Robin sequence and Treacher Collins hypoplastic mandible comparison using three-dimensional morphometric analysis. journal of craniofacial surgery Chung, M. T., Levi, B., Hyun, J. S., Lo, D. D., Montoro, D. T., Lisiecki, J., Bradley, J. P., Buchman, S. R., Longaker, M. T., Wan, D. C. 2012; 23 (7): 1959-1963

  Abstract

  Pierre Robin sequence and Treacher Collins syndrome are both associated with mandibular hypoplasia. It has been hypothesized, however, that the mandible may be differentially affected. The purpose of this study was to therefore compare mandibular morphology in children with Pierre Robin sequence with children with Treacher Collins syndrome using three-dimensional analysis of computed tomographic scans. A retrospective analysis was performed identifying children with Pierre Robin sequence and Treacher Collins syndrome undergoing computed tomography. Three-dimensional reconstruction was performed, and ramus height, mandibular body length, and gonial angle were measured. These were then compared with those in control children with normal mandibles and with the clinical norms corrected for age and sex based on previously published measurements. Mandibular body length was found to be significantly shorter for children with Pierre Robin sequence, whereas ramus height was significantly shorter for children with Treacher Collins syndrome. This resulted in distinctly different ramus height-mandibular body length ratios. In addition, the gonial angle was more obtuse in both the Pierre Robin sequence and Treacher Collins syndrome groups compared with the controls. Three-dimensional mandibular morphometric analysis in patients with Pierre Robin sequence and Treacher Collins syndrome thus revealed distinctly different patterns of mandibular hypoplasia relative to normal controls. These findings underscore distinct considerations that must be made in surgical planning for reconstruction.

  View details for DOI 10.1097/SCS.0b013e318258bcf1

  View details for PubMedID 23154353

  View details for PubMedCentralID PMC3544559

• Models of Cranial Suture Biology JOURNAL OF CRANIOFACIAL SURGERY Grova, M., Lo, D. D., Montoro, D., Hyun, J. S., Chung, M. T., Wan, D. C., Longaker, M. T. 2012; 23: 1954-1958

  Abstract

  Craniosynostosis is a common congenital defect caused by premature fusion of cranial sutures. The severe morphologic abnormalities and cognitive deficits resulting from craniosynostosis and the potential morbidity of surgical correction espouse the need for a deeper understanding of the complex etiology for this condition. Work in animal models for the past 20 years has been pivotal in advancing our understanding of normal suture biology and elucidating pathologic disease mechanisms. This article provides an overview of milestone studies in suture development, embryonic origins, and signaling mechanisms from an array of animal models including transgenic mice, rats, rabbits, fetal sheep, zebrafish, and frogs. This work contributes to an ongoing effort toward continued development of novel treatment strategies.

  View details for DOI 10.1097/SCS.0b013e318258ba53

  View details for Web of Science ID 000209481500006

• Pierre Robin Sequence and Treacher Collins Hypoplastic Mandible Comparison Using Three-Dimensional Morphometric Analysis JOURNAL OF CRANIOFACIAL SURGERY Chung, M. T., Levi, B., Hyun, J. S., Lo, D. D., Montoro, D. T., Lisiecki, J., Bradley, J. P., Buchman, S. R., Longaker, M. T., Wan, D. C. 2012; 23: 1959-1963

  Abstract

  Pierre Robin sequence and Treacher Collins syndrome are both associated with mandibular hypoplasia. It has been hypothesized, however, that the mandible may be differentially affected. The purpose of this study was to therefore compare mandibular morphology in children with Pierre Robin sequence with children with Treacher Collins syndrome using three-dimensional analysis of computed tomographic scans. A retrospective analysis was performed identifying children with Pierre Robin sequence and Treacher Collins syndrome undergoing computed tomography. Three-dimensional reconstruction was performed, and ramus height, mandibular body length, and gonial angle were measured. These were then compared with those in control children with normal mandibles and with the clinical norms corrected for age and sex based on previously published measurements. Mandibular body length was found to be significantly shorter for children with Pierre Robin sequence, whereas ramus height was significantly shorter for children with Treacher Collins syndrome. This resulted in distinctly different ramus height-mandibular body length ratios. In addition, the gonial angle was more obtuse in both the Pierre Robin sequence and Treacher Collins syndrome groups compared with the controls. Three-dimensional mandibular morphometric analysis in patients with Pierre Robin sequence and Treacher Collins syndrome thus revealed distinctly different patterns of mandibular hypoplasia relative to normal controls. These findings underscore distinct considerations that must be made in surgical planning for reconstruction.

  View details for DOI 10.1097/SCS.0b013e318258bcf1

  View details for Web of Science ID 000209481500007

  View details for PubMedCentralID PMC3544559

• Models of cranial suture biology. journal of craniofacial surgery Grova, M., Lo, D. D., Montoro, D., Hyun, J. S., Chung, M. T., Wan, D. C., Longaker, M. T. 2012; 23 (7): 1954-1958

  Abstract

  Craniosynostosis is a common congenital defect caused by premature fusion of cranial sutures. The severe morphologic abnormalities and cognitive deficits resulting from craniosynostosis and the potential morbidity of surgical correction espouse the need for a deeper understanding of the complex etiology for this condition. Work in animal models for the past 20 years has been pivotal in advancing our understanding of normal suture biology and elucidating pathologic disease mechanisms. This article provides an overview of milestone studies in suture development, embryonic origins, and signaling mechanisms from an array of animal models including transgenic mice, rats, rabbits, fetal sheep, zebrafish, and frogs. This work contributes to an ongoing effort toward continued development of novel treatment strategies.

  View details for DOI 10.1097/SCS.0b013e318258ba53

  View details for PubMedID 23154351

• Craniosynostosis Molecular pathways and future pharmacologic therapy ORGANOGENESIS Senarath-Yapa, K., Chung, M. T., McArdle, A., Wong, V. W., Quarto, N., Longaker, M. T., Wan, D. C. 2012; 8 (4): 103-113

  View details for DOI 10.4161/org.23307

  View details for Web of Science ID 000314500600002

• Repair of a Critical-sized Calvarial Defect Model Using Adipose-derived Stromal Cells Harvested from Lipoaspirate JOVE-JOURNAL OF VISUALIZED EXPERIMENTS Lo, D. D., Hyun, J. S., Chung, M. T., Montoro, D. T., Zimmermann, A., Grova, M. M., Lee, M., Wan, D. C., Longaker, M. T. 2012

  View details for DOI 10.3791/4221

  View details for Web of Science ID 000209225700022

• Regenerative Surgery: Tissue Engineering in General Surgical Practice WORLD JOURNAL OF SURGERY Wong, V. W., Wan, D. C., Gurtner, G. C., Longaker, M. T. 2012; 36 (10): 2288-2299

  Abstract

  Tissue engineering is a broad interdisciplinary field that aims to develop complex tissue and organ constructs through a combination of cell-, biomaterial-, and molecular-based approaches. This approach has the potential to transform the surgical treatment for diseases including trauma, cancer, and congenital malformations. A fundamental knowledge of key concepts in regenerative medicine is imperative for surgeons to maintain a leading role in developing and implementing these technologies. Researchers have started to elucidate the biologic mechanisms that maintain organ homeostasis throughout life, indicating that humans may have the latent capacity to regenerate complex tissues. By exploiting this intrinsic potential of the body, we can move even closer to developing functional, autologous replacement parts for a wide range of surgical diseases.

  View details for DOI 10.1007/s00268-012-1710-1

  View details for PubMedID 22777416

• Craniosynostosis: Molecular pathways and future pharmacologic therapy. Organogenesis Senarath-Yapa, K., Chung, M. T., McArdle, A., Wong, V. W., Quarto, N., Longaker, M. T., Wan, D. C. 2012; 8 (4)

  Abstract

  Craniosynostosis describes the premature fusion of one or more cranial sutures and can lead to dramatic manifestations in terms of appearance and functional impairment. Contemporary approaches for this condition are primarily surgical and are associated with considerable morbidity and mortality. The additional post-operative problems of suture refusion and bony relapse may also necessitate repeated surgeries with their own attendant risks. Therefore, a need exists to not only optimize current strategies but also to develop novel biological therapies which could obviate the need for surgery and potentially treat or even prevent premature suture fusion. Clinical studies of patients with syndromic craniosynostosis have provided some useful insights into the important signaling pathways and molecular events guiding suture fate. Furthermore, the highly conserved nature of craniofacial development between humans and other species have permitted more focused and step-wise elucidation of the molecular underpinnings of craniosynostosis. This review will describe the clinical manifestations of craniosynostosis, reflect on our understanding of syndromic and non-syndromic craniosynostoses and outline the different approaches that have been adopted in our laboratory and elsewhere to better understand the pathogenesis of premature suture fusion. Finally, we will assess to what extent our improved understanding of the pathogenesis of craniosynostosis, achieved through laboratory-based and clinical studies, have made the possibility of a non-surgical pharmacological approach both realistic and tangible.

  View details for PubMedID 23249483

• Autologous Fat Transplantation in the Craniofacial Patient: The UCLA Experience JOURNAL OF CRANIOFACIAL SURGERY Lim, A. A., Fan, K., Allam, K. A., Wan, D., Tabit, C., Liao, E., Kawamoto, H. K., Bradley, J. P. 2012; 23 (4): 1061-1066

  Abstract

  Patients with congenital craniofacial malformations present with complex challenges for reconstruction. Successful management requires individualized treatment often involving rebuilding the facial skeleton de novo, as well as correcting the overlying soft-tissue deficiencies in the final stages. At the University of California, Los Angeles (UCLA) Craniofacial Clinic, serial autologous fat transplantation performed during staged reconstruction is the preferred method.A total of 27 patients with a diagnosis of either craniofacial microsomia/Goldenhar (CM) (n = 19) or Treacher Collins syndrome (TC) (n = 8) were treated at the UCLA Craniofacial Clinic by autologous fat transfer between July 1999 and February 2009. Two-dimensional analysis was conducted on standardized preoperative and postoperative photographs to determine facial symmetry for every patient. Results was grouped based on pathology and analyzed by comparing adipocyte donor site (abdomen vs other).The mean ages at the time of first fat transfer were 17 years for the CM group and 15 years for the TC group. The average numbers of fat transfers per patient were 2.05 (CM) and 2.12 (TC). A mean of 3.74 procedures other than fat grafting was performed in each CM patient, whereas 4.38 other procedures were performed in each TC patient. In CM patients, less than 10.5 months between procedures resulted in improved symmetry. There was an average 6.63% improvement in facial symmetry in the CM group, and a 7.67% improvement in the TC group.Based on the UCLA experience, the durability of facial asymmetry and contour correction with fat transplantation is attainable in the craniofacial patient but may also require concomitant skeletal correction in the most severe cases.

  View details for DOI 10.1097/SCS.0b013e31824e695b

  View details for Web of Science ID 000306710200069

  View details for PubMedID 22777454

• Fat Grafting Versus Adipose-Derived Stem Cell Therapy: Distinguishing Indications, Techniques, and Outcomes AESTHETIC PLASTIC SURGERY Tabit, C. J., Slack, G. C., Fan, K., Wan, D. C., Bradley, J. P. 2012; 36 (3): 704-713

  Abstract

  With adipose-derived stem cells (ASCs) at the forefront of research and potential clinical applications, it is important that clinicians be able to distinguish them from the fat grafting currently used clinically and to understand how the two approaches relate to one another. At times, there has been confusion in clinically considering the two therapies to be the same. This report is aimed at distinguishing clearly between fat grafting and ASC therapy with regard to the indications, harvesting, processing, application techniques, outcomes, and complications. Findings have shown that autologous fat transfer, a widely used procedure for soft tissue augmentation, is beneficial for reconstructive and cosmetic procedures used to treat patients with volume loss due to disease, trauma, congenital defects, or the natural process of aging. On the other hand, ASCs have been identified as an ideal source of cells for regenerative medicine, with the potential to serve as soft tissue therapy for irradiated, scarred, or chronic wounds. Recent advances in tissue engineering suggest that the supplementation of fat grafts with ASCs isolated in the stromal vascular fraction may increase the longevity and quality of the fat graft. Research suggests that ASC supplementation may be a great clinical tool in the future, but more data should be acquired before clinical applications.

  View details for DOI 10.1007/s00266-011-9835-4

  View details for Web of Science ID 000304203800034

  View details for PubMedID 22069062

• Craniofacial Reconstruction With Induced Pluripotent Stem Cells JOURNAL OF CRANIOFACIAL SURGERY Wan, D. C., Wong, V. W., Longaker, M. T. 2012; 23 (3): 623-626

  View details for DOI 10.1097/SCS.0b013e318252f41b

  View details for Web of Science ID 000304479600041

  View details for PubMedID 22627398

  View details for PubMedCentralID PMC3544558

• Rethinking the Blastema PLASTIC AND RECONSTRUCTIVE SURGERY Hyun, J. S., Chung, M. T., Wong, V. W., Montoro, D., Longaker, M. T., Wan, D. C. 2012; 129 (5): 1097-1103

  Abstract

  The phenomenon of tissue regeneration has been well documented across many species. Although some possess the capacity to completely restore an entire amputated limb, others are limited to just the distal digit tip. Initiation of limb regeneration has been described to start with the formation of a blastema, the composition of which has long been thought to consist of undifferentiated pluripotent cells derived through the process of dedifferentiation. Competing theories have been proposed, however, including cellular contributions through transdifferentiation and tissue-specific stem cells. Recent studies have now begun to shed light on this controversy, demonstrating tissue resident stem cells to be an evolutionarily conserved measure for limb regeneration.

  View details for DOI 10.1097/PRS.0b013e31824a2c49

  View details for Web of Science ID 000303497300059

  View details for PubMedID 22544093

• Training the Contemporary Surgeon-Scientist PLASTIC AND RECONSTRUCTIVE SURGERY Wan, D. C., Wang, K. C., Longaker, M. T. 2012; 129 (4): 1023-1025

  View details for DOI 10.1097/PRS.0b013e31824421e8

  View details for Web of Science ID 000302227100076

  View details for PubMedID 22456371

• The commissure-based triangular flap for lip revision following reconstruction of a through-and-through defect JOURNAL OF PLASTIC RECONSTRUCTIVE AND AESTHETIC SURGERY Tsao, C., Wan, D. C., Chen, W., Kao, D. S., Levi, B. 2012; 65 (2): 271-273

  View details for DOI 10.1016/j.bjps.2011.08.007

  View details for Web of Science ID 000299111100028

  View details for PubMedID 21945062

• Stem Cells: Update and Impact on Craniofacial Surgery JOURNAL OF CRANIOFACIAL SURGERY Levi, B., Glotzbach, J. P., Wong, V. W., Nelson, E. R., Hyun, J., Wan, D. C., Gurtner, G. C., Longaker, M. T. 2012; 23 (1): 319-322

  View details for DOI 10.1097/SCS.0b013e318241dbaf

  View details for Web of Science ID 000300234900099

  View details for PubMedID 22337434

  View details for PubMedCentralID PMC3282019

• Cranial Suture Biology: From Pathways to Patient Care JOURNAL OF CRANIOFACIAL SURGERY Levi, B., Wan, D. C., Wong, V. W., Nelson, E., Hyun, J., Longaker, M. T. 2012; 23 (1): 13-19

  Abstract

  Craniosynostosis describes the premature pathologic partial or complete fusion of 1 or more of the cranial sutures. Over the past few decades, research on craniosynostosis has progressed from gross description of deformities to an understanding of some of the molecular etiologies behind premature suture fusion. Studies on patients with syndromic craniosynostosis have resulted in the identification of several genes, molecular events, and deformational forces involved in abnormal growth and development of the cranial vault. Conservation of craniofacial development and sequence homology between humans and other species have also led to insightful discoveries in cranial suture development. In this review, we discuss the development of the cranial vault and explain the basic science behind craniosynostosis in humans as well as in animal models and how these studies may lead to future advances in craniosynostosis treatments.

  View details for DOI 10.1097/SCS.0b013e318240c6c0

  View details for Web of Science ID 000300234900033

  View details for PubMedID 22337368

• Open Reduction and Internal Fixation of Mandibular Angle Fractures Using Temporary Kirschner Wire Fixation PLASTIC AND RECONSTRUCTIVE SURGERY Perry, A. D., Wan, D. C., Shih, H., Tanna, N., Bradley, J. P. 2012; 129 (1): 192E-194E

  View details for DOI 10.1097/PRS.0b013e3182365ceb

  View details for Web of Science ID 000298857100047

  View details for PubMedID 22186559

• Repair of a critical-sized calvarial defect model using adipose-derived stromal cells harvested from lipoaspirate. Journal of visualized experiments : JoVE Lo, D. D., Hyun, J. S., Chung, M. T., Montoro, D. T., Zimmermann, A., Grova, M. M., Lee, M., Wan, D. C., Longaker, M. T. 2012

  Abstract

  Craniofacial skeletal repair and regeneration offers the promise of de novo tissue formation through a cell-based approach utilizing stem cells. Adipose-derived stromal cells (ASCs) have proven to be an abundant source of multipotent stem cells capable of undergoing osteogenic, chondrogenic, adipogenic, and myogenic differentiation. Many studies have explored the osteogenic potential of these cells in vivo with the use of various scaffolding biomaterials for cellular delivery. It has been demonstrated that by utilizing an osteoconductive, hydroxyapatite-coated poly(lactic-co-glycolic acid) (HA-PLGA) scaffold seeded with ASCs, a critical-sized calvarial defect, a defect that is defined by its inability to undergo spontaneous healing over the lifetime of the animal, can be effectively show robust osseous regeneration. This in vivo model demonstrates the basis of translational approaches aimed to regenerate the bone tissue - the cellular component and biological matrix. This method serves as a model for the ultimate clinical application of a progenitor cell towards the repair of a specific tissue defect.

  View details for DOI 10.3791/4221

  View details for PubMedID 23149856

  View details for PubMedCentralID PMC3499066

• Paramedian Mandibular Cleft: Revisiting the Tessier Classification JOURNAL OF CRANIOFACIAL SURGERY Tanna, N., Wan, D. C., Perry, A. D., Kawamoto, H. K., Bradley, J. P. 2012; 23 (1): E38-E40

  Abstract

  Mandibular clefts are extremely rare, with less than 100 cases reported in the literature. Almost universally, these isolated cases of lower facial clefting have been noted to occur through the midline of the lip and/or mandible. The defect can vary, ranging from mild notching of the lower lip or mandibular alveolus to complete mandibular cleavage. The authors present a rare case of a paramedian mandibular cleft in a patient who also had Goldenhar syndrome and Tessier number 2/12 cleft. With its presentation, the authors revisit the Tessier classification of craniofacial clefts and the embryogenesis of lower facial clefts.

  View details for DOI 10.1097/SCS.0b013e318241db58

  View details for Web of Science ID 000300234900017

  View details for PubMedID 22337459

• Correction of Hypertelorbitism: Evaluation of Relapse on Long-Term Follow-Up JOURNAL OF CRANIOFACIAL SURGERY Wan, D. C., Levi, B., Kawamoto, H., Tanna, N., Tabit, C., do Amaral, C. R., Bradley, J. P. 2012; 23 (1): 113-117

  Abstract

  Hypertelorbitism has been associated with a variety of congenital deformities. Appropriate timing for surgical correction remains controversial. We present our long-term experience of 33 patients with hypertelorbitism undergoing facial bipartition or orbital box osteotomy.Patients with hypertelorbitism treated with either facial bipartition or orbital box osteotomy and repositioning who had long-term follow-up were studied (n=33). Age at the time of first surgery, preoperative interdacryon distance, and immediate postoperative interdacryon distance were recorded. Relapse was determined on postoperative follow-up, and the need for secondary correction was noted. Physician satisfaction score (range, 0-4) was also assessed.Patients had a mean total follow-up of 14.0 years. With regard to age at the time of initial procedure, patients younger than 6 years were all noted to have relapse, and 83% underwent revision surgery. In patients 6 years or older, only 11% had relapse and required a second operation. Yet, satisfaction scores were similar (3.2 versus 3.5). With regard to the severity of hypertelorbitism, there was no relapse noted among patients with mild hypertelorbitism (interorbital distance [IOD], 30-34 mm). Among those with moderate hypertelorbitism (IOD, 35-40 mm), 29.4% developed relapse. By contrast, all patients with severe hypertelorbitism (IOD, >40 mm) were noted to have relapse requiring repeat correction. Satisfaction scores were similar (3.4 versus 3.3 versus 3.1).Relapse after surgery for hypertelorbitism is related to the age of the patient at correction and the preoperative severity. When possible, surgical repositioning of the orbits should be delayed until later childhood.

  View details for DOI 10.1097/SCS.0b013e318240fa84

  View details for Web of Science ID 000300234900050

  View details for PubMedID 22337385

• Nonintegrating Knockdown and Customized Scaffold Design Enhances Human Adipose-Derived Stem Cells in Skeletal Repair STEM CELLS Levi, B., Hyun, J. S., Nelson, E. R., Li, S., Montoro, D. T., Wan, D. C., Jia, F. J., Glotzbach, J. C., James, A. W., Lee, M., Huang, M., Quarto, N., Gurtner, G. C., Wu, J. C., Longaker, M. T. 2011; 29 (12): 2018-2029

  Abstract

  An urgent need exists in clinical medicine for suitable alternatives to available techniques for bone tissue repair. Human adipose-derived stem cells (hASCs) represent a readily available, autogenous cell source with well-documented in vivo osteogenic potential. In this article, we manipulated Noggin expression levels in hASCs using lentiviral and nonintegrating minicircle short hairpin ribonucleic acid (shRNA) methodologies in vitro and in vivo to enhance hASC osteogenesis. Human ASCs with Noggin knockdown showed significantly increased bone morphogenetic protein (BMP) signaling and osteogenic differentiation both in vitro and in vivo, and when placed onto a BMP-releasing scaffold embedded with lentiviral Noggin shRNA particles, hASCs more rapidly healed mouse calvarial defects. This study therefore suggests that genetic targeting of hASCs combined with custom scaffold design can optimize hASCs for skeletal regenerative medicine.

  View details for DOI 10.1002/stem.757

  View details for PubMedID 21997852

• CD105 Protein Depletion Enhances Human Adipose-derived Stromal Cell Osteogenesis through Reduction of Transforming Growth Factor beta 1 (TGF-beta 1) Signaling JOURNAL OF BIOLOGICAL CHEMISTRY Levi, B., Wan, D. C., Glotzbach, J. P., Hyun, J., Januszyk, M., Montoro, D., Sorkin, M., James, A. W., Nelson, E. R., Li, S., Quarto, N., Lee, M., Gurtner, G. C., Longaker, M. T. 2011; 286 (45): 39497-39509

  Abstract

  Clinically available sources of bone for repair and reconstruction are limited by the accessibility of autologous grafts, infectious risks of cadaveric materials, and durability of synthetic substitutes. Cell-based approaches for skeletal regeneration can potentially fill this need, and adipose tissue represents a promising source for development of such therapies. Here, we enriched for an osteogenic subpopulation of cells derived from human subcutaneous adipose tissue utilizing microfluidic-based single cell transcriptional analysis and fluorescence-activated cell sorting (FACS). Statistical analysis of single cell transcriptional profiles demonstrated that low expression of endoglin (CD105) correlated with a subgroup of adipose-derived cells with increased osteogenic gene expression. FACS-sorted CD105(low) cells demonstrated significantly enhanced in vitro osteogenic differentiation and in vivo bone regeneration when compared with either CD105(high) or unsorted cells. Evaluation of the endoglin pathway suggested that enhanced osteogenesis among CD105(low) adipose-derived cells is likely due to identification of a subpopulation with lower TGF-β1/Smad2 signaling. These findings thus highlight a potential avenue to promote osteogenesis in adipose-derived mesenchymal cells for skeletal regeneration.

  View details for DOI 10.1074/jbc.M111.256529

  View details for PubMedID 21949130

• Palatogenesis Engineering, pathways and pathologies ORGANOGENESIS Levi, B., Brugman, S., Wong, V. W., Grova, M., Longaker, M. T., Wan, D. C. 2011; 7 (4): 242-254

  Abstract

  Cleft palate represents the second most common birth defect and carries substantial physiologic and social challenges for affected patients, as they often require multiple surgical interventions during their lifetime. A number of genes have been identified to be associated with the cleft palate phenotype, but etiology in the majority of cases remains elusive. In order to better understand cleft palate and both surgical and potential tissue engineering approaches for repair, we have performed an in-depth literature review into cleft palate development in humans and mice, as well as into molecular pathways underlying these pathologic developments. We summarize the multitude of pathways underlying cleft palate development, with the transforming growth factor beta superfamily being the most commonly studied. Furthermore, while the majority of cleft palate studies are performed using a mouse model, studies focusing on tissue engineering have also focused heavily on mouse models. A paucity of human randomized controlled studies exists for cleft palate repair, and so far, tissue engineering approaches are limited. In this review, we discuss the development of the palate, explain the basic science behind normal and pathologic palate development in humans as well as mouse models and elaborate on how these studies may lead to future advances in palatal tissue engineering and cleft palate treatments.

  View details for DOI 10.4161/org.7.4.17926

  View details for Web of Science ID 000299593000002

  View details for PubMedID 21964245

  View details for PubMedCentralID PMC3265826

• Distraction Osteogenesis of Costocartilaginous Rib Grafts and Treatment Algorithm for Severely Hypoplastic Mandibles PLASTIC AND RECONSTRUCTIVE SURGERY Wan, D. C., Taub, P. J., Allam, K. A., Perry, A., Tabit, C. J., Kawamoto, H. K., Bradley, J. P. 2011; 127 (5): 2005-2013

  Abstract

  In craniofacial microsomia, patients with severely hypoplastic mandibles (Pruzansky type III) require replacement of the ramus and condyle unit. Autogenous costocartilaginous rib graft and distraction osteogenesis are the most important techniques used, but long-term results need to be looked at to determine optimal management.Of the 485 patients with craniofacial microsomia and mandibular abnormality identified by the authors' craniofacial multidisciplinary clinic, 31 patients were identified with Pruzansky type III mandibles who underwent treatment and were available for study. Patients primarily had either costocartilaginous grafts or mandibular distraction after molar extraction. Outcomes assessed rib failure, undergrowth, or overgrowth. Reoperation included regrafting for graft failure, rib distraction for undergrowth, and mandibular setback for overgrowth. Details surrounding complications for each modality including osteotomy site were recorded.For primary mandibular reconstruction, 27 patients underwent costocartilaginous rib graft surgery (30 grafts, three bilateral) at 9.9 ± 4.1 years; four patients underwent mandibular distraction at 7.4 ± 2.3 years. Rib graft failure in seven of 30 cases (23 percent) required regrafting. Undergrowth in 17 cases (57 percent) required rib distraction. Overgrowth in three cases (10 percent) required correction at the time of orthognathic correction. For rib graft distraction, osteotomy site locations included native mandible (25 percent), rib-mandible junction (19 percent), and rib graft (56 percent). The rib-mandible junction site had graft-related complications (100 percent) that the other sites did not.For the severely hypoplastic mandibles (Pruzansky type III), costocartilaginous grafts are an accepted modality. However, when rib graft growth is insufficient, secondary distraction should be performed within the native mandible or rib graft and not at the rib graft-mandible junction site.

  View details for DOI 10.1097/PRS.0b013e31820cf4d6

  View details for Web of Science ID 000290148100032

  View details for PubMedID 21532427

• Treatment of Apert Syndrome: A Long-Term Follow-Up Study PLASTIC AND RECONSTRUCTIVE SURGERY Allam, K. A., Wan, D. C., Khwanngern, K., Kawamoto, H. K., Tanna, N., Perry, A., Bradley, J. P. 2011; 127 (4): 1601-1611

  Abstract

  Patients with Apert syndrome have severe malformations of the skull and face requiring multiple complex reconstructive procedures. The authors present a long-term follow-up study reporting both surgical results and psychosocial status of patients with Apert syndrome.A retrospective study was performed identifying patients with Apert syndrome treated between 1975 and 2009. All surgical procedures were recorded and a review of psychosocial and educational status was obtained when patients reached adulthood.A total of 31 patients with Apert syndrome were identified; nine with long-term follow-up had complete records for evaluation. The average patient age was 30.4 years. Primary procedures performed included strip craniectomy and fronto-orbital advancement. Monobloc osteotomy and facial bipartition were performed in eight patients, and all underwent surgical orthognathic correction. Multiple auxiliary procedures were also performed to achieve better facial symmetry. Mean follow-up after frontofacial advancement was 22.5 years. Psychosocial evaluation demonstrated good integration of patients into mainstream life.This report presents one of the longest available follow-up studies for surgical correction of patients with Apert syndrome. Although multiple reconstructive procedures were necessary, they play an important role in enhancing the psychosocial condition of the patients, helping them integrate into mainstream life.

  View details for DOI 10.1097/PRS.0b013e31820a64b6

  View details for Web of Science ID 000288840200025

  View details for PubMedID 21187805

• Acute Skeletal Injury Is Necessary for Human Adipose-Derived Stromal Cell-Mediated Calvarial Regeneration PLASTIC AND RECONSTRUCTIVE SURGERY Levi, B., James, A. W., Nelson, E. R., Peng, M., Wan, D. C., Commons, G. W., Lee, M., Wu, B., Longaker, M. T. 2011; 127 (3): 1118-1129

  Abstract

  Studies have demonstrated that human adipose-derived stromal cells (ASCs) are able to repair acute calvarial injuries. The more clinically relevant repair of an established skeletal defect, however, has not been addressed. The authors sought to determine whether human ASCs could heal chronic (established) calvarial defects.Critical-sized (4 mm) mouse parietal defects were created. Human ASCs were engrafted either immediately postoperatively (acute defect) or 8 weeks following defect creation (established defect). Methods of analysis included microcomputer tomography scans, histology, and in situ hybridization. Finally, human ASCs were treated in vitro with platelet-rich plasma to simulate an acute wound environment; proliferation and osteogenic differentiation were assessed (alkaline phosphatase, alizarin red, and quantitative reverse transcriptase polymerase chain reaction).Nearly complete osseous healing was observed when calvarial defects were immediately engrafted with human ASCs. In contrast, when human ASCs were engrafted into established defects, little bone formation occurred. Histological analysis affirmed findings by microcomputer tomography, showing more robust staining for alkaline phosphatase and picrosirius red in an acute than in an established human ASC-engrafted defect. In situ hybridization and quantitative reverse transcriptase polymerase chain reaction showed an increase in bone morphogenetic protein (BMP) expression (BMP-2, BMP-4, and BMP-7) acutely following calvarial defect creation. Finally, in vitro treatment of human ASCs with platelet-rich plasma enhanced osteogenic differentiation and increased BMP-2 expression.Although human ASCs can be utilized to heal an acute mouse calvarial defect, they do not enhance healing of an established (or chronic) defect. Endogenous BMP signaling activated after injury may explain these differences in healing. Platelet-rich plasma enhances osteogenic differentiation of human ASCs in vitro and may prove a promising therapy for future skeletal tissue engineering efforts.

  View details for DOI 10.1097/PRS.0b013e318205f274

  View details for Web of Science ID 000287680200012

  View details for PubMedID 21364415

  View details for PubMedCentralID PMC3073240

• The Spectrum of Median Craniofacial Dysplasia PLASTIC AND RECONSTRUCTIVE SURGERY Allam, K. A., Wan, D. C., Kawamoto, H. K., Bradley, J. P., Sedano, H. O., Saied, S. 2011; 127 (2): 812-821

  Abstract

  Given the multiple permutations in craniofacial malformations, classification of median craniofacial dysplasia or midline Tessier no. 0 to 14 clefts has been difficult and disjointed. In this review, the authors present a summary of normal embryology, prior terminology, and their proposed new classification system. Median craniofacial dysplasia has tissue agenesis and holoprosencephaly at one end (the hypoplasias), frontonasal hyperplasia and excessive tissue (the hyperplasias) at the other end, and abnormal splitting or clefting and normal tissue volume (dysraphia) occupying the middle portion of the spectrum. These three distinct subclassifications have different forms of anomalies within their groups.

  View details for DOI 10.1097/PRS.0b013e318200aa08

  View details for Web of Science ID 000286928100040

  View details for PubMedID 21285785

• Quality of Innervation in Sensate Medial Plantar Flaps for Heel Reconstruction PLASTIC AND RECONSTRUCTIVE SURGERY Wan, D. C., Gabbay, J., Levi, B., Boyd, J. B., Granzow, J. W. 2011; 127 (2): 723-730

  Abstract

  Reconstruction of the heel represents a difficult challenge for surgeons, given the demand for thick, durable skin capable of withstanding both pressure and shear. The authors describe the use of a sensate medial plantar flap for heel reconstruction in three patients and document the long-term retention of sensation compared with the contralateral uninjured heel and corresponding donor site.A medial plantar flap was harvested to include the branch of the medial plantar nerve to the instep to preserve innervation. Sharp pain, light and deep pressure, vibration, cold temperature, and static and dynamic two-point discrimination were examined between 6 months and 1 year after surgery.Sharp pain, vibration, and deep pressure sensation were present equally in the medial plantar flap, contralateral heel, and contralateral instep. Cold perception, light pressure, and static two-point and dynamic two-point discrimination were significantly less in the normal contralateral heel when compared with the heel reconstructed by the innervated flap. There were no significant differences in sensation between the medial plantar flap and the contralateral instep.The medial plantar flap is capable of providing durable, sensate coverage of plantar hindfoot defects with minimal donor-site morbidity. Furthermore, that sensation remains identical to that of the instep donor site and superior to that of the normal heel pad.

  View details for DOI 10.1097/PRS.0b013e3181fed76d

  View details for Web of Science ID 000286928100029

  View details for PubMedID 20966816

• Craniofacial Microsomia Soft-Tissue Reconstruction Comparison: Inframammary Extended Circumflex Scapular Flap versus Serial Fat Grafting 89th Annual Meeting of the American-Association-of-Plastic-Surgeons Tanna, N., Wan, D. C., Kawamoto, H. K., Bradley, J. P. LIPPINCOTT WILLIAMS & WILKINS. 2011: 802–11

  Abstract

  The authors investigated the use of serial autologous fat grafting to restore soft-tissue contour in craniofacial microsomia patients.Patients with moderate to severe craniofacial microsomia were divided into two groups. Microvascular free flap patients had reconstruction with inframammary extended circumflex scapular flaps at skeletal maturity (n = 10). Alternatively, patients had fat grafting during multiple staged operations for mandible and ear reconstruction (n = 21). Sex, age, severity of deformity [determined by OMENS (orbital deformity, mandibular hypoplasia, ear deformity, nerve involvement, and soft-tissue deficiency) classification], number of procedures, operative times, and augmentation volumes were recorded. A digital three-dimensional photogrammetry system was used to determine "final fat take" and symmetry (affected side versus unaffected side). Physician and patient satisfaction were elicited.Microvascular free flap and fat grafting groups had similar OMENS scores, 2.4 and 2.3, and similar mean prereconstruction symmetry scores, 74 percent and 75 percent, respectively. Although the mean number of procedures was less for the microvascular free flap group versus the fat grafting group (2.2 versus 4.3), the combined surgical time was greater for the microvascular free flap group. The complication rate for the microvascular free flap group was 12 percent and that for the fat grafting group was 5 percent. The mean microvascular free flap volume implanted was 131 cc, with a final measured volume of 106 cc. Mean fat grafting volume injected per case was 33 cc, with total fat injections of 146 cc and a final measured volume of 121 cc. There was a mean fat loss of 25 cc and 83 percent fat take. Symmetry score was 121 percent for the microvascular free flap group and 99 percent for the fat grafting group. No statistically significant difference in patient or physician satisfaction was noted.Serial fat grafting provided a useful alternative to microvascular free tissue transfer after skeletal reconstruction.

  View details for DOI 10.1097/PRS.0b013e3181fed6e4

  View details for Web of Science ID 000286928100039

  View details for PubMedID 21285784

• Differential Expression of Sclerostin in Adult and Juvenile Mouse Calvariae PLASTIC AND RECONSTRUCTIVE SURGERY Kwan, M. D., Quarto, N., Gupta, D. M., Slater, B. J., Wan, D. C., Longaker, M. T. 2011; 127 (2): 595-602

  Abstract

  An understanding of the molecular mechanisms controlling bone formation is central to skeletal tissue engineering efforts. The observation that immature animals are able to heal calvarial defects while adult animals are not has proven to be a useful tool for examining these mechanisms. Thus, the authors compared expression of sclerostin, a bone inhibitor, between the calvariae of juvenile and adult mice.Parietal bone was harvested from juvenile (6-day-old; n = 20) and adult (60-day-old; n = 20) mice. Sclerostin transcript and protein levels were compared between the parietal bone of juvenile and adult mice using polymerase chain reaction, Western blotting, and immunohistochemistry. Finally, osteoblasts from the parietal bone of juvenile and adult mice were harvested and cultured under osteogenic differentiation conditions with and without recombinant sclerostin (200 ng/ml). Terminal osteogenic differentiation was assessed at 21 days with alizarin red staining.Polymerase chain reaction, Western blot analysis, and immunohistochemistry all confirmed greater expression of sclerostin in the parietal bone of adult mice when compared with that of juvenile mice. Osteoblasts, whether from juvenile or adult parietal bones, demonstrated reduced capacity for osteogenic differentiation when exposed to recombinant sclerostin.Given the role of sclerostin in inhibiting bone formation, the authors' findings suggest that differences in expression levels of sclerostin may play a role in the differential regenerative capacity of calvariae from juvenile and adult animals. These findings suggest it as a potential target to abrogate in future tissue engineering studies.

  View details for DOI 10.1097/PRS.0b013e3181fed60d

  View details for Web of Science ID 000286928100014

  View details for PubMedID 21285764

  View details for PubMedCentralID PMC3072034

• Salvage of the Crucified Chin PLASTIC AND RECONSTRUCTIVE SURGERY Wan, D. C., Longaker, M. T., Allam, K. A., Perry, A., Kawamoto, H. K. 2011; 127 (1): 352-354

  View details for DOI 10.1097/PRS.0b013e3181fad3d6

  View details for Web of Science ID 000285992100048

  View details for PubMedID 21200230

• Correction of Large Facial Encephalocele With Bilateral Rare Craniofacial Clefts JOURNAL OF CRANIOFACIAL SURGERY Wan, D. C., Lazareff, J. A., Jarrahy, R., Bradley, J. P. 2011; 22 (1): 338-342

  Abstract

  Treatment of Tessier number 3, 11 craniofacial clefts represent a surgical challenge with complex bone and soft tissue deficits of the lip, cheek, medial orbit, and forehead. The severity of the presenting defect will ultimately determine the number of reconstructive stages required as well as the timing of each stage. Initial surgery in infancy is aimed at functional correction. We present the case of a patient with an expanding fronto-orbital encephalocele, a right number 3, 11 cleft and a left number 3, 10 cleft. The initial procedure repaired the encephalocele and reconstructed the supraorbital and forehead regions. Subsequent surgeries corrected the bilateral facial clefts with cleft lip repair, rotation of the forehead and nasal unit, cheek advancement, and a lower eyelid transposition flap.

  View details for DOI 10.1097/SCS.0b013e3181f7e0fb

  View details for Web of Science ID 000286195600080

  View details for PubMedID 21239931

• Deformational Plagiocephaly: A Look Into the Future JOURNAL OF CRANIOFACIAL SURGERY Levi, B., Wan, D. C., Longaker, M. T., Habal, M. B. 2011; 22 (1): 3-5

  View details for DOI 10.1097/SCS.0b013e3181fb7ee5

  View details for Web of Science ID 000286195600002

  View details for PubMedID 21239916

• Gradual Orbital Contraction after Facial Bipartition: Correction of Wide No. 0 to 14 Craniofacial Cleft PLASTIC AND RECONSTRUCTIVE SURGERY Wan, D. C., Tanna, N., Allam, K. A., Perry, A., Bradley, J. P. 2010; 126 (6): 2109-2112

  View details for DOI 10.1097/PRS.0b013e3181f44802

  View details for Web of Science ID 000284832400060

  View details for PubMedID 21124151

• Depot-Specific Variation in the Osteogenic and Adipogenic Potential of Human Adipose-Derived Stromal Cells PLASTIC AND RECONSTRUCTIVE SURGERY Levi, B., James, A. W., Glotzbach, J. P., Wan, D. C., Commons, G. W., Longaker, M. T. 2010; 126 (3): 822-834

  Abstract

  Adipose-derived stromal cells hold promise for use in tissue regeneration. However, multiple facets of their biology remain unclear. The authors examined the variations in osteogenesis and adipogenesis in adipose-derived stromal cells between subcutaneous fat depots and potential molecular causes.Adipose-derived stromal cells were isolated from human patients from subcutaneous fat depots, including arm, flank, thigh, and abdomen (n = 5 patients). Osteogenic and adipogenic differentiation was performed (alkaline phosphatase, alizarin red, and oil red O staining, and quantitative real-time polymerase chain reaction). Co-cultures were established to assess the paracrine effect of human adipose-derived stromal cells on mouse osteoblasts. Finally, HOX gene expression was analyzed by quantitative real-time polymerase chain reaction.Subcutaneous fat depots retain markedly different osteogenic and adipogenic potentials. Osteogenesis was most robust in adipose-derived stromal cells from the flank and thigh, as compared with those from the arm and abdomen (p < 0.05 by all markers examined). This was accompanied by elevations of BMP4 and BMPR1B (p < 0.05 by all markers examined). The osteogenic advantage of cells from the flank and thigh was again observed when analyzing the paracrine effects of these cells. Conversely, those cells isolated from the flank had a lesser ability to undergo adipogenic differentiation. Adipose-associated HOX genes were less expressed in flank-derived adipose-derived stromal cells.Variations exist between fat depots in terms of adipose-derived stromal cell osteogenic and adipogenic differentiation. Differences in HOX expression and bone morphogenetic protein signaling may underlie these observations. This study indicates that the choice of fat depot derivation of adipose-derived stromal cells may be an important one for future efforts in tissue engineering.

  View details for DOI 10.1097/PRS.0b013e3181e5f892

  View details for Web of Science ID 000281606700011

  View details for PubMedID 20811215

• Inclusion of Mesh in Donor-Site Repair of Free TRAM and Muscle-Sparing Free TRAM Flaps Yields Rates of Abdominal Complications Comparable to Those of DIEP Flap Reconstruction PLASTIC AND RECONSTRUCTIVE SURGERY Wan, D. C., Tseng, C. Y., Anderson-Dam, J., Dalio, A. L., Crisera, C. A., Festekjian, J. H. 2010; 126 (2): 367-374

  Abstract

  Pedicled and free transverse rectus abdominis musculocutaneous (TRAM) flaps remain popular for autologous breast reconstruction, but the incidence of abdominal donor-site bulge and hernia is significantly greater when compared with deep inferior epigastric artery perforator (DIEP) flap reconstruction. Mesh repair after muscle harvest, however, may reduce the complication rate to that observed with perforator flaps alone.A retrospective review of all free flap breast reconstructions at the University of California, Los Angeles Medical Center from 2002 to 2007 was performed. Abdominal bulge and hernia were noted for patients undergoing free TRAM and muscle-sparing free TRAM flap reconstructions and were compared with those observed following DIEP flap reconstructions.A total of 275 free TRAM plus muscle-sparing free TRAM flaps and 200 DIEP flaps were performed. Among patients with free and muscle-sparing free TRAM flaps, 11.3 percent were found to have postoperative abdominal bulge or hernia. Only 3.5 percent of DIEP flap patients had abdominal complications. Incorporating mesh into the rectus fascia repair significantly reduced the abdominal complications reported to 5.1 percent. Of the 86 free and muscle-sparing free TRAM flaps that were bilateral, 12.8 percent had hernias/bulges. Use of mesh with bilateral free and muscle-sparing free TRAM flaps reduced the complication rate to 3.7 percent.Incorporating mesh into rectus fascia repair in free and muscle-sparing free TRAM flap cases significantly reduces the rate of postoperative abdominal complications to levels equivalent to those for DIEP flap reconstructions. The authors advocate deciding intraoperatively between DIEP and muscle-sparing free TRAM flap dissections based on ease of dissection and whichever offers optimal safety and flap perfusion. Routine use of mesh in donor-site repair will decrease postoperative abdominal morbidity in unilateral and bilateral cases.

  View details for DOI 10.1097/PRS.0b013e3181de1b7e

  View details for Web of Science ID 000280143800004

  View details for PubMedID 20679822

• Regulation of Human Adipose-Derived Stromal Cell Osteogenic Differentiation by Insulin-Like Growth Factor-1 and Platelet-Derived Growth Factor-alpha PLASTIC AND RECONSTRUCTIVE SURGERY Levi, B., James, A. W., Wan, D. C., Glotzbach, J. P., Commons, G. W., Longaker, M. T. 2010; 126 (1): 41-52

  Abstract

  Human adipose-derived stromal cells possess a great potential for tissue engineering purposes. The authors' laboratory is interested in harnessing human adipose-derived stromal cells for skeletal tissue regeneration and identifying those factors that enhance human adipose-derived stromal cell osteogenic differentiation. The authors hypothesized that insulin-like growth factor (IGF) and platelet-derived growth factor (PDGF) would stimulate human adipose-derived stromal cell osteogenesis and that IGF would stimulate adipogenesis.Adipose-derived stromal cells were harvested from human lipoaspirate. Previously, a microarray analysis examined gene expression throughout osteogenic differentiation. In a candidate fashion, the authors added recombinant IGF-1 and PDGF-alpha individually and in combination. Osteogenesis and adipogenesis were assessed by alkaline phosphatase, alizarin red, and oil red O staining, and quantitative real-time polymerase chain reaction (RUNX2, ALP, OCN, IGF1, PPARG, LPL, AP2, and GCP1). Finally, intersection between IGF and PDGF signaling pathways was evaluated.IGF-1 was observed to increase osteogenic differentiation by all markers (p < 0.01). However, PDGF-alpha when added alone primarily did not affect osteogenic markers. PDGF-alpha positively regulated transcription of IGF1. Addition of PDGF-alpha in combination with or before IGF-1 enhanced osteogenesis more than either alone. IGF-1 increased whereas PDGF-alpha diminished human adipose-derived stromal cell adipogenesis.IGF signaling significantly increased osteogenesis in human adipose-derived stromal cells and may be used for tissue-engineering purposes. The combination of PDGF and IGF may be more beneficial than either alone in driving adipose-derived stromal cell osteogenesis. Future in vivo applications will focus on the combination of adipose-derived stromal cells, biomimetic scaffolds, and recombinant IGF.

  View details for DOI 10.1097/PRS.0b013e3181da8858

  View details for Web of Science ID 000279097500006

  View details for PubMedID 20220555

  View details for PubMedCentralID PMC3016898

• Origin Matters: Differences in Embryonic Tissue Origin and Wnt Signaling Determine the Osteogenic Potential and Healing Capacity of Frontal and Parietal Calvarial Bones JOURNAL OF BONE AND MINERAL RESEARCH Quarto, N., Wan, D. C., Kwan, M. D., Panetta, N. J., Li, S., Longaker, M. T. 2010; 25 (7): 1680-1694

  Abstract

  Calvarial bones arise from two embryonic tissues, namely, the neural crest and the mesoderm. In this study we have addressed the important question of whether disparate embryonic tissue origins impart variable osteogenic potential and regenerative capacity to calvarial bones, as well as what the underlying molecular mechanism(s). Thus, by performing in vitro and in vivo studies, we have investigated whether differences exist between neural crest-derived frontal and paraxial mesodermal-derived parietal bone. Of interest, our data indicate that calvarial bone osteoblasts of neural crest origin have superior potential for osteogenic differentiation. Furthermore, neural crest-derived frontal bone displays a superior capacity to undergo osseous healing compared with calvarial bone of paraxial mesoderm origin. Our study identified both in vitro and in vivo enhanced endogenous canonical Wnt signaling in frontal bone compared with parietal bone. In addition, we demonstrate that constitutive activation of canonical Wnt signaling in paraxial mesodermal-derived parietal osteoblasts mimics the osteogenic potential of frontal osteoblasts, whereas knockdown of canonical Wnt signaling dramatically impairs the greater osteogenic potential of neural crest-derived frontal osteoblasts. Moreover, fibroblast growth factor 2 (FGF-2) treatment induces phosphorylation of GSK-3beta and increases the nuclear levels of beta-catenin in osteoblasts, suggesting that enhanced activation of Wnt signaling might be mediated by FGF. Taken together, our data provide compelling evidence that indeed embryonic tissue origin makes a difference and that active canonical Wnt signaling plays a major role in contributing to the superior intrinsic osteogenic potential and tissue regeneration observed in neural crest-derived frontal bone.

  View details for DOI 10.1359/jbmr.091116

  View details for Web of Science ID 000280395900023

  View details for PubMedID 19929441

  View details for PubMedCentralID PMC3154006

• Elucidating Mechanisms of Osteogenesis in Human Adipose-Derived Stromal Cells via Microarray Analysis JOURNAL OF CRANIOFACIAL SURGERY Lee, J., Gupta, D., Panetta, N. J., Levi, B., James, A. W., Wan, D., Commons, G. W., Longaker, M. T. 2010; 21 (4): 1136-1141

  Abstract

  The osteogenic potential of human adipose-derived stromal cells (hASCs), the ease of cell procurement, and the shortcomings of conventional skeletal reconstruction call for further analysis of the molecular mechanisms governing hASC osteogenic differentiation. We have examined the expression profile of the human transcriptome during osteogenic differentiation of ASCs using microarray. Subsequently, we analyzed those genes related to osteogenesis that have not been previously studied about hASCs. We have preliminarily assessed the role of IGFBP3, TGF-B3, TNC, CTGF, DKK-1, and PDGFRB in hASC osteogenic differentiation.We compared the expression profile of undifferentiated hASCs to that of hASCs treated with osteogenic differentiation medium for 1, 3, or 7 days using the Human Exonic Evidence-Based Oligonucleotide chip. Genes significantly overexpress or underexpressed were validated with quantitative reverse transcription-polymerase chain reaction. The osteogenic capability of ASCs was verified by Alizarin Red staining.IGFBP3, TGF-B3, TNC, CTGF, and PDGFRB were all upregulated in early osteogenesis, and TGF-B3, TNC, and PDGFRB were upregulated in late osteogenesis by microarray and quantitative reverse transcription analysis. In contrast, DKK-1 was downregulated in early and late osteogenesis. Alizarin Red staining showed a significant increase in mineralization in hASCs, even after 1 day in osteogenic differentiation medium.Factors that commit hASCs to an osteogenic pathway remain largely unknown. We have described 6 genes that play key roles in hASC osteogenic differentiation. We plan to further exploit these data via in vitro treatment of hASCs with these soluble cytokines and in vivo translation using a nude mouse calvarial defect model.

  View details for DOI 10.1097/SCS.0b013e3181e488d6

  View details for Web of Science ID 000280149100044

  View details for PubMedID 20613589

• Amelioration of Acquired Nasopharyngeal Stenosis, with Bilateral Z-Pharyngoplasty ANNALS OF PLASTIC SURGERY Wan, D. C., Kumar, A., Head, C. S., Katchikian, H., Bradley, J. P. 2010; 64 (6): 747-750

  Abstract

  Nasopharyngeal stenosis as a postoperative complication following pharyngeal surgery (tonsillectomy/adenoidectomy) is rare and may be difficult to treat. All patients with severe nasopharyngeal stenosis treated at UCLA with a bilateral Z-pharyngoplasty procedure from 1999 to 2006 were studied (n = 6). Degree of pharyngeal stenosis preoperatively and following a bilateral Z-pharyngoplasty was graded 0-4 based on (1) symptomatology (snoring, hyponasal speech, difficulty with nasal breathing, difficulty breathing during exercise, obstructive sleep apnea, daytime fatigue, anosmia, rhinorrea, dysphagia, or difficulty in blowing nose) and (2) measurement of stricture at the time of direct nasolaryngoscopy. Nasopharyngeal stenosis after pharyngeal surgery (adenotonsillectomy--67%, uvuloplasty--17%, pharyngoplasty--17%) failed to be alleviated by a mean of 2.3 procedures (kenalog injection or scar excision) and required corrective bilateral Z-pharyngoplasty a mean of 9.2 months after the original surgery. Symptomatic grading of the nasopharyngeal stenosis improved from a mean score of 3.3 (severe stenosis) preoperatively to a score of 0.2 (minimal to no stenosis) in follow-up. Endoscopic stricture measurement improved from 6.1 x 6.3 mm preoperatively to 28.1 x 39.3 mm in follow-up. Bilateral Z-pharyngoplasty was effective in alleviating severe postsurgical nasopharyngeal stenosis.

  View details for DOI 10.1097/SAP.0b013e3181a73009

  View details for Web of Science ID 000278116900012

  View details for PubMedID 20489403

• Marjolin Ulcer in Hidradenitis Suppurativa Case Reports ANNALS OF PLASTIC SURGERY Grewal, N. S., Wan, D. C., Roostaeian, J., Rubayi, S. R. 2010; 64 (3): 315-317

  Abstract

  Hidradenitis suppurativa is a chronic, recurrent, inflammatory disease of apocrine gland-bearing skin areas. Long-standing low-grade infection and chronic abscess formation result in ulcers, fistulas, and progressive scars. A rare complication is the development of squamous cell carcinoma, known as Marjolin ulcer. We report 3 cases in which squamous cell carcinoma developed despite medical treatments and local excisions. Because of the poor prognosis associated with squamous cell carcinoma, we advocate wide excision of hidradenitis suppurativa lesions when other treatments have failed.

  View details for DOI 10.1097/SAP.0b013e3181a7302a

  View details for Web of Science ID 000275061800013

  View details for PubMedID 20179481

• Human Adipose-Derived Stromal Cells Respond to and Elaborate Bone Morphogenetic Protein-2 during In Vitro Osteogenic Differentiation PLASTIC AND RECONSTRUCTIVE SURGERY Panetta, N. J., Gupta, D. M., Lee, J. K., Wan, D. C., Commons, G. W., Longaker, M. T. 2010; 125 (2): 483-493

  Abstract

  Interest in the potential application of adipose-derived stromal cells in cell-mediated tissue engineering of bone and other mesenchymal-derived tissues is growing. This study aimed to investigate the hypothesis that human adipose-derived stromal cells respond to and elaborate bone morphogenetic protein (BMP) 2, which could represent an important target of molecular manipulation to enhance the osteogenic potential of human adipose-derived stromal cells.Human adipose-derived stromal cells were differentiated for 10 days toward the osteogenic lineage in osteogenic differentiation media alone or supplemented with recombinant human BMP2 (rhBMP2). Alizarin red staining was quantified by spectrophotometry. Gene expression analyses were performed using quantitative real-time polymerase chain reaction. BMP2 levels in conditioned media were titered by enzyme-linked immunosorbent assay daily during osteogenic differentiation. Human adipose-derived stromal cells were cultured in complete or partially (50 percent) changed osteogenic differentiation media, or unchanged osteogenic differentiation media, to assay for pro-osteogenic secreted factors. In addition, human adipose-derived stromal cells were cultured in osteogenic differentiation media supplemented with BMP2/BMP4-neutralizing antibody.Exogenous rhBMP2 significantly augmented the in vitro osteogenic potential of human adipose-derived stromal cells in a dose-dependent fashion, and significantly increased transcript levels of RUNX2 and osteocalcin. BMP2, BMP4, BMPR1B, and SMAD1/5 expression was significantly increased during differentiation. Enzyme-linked immunosorbent assay demonstrated significantly increased BMP2 elaboration during differentiation. Culture in conditioned osteogenic differentiation media led to significantly increased matrix mineralization. Mineralization was significantly decreased when osteogenic differentiation media was supplemented with a BMP2/BMP4-neutralizing antibody.These data strongly support that BMP signaling is dynamic and important during normal in vitro osteogenic differentiation of human adipose-derived stromal cells. Thus, BMP2 may be used to enhance the osteogenic differentiation of human adipose-derived stromal cells for bone tissue engineering. Future studies will examine the effect of rhBMP2 on osteogenic differentiation of human adipose-derived stromal cells in vivo.

  View details for DOI 10.1097/PRS.0b013e3181c82d75

  View details for Web of Science ID 000274741700008

  View details for PubMedID 20124834

• Craniofacial surgery, from past pioneers to future promise. Journal of maxillofacial and oral surgery Wan, D. C., Kwan, M. D., Kumar, A., Bradley, J. P., Longaker, M. T. 2009; 8 (4): 348-356

  Abstract

  As a surgical subspecialty devoted to restoration of normal facial and calvarial anatomy, craniofacial surgeons must navigate the balance between pathologic states of bone excess and bone deficit. While current techniques employed take root in lessons learned from the success and failure of early pioneers, craniofacial surgery continues to evolve, and novel modalities will undoubtedly arise integrating past and present experiences with future promise to effectively treat craniofacial disorders.This review provides an overview of current approaches in craniofacial surgery for treating states of bone excess and deficit, recent advances in our understanding of the molecular and cellular processes underlying craniosynostosis, a pathological state of bone excess, and current research efforts in cellular-based therapies for bone regeneration.The surgical treatment of bone excess and deficit has evolved to improve both the functional and morphological outcomes of affected patients. Recent progress in elucidating the molecular and cellular mechanisms governing bone formation will be instrumental for developing improved therapies for the treatment of pathological states of bone excess and deficit.While significant advances have been achieved in craniofacial surgery, improved strategies for addressing states of bone excess and bone deficit in the craniofacial region are needed. Investigations on the biomolecular events involved in craniosynostosis and cellular-based bone tissue engineering may soon be added to the armamentarium of surgeons treating craniofacial dysmorphologies.

  View details for DOI 10.1007/s12663-009-0084-x

  View details for PubMedID 23139542

  View details for PubMedCentralID PMC3454104

• Tissue Harvest by Means of Suction-Assisted or Third-Generation Ultrasound-Assisted Lipoaspiration Has No Effect on Osteogenic Potential of Human Adipose-Derived Stromal Cells PLASTIC AND RECONSTRUCTIVE SURGERY Panetta, N. J., Gupta, D. M., Kwan, M. D., Wan, D. C., Commons, G. W., Longaker, M. T. 2009; 124 (1): 65-73

  Abstract

  Human adipose-derived stromal cells readily undergo osteogenic differentiation in vitro and in vivo. Thus, interest in their potential role in skeletal tissue engineering continues to escalate. Very little is known regarding the effects that energy delivered by means of third-generation ultrasound-assisted lipoaspiration may have on the osteogenic potential of these cells. The authors investigated whether differences in adipose-derived stromal cell yield, and the in vitro proliferation and osteogenic potential of these cells obtained by suction-assisted lipoaspiration or third-generation ultrasound-assisted lipoaspiration, exist.Adipose-derived stromal cells were harvested from lipoaspiration specimens of patients undergoing elective suction-assisted lipoaspiration and third-generation ultrasound-assisted lipoaspiration. Harvested cells were seeded to evaluate proliferative capacity and in vitro osteogenic potential. Alkaline phosphatase and alizarin red staining were performed to evaluate early and terminal osteogenic differentiation, respectively. Quantitative real-time polymerase chain reaction analysis was used to examine osteogenic gene expression patterns of RUNX2/CFBA1 (early differentiation) and osteocalcin (late differentiation).No significant differences in the proliferative capacity (n = 3), alkaline phosphatase staining (n = 3), or extracellular matrix mineralization (n = 3) of suction-assisted lipoaspiration- or third-generation ultrasound-assisted lipoaspiration-derived cells were appreciated. Transcript levels of markers of early and terminal osteogenic differentiation were not significantly different (n = 3).These findings suggest that exposure of adipose-derived stromal cells to ultrasound energy during tissue harvest by means of third-generation ultrasound-assisted lipoaspiration does not impart a negative consequence toward their proliferative capacity or osteogenic potential. Thus, the cells harvested using third-generation ultrasound-assisted lipoaspiration are comparable to those obtained by means of suction-assisted lipoaspiration for use in the study of osteogenic differentiation and skeletal tissue engineering.

  View details for DOI 10.1097/PRS.0b013e3181ab10cd

  View details for Web of Science ID 000267895000011

  View details for PubMedID 19568046

• Craniofacial Autologous Fat Transfer JOURNAL OF CRANIOFACIAL SURGERY Wan, D. C., Lim, A. T., Longaker, M. T. 2009; 20 (2): 273-274

  View details for DOI 10.1097/SCS.0b013e31819921d3

  View details for Web of Science ID 000264570300003

  View details for PubMedID 19305242

• Taz is a transcriptional modulator of human adipose-derived stromal cell differentiation towards the osteogenic lineage 13th International Congress of the International-Society-of-Craniofacial-Surgery / Paris Distraction Symposium Gupta, D. M., Panetta, N. J., Vial, I. N., Lee, J. K., Wan, D. C., Gurtner, G. C., Longaker, M. T. MEDIMOND S R L. 2009: 87–89

  View details for Web of Science ID 000303383400018

• Human adipose-derived stromal cells elaborate and respond to bone morphogenetic protein-2 (bmp-2) during in vitro osteogenic differentiation 13th International Congress of the International-Society-of-Craniofacial-Surgery / Paris Distraction Symposium Gupta, D. M., Panetta, N. J., Wan, D. C., Commons, G. W., Longaker, M. T. MEDIMOND S R L. 2009: 79–81

  View details for Web of Science ID 000303383400016

• Tissue-harvest procedure has no effect on adipose-derived stromal cell-mediated bone tissue engineering in vitro 13th International Congress of the International-Society-of-Craniofacial-Surgery / Paris Distraction Symposium Panetta, N. J., Gupta, D. M., Kwan, M. D., Wan, D. C., Commons, G. W., Longaker, M. T. MEDIMOND S R L. 2009: 163–165

  View details for Web of Science ID 000303383400031

• Global age-dependent differences in gene expression in response to calvarial injuryd JOURNAL OF CRANIOFACIAL SURGERY Wan, D. C., Kwan, M. D., Gupta, D. M., Wang, Z., Slater, B. J., Panetta, N. J., Morrell, N. T., Longaker, M. T. 2008; 19 (5): 1292-1301

  Abstract

  Children less than 2 years of age are capable of healing large calvarial defects, whereas adults have been found to lack this endogenous ability. In this study, we used microarray analysis to compare genomewide expression patterns during active regeneration after injury with calvaria in skeletally immature and mature mice. Parietal bone defects were created in 6-day-old (juvenile) and 60-day-old (adult) mice using a 4-mm trephine bit (n = 20 mice per age group). The calvarial disc was removed, leaving the underlying dura mater intact. Two weeks after injury, the region of regeneration with the underlying dura mater was harvested, and RNA was extracted for microarray analysis. The 25 most differentially upregulated genes in juvenile regenerates compared with adults were listed, as well as selected bone-related genes. In addition, QRT-PCR confirmation of specific genes was performed for validation. Juvenile regenerates expressed significantly greater amounts of BMP-2, -4, -7, as well as FGF-2 and its receptor FGFR-1. Various other growth factors were also noted to be upregulated, including IGF-2 and Ptn. This corresponded with the increased expression of markers for osteogenic differentiation of Sparc and Oc. Markers of osteoclast activity, Acp5, Ctsk, and Mmp2, were noted to be greater in juvenile regenerates compared with adults. The observation of Mmp14 upregulation, however, highlights the importance of balanced osteoclast-mediated bone resorption for ultimate healing. The 2 most differentially regulated genes, transthyretin (Ttr) and prostaglandin D2 synthase (Ptgds), highlight the potential role of retinoic acid signaling and the prostaglandin axis on skeletal regeneration. These findings underscore the multitude of biomolecular mechanisms at play, allowing juvenile calvaria to heal after injury. The identification of various growth factors and cytokines involved also suggests novel therapeutic strategies for tissue-engineering purposes.

  View details for Web of Science ID 000259503400015

  View details for PubMedID 18812854

• Microarray analysis of the role of regional dura mater in cranial suture fate PLASTIC AND RECONSTRUCTIVE SURGERY Kwan, M. D., Wan, D. C., Wang, Z., Gupta, D. M., Slater, B. J., Longaker, M. T. 2008; 122 (2): 389-399

  Abstract

  Craniosynostosis, the premature fusion of cranial sutures, results in serious neurologic and morphologic abnormalities when left untreated. Surgical excision of the fused sutures and remodeling of the skull remains the standard therapy. Development of novel, minimally invasive therapies for craniosynostosis will undoubtedly be dependent on a more thorough understanding of the molecular mechanisms underlying this abnormality. Significant evidence suggests the influence of regional dura mater on the behavior of the overlying suture complex. The mouse model has been instrumental in investigating this observation because of the natural juxtaposition of the posterior frontal suture, which fuses early in life, with the other cranial sutures, which remain patent.The authors used microarray analysis to compare genomic changes in the dura mater underlying the posterior frontal and sagittal sutures of mice. Suture-associated dura mater was harvested from mice before (postnatal day 5), during (postnatal day 10), and after (postnatal day 20) posterior frontal suture fusion (n = 20 mice for each of the three time points).Microarray results confirmed differential regulation of genes involved in paracrine signaling, extracellular matrix, and bone remodeling between the dura mater underlying the fusing posterior frontal suture and the patent sagittal suture.These data confirm global differences in gene expression between regional dura mater underlying fusing and patent sutures. These results provide further insight into potential molecular mechanisms that may play a role in cranial suture biology.

  View details for DOI 10.1097/PRS.0b013e31817d6244

  View details for Web of Science ID 000258136900008

  View details for PubMedID 18626354

• Dissecting the influence of regional dura mater on cranial suture biology PLASTIC AND RECONSTRUCTIVE SURGERY Slater, B. J., Kwan, M. D., Gupta, D. M., Amasha, R. R., Wan, D. C., Longaker, M. T. 2008; 122 (1): 77-84

  Abstract

  Craniosynostosis is a relatively common developmental disorder that leads to a number of serious consequences. Previous studies have shown the influence of dura mater on the overlying cranial suture. This study was conducted to determine the role of regional dura mater versus the intrinsic nature of the suture in directing the overlying suture's fate.The authors examined the effect of regional dura mater on the fate and morphology of the posterofrontal and coronal sutures. In 8-day-old Sprague-Dawley rats, calvarial disks, consisting of the posterofrontal and coronal sutures, were excised and placed in one of three positions: (1) native position (control group), (2) rotated 45 degrees, or (3) rotated 90 degrees (n = 5 animals per group). The animals were euthanized 1 month postoperatively, and the sutures were analyzed histologically.The control group revealed normal suture morphology (n = 5). In the 45-degree rotation group, which placed the posterofrontal and coronal sutures over non-suture-associated dura mater, the posterofrontal sutures fused with thin morphology, and the coronal sutures remained patent (n = 5). In the 90-degree rotation group, the posterofrontal sutures, which were positioned over coronal suture-associated dura mater, were found to be fused with thinner morphology. The coronal sutures of the 90-degree rotation group, which were placed over posterofrontal suture-associated dura mater, remained patent but had acquired a posterofrontal-like morphology (n = 5).This study further elucidates variations in the biology of dura mater, depending on its location. Furthermore, these results illustrate the interplay between regional dura mater and the inherent characteristics of the suture complex in determining suture biology.

  View details for DOI 10.1097/PRS.0b013e318177478c

  View details for Web of Science ID 000257104300008

  View details for PubMedID 18594389

• Testicular carcinoma presenting as cutaneous nasal metastasis: Case report and review of the literature BRITISH JOURNAL OF ORAL & MAXILLOFACIAL SURGERY Gleizal, A., Torossian, J. M., Wan, D. C., Beziat, J. 2008; 46 (5): 416-418

  Abstract

  Testicular choriocarcinoma is a highly malignant germ cell neoplasm, which metastasises to lungs, and brain. Spread to the skin, however, is rare, with only 11 cases reported to our knowledge. This is the second reported case of a skin metastasis of choriocarcinoma to the head and neck, and the third in which a cutaneous metastasis was the first finding at initial presentation. A review of published reports showed that it had been described as individual firm, reddish or violaceous subcutaneous nodules with typical histological features.

  View details for DOI 10.1016/j.bjoms.2007.10.006

  View details for Web of Science ID 000257639900019

  View details for PubMedID 18155815

• Molecular mechanisms of FGF-2 inhibitory activity in the osteogenic context of mouse adipose-derived stem cells (mASCs) BONE Quarto, N., Wan, D. C., Longaker, M. T. 2008; 42 (6): 1040-1052

  Abstract

  Adipose-derived adult stem cells (ASCs), like their bone-marrow derived counterparts, possess the ability to differentiate down osteogenic, chondrogenic, adipogenic, and myogenic pathways. For bone differentiation of mouse ASCs (mASCs), retinoic-acid mediated upregulation of BMPR-IB has been found to be necessary. Interestingly, our previous work has also shown Fibroblast Growth Factor-2 (FGF-2) to strongly inhibit this osteogenic differentiation, even in the presence of retinoic acid. In this report, we investigated the molecular mechanisms underlying FGF-2 mediated osteogenic inhibition, demonstrating that addition of exogenous FGF-2 to mASCs antagonizes upregulation of BMPR-IB gene expression in response to retinoic acid. In addition, constitutive expression of BMPR-IB, but not BMPR-IA or BMPR-II, was found to counteract the inhibitory effects of FGF-2. Finally, p53(-/-) mASCs and human ASCs, both of which express high levels of endogenous BMPR-IB, underwent normal osteogenic differentiation even in the presence of FGF-2. Collectively, our data therefore indicate that FGF-2 antagonizes the response of mASCs to retinoic acid and also suggest that threshold levels of BMPR-IB may play a crucial role both in counteracting the inhibitory role of FGF-2 and in promoting osteogenic differentiation of ASCs in the absence of retinoic acid. Moreover, the present study also indicates that differences exist between mouse and human ASCs in relationship to FGF-2 activity in the osteogenic context.

  View details for DOI 10.1016/j.bone.2008.01.026

  View details for Web of Science ID 000256330000006

  View details for PubMedID 18420480

• Cell-based therapies for skeletal regenerative medicine HUMAN MOLECULAR GENETICS Kwan, M. D., Slater, B. J., Wan, D. C., Longaker, M. T. 2008; 17: R93-R98

  Abstract

  Skeletal deficits represent a substantial biomedical burden on the US healthcare system. Current strategies for reconstructing bony defects are fraught with inadequacies. Cell-based therapies for skeletal regeneration offer a paradigm shift that may provide alternative solutions. Substantial work has identified a host of cellular sources that possess the potential for osteogenic differentiation. Significant efforts have been devoted toward characterizing the role of postnatal cellular sources that are relatively abundant and easily accessible. Among these, the potential of using adipose-derived stromal cells for skeletal regeneration has garnered much interest. Integral to these efforts directed at characterizing cellular sources are studies that seek to understand the factors that initiate and regulate osteogenic differentiation of progenitor cells. Specifically, focus has been directed on elucidating the role of bone morphogenetic protein and fibroblast growth factor signaling in regulating osteogenic differentiation of osteoprogenitor cells. Concurrent studies in the field of scaffold design have also helped to advance the potential for cell-based therapies.

  View details for DOI 10.1093/hmg/ddn071

  View details for Web of Science ID 000258261600015

  View details for PubMedID 18632703

• Cranial Sutures: A Brief Review PLASTIC AND RECONSTRUCTIVE SURGERY Slater, B. J., Lenton, K. A., Kwan, M. D., Gupta, D. M., Wan, D. C., Longaker, M. T. 2008; 121 (4): 170E-178E

  Abstract

  Craniosynostosis, or the premature fusion of one or more cranial sutures, is a relatively common congenital defect that causes a number of morphologic and functional abnormalities. With advances in genetics and molecular biology, research of craniosynostosis has progressed from describing gross abnormalities to understanding the molecular interactions that underlie these cranial deformities. Animal models have been extremely valuable in improving our comprehension of human craniofacial morphogenesis, primarily by human genetic linkage analysis and the development of knock-out animals. This article provides a brief review of perisutural tissue interactions, embryonic origins, signaling molecules and their receptors, and transcription factors in maintaining the delicate balance between proliferation and differentiation of cells within the suture complex that determines suture fate. Finally, this article discusses the potential implications for developing novel therapies for craniosynostosis.

  View details for DOI 10.1097/01.prs.0000304441.99483.97

  View details for Web of Science ID 000207666900003

  View details for PubMedID 18349596

• Highlights of the proceedings from the 12th International Congress of the International Society of Craniofacial Surgery: ISCFS 2007. journal of craniofacial surgery Wan, D. C., Kwan, M. D., Bradley, J. P. 2008; 19 (2): 551-554

  View details for DOI 10.1097/SCS.0b013e3181642654

  View details for PubMedID 18362757

• Myoplasty for congenital macrostomia CLEFT PALATE-CRANIOFACIAL JOURNAL Gleizal, A., Wan, D. C., Kwan, M. D., Beziat, J. 2008; 45 (2): 179-186

  Abstract

  To describe the different myoplasty techniques that could be used for limited commissural reconstruction.Twelve cases of congenital macrostomia are reported, with different cleft lengths and termination sites. For each case, an orbicular myoplasty was performed, and in the case of extension to the area of the tragus or tonsillar pillars, a masseteric myoplasty or pharyngoplasty was performed. Functional and aesthetic results were analyzed.Functional results were excellent, with normal phonation, facial expression, and deglutition in the case of posterior extension. Aesthetic results were good, with only two cases of skin fasciculation during facial movement.Myoplasty in macrostomia could be limited to an orbicular reorientation in the case of a short cleft or can include a masseteric myoplasty or pharnygoplasty should the cleft extend further. Analyzing 90 reported cases of congenital macrostomia in the world literature, an important point has emerged. In some cases, the cleft could continue sagittally to the tonsillar pillars or laterally, distal to the anterior border of the masseter, to the region of the tragus. Repair in these cases requires reconstruction of the tonsillar pillars and masseteric repair in addition to orbicular removal. No reports in the world literature have referred to these other myoplasties that could be necessary, even if such pathology is very rare. In addition, no classification of congenital macrostomia was found in the world literature. We therefore propose a surgical classification of macrostomia relative to the nature of myoplasty required.

  View details for DOI 10.1597/05-190.1

  View details for Web of Science ID 000254373500009

  View details for PubMedID 18333640

• Current treatment of craniosynostosis and future therapeutic directions. Frontiers of oral biology Wan, D. C., Kwan, M. D., Lorenz, H. P., Longaker, M. T. 2008; 12: 209-230

  Abstract

  Normal craniofacial development is contingent upon coordinated growth between the brain and overlying calvaria. Craniosynostosis, the premature fusion of one or more cranial sutures, perturbs this natural framework, resulting in dramatic dysmorphology of the skull and face along with a multitude of associated functional abnormalities. Traditional approaches to the treatment of craniosynostosis have employed complex surgical remodeling of the skull vault and facial deformities all aimed at increasing the amount of intracranial volume and restoring a more normal craniofacial appearance. Significant morbidity and mortality, however, have plagued these procedures, driving dramatic evolution in our approach towards the treatment of pathologically fused sutures. Recent clinical and genetic studies have identified multiple forms of human craniosynostosis, each associated with mutations within various cytokine signaling pathways. Knowledge garnered from these investigations bear promise for the future development of alternative strategies to enhance or perhaps even replace contemporary approaches for the treatment of craniosynostosis.

  View details for DOI 10.1159/0000115043

  View details for PubMedID 18391503

• Applications of an athymic nude mouse model of nonhealing critical-sized calvarial defects JOURNAL OF CRANIOFACIAL SURGERY Gupta, D. M., Kwan, M. D., Slater, B. J., Wan, D. C., Longaker, M. T. 2008; 19 (1): 192-197

  Abstract

  Calvarial bone defects are a common clinical scenario in craniofacial surgery. Numerous approaches are used to reconstruct skull defects, and each possesses its own inherent disadvantages. This fact underscores the opportunity to develop a novel method to repair osseous defects in craniofacial surgery. Recent literature strongly suggests that cell-based therapies in the form of regenerative medicine may be a developing paradigm in reconstructive surgery. Although numerous studies have probed osteoprogenitor cells from mice, few have explored the biology of human cells in the setting of osteogenesis in an equally rigorous manner. This study proposes a nude mouse model of critical-sized calvarial defects to study the in vivo biology of human osteoprogenitor cells. Critical-sized 4.0-mm calvarial defects were created in nude mice (n = 15) with a custom trephine drill bit outfitted to a dental drill handpiece. During the craniotomy, the dura mater was spared from injury. Gross inspection, routine histology, and micro-computed tomographic scanning were performed at 2, 4, 8, and 16 weeks postoperatively. There was no calvarial healing in any of the animals by 16 weeks. The dura mater remained intact in all subjects. Gross, histologic, and radiographic assays confirmed these findings. Although several studies have implanted human osteoprogenitor cells in vivo in various animal models, few have documented the appropriate controls or conditions necessary to support the potential to translate benchtop findings into clinical applications. We propose in this study that the nude mouse critical-sized calvarial defect model will be valuable with increasing investigations with human osteoprogenitor cells.

  View details for Web of Science ID 000252619900032

  View details for PubMedID 18216688

• Noggin suppression enhances in vitro osteogenesis and accelerates in vivo bone formation JOURNAL OF BIOLOGICAL CHEMISTRY Wan, D. C., Pomerantz, J. H., Brunet, L. J., Kim, J., Chou, Y., Wu, B. M., Harland, R., Blau, H. M., Longaker, M. T. 2007; 282 (36): 26450-26459

  Abstract

  Several investigations have demonstrated a precise balance to exist between bone morphogenetic protein (BMP) agonists and antagonists, dictating BMP signaling and osteogenesis. We report a novel approach to manipulate BMP activity through a down-regulation of the potent BMP antagonist Noggin, and examined the effects on the bone forming capacity of osteoblasts. Reduction of noggin enhanced BMP signaling and in vitro osteoblast bone formation, as demonstrated by both gene expression profiles and histological staining. The effects of noggin suppression on in vivo bone formation were also investigated using critical-sized calvarial defects in mice repaired with noggin-suppressed osteoblasts. Radiographic and histological analyses revealed significantly more bone regeneration at 2 and 4 weeks post-injury. These findings strongly support the concept of enhanced osteogenesis through a down-regulation in Noggin and suggest a novel approach to clinically accelerate bone formation, potentially allowing for earlier mobilization of patients following skeletal injury or surgical resection.

  View details for DOI 10.1074/jbc.M703282200

  View details for Web of Science ID 000249239600050

  View details for PubMedID 17609215

• Geometric morphometric analysis of craniofacial deformity in the noggin mutant 93rd Annual Clinical Congress of the American-College-of-Surgeons Gupta, D. M., Young, N. M., Wan, D. C., Brunet, L. J., Harland, R. M., Helms, J. A., Longaker, M. T. ELSEVIER SCIENCE INC. 2007: S60–S60

  View details for Web of Science ID 000249397300124

• Differential expression of sclerostin in the calvaria of young and adult mice 93rd Annual Clinical Congress of the American-College-of-Surgeons Kwan, M. D., Slater, B., Deepak, G., Wan, D., Longaker, M. T. ELSEVIER SCIENCE INC. 2007: S59–S59

  View details for Web of Science ID 000249397300121

• Refining retinoic acid stimulation for osteogenic differentiation of murine adipose-derived adult stromal cells TISSUE ENGINEERING Wan, D. C., Siedhoff, M. T., Kwan, M. D., Nacamuli, R. P., Wu, B. M., Longaker, M. T. 2007; 13 (7): 1623-1631

  Abstract

  Murine adipose-derived adult stromal cells (ADAS) seeded onto appropriate scaffolds and pre-incubated with retinoic acid have been shown to generate in vivo bone rapidly. Prompt resorption ensues, however, as a result of osteoclastogenesis, likely secondary to retinoic acid carryover. In this study, we determined the effects of abbreviated retinoic acid exposure on ADAS osteogenic differentiation. Histological staining and gene expression analysis revealed that longer retinoic acid exposure resulted in better in vitro bone differentiation. However, significant osteogenesis was observed in ADAS after just 15 days of retinoic acid supplementation, suggesting that continual culture with retinoic acid is unnecessary for initiation of the osteogenic program. This was confirmed using ADAS pre-incubated in monolayer with an abbreviated 15 days of retinoic acid exposure before implantation into critical-sized calvarial defects. Similar rates of regeneration were observed between ADAS exposed to for 15 days or for a full 25-day course of retinoic acid before defect repair. Furthermore, by limiting retinoic acid exposure to ADAS in monolayer without scaffold, accelerated bone formation was observed without concomitant osteoclastic resorption. These data suggest that skeletal regeneration may be improved by modulating retinoic acid exposure before implantation, markedly accelerating the repair of bone defects using ADAS.

  View details for DOI 10.1089/ten.2006.0283

  View details for Web of Science ID 000248035500022

  View details for PubMedID 17518707

• Re: Differential effects of FGFR2 mutation in ophthalniologic findings in Apert syndrome. Discussion JOURNAL OF CRANIOFACIAL SURGERY Kwan, M. D., Wan, D. C., Lorenz, H. P., Longaker, M. T. 2007; 18 (2): 459-460

  View details for Web of Science ID 000245424400039

  View details for PubMedID 17414305

• Bilateral macrostomia as an isolated pathology CLEFT PALATE-CRANIOFACIAL JOURNAL Gleizal, A., Wan, D. C., Picard, A., Lavis, J., Vazquez, M., Beziat, J. 2007; 44 (1): 58-61

  Abstract

  Congenital macrostomia is a lateral orofacial cleft between the maxillary and mandibular components of the first branchial arch. Bilateral macrostomia is a poorly characterized malformation, with only 14 cases reported in the literature. The purpose of this study was to compare our experience with the world literature.A retrospective analysis of 20 cases of bilateral congenital macrostomia was conducted; 6 cases were drawn from 2 maxillofacial surgery units and 14 cases from the world literature. Cases of bilateral congenital macrostomia were compared with cases of unilateral forms using a review of the literature post-1954. Among the six cases identified from the two maxillofacial surgery units, three were treated with linear sutures and three with Z-plasty. Subsequent aesthetic and functional results were analyzed.Compared to unilateral forms, bilateral macrostomia is more often isolated without ear or skin deformities. Moreover, there are a greater proportion of larger defects among cases with bilateral macrostomia when compared to unilateral macrostomia. Alimentation, phonation, and mouth opening were always normal. The two sides were always symmetric. Only one case presented with the complication of skin contractions during lip movement.The etiopathogenesis of bilateral macrostomia is unclear. Although over 50% of the reported cases of bilateral macrostomia are isolated, this condition presents a therapeutic challenge. In the case of bilateral forms, the surgeon must define the commissure position without a normal side. Repair thus requires extraoral landmarks and normal measurements.

  View details for Web of Science ID 000243465200008

  View details for PubMedID 17214527

• Applications of an Athymic nude mouse model of nonhealing critical-sized calvarial defects 12th Biennial Meeting of the International-Society-Craniofacial-Surgery Gupta, D. M., Kwan, M. D., Slater, B. J., Wan, D. C., Longaker, M. T. MEDIMOND S R L. 2007: 53–55

  View details for Web of Science ID 000257312900014

• Gene expression differences between the dura mater of fusing and patent sutures in the mouse model 12th Biennial Meeting of the International-Society-Craniofacial-Surgery Kwan, M. D., Wan, D. C., Wang, Z., Gupta, D. M., Slater, B. J., Beck, D., Longaker, M. T. MEDIMOND S R L. 2007: 21–24

  View details for Web of Science ID 000257312900006

• Noggin suppression enhances in vivo bone formation 12th Biennial Meeting of the International-Society-Craniofacial-Surgery Wan, D. C., Pomerantz, J. H., Brunet, L. J., Kim, J., Chou, Y., Kwan, M. D., Slater, B. J., Gupta, D. M., Wu, B. M., Harland, R. M., Blau, H. M., Longaker, M. T. MEDIMOND S R L. 2007: 49–52

  View details for Web of Science ID 000257312900013

• Differential expression of sclerostin between juvenile and adult mice 12th Biennial Meeting of the International-Society-Craniofacial-Surgery Kwan, M. D., Gupta, D. M., Slater, B. J., Wan, D. C., Quarto, N., Longaker, M. T. MEDIMOND S R L. 2007: 17–19

  View details for Web of Science ID 000257312900005

• Geometric morphometric analysis identifies craniofacial deformity in the noggin mutant 12th Biennial Meeting of the International-Society-Craniofacial-Surgery Gupta, D. M., Young, N. M., Wan, D. C., Kwan, M. D., Slater, B. J., Brunet, L. J., Harland, R. M., Helms, J. A., Longaker, M. T. MEDIMOND S R L. 2007: 13–15

  View details for Web of Science ID 000257312900004

• Microarray analysis of differential gene expression between juvenile and adult calvarial defects 12th Biennial Meeting of the International-Society-Craniofacial-Surgery Wan, D. C., Kwan, M. D., Wang, Z., Slater, B. J., Gupta, D. M., Longaker, M. T. MEDIMOND S R L. 2007: 61–63

  View details for Web of Science ID 000257312900016

• Refining retinoic acid stimulation of murine adipose-derived stromal cells accelerates in vivo bone formation 12th Biennial Meeting of the International-Society-Craniofacial-Surgery Wan, D. C., Siedhoff, M. T., Kwan, M. D., Nacamuli, R. P., Slater, B. J., Gupta, D. M., Wu, B. M., Longaker, M. T. MEDIMOND S R L. 2007: 57–59

  View details for Web of Science ID 000257312900015

• Rotation of cranial sutures to determine the role of regional dura mater on cranial suture fate 12th Biennial Meeting of the International-Society-Craniofacial-Surgery Slater, B. J., Kwan, M. D., Gupta, D. M., Amasha, R. R., Wan, D. C., Longaker, M. T. MEDIMOND S R L. 2007: 65–67

  View details for Web of Science ID 000257312900017

• Osteogenic differentiation of mouse adipose-derived stromal cells requires retinoic acid and bone morphogenetic protein type IB signaling 12th Biennial Meeting of the International-Society-Craniofacial-Surgery Wan, D. C., Shi, Y. Y., Nacamull, R. P., Quarto, N., Kwan, M. D., Gupta, D. M., Slater, B. J., LYONS, K. M., Longaker, M. T. MEDIMOND S R L. 2007: 45–47

  View details for Web of Science ID 000257312900012

• Differential gene expression between juvenile and adult dura mater: A window into what genes play a role in the regeneration of membranous bone PLASTIC AND RECONSTRUCTIVE SURGERY Wan, D. C., Aalami, O. O., Wang, Z., Nacamuli, R. P., Lorget, F., Derynck, R., Longaker, M. T. 2006; 118 (4): 851-861

  Abstract

  Although reossification of large calvarial defects is possible in children, adults lack this tissue engineering capacity. In this study, the authors compared the differences in gene expression between juvenile and adult dura mater using a mouse cDNA microarray with 42,000 unique elements.Non-suture-associated parietal bone was harvested from 6-day-old and 60-day-old mice. The dura mater was carefully dissected from the calvarial disk and snap-frozen. RNA was extracted from pooled dura mater for microarray analysis. The 25 most differentially expressed genes were listed, as were selected bone-related genes. In addition, quantitative real-time reverse-transcriptase polymerase chain reaction confirmation of selected genes-BMP-2, BMP-4, and BMP-7; and osteopontin (OP), osteocalcin (OC), and FGFR-1-was performed.Juvenile dura mater expressed significantly greater amounts of BMP-2 and OP. Minimal difference in OC expression was observed between juvenile and adult dura mater. Extracellular matrix proteins (Col3a1, 5a1, 6a1, and fibronectin 1), osteoblast differentiation markers (Runx2/Cbfa1, Itm2a, and FGFR-1), and the growth factor Ptn were among other genes with greater expression in juvenile dura mater. Markers of osteoclasts (Acp5, MMP9, Ctsk) and the multiple candidate gene Ntrk2 were also expressed at higher levels in the juvenile dura mater.These findings suggest a more differentiated osteoprogenitor population to exist along with a greater presence of osteoclasts in the juvenile dura mater relative to adults. In addition to establishing a baseline difference in gene expression between juvenile and adult dura mater, new genes potentially critical to the regenerative potential of juvenile calvaria were identified.

  View details for DOI 10.1097/01.prs.0000232366.23897.2b

  View details for Web of Science ID 000240700100004

  View details for PubMedID 16980845

• BMP antagonism via noggin in adult dura mater 61st Annual Session of the Surgical Forum 2006 Clinical Congress Kwan, M. D., Wan, D., Longaker, M. ELSEVIER SCIENCE INC. 2006: S55–S55

  View details for Web of Science ID 000240406800108

• Fluorescence-activated cell sorting with CD105 identifies osteoprogenitors within mouse and human-derived AMCs 61st Annual Session of the Surgical Forum 2006 Clinical Congress Wan, D. C., Kwan, M., Nacamuli, R., Tataria, M., Longaker, M. ELSEVIER SCIENCE INC. 2006: S42–S42

  View details for Web of Science ID 000240406800076

• Osteogenic differentiation of mouse adipose-derived adult stromal cells requires retinoic acid and bone morphogenetic protein receptor type IB signaling PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Wan, D. C., Shi, Y., Nacamuli, R. P., Quarto, N., Lyons, K. M., Longaker, M. T. 2006; 103 (33): 12335-12340

  Abstract

  Although the multilineage potential of human adipose-derived adult stromal cells (ADAS) has been well described, few published studies have investigated the biological and molecular mechanisms underlying osteogenic differentiation of mouse ADAS. We report here that significant osteogenesis, as determined by gene expression and histological analysis, is induced only when mouse ADAS are cultured in the presence of retinoic acid with or without recombinant human bone morphogenetic protein (BMP)-2 supplementation. Furthermore, a dynamic expression profile for the BMP receptor (BMPR) isoform IB was observed, with dramatic up-regulation during osteogenesis. Western blot analysis revealed that retinoic acid enhanced levels of BMPR-IB protein during the first 7 days of osteogenic differentiation and that RNAi-mediated suppression of BMPR-IB dramatically impaired the ability of ADAS to form bone in vitro. In contrast, absence of BMPR-IA did not significantly diminish ADAS osteogenesis. Our data therefore demonstrate that the osteogenic commitment of multipotent mouse ADAS requires retinoic acid, which enhances expression of the critical BMPR-IB isoform.

  View details for DOI 10.1073/pnas.0604849103

  View details for Web of Science ID 000239867500026

  View details for PubMedID 16894153

  View details for PubMedCentralID PMC1567881

• Craniofacial bone tissue engineering. Dental clinics of North America Wan, D. C., Nacamuli, R. P., Longaker, M. T. 2006; 50 (2): 175-?

  Abstract

  Repair and reconstruction of the craniofacial skeleton represents a significant biomedical burden, with thousands of procedures per-formed annually secondary to injuries and congenital malformations. Given the multitude of current approaches, the need for more effective strategies to repair these bone deficits is apparent. This article explores two major modalities for craniofacial bone tissue engineering: distraction osteogenesis and cellular based therapies. Current understanding of the guiding principles for each of these modalities is elaborated on along with the knowledge gained from clinical and investigative studies. By laying this foundation, future directions for craniofacial distraction and cell-based bone engineering have emerged with great promise for the advancement of clinical practice.

  View details for PubMedID 16530056

• The ISCFS: A body for clinical, educational, and research innovation JOURNAL OF CRANIOFACIAL SURGERY Longaker, M. T., Wan, D. C. 2006; 17 (2): 215-216

  View details for Web of Science ID 000236747300002

  View details for PubMedID 16633164

• Murine models of mandibular distraction osteogenesis: Towards defining the mechanical environment and the role of angiogenesis 5th International Congress of the Maxillofacial and Craniofacial Distraction Kwan, M. D., Wan, D. C., Loboa, E. G., Fang, T. D., Longaker, M. T. MEDIMOND S R L. 2006: 1–4

  View details for Web of Science ID 000243535300001

• Noggin suppression enhances osteogenesis of murine osteoblasts 91st Annual Clinical Congress of the American-College-of-Surgeons Wan, D. C., Pomerantz, J., Nacamuli, R., Siedhoff, M., Blau, H., Longaker, M. T. ELSEVIER SCIENCE INC. 2005: S62–S62

  View details for Web of Science ID 000231745800129

• Cranial suture biology CURRENT TOPICS IN DEVELOPMENTAL BIOLOGY, VOL 66 Lenton, K. A., Nacamuli, R. P., Wan, D. C., Helms, J. A., Longaker, M. T. 2005; 66: 287-?

  View details for Web of Science ID 000228212000009

  View details for PubMedID 15797457

• New developments in pediatric plastic surgery research CLINICS IN PLASTIC SURGERY Nacamuli, R. P., Wan, D. C., Lenton, K. A., Longaker, M. T. 2005; 32 (1): 123-?

  Abstract

  Pediatric plastic surgery research is a rapidly expanding field. Unique in many ways, researchers in this field stand at the union of multiple scientific specialties, including biomedical engineering, tissue engineering, polymer science, molecular biology, developmental biology, and genetics. The goal of this scientific effort is to translate research advances into improved treatments for children with congenital and acquired defects. Although the last decade has seen a dramatic acceleration in research related to pediatric plastic surgery, the next 10 years will no doubt lead to novel treatment strategies with improved clinical outcomes.

  View details for DOI 10.1016/j.cps.2004.10.003

  View details for Web of Science ID 000226935600013

  View details for PubMedID 15636770

• Mechanisms of osteogenic differentiation of mouse adipose-derived mesenchymal cells 11th International Congress of the International-Society-of-Craniofacial-Surgery Shi, Y. Y., Nacamuli, R. P., Salim, A., Quarto, N., LYONS, K. M., Wan, D. C., Cowan, C. M., Helms, J. A., Longaker, M. T. MEDIMOND S R L. 2005: 63–65

  View details for Web of Science ID 000243381600016

• Embryologic tissue derivation affects post-natal calvarial healing 11th International Congress of the International-Society-of-Craniofacial-Surgery Wan, D. C., Shi, Y. Y., Siedhoff, M. T., Nacamuli, R. P., Longaker, M. T. MEDIMOND S R L. 2005: 11–13

  View details for Web of Science ID 000243381600003

• Distinct biologic properties of FACS-sorted murine adipose-derived mesenchymal cells 11th International Congress of the International-Society-of-Craniofacial-Surgery Siedhoff, M. T., Nacamuli, R. P., Wan, D. C., Shi, Y. Y., Bhattacharya, D., Weissman, I. L., Longaker, M. T. MEDIMOND S R L. 2005: 55–57

  View details for Web of Science ID 000243381600014

• Noggin suppression enhances osteogenesis of murine osteoblasts 11th International Congress of the International-Society-of-Craniofacial-Surgery Wan, D. C., Pomerants, J. H., Nacamuli, R. P., Kim, J. B., Blau, H. M., Longaker, M. T. MEDIMOND S R L. 2005: 3–5

  View details for Web of Science ID 000243381600001

• Determining the most effective time course of retinoic acid priming for murine adipose-derived mesenchymal cell osteogenesis 11th International Congress of the International-Society-of-Craniofacial-Surgery Siedhoff, M. T., Nacamuli, R. P., Wan, D. C., Shi, Y. Y., Longaker, M. T. MEDIMOND S R L. 2005: 51–53

  View details for Web of Science ID 000243381600013

• Identifying optimal retinoic acid dose for adipose-derived mesenchymal cell osteogenesis 11th International Congress of the International-Society-of-Craniofacial-Surgery Wan, D. C., Shi, Y. Y., Siedhoff, M. T., Nacamuli, R. P., Longaker, M. T. MEDIMOND S R L. 2005: 59–61

  View details for Web of Science ID 000243381600015

• Quantitative transcriptional analysis of fusing and nonfusing cranial suture complexes in mice 11th International Congress of the International-Society-of-Craniofacial-Surgery Nacamuli, R. P., Song, H. M., Fang, T. D., Fong, K. D., Mathy, J. A., Shi, Y. Y., Salim, A., Wan, D. C., Longaker, M. T. MEDIMOND S R L. 2005: 277–279

  View details for Web of Science ID 000243381600071