Medical Education, Texas A&M University College of Medicine (2017)
Bachelor of Science, Tulane University (2013)
Derrick Wan, Postdoctoral Faculty Sponsor
Fat Grafts Augmented With Vitamin E Improve Volume Retention and Radiation-Induced Fibrosis.
Aesthetic surgery journal
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
A comparative analysis of deferoxamine treatment modalities for dermal radiation-induced fibrosis.
Journal of cellular and molecular medicine
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
Standardizing dimensionless cutometer parameters to determine in-vivo elasticity of human skin.
Advances in wound care
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
Decellularized Adipose Matrices can Alleviate Radiation-induced Skin Fibrosis.
Advances in wound care
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
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
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
- Response to: Vitamin E Improves Volumetry and Regenerative Effects of Fat Grafting. Aesthetic surgery journal 2022
Tension offloading improves cutaneous scar formation in Achilles tendon repair.
Journal of surgical case reports
2022; 2022 (3): rjac066
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
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
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
WILEY. 2022: A16
View details for Web of Science ID 000763583000040
The Oral Mucosa Hosts Distinct Fibroblast Subpopulations to Facilitate Regenerative Wound Repair
WILEY. 2022: A12-A13
View details for Web of Science ID 000763583000035
Transdermal Deferoxamine Enhances Wound Healing In Chronically Irradiated Skin In Mice
WILEY. 2022: A29-A30
View details for Web of Science ID 000763583000068
Local Vitamin E Administration Improves Fat Graft Retention and Radiation-Induced Fibrosis in a Mouse Model
ELSEVIER SCIENCE INC. 2021: S199
View details for Web of Science ID 000718303100374
Analysis of Online Educational Materials Relating to Craniosynostosis
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
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
ELSEVIER SCIENCE INC. 2021: E198
View details for Web of Science ID 000718306700482
Dermal Iron Chelation Reduces Indirect Radiation Injury
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
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
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
ELSEVIER SCIENCE INC. 2021: E162
View details for Web of Science ID 000718306700394
Temperature Influence on Scanning Laser Doppler Flowmetry in Anesthetized Mice
ELSEVIER SCIENCE INC. 2021: E157
View details for Web of Science ID 000718306700381
Acellular Dermal Matrix Grafts Decrease Radiation-Induced Contracture and Dermal Thickening
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
ELSEVIER SCIENCE INC. 2021: E197-E198
View details for Web of Science ID 000718306700481
Fibroblast Sub-Populations Dynamically Change Composition to Heal Dorsal Skin Radiation Wounds in Wild-Type Mice
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
ELSEVIER SCIENCE INC. 2021: S196
View details for Web of Science ID 000718303100368
Topical Deferoxamine Patch Is Superior to Direct Injection for the Treatment of Radiation-Induced Skin Fibrosis
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
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
ELSEVIER SCIENCE INC. 2021: S201-S202
View details for Web of Science ID 000718303100378
Understanding Scarring in the Oral Mucosa.
Advances in wound care
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
Readability of Online Patient Information Relating to Cleft Palate Surgery.
The Cleft palate-craniofacial journal : official publication of the American Cleft Palate-Craniofacial Association
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
Single Cell RNA Sequencing Reveals Fibroblast Heterogeneity Across Embryonic Origins Of Skin
WILEY. 2021: A11-A12
View details for Web of Science ID 000650720500037
The Adrenergic System in Plastic and Reconstructive Surgery: Physiology and Clinical Considerations.
Annals of plastic surgery
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
Angiogenic CD34+CD146+ adipose-derived stromal cells augment recovery of soft tissue after radiotherapy.
Journal of tissue engineering and regenerative medicine
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
Fat Grafting Depletes Profibrotic Prrx1-Positive Fibroblasts in Irradiated Skin and Mitigates Radiation-Induced Groin Contracture
ELSEVIER SCIENCE INC. 2020: S225–S226
View details for Web of Science ID 000582792300411
Radiation-Induced Soft Tissue Atrophy Impaired by Enhancement of Fat Grafts with CD146+Subpopulation of Adipose-Derived Stromal Cells
ELSEVIER SCIENCE INC. 2020: E186
View details for Web of Science ID 000582798100421
Grafted Fat Depletes the Profibrotic Engrailed-1-Positive Fibroblast Subpopulation and Ameliorates Radiation-Induced Scalp Fibrosis
ELSEVIER SCIENCE INC. 2020: E186
View details for Web of Science ID 000582798100420
Adipose-Derived Stromal Cells within Transplanted Fat Hone to Blood Vessels and Assume a Pericyte Structure
ELSEVIER SCIENCE INC. 2020: E183
View details for Web of Science ID 000582798100412
No Significant Difference in Outcomes for Surgical Treatment of Thyroid Cancer in Kidney Transplant Recipients - Analysis of the HCUP NIS Data
International Archives of Endocrinology Clinical Research
2019; 5 (1): 7
View details for DOI 10.23937/2572-407X.1510019