All Publications

  • Minimalistic, disposable wireless electrochemical sensors: Integrating self-powered amperometry with direct inductive coupling. Biosensors & bioelectronics Rho, J., Yang, A., Sands, J., Wong, H. P., Poon, A. S. 2025; 290: 117940

    Abstract

    Point-of-care (PoC) biomolecular sensing enables rapid diagnosis and prognosis to significantly improve medical accessibility. Wireless electrochemical sensing strategies typically use dedicated RFID or Bluetooth chips for wireless transmission along with a microcontroller and potentiostat to convert chemical signals into electrical outputs. However, integrating chips and multiple active components into a sensor limits its miniaturization, power efficiency, and usage in disposable applications. We therefore propose a minimalistic yet sensitive and efficient sensor design using only one active component: an LED. The LED, paired with a photoresistor, converts currents from analyte concentrations into resistive changes, which are directly transmitted via inductive coupling. This pairing further functions as a buffer, isolating the electrochemical cell from the inductive link for stable wireless transmission. LED and electrochemical cell power is derived from a galvanic cell consisting of a pair of electrodes activated upon contact with bodily fluids. The integrated sensor was characterized with H2O2 measurement and incorporated into a diaper to demonstrate usability by measuring uric acid in artificial urine. The proposed approach to sensor design enables battery-free amperometry to be integrated with chip-free wireless data transmission, a promising step towards cost-effective and disposable electrochemical sensing.

    View details for DOI 10.1016/j.bios.2025.117940

    View details for PubMedID 40961644

  • Incorporating Bone-Derived ECM into Macroporous Microribbon Scaffolds Accelerates Bone Regeneration. Advanced healthcare materials Villicana, C., Su, N., Yang, A., Tong, X., Lee, H. P., Ayushman, M., Lee, J., Tai, M., Kim, T., Yang, F. 2025: e2402138

    Abstract

    Tissue-derived extracellular matrix (tdECM) hydrogels serve as effective scaffolds for tissue regeneration by promoting a regenerative immune response. While most tdECM hydrogels are nanoporous and tailored for soft tissue, macroporosity is crucial for bone regeneration. Yet, there's a shortage of macroporous ECM-based hydrogels for this purpose. The study aims to address this gap by developing a co-spinning technique to integrate bone-derived ECM (bECM) into gelatin-based, macroporous microribbon (µRB) scaffolds. The effect of varying doses of bECM on scaffold properties was characterized. In vitro studies revealed 15% bECM as optimal for promoting MSC osteogenesis and macrophage (Mφ) polarization. When implanted in a mouse critical-sized cranial bone defect model, 15% bECM with tricalcium phosphate (TCP) microparticles significantly accelerated bone regeneration and vascularization, filling over 55% of the void by week 2. Increasing bECM to 25% enhanced mesenchymal stem cell (MSC) recruitment and decreased M1 Mφ polarization but reduced overall bone formation and vascularization. The findings demonstrate co-spun gelatin/bECM hydrogels as promising macroporous scaffolds for robust endogenous bone regeneration, without the need for exogenous cells or growth factors. While this study focused on bone regeneration, this platform holds the potential for incorporating various tdECM into macroporous scaffolds for diverse tissue regeneration applications.

    View details for DOI 10.1002/adhm.202402138

    View details for PubMedID 39891301

  • Aspirin synergizes with mineral particle-coated macroporous scaffolds for bone regeneration through immunomodulation. Theranostics Su, N., Villicana, C., Zhang, C., Lee, J., Sinha, S., Yang, A., Yang, F. 2023; 13 (13): 4512-4525

    Abstract

    Rationale: Mineral particles have been widely used in bone tissue engineering scaffolds due to their osteoconductive and osteoinductive properties. Despite their benefits, mineral particles can induce undesirable inflammation and subsequent bone resorption. Aspirin (Asp) is an inexpensive and widely used anti-inflammatory drug. The goal of this study is to assess the synergistic effect of Asp and optimized mineral particle coating in macroporous scaffolds to accelerate endogenous bone regeneration and reduce bone resorption in a critical-sized bone defect model. Methods: Four commonly used mineral particles with varying composition (hydroxyapatite v.s. tricalcium phosphate) and size (nano v.s. micro) were used. Mineral particles were coated onto gelatin microribbon (µRB) scaffolds. Macrophages (Mφ) were cultured on gelatin µRB scaffolds containing various particles, and Mφ polarization was assessed using PCR and ELISA. The effect of conditioned medium from Mφ on mesenchymal stem cell (MSC) osteogenesis was also evaluated in vitro. Scaffolds containing optimized mineral particles were then combined with varying dosages of Asp to assess the effect in inducing endogenous bone regeneration using a critical-sized cranial bone defect model. In vivo characterization and in vitro cell studies were performed to elucidate the effect of tuning Asp dosage on Mφ polarization, osteoclast (OC) activity, and MSC osteogenesis. Results: Micro-sized tricalcium phosphate (mTCP) particles were identified as optimal in promoting M2 Mφ polarization and rescuing MSC-based bone formation in the presence of conditioned medium from Mφ. When implanted in vivo, incorporating Asp with mTCP-coated µRB scaffolds significantly accelerated endogenous bone formation in a dose-dependent manner. Impressively, mTCP-coated µRB scaffolds containing 20 µg Asp led to almost complete bone healing of a critical-sized cranial bone defect as early as week 2 with no subsequent bone resorption. Asp enhanced M2 Mφ polarization, decreased OC activity, and promoted MSC osteogenesis in a dosage-dependent manner in vivo. These results were further validated using in vitro cell studies. Conclusions: Here, we demonstrate Asp and mineral particle-coated microribbon scaffold provides a promising therapy for repairing critical-sized cranial bone defects via immunomodulation. The leading formulation supports rapid endogenous bone regeneration without the need for exogenous cells or growth factors, making it attractive for translation. Our results also highlight the importance of optimizing mineral particles and Asp dosage to achieve robust bone healing while avoiding bone resorption by targeting Mφ and OCs.

    View details for DOI 10.7150/thno.85946

    View details for PubMedID 37649612

    View details for PubMedCentralID PMC10465219

  • Small molecule C381 targets the lysosome to reduce inflammation and ameliorate disease in models of neurodegeneration Proc Natl Acad Sci U S A . Vest*, R. T., Chou*, C., Zhang, H., Haney, M. S., Li, L., Laqtom, N. N., Chang, B., Shuken, S., Nguyen, A., Yerra, L., Yang, A. C., Green, C., Tanga, M., Abu-Remaileh, M., Bassik, M. C., Frydman, J., Luo, J., Wyss-Coray, T. 2022; 119 (11): e2121609119

    View details for DOI 10.1073/pnas.2121609119