Light-Polymerized Biomimetic Skin: Vascularized 3D-Bioprinted Constructs with Human-Matched Biomechanics

This study develops a biomimetic, vascularized skin model using advanced photopolymerization-based 3D bioprinting to address limitations in structural integrity, mechanical properties, and physiological functionality of current skin substitutes. The research synthesizes photocrosslinkable bioinksmethacrylated gelatin (GelMA) and methacrylated hyaluronic acid (HAMA)at varying ratios (e.g., 5:1 GelMA:HAMA). These bioinks are processed via digital light processing (DLP) printing (405 nm wavelength, 25 m XY resolution) to create stratified constructs mimicking epidermal topography and dermal layers, incorporating a 500 m diameter vascular channel to enhance nutrient diffusion. Biomechanical evaluation through uniaxial compression testing reveals that the 5% GelMA/1% HAMA formulation achieves a compressive modulus of 193.09 kPa, aligning with human dermal properties (50500 kPa). However, the embedded vascular architecture reduces stiffness due to mechanical discontinuity, and the bioinks fracture toughness requires optimization to mitigate permanent deformation during inelastic phases. Comparisons with murine skin highlight methodological constraints, as untreated tissue exhibits unrepresentative modulus values (986.3 kPa) without preconditioning.While the bioprinted model demonstrates human-relevant mechanics, future work must refine vascular branching, implement crosslinking gradients, and validate long-term ECM remodeling to advance clinical applicability for chronic wound repair and personalized medicine.