Application of 3D-printed tissue-engineered skin substitute using innovative biomaterial loaded with human adipose-derived stem cells in wound healing

Large-scale skin injuries often lead to impaired wound healing with scarring, morbidity, or mortality. This study explores in vivo application of a 3D-printed tissue-engineered skin substitute composed of adipose tissue decellularized extracellular matrix (dECM), methacrylated gelatin (GelMA), and methacrylated hyaluronic acid (HAMA), loaded with human adipose-derived stem cells (hADSCs). Adipose tissue was decellularized, lyophilized, solubilized to obtain a thermo-sensitive dECM pre-gel, and blended with GelMA-HAMA to improve printability. Rheology assessed phase-transition behavior; SEM characterized microstructure. A 3D-printed grid-like scaffold encapsulating hADSCs was fabricated and evaluated in a nude mouse full-thickness wound model against three controls: full-thickness skin graft, microskin graft, and untreated wounds. dECM met decellularization criteria (24.5 ± 7.1 ng DNA/mg). The composite precursor underwent a gel–sol transition at ~17.5°C with G'≈G''≈8 Pa; crosslinked hydrogels exhibited porous 3D networks. In vivo, 3D-printed skin substitutes accelerated wound closure, attenuated inflammation, increased local perfusion, enhanced re-epithelialization, collagen deposition and alignment, and promoted angiogenesis. In summary, 3D-printed dECM–GelMA–HAMA skin substitutes loaded with hADSCs can be rapidly fabricated and improve wound healing quality, with hADSCs and the stable printed scaffold both contributing to therapeutic effects.