Silk fibroin nanofibers-GelMA hydrogel composite loaded with embryonic fibroblasts: A strategy for enhanced wound healing

Synthetic and natural polymer scaffolds have been widely utilized in the design of wound dressings to promote skin tissue regeneration and repair. This study developed an innovative bilayer wound dressing by integrating electrospun silk fibroin (SF) nanofibers into a photo-crosslinkable gelatin methacryloyl (GelMA) hydrogel, creating a GelMA/SF composite scaffold specifically designed as a delivery platform for mouse embryonic fibroblasts (MEFs). The incorporation of SF nanofibers substantially improved the compressive stress, water retention capacity, and structural stability of the hydrogel, thereby providing a more stable and supportive microenvironment for the loaded MEFs. In vitro, the GelMA/SF composite not only supported high cell viability but also significantly enhanced the biological activity of the encapsulated MEFs, facilitating their proliferation and extracellular matrix synthesis. In a full-thickness skin wound model, the MEFs-laden GelMA/SF composite actively accelerated wound healing by effectively modulating inflammation, enhancing re-epithelialization, stimulating angiogenesis, and promoting organized collagen deposition. Moreover, this cell-loaded composite system markedly inhibited pathological scarring and uniquely induced wound-induced hair follicle neogenesis. These findings demonstrate that the GelMA/SF composite serves as a highly effective cell delivery platform, enabling functional skin regeneration with reduced scar formation.