Extensive skin injuries often lead to chronic wound healing, scar formation, and elevated mortality rates. Existing treatment options, including autologous, allogeneic, and xenogeneic skin grafts, are constrained by donor scarcity, low graft survival rates, scarring, flap edema, and the inability to regenerate skin appendages. Consequently, the development of tissue-engineered skin substitutes comprising scaffolds, cells, and bioactive factors has emerged as a promising approach for repairing extensive skin defects. Herein, we optimized the electrospinning technique to construct a three-dimensional polycaprolactone (PCL) nanofiber scaffold with a thickness of 5 μm ± 0.7 μm and a porosity of 85%. Dopamine self-polymerization was employed to form a polydopamine (PDA) coating, which was subsequently combined with type I collagen (COL) to produce a polycaprolactone-polydopamine-collagen (PPC) scaffold. The PPC scaffold demonstrated significantly enhanced mechanical strength and hydrophilicity, along with excellent biocompatibility. The biocompatibility of the PPC nanofiber scaffold was markedly improved, effectively promoting the migration, adhesion, and proliferation of keratinocytes (KCs). Co-culturing autologous KCs with the PPC scaffold to construct an epidermal membrane graft significantly accelerated wound healing, resulting in a more complete neo-skin tissue structure and improved wound healing quality. Moreover, qPCR and Western blot analyses were employed to assess key protein and gene expression levels in the Wnt signaling pathway, revealing that our epidermal cell membrane could activate the Wnt signaling pathway, thereby promoting wound healing. This tissue-engineered epidermis offers a promising alternative to traditional skin grafting methods and may address the limitations associated with extensive skin injuries.
