S-nitrosated keratin composite mats with NO release capacity for wound healing

Wound repair is a dynamic and complex process that involves various interactions between repair cells, growth factors and the extracellular matrix. Nitric oxide (NO) plays a pivotal role in wound healing, including causing the contraction of wound surfaces, dilating blood vessels, participating in inflammation, and promoting collagen synthesis, angiogenesis, and fibroblast proliferation. Here, we prepared a novel keratin-based nitric oxide donor, called S-nitrosated keratin (KSNO). Then, KSNO was coelectrospun with polyurethane (PU) and gelatin (Gel) to produce PU/Gel/KSNO biocomposite mats. The prepared mats released NO without cytotoxicity, promoted the proliferation of L929 murine fibroblasts and human umbilical vein endothelial cells (HUVECs), and inhibited bacterial growth. These mats could also accelerate the cell adhesion and growth along the random arrangement of electrospun fibers, and simulate the structure of the natural extracellular matrix to provide good scaffolds for cell. The effect of PU/Gel/KSNO on promoting wound healing was investigated on a full-thickness excisional cutaneous wound model in rats. The results demonstrated that these mats accelerated wound healing without inflammatory reaction. In conclusion, PU/Gel/KSNO mats display excellent bioactivity and biocompatibility and have potential in the field of wound repair.