Functionalized gelatin/poly(l-lactide-co-ε-caprolactone) fibrous membrane promotes scarless wound healing by modulating inflammation and reducing fibrosis

In cases of deep skin defects, spontaneous tissue regeneration and excessive collagen deposition can result in the formation of proliferative scarring. Salvianolic acid B (SAB) demonstrates promising applications in the treatment of fibrotic diseases, including scarring. This study prepared biodegradable gelatin (Gel) and poly(lactic-co-ε-caprolactone) (PLCL) nanofibrous membranes using electrospinning technology and functionalized them with salvianolic acid B to create fibrous membrane dressings with anti-scarring properties. The resulting Gel/PLCL/SAB (GPS) fibrous membrane exhibited good mechanical properties and biodegradability. In vitro experiments demonstrated that the fibrous membranes of Gel/PLCL containing 0.5 wt% SAB (GPS_0.5) exhibited good cytocompatibility, regulated macrophage function and polarization, and inhibited fibrosis-related genes, including CD36, α-SMA, and collagen I. In a mouse model of full-thickness skin defects, the GPS_0.5 fibrous membrane effectively modulated the immune microenvironment and promoted vascular regeneration, thereby accelerating skin healing. Furthermore, the GPS_0.5 fibrous membrane reduced the expression of CD36 and TGF-β1, downregulated collagen I and III, and promoted the regeneration of hair follicles, sebaceous glands, and other appendages, ultimately reducing scar formation. Thus, SAB-loaded Gel/PLCL fibrous membranes hold potential as bifunctional skin dressings that promote wound healing and inhibit fibrosis.