Fetal Bovine Hide Collagen-Chitosan Composite Sponges: Preparation, Physicochemical Profiling, and Cutaneous Wound Healing Efficacy.

The escalating production of fetal bovine serum generates substantial quantities of fetal bovine hide as an underutilized byproduct. In this study, we extracted collagen from this source, characterized it as predominantly type I collagen with intact triple-helical features, and fabricated a series of composite sponge dressings by blending it with chitosan. The best-balanced formulation (COL1/CS1, 1:1 ratio) exhibited markedly superior physicochemical properties relative to pure collagen sponges, as evidenced by higher porosity (91.3%), water uptake (2010%), moisture retention (23.7%), and water vapor transmission rate (4169.02 ± 86.45 g/m2/day). We hypothesize that the intrinsically lower cross-linking density of fetal collagen may expose a greater abundance of carboxyl and hydroxyl moieties, thereby fostering electrostatic complexation and hydrogen bonding with chitosan's amino groups. This molecular interplay appears to promote the genesis of a highly uniform, interconnective porous network. In vitro, the COL1/CS1 sponge elicited a hemolysis rate below 5%, a blood coagulation index as low as 7.02%, no cytotoxicity toward L929 and MRC-5 cells, and a pronounced capacity to stimulate cell proliferation and wound repopulation. In a murine full-thickness excisional wound model, the COL1/CS1 group achieved a 98.1% closure rate by day 14, significantly outpacing both the pure collagen and untreated controls. Histological examinations corroborated these findings, revealing accelerated granulation tissue deposition, robust neovascularization, and orderly collagen remodeling, with no overt toxicity observed in vital organs under the tested conditions. This work presents a viable valorization pathway for an agricultural byproduct into high-value biomedical constructs and provides insights into how source-dependent collagen attributes may influence the functional performance of biomaterials.