Gelatin modified nonisocyanate polyurethane/siloxane functionalized with quaternary ammonium groups as antibacterial wound dressing membrane

This work presents antibacterial wound dressing membranes based on a nonisocyanate polyurethane-siloxane framework. These membranes protect wounded skin by providing mechanical strength, maintaining a moist environment, and ensuring hygiene through chemically anchored antibacterial moieties. Methoxysilane-functionalized soybean oil-based polyhydroxyurethane with quaternary ammonium groups was synthesized and combined with GPTMS and TEOS. Hydrolysis-condensation reactions formed membranes with siloxane domains and pendant epoxy groups. Gelatin was incorporated to enhance biocompatibility and mechanical strength. The resulting films demonstrated tensile strengths of 7.9 MPa (dry) and 0.61 MPa (swelled). Fluid handling capacities were 2.66-2.81 g/10 cm²/day (serum) and 0.79-1.10 g/10 cm²/day (serum vapor), making them suitable for light to moderately exuding wounds. Cytocompatibility was confirmed by MTT assays, showing over 80% fibroblast viability on dressings and over 90% viability in leachate-containing media. The blood compatibility of the dressing was confirmed by standard methods. The dressings also exhibited strong antibacterial activity, with 82% killing of Staphylococcus aureus and 52% killing of Escherichia coli. These results highlight the potential of these membranes for advanced wound care applications.