Synthesis and characterization of gelatin-based quaternizable hydrogels

Gelatin, a water-soluble natural polymer with excellent film-forming properties, exhibits high biocompatibility due to its amino acid composition, which closely resembles that of proteins. However, gelatin has poor mechanical properties and poses a risk of bacterial infection when films are composed solely of gelatin. In this study, gelatin-based crosslinked polymers with quaternary amine groups, exhibiting potential antibacterial properties, were developed. To achieve this, gelatin was first modified with methacrylate via an isocyanate-amine reaction, and the resulting material was characterized using Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR). Hydrogels were successfully synthesized by photopolymerization of gelatin methacryloyl, with a tertiary amine-containing monomer and a four-arm crosslinker, and characterized using FTIR, scanning electron microscope (SEM), and thermogravimetric analysis (TGA). Subsequently, the hydrogel was prepared as a film on a glass surface, and quaternization of the tertiary amine groups imparted polycationic properties to the hydrogel coatings, enabling further investigation into their antibacterial potential.