Synthesis and Characterization of Antibacterial Poly{2-[(methacryloyloxy)ethyl]trimethylammonium Chloride}/Chitosan Semi-Interpenetrating Networks for Papain Release

Annually, thousands of individuals suffer from skin injuries resulting from trauma, surgeries, or diabetes. Inadequate wound treatment can delay healing and increase the risk of severe infections. In this context, a promising synthetic polymer with potent antimicrobial properties, Poly{2-[(methacryloyloxy)ethyl]trimethylammonium chloride} (PMETAC), is synthesized and crosslinked with N,N'-Methylenebis(acrylamide) (BIS) in the presence of Chitosan (CH), a natural, biocompatible polysaccharide that promotes cell regeneration and provides additional beneficial properties. These semi-interpenetrating (semi-IPN) networks are chosen as a matrix for releasing papain, a proteolytic enzyme with healing and debridement properties. By integrating the properties of the materials, this study evaluates PMETAC-based hydrogels with different CH concentrations (5%, 10%, and 25%) to understand their physicochemical and biological performance, including antibacterial activity and cytocompatibility. By incorporating 25% CH led to a 19% increase in pore size and a 48% increase in maximum pore volume compared to the control PMETAC hydrogel. Additionally, all formulations demonstrate ≈100% reduction of E. coli and S. aureus, showcasing their remarkable antibacterial efficacy. The inclusion of CH also significantly improves fibroblast viability, with 25% CH formulation standing out as the most promising candidate for multifunctional dressings, highlighting their potential in the treatment of hard-to-heal wounds in regenerative medicine.