Nonantibiotic-Dependent Photothermal-Chemodynamic Synergistic Antibacterial and Hemostatic Sponge Based on TiB2 Nanosheet-Decorated Gelatin/Sodium Alginate Composites.

Abstract

Conventional antibacterial materials face challenges in simultaneously integrating efficient antibacterial activity, rapid hemostasis, and high biocompatibility. Herein, we report a rationally designed composite sponge (TGSS) composed of a highly porous gelatin/sodium alginate (Gel/SA) matrix decorated with titanium diboride nanosheets (TiB2 NSs). The TiB2 NSs not only endow the TGSS with efficient near-infrared (NIR)-triggered photothermal conversion for localized thermal ablation of bacteria but also confer Fenton-like catalytic activity that converts endogenous H2O2 into cytotoxic hydroxyl radicals (·OH), enabling selective oxidative damage to microbial cells. Owing to photothermal-chemodynamic synergy, TGSS achieves exceptional antibacterial performance with 99.09% inhibition against Escherichia coli (E. coli) and 99.99% against Staphylococcus aureus (S. aureus) under NIR irradiation. Concurrently, the highly porous Gel/SA scaffold promotes rapid blood coagulation via intrinsic pathway activation and physical adsorption, resulting in significantly reduced bleeding time and blood loss. Importantly, the polymeric matrix effectively immobilizes TiB2 nanosheets (TiB2 NSs), suppressing nanoparticle leaching and thereby mitigating potential nanotoxicity. Furthermore, TGSS demonstrated favorable biocompatibility, as evidenced by a hemolysis rate below 5% and cell viability maintained above 90% after 48 h in cytotoxicity assays. Collectively, TGSS effectively prevents bacterial infection and accelerates blood coagulation, showcasing significant potential as a multifunctional wound dressing.