Biodegradable hydrogel with thermo-response and hemostatic effect for photothermal enhanced anti-infective therapy

Massive bleeding and infectious complication remain the leading cause of worldwide trauma deaths. To tackle this issue, a platelet-inspired degradable antibacterial hydrogel (Gel/PP-TA-Ag) is synthesized based on gelatin methacrylate (GelMA), tannic acid (TA), polyphosphate (PolyP) and gallic acid functionalized silver nanoparticles (Ag NPs) via a facile photopolymerization process. Accompanied by the degradation of the hydrogel, the released PolyP can activate the coagulation pathway, resulting in a better hemostatic effect than commercial gauze in the mice-bleeding model. Simultaneously, benefiting from hyperthermia originated from Ag NPs and photothermal accelerated release of TA and Ag⁺, 97.57% of methicillin-resistant Staphylococcus aureus (MRSA) and 95.99% of E. coli are eliminated in vitro. Moreover, in vivo experiments reveal that 91.76% of MRSA in wounds is removed, and the wound healing is effectively improved with more angiogenesis and collagen deposition. The level of inflammation in the wounds is also significantly reduced. As a result, Gel/PP-TA-Ag hydrogel possesses great potential in achieving satisfactory efficacy in infected wound healing.