Rapidly photocrosslinkable charged silk-based hydrogel for emergency hemostasis and multifunctional wound therapy

Achieving rapid hemostasis, infection control, and tissue regeneration remains a central challenge in acute wound management, particularly under emergency and battlefield conditions. Current hemostatic materials often suffer from delayed coagulation, low bioactivity, and potential immunogenicity, limiting their use in critical care. Here, we present a chemically engineered charged silk-based hydrogel (SAMA) that integrates ultrafast gelation, intrinsic antibacterial activity, and programmable biological function. SAMA is synthesized via dual side-chain modification of silk fibroin with methacrylate (MA) for photo-crosslinking and dimethylamino groups (DMA) for surface charge tuning. The hydrogels enable photo-triggered crosslinking within 8 s under 405 nm light, while offering programmable surface charge and aqueous stability. The positively charged SAMA-5.0(+) hydrogel markedly enhances coagulation and platelet activation, as evidenced by reduced blood loss, shortened clotting time, and elevated CD62P⁺/PAC-1⁺ platelet populations. The hydrogels exhibit over 95 % antibacterial efficacy against Staphylococcus aureus and Escherichia coli, while maintaining excellent cytocompatibility, hemocompatibility, and promoting favorable responses in endothelial and immune cells. Mechanistically, SAMA(+) induces macrophage polarization toward the anti-inflammatory M2 phenotype, suppressing IL-6-mediated inflammation and facilitating angiogenesis and collagen remodeling. Controlled release assays demonstrate first-order kinetics for both the model protein (BSA) and ropivacaine, enabling sustained and timely delivery under neutral and mildly acidic wound environments. These findings position charged SAMA hydrogels as a clinically translatable solution for acute wound care, integrating rapid sealing, antimicrobial protection, immune regulation, and tissue repair into a low-cost platform suitable for wound and emergency applications.