Light-activated chitosan hydrogel: A bioadhesive platform for emergency hemostasis and bacteria-infected wound...

Current surgical adhesives struggle with slow curing, weak wet adhesion, and a lack of antimicrobial properties, leading to ineffective hemostasis and infection control. We developed a novel light-activated chitosan hydrogel (GTCS) through initiator-free photopolymerization via disulfide ring opening. Unlike toxic acrylate-based systems requiring photoinitiators, this method eliminates cytotoxicity risks in existing photopolymerized biomaterials. The GTCS is dual-functionalized with gallic acid (GA) and α-thioctic acid (TA), enabling fast initiator-free photopolymerization (11 s) under UV light. The optimized GTCS2 hydrogel demonstrates superior adhesion strength (31.40 ± 5.09 kPa) and shows broad-spectrum antibacterial efficacy (>98 % killing against E. coli and S. aureus) via membrane disruption and ROS generation. Crucially, GTCS2 achieves hemostasis in 32 ± 3.6 s (vs. 158.33 ± 13.05 s for gelatin sponge) with a 70 % reduction in blood loss (0.81 ± 0.16 g vs. 2.62 ± 0.42 g). In infected wounds, it accelerates healing (93.23 % closure at day 14 vs. 86.05 % of commercial 3 M dress) by suppressing bacterial colonization, scavenging pathological ROS, and modulating pro-inflammatory cytokines (TNF-α, IL-6). Integrating injectability, rapid light-triggered curing, robust adhesion, and intrinsic antibacterial/antioxidant activity, this multifunctional platform offers a transformative solution for emergency hemorrhage control and infected wound management.