Horseradish Peroxidase/Hydrogen Peroxide-Cross-Linked Quaternized Chitosan/Protocatechualdehyde Hydrogels with Strong...

Burns, a severe form of trauma, often cause significant skin damage due to bacterial infection and severe inflammation. Hydrogel, due to its remarkable physicochemical properties, shows great potential as a biomaterial for managing localized burn wounds. In this study, we designed a hydrogel composed of quaternized chitosan (QCS) and protocatechualdehyde (PA), cross-linked via Schiff's base reaction and horseradish peroxidase (HRP) and hydrogen peroxide (H₂O₂) catalysis. This hydrogel exhibits multiple functionalities, including tissue adhesion, strong antioxidant, and antibacterial activities, as well as rapid hemostasis. HRP and H₂O₂ catalyze the polymerization of PA monomer and color darkening, endowing the hydrogel with near-infrared (NIR) responsiveness and a photothermal antimicrobial property. Moreover, within a murine model of full-thickness burn injury, the hydrogel assisted by NIR irradiation efficiently inhibits bacterial infection, promotes angiogenesis and collagen deposition, and mitigates inflammatory response. Our study demonstrates that the HRP/H₂O₂-catalyzed QCS-PA (QP) hydrogel possesses excellent antioxidant, antibacterial, and anti-inflammatory properties, offering a new therapeutic strategy for wound healing.