Self-Healing Nanozyme\nHydrogel with Nitric Oxide Production\nand Photothermal Effect to Promote Wound Healing

Bacterial-infected skin wounds are a severe global healthcare\nproblem.\nBacterial invasion and an immoderate inflammatory response are major\nobstacles in the wound healing process. To mitigate these issues,\na multifunctional nanozyme hydrogel dressing (FeCu/S/OxC/G) was prepared\nby loading sodium nitroprusside and iron–copper nanoparticles\ninto a hydrogel network that was made of sodium periodate oxidized\nchondroitin sulfate, gelatin, and borax. Owing to different types\nof dynamic bonds, including Schiff base bonds and hydrogen bonds,\nthe hydrogel showed self-healing ability, good injectability, and\nexcellent adhesive performance. In vitro results demonstrated that\nthe FeCu/S/OxC/G + H<sub>2</sub>O<sub>2</sub> + NIR group exhibited\na higher inactivation rate of Staphylococcus aureus and fewer biofilms than other groups, indicating the combined antibacterial\neffects of POD-like activity, nitric oxide, and photothermal therapy.\nIn vivo results verified that FeCu/S/OxC/G hydrogel together with\nNIR laser irradiation could maximally increase the wound healing rate\nof S. aureus-infected mice via promoting\nepidermal formation, accelerating collagen deposition, and reducing\nthe expression of inflammatory factors. This study provided a promising\ntherapeutic strategy with combined antibacterial and anti-inflammatory\neffects for wound healing.