Self-Healing Nanozyme Hydrogel with Nitric Oxide Production and Photothermal Effect to Promote Wound Healing

Abstract

Bacterial-infected skin wounds are a severe global healthcare problem. Bacterial invasion and an immoderate inflammatory response are major obstacles in the wound healing process. To mitigate these issues, a multifunctional nanozyme hydrogel dressing (FeCu/S/OxC/G) was prepared by loading sodium nitroprusside and iron–copper nanoparticles into a hydrogel network that was made of sodium periodate oxidized chondroitin sulfate, gelatin, and borax. Owing to different types of dynamic bonds, including Schiff base bonds and hydrogen bonds, the hydrogel showed self-healing ability, good injectability, and excellent adhesive performance. In vitro results demonstrated that the FeCu/S/OxC/G + H₂O₂ + NIR group exhibited a higher inactivation rate of Staphylococcus aureus and fewer biofilms than other groups, indicating the combined antibacterial effects of POD-like activity, nitric oxide, and photothermal therapy. In vivo results verified that FeCu/S/OxC/G hydrogel together with NIR laser irradiation could maximally increase the wound healing rate of S. aureus-infected mice via promoting epidermal formation, accelerating collagen deposition, and reducing the expression of inflammatory factors. This study provided a promising therapeutic strategy with combined antibacterial and anti-inflammatory effects for wound healing.