Copper Nanodots-Based Hybrid Hydrogels with Peroxidase Activity for Acute and Infected Wound Repair.

Effectively controlling bacterial infection, reducing the inflammatory response and promoting vascular regeneration are all essential strategies for wound repair. Nanozyme technology has potential applications in the treatment of infections due to its non-antibiotic-dependent, topical and noninvasive nature. In the context of wound management, copper-based nanozymes have emerged as viable alternatives to antibiotics, offering additional advantages in promoting angiogenesis. In this study, an ultrasmall cupric enzyme with high enzymatic activity was synthesized and added to a nontoxic, self-healing, injectable cationic guar gum (CG) hydrogel network. The nanozyme exhibited remarkable antioxidant properties under neutral conditions, effectively scavenging reactive nitrogen and oxygen species (RNOS). Under acidic conditions, Cu NDs have peroxide enzyme-like (POD) activity, which allows them to eliminate hydrogen peroxides and produce free radicals locally. In vitro antibacterial experiments showed that they can effectively kill bacteria and remove biofilms. In vitro and in vivo animal experiments showed that low concentrations of Cu ND/CG decrease the expression of the inflammatory factors Interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) in cells and tissues, effectively controlling inflammatory responses. Cu ND/CG hydrogels also inhibit HIF-1α expression and promote VEGF expression in the wound, with an ability to promote vascular regeneration. Comprehensive in vivo safety assessments revealed a favourable biosafety profile, as the nanomaterials had no obvious toxic effects on mice. These findings suggest that Cu ND/CG hydrogels offer a promising biomedical solution for the effective treatment of acute and infected wounds. This study underscores the potential of our innovative nanomaterials in the field of wound healing. This article is protected by copyright. All rights reserved.