Dual-responsive metal polyphenol network nanosheets for diabetic wound healing

Diabetic wound healing poses a significant challenge in the biomedical domain. Inadequate angiogenesis and fibroblast dysfunction are two primary characteristics of diabetic microenvironment. Fibroblast dysfunction is characterized by excessive accumulation of reactive oxygen species (ROS) and fragmented mitochondria. Herein, we developed a microenvironment responsive zinc–gallic acid nanosheets (ZnGA NSs) for diabetic wound healing, which slowly release Zn2+ and gallic acid (GA) in response to low pH and excessive ROS. The released Zn2+ enhanced cell proliferation, migration, and endothelial tube formation. And the released GA activated antioxidant enzyme system via the KEAP1/NRF2 pathway and promoted mitochondrial fusion by upregulating MFN1/2 and OPA1, which ultimately reprograms dysfunctional fibroblast. The application of ZnGA NSs effectively facilitated wound healing in a rat diabetic model with full-thickness cutaneous defects. More importantly, skin wounds treated with ZnGA NSs exhibited enhanced angiogenesis, alleviated inflammation, and improved tissue regeneration. These findings highlight the potential of ZnGA NSs as a promising therapeutic modality for diabetic wound treatment.