Preparation of pro-angiogenic, antibacterial and EGCG-modified ZnO quantum dots for treating bacterial infected wound of diabetic rats

The complex wound environment and abnormalities in self-metabolism of diabetic skin defects lead to impaired angiogenesis, which can easily lead to bacterial infection and increased inflammation. Therefore, there is an urgent need for multifunctional composites with antimicrobial and pro-angiogenic properties to improve the current therapeutic outcomes of diabetic wounds. In this study, we described an EGCG-modified zinc oxide quantum dots (ZnO QDs) hydrogel (ZnO-EGCG@H) for the treatment of delayed diabetic wounds. In vitro antimicrobial assays showed that ZnO-EGCG@H effectively cleared 95.6% of MRSA and 97% of AmprE. coli with good bactericidal activity. Western blotting assay analysis showed that ZnO-EGCG@H downregulated trauma inflammatory factors (TNF-α, IL-6) by 46.9% and 57%, respectively, while upregulating 1.7-fold VEGF and 2-fold EGF, accelerating wound healing by reducing inflammatory response and promoting proliferation of vascular endothelial cells and skin epidermal cells. After 15 days of ZnO-EGCG@H treatment, the rate of skin lesion closure in rats was 96.3%, which was much better than that of 65.4% in the control group. Safety experiments showed that ZnO-EGCG@H was reassuringly biocompatible and harmless to vital organs. The obtained results suggested that ZnO-EGCG@H had the potential to be a safe and effective treatment method with a promising future as a diabetic wound treatment material.