NIR II-triggered core-shell upconversion nanocomposites for peroxynitrite-boosted anti-infection against diabetic wound

Infectious diseases due to bacterial resistance remains the great challenges in clinic, especially the antibiotic therapy of diabetic wound. Our previous studies verified that kanamycin-derived carbon-nanodots (KCDs) under light irradiation exhibited enhanced antibacterial activity by damaging bacterial biofilms in a reactive oxygen species (ROS)-dependent manner, and effectively promoted wound healing and tissue remodeling. In the present study, KCDs and nitric oxide donor (BNN6) were co-loaded in dendritic silica-coated NaYF4: Yb3+/Tm3+@NaYF4 three-layer core-shell upconversion materials (USKB). Near-infrared light (NIR) triggered USKB to radiate ultraviolet light, and excited KCDs and BNN6 to produce superoxide anion and nitric oxide (NO), respectively. NO reacted with superoxide anion to form highly cytotoxic peroxynitrite (ONOO- ) and boosted the antibacterial activity. The results showed that USKB under NIR-II exhibited enhanced antibacterial efficiency by peroxynitriteboosted biofilm removel in vitro, and effectively promoted diabetic wound healing in vivo by relieving inflammatory environment and recruiting M2- macrophages. Importantly, USKB nanocomposites showed less side effects and good biocompatibility in vivo. Taken together, our findings present a superior paradigm for designing peroxynitrite-boosted anti-infection against diabetic wound.