Laser Activatable CuS Nanodots to Treat Multidrug-Resistant Bacteria and Release Copper Ion to Accelerate Wound Healing for Infected Chronic Nonhealing Wounds.

Chronic non-healing wounds have imposed serious challenges in the clinical practice, especially for the patients infected with multidrug-resistant (MDR) microbes. Herein, we developed an ultrasmall copper sulfide (covellite) nanodots (CuS NDs)-based dual functional nanosystem to cure multidrug-resistant bacteria-infected chronic non-healing wound. The nanosystem could eradicate multidrug-resistant bacteria and expedite wound healing simultaneously, owing to the photothermal effect and remote control of copper ion release. The antibacterial results indicated that the combination treatment of photothermal CuS NDs with photothermal initiated a strong antibacterial effect for drug-resistant pathogens including methicillin-resistant S. aureus (MRSA) and extended-spectrum beta-lactamase (ESBL) E. coli both in vitro and in vivo. Meanwhile, the released Cu2+ could promote fibroblast cell migration and endothelial cell angiogenesis, thus accelerating wound healing effects. In MRSA-infected diabetic mice model, the nanosystem exhibited synergistic wound healing effect of the infectious wounds in vivo, and demonstrated negligible toxicity and nonspecific damage to major organs. The combination ultrasmall CuS NDs with photothermal therapy displayed enhanced therapeutic efficacy for chronic non-healing wound in multidrug-resistant bacterial infections, which may represent a promising class of antibacterial strategy for clinical translation.