A light-triggered nitric oxide-photothermal nanoplatform for combating bacterial infections and promoting wound healing

Abstract

Bacterial infections pose a significant and ongoing threat to the general population, leading to high rates of morbidity and death globally. Antibiotics are commonly used to treat bacterial infections, but bacterial resistance to antibiotics develops rapidly over time. Photothermal therapy (PTT) has emerged as a possible antibiotic replacement therapy owing to its high spatiotemporal controllability and targeted destruction. However, relying solely on the heat generated by PTT for bacterial eradication may lead to secondary damage to healthy tissues due to excessive heat, potentially compromising the therapeutic results. Combining PTT with multiple antibacterial therapies can enhance antibacterial efficacy while minimizing the side effects associated with a single antibacterial approach. Herein, we propose an antibacterial nanoplatform composed of gold nanorod–copper sulfide photothermal hybrid nanoparticles (Au NR-CuS NPs, in short AC) and a ruthenium nitrosyl nitric oxide donor (in short Ru–NO). The constructed nanoplatform (Au NR-CuS@Ru–NO NPs, in short ACRN) exhibited combined mild photothermal/nitric oxide (mPTT/NO) antibacterial performance under single laser irradiation at 808 nm. When exposed to 808 nm laser irradiation, ACRN exhibited strong broad-spectrum antibacterial activity, according to in vitro tests. Crucially, it may considerably prevent the formation of biofilms of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Due to the presence of NO, ACRN promoted wound healing by improving anti-inflammation, collagen deposition, and angiogenesis and markedly lessened wound inflammation in S. aureus-infected mice. Therefore, this work proposes a novel strategy aimed at enhancing the antibacterial efficacy of antibiotic-free treatment and provides the groundwork for the design of a nanoplatform based on mPTT/NO synergy.