Nanoliquid Dressing with Enhancing Anti-Infection Performance under the Moderate Photothermal Effect for Wound Treatment.

Nonhealing wounds have become a major healthcare burden worldwide. Chronic wound healing is universally hampered by the presence of bacterial infections that form biofilms. Therefore, in this study, a novel nanoliquid dressing based on a mild photothermal heating strategy was designed to provide safe healing of biofilm-infected wounds. Dilute nitric acid (HNO3) solution was employed to induce a redox process triggered by copper sulfide (CuS) nanoplates in the nanoliquid dressing. This redox process was further promoted by the mild photothermal effect (≤47.5 °C) that generated a sufficient amount of reactive oxygen species, resulting in less thermal injury to normal tissues. Correspondingly, with the safe concentration of CuS nanoplates (0.4 mg/mL), excellent bactericidal efficiencies up to 98.3 and 99.3% against ampicillin-resistant Escherichia coli (Ampr E. coli) and Staphylococcus aureus (S. aureus) were achieved, respectively. Moreover, the nanoliquid dressing exhibited a near-infrared enhanced destructive effect on mature biofilms. According to in vivo wound healing experiments in mice, the nanoliquid dressing increased the healing rate and reduced the inflammatory response. This study provides a novel insight into treating the biofilm-infected chronic wounds in the "post-antibiotic era".