Vancomycin modified copper sulfide nanoparticles for photokilling of vancomycin-resistant enterococci bacteria

Due to the overuse of antibiotics, vancomycin resistant enterococci (VRE) has caused serious infections and become more and more difficult to deal with. Herein, we reported a facile one-pot strategy to synthesize copper sulfide nanoparticles using vancomycin (Van) as reductant and capping agent ([email protected]). The as-prepared [email protected] nanocomposites presented excellent uniformity in particle size and strong near infrared (NIR) absorbance. Fourier Transform infrared spectroscopy (FTIR) and Energy dispersive spectrometry (EDS) analysis confirmed the successful modification of Van molecules on the surface of [email protected] nanoparticles. Bacterial TEM images verified the specific binding affinity between [email protected] and VRE pathogen. [email protected] also exhibited effective photokilling capability based on a combination of photothermal therapy (PTT) and photodynamic therapy (PDT). Fluorescent bacterial viability staining and bacterial growth curves monitoring were performed to explore the photokilling ablation of [email protected] against VRE pathogens. The in vitro results indicated that [email protected] nanocomposites had no antibacterial activity in the dark but displayed satisfying bactericidal effect against VRE pathogens upon the NIR irradiation. Mouse infection assays were also implemented to evaluate in vivo antibacterial photokilling effectiveness. [email protected] with NIR irradiation showed the highest antibacterial capability and fastest infection regression compared with the control groups. Considering the low cost, easy preparation, good biocompatibility and excellent photokilling capability, [email protected] nanocomposites will shed bright light on the photokilling ablation of vancomycin-resistant pathogenic bacteria.