Roxarsone Delivery Nanocomposite Based on Nitrite-Functionalized Mesoporous Polydopamine for Multidrug-Resistant Bacterial Infections via Enhanced Chemo-Photothermal Therapy

Graphical An anti-infection nanocomposite was constructed by loading bactericide Roxarsone onto nitrosylated mesoporous polydopamine. The designed nanocomposite achieves NO-enhanced chemo-photothermal antibacterial therapy under near-infrared laser irradiation, and in vitro antibacterial evaluation has confirmed the effective elimination against the Gram-negative tetracycline-resistant Escherichia coil and Gram-positive methicillin-resistant Staphylococcus aureus of the nanocomposite. Current treatments for infections caused by multidrug-resistant bacteria still remain challenging and therapeutic materials with high efficacy are of demand. Herein, a bactericidal nanocomposite was constructed by loading Roxarsone (ROX) onto nitrosylated mesoporous polydopamine (named mPDA@NO-ROX). The designed nanocomposite exhibited considerable photothermal effect and controlled NO and ROX co-delivery under the irradiation of near-infrared laser (NIR) to achieve enhanced chemo-photothermal antibacterial therapy. The in vitro antibacterial evaluation of the mPDA@NO-ROX demonstrated the effective elimination of the Gram-negative tetracycline-resistant Escherichia coil and Gram-positive methicillin-resistant Staphylococcus aureus under mild NIR irradiation compared to merely ROX loaded unmodified mPDA, indicating the NO enhanced chemo-photothermal therapy. In addition, the cytotoxicity experiments indicated that mPDA@NO-ROX exhibited only 5 % of hemolysis rate and high cell viability at 1 mg mL −1 against mammalian fibroblasts, suggesting the excellent biocompatibility. In conclusion, the mPDA@NO-ROX could be a promising candidate for anti-infection therapy of multidrug-resistant bacteria.