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

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.