Ag Nanoparticles\non MXene Nanosheets for Combined\nIonic and Photothermal Therapy of Bacterial Infections

In view of the increasing bacterial resistance, 2D MXenes\nare promising\nalternatives to antibiotics. However, MXene-based photothermal therapy\n(PTT) suffers from unsatisfactory antibacterial efficiency and heat-resistant\nstrains. Here, we prepared a Ti<sub>3</sub>C<sub>2</sub> MXene and\nAg hybridized antibacterial nanocomposite [MXene/metal-polyphenol\nnetworks (MPNs)/Ag] through the in situ reduction of Ag nanoparticles\non MPN wrapped MXene matrix. The use of MPNs as the reducing agents\nof Ag<sup>+</sup> and anchoring agents of Ag nanoparticles endowed\nMXene/MPN/Ag with a tight immobilization capacity and improved colloidal\ndispersion stability of Ag nanoparticles. The pH-triggered decomposition\nof MPNs led to the pH-responsive release of Ag to achieve combined\nMXene-based PTT and Ag-mediated therapy for enhanced antibacterial\nefficiency. In vitro antibacterial experiments revealed its satisfactory\nbactericidal activities against both planktonic bacteria and bacteria\nin stubborn biofilms. In vivo antibacterial assays solidly confirmed\nits high antibacterial therapeutic efficiency, strong anti-inflammatory\nability, and good biosafety. Therefore, the in situ combination of\nAg nanoparticles with MXenes offers a promising microenvironment-responsive\n2D bactericidal candidate for infection that could be applied in future\nantibacterial treatments.