Synthesis of Ti₃C₂T /MnO₂ composites for synergistic catalytic/photothermal-based bacterial inhibition

Human inflammation caused by bacterial infection threatens global public health. The abuse of antibiotics often leads to the development of drug resistance in bacteria. To address this issue, nanozymes with peroxidase-like (POD-like) activity have often been reported for bacteriostasis with the assistance of catalytic substrate hydrogen peroxide (H₂O₂). However, it is difficult to achieve efficient bactericidal outcomes only through exertion of the POD-like activity of nanozymes. Here, MnO₂ loaded Ti₃C₂T (Ti₃C₂T /MnO₂) was prepared by a two-step reaction method, in which MnO₂ showed high oxidase-like (OXD-like) activity to elevate the levels of reactive oxygen species (ROS) without H₂O₂ and Ti₃C₂T exhibited high photothermal conversion efficiency to induce hyperthermia. Thus, the obtained Ti₃C₂T /MnO₂ realized synergistic catalytic/photothermal-based bacterial inhibition, including for Gram-negative bacteria (Escherichia coli), Gram-positive bacteria (Staphylococcus aureus), and methicillin-resistant Staphylococcus aureus. Importantly, Ti₃C₂T /MnO₂ with near-infrared light irradiation successfully promoted Staphylococcus aureus-infected wound healing in mouse models, representing an alternative treatment to fight against bacterial infection.