Synthesis of Ti 3 C 2 T x /MnO 2 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 (H 2 O 2 ). However, it is difficult to achieve efficient bactericidal outcomes only through exertion of the POD-like activity of nanozymes. Here, MnO 2 loaded Ti 3 C 2 T x (Ti 3 C 2 T x /MnO 2 ) was prepared by a two-step reaction method, in which MnO 2 showed high oxidase-like (OXD-like) activity to elevate the levels of reactive oxygen species (ROS) without H 2 O 2 and Ti 3 C 2 T x exhibited high photothermal conversion efficiency to induce hyperthermia. Thus, the obtained Ti 3 C 2 T x /MnO 2 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, Ti 3 C 2 T x /MnO 2 with near-infrared light irradiation successfully promoted Staphylococcus aureus -infected wound healing in mouse models, representing an alternative treatment to fight against bacterial infection.