NIR-Responsive Ti3 C2 MXene Colloidal Solution for Curing Purulent Subcutaneous Infection through the "Nanothermal Blade" Effect.

Pathogenic microorganisms' infections have always been a difficult clinical challenge and lead to serious health problems. Thus, a new strategy is urgently needed. In this study, a simple preparation method for Ti3 C2 MXene colloidal solution is proposed. In vitro, Staphylococcus aureus is treated with 250 µg mL-1 of Ti3 C2 colloidal solution under 5 min of 808 nm near-infrared (NIR) laser irradiation twice. Staphylococcus aureus is eliminated by the "nanothermal blade" effect from Ti3 C2 combined with NIR; the antibacterial rate is 99%, which is higher than the antibacterial rate of pure Ti3 C2 alone 78%. The antibacterial mechanism underlying this treatment may be that the thermal Ti3 C2 nanosheets first transfer heat to the cell membrane, disrupting the membrane structure, disturbing the metabolism and causing leakage of bacterial protein and deoxyribonucleic acid, consequently leading to bacterial death. In vivo results indicate that Ti3 C2 colloidal solution under NIR can effectively kill Staphylococcus aureus and prevent inflammation. Moreover, 250 µg mL-1 Ti3 C2 colloidal solution is nontoxic to mouse organs during the therapeutic process. Therefore, Ti3 C2 colloidal solution can be an ideal candidate for subcutaneous infection application. The antibacterial mechanism proposed in this study aids the investigation of other MXenes as antibacterial agents.