NIR‐Responsive Ti₃C₂ MXene Colloidal Solution for Curing Purulent Subcutaneous Infection through the “Nanothermal Blade” Effect

Abstract

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.