Engineering a new member of MXenes M5C4 phases nanoplatforms as synergistically photothermal and chemodynamic therapeutics for methicillin-resistant Staphylococcus aureus

The explosion of the transition metal carbides or nitrides (MXenes) in nanomedicine as the nanotherapeutic agents with emerging and versatile are still in the initial stage. Despite the utmost endeavor devoted to photonic bacteria hyperthermia, current photothermal agents still have limitations that hinder clinical translation, such as low photothermal efficiency, single-site effect, and low biocompatibility. Recently, photothermal therapy (PTT) and chemodynamic therapy (CDT) to synergistically exert high-performance bactericidal functions were gaining popularity. Herein, a PTT-CDT synergistic strategy was proposed to prevent drug-resistant bacterial infections by fabricating a new member of MXenes—M5C4 (Mo4VC4). Currently reported MXenes (Mn+1Xn, where M is transition metal and X is C or N) include M2X, M3X2, and M4X3 types. Compared with traditional MXenes, Mo4VC4 exhibits persistent hyperthermia in the near-infrared region (NIR-II) by PTT and highly efficient hydroxyl radical (•OH) production by CDT. Immediately, Mo4VC4 exhibited marked hyperthermia and caused •OH-induced death of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa in vitro and in vivo through PTT-CDT synergy, and also accelerated abscess resolution and promoted healing of MRSA-infected wound. Overall, Mo4VC4 has good biocompatibility and demonstrates the vast potential of this new member of MXenes as a nanotherapeutic agent in anti-infective therapy without antibiotics.