Photothermally activated multifunctional MoS2 bactericidal nanoplatform for combined chemo/photothermal/photodynamic triple-mode therapy of bacterial and biofilm infections

Combined therapy can improve the curative effect and reduce side effect, so it has a broad application prospect in the treatment of bacterial infections especially bacterial biofilm infections. Herein, we propose a photothermal-activated multifunctional nano-antibacterial platform that is constructed by Introducing indocyanine green (ICG) photosensitizers and silver nanoparticles (AgNPs) onto Molybdenum disulfide (MoS2) nanosheets surface. The constructed nanoplatform (MoS2/ICG/Ag) has the combined chemo/photothermal/photodynamic triple-mode antibacterial capability under a single 808 nm laser irradiation. Briefly, the photonic hyperthermia generated by MoS2 nanosheets can not only directly kill bacteria, but also accelerate the release of ICG and silver ions, and the latter is a commonly used chemical antibacterial reagent. The released ICG can catalyze the conversion of oxygen into singlet oxygen with the help of 808 nm light, achieving the photodynamic sterilization. Encouragingly, the loaded ICG and AgNPs can in turn enhance the heat, which is a mutually reinforcing effect that can produce a combined or even synergistic therapeutic effect. In vitro experiments demonstrate that the MoS2/ICG/Ag with triple bactericidal modalities has good broad-spectrum antibacterial performance. Importantly, it can remarkably inhibit the S. aureus biofilms formation and effectively eradicate the bacteria deep in the biofilms. In addition, the MoS2/ICG/Ag is successfully used for treating S. aureus biofilms-infected wound in vivo with minimal toxicity. Taken together, the developed MoS2/ICG/Ag nanoplatform may serve as a potential nano-antibacterial agent for photothermally activated multimodal combined antibacterial and antibiofilm therapy.