Functionalized Nano-MoS₂ with Peroxidase Catalytic and Near-Infrared Photothermal Activities for Safe and Synergetic Wound Antibacterial Applications

Abstract

We have developed a biocompatible antibacterial system based on polyethylene glycol functionalized molybdenum disulfide nanoflowers (PEG-MoS 2 NFs). The PEG-MoS 2 NFs have high near-infrared (NIR) absorption and peroxidase-like activity, which can efficiently catalyze decomposition of low concentration of H 2 O 2 to generate hydroxyl radicals (·OH). The conversion of H 2 O 2 into ·OH can avoid the toxicity of high concentration of H 2 O 2 and the ·OH has higher antibacterial activity, making resistant bacteria more vulnerable and wounds more easily cured. The PEG-MoS 2 NFs combine the catalysis with NIR photothermal effect, providing a rapid and effective killing outcome in vitro for Gram-negative ampicillin resistant Escherichia coli (Amp r E. coli ) and Gram-positive endospore-forming Bacillus subtilis ( B. subtilis ) as compared to catalytic treatment or photothermal therapy (PTT) alone. Wound healing results indicate that the synergy antibacterial system could be conveniently used for wound disinfection in vivo . Interestingly, glutathione (GSH) oxidation can be accelerated due to the 808 nm irradiation induced hyperthermia at the presence of PEG-MoS 2 NFs proved by X-ray near-edge absorption spectra and X-ray spectroscopy. The accelerated GSH oxidation can result in bacterial death more easily. A mechanism based on ·OH-enhanced PTT is proposed to explain the antibacterial process.