Cell Wall Binding Strategies Based on Cu₃SbS₃ Nanoparticles for Selective Bacterial Elimination and Promotion of Infected Wound Healing

Abstract

Utilizing nanomaterials as an alternative to antibiotics, with a focus on maintaining high biosafety, has emerged as a promising strategy to combat antibiotic resistance. Nevertheless, the challenge lies in the indiscriminate attack of nanomaterials on both bacterial and mammalian cells, which limits their practicality. Herein, Cu 3 SbS 3 nanoparticles (NPs) capable of generating reactive oxygen species (ROS) are discovered to selectively adsorb and eliminate bacteria without causing obvious harm to mammalian cells, thanks to the interaction between O of Nacetylmuramic acid in bacterial cell walls and Cu of the NPs. Coupled with the short diffusion distance of ROS in the surrounding medium, a selective antibacterial effect is achieved. Additionally, the antibacterial mechanism is then identified: Cu 3 SbS 3 NPs catalyze the generation of O 2•− , which has subsequently been conversed by superoxide dismutase to H 2 O 2 . The latter is secondary catalyzed by the NPs to form •OH and 1 O 2 , initiating an in situ attack on bacteria. This process depletes bacterial glutathione in conjunction with the disruption of the antioxidant defense system of bacteria. Notably, Cu 3 SbS 3 NPs are demonstrated to efficiently impede biofilm formation; thus, a healing of MRSA-infected wounds was promoted. The bacterial cell wall−binding nanoantibacterial agents can be widely expanded through diversified design.