Copper Telluride@Sodium Alginate-Poly(vinyl Alcohol) Nanofiber/Gauze Wound Dressing for Gram-Negative Bacteria-Infected Wounds.

Bacterial infections cause great difficulties in the healing process of wound repair and may worsen this condition, seriously jeopardizing human health. Gram-negative bacteria are more problematic sources of infection because of their outer membrane and endotoxins. In this study, copper telluride@sodium alginate-poly(vinyl alcohol) nanofiber/gauze (CuTe@SA-PVA NF/G) was constructed and applied to Gram-negative bacterium-infected wounds to achieve good anti-infective effects through the powerful antimicrobial mechanism of copper telluride (CuTe) nanozymes. CuTe nanoflowers with peroxidase-like (POD-like), oxidase-like (OXD-like), and glutathione peroxidase-like (GSH-Px-like) activities were synthesized via a simple one-pot method to combat bacterial survival by generating reactive oxygen species (ROS) and consuming GSH. The results of in vitro antimicrobial experiments confirmed that the killing effect of CuTe nanozymes on Gram-negative bacteria far exceeded that on Gram-positive bacteria and that they could effectively eradicate all kinds of Gram-negative bacteria and disrupt the existence of their biofilms. The results revealed that CuTe nanozymes damage Gram-negative bacteria by inhibiting bacterial dormancy, affecting iron metabolism, inhibiting flagellar motility, and decreasing the production of extracellular polysaccharide (EPS) and lipopolysaccharide (LPS). To further adapt to clinical applications, we used electrostatic spinning technology to prepare CuTe@SA-PVA NF/G wound dressings with good biosafety, which were applied to Gram-negative bacterium-infected wounds and pressure ulcer-infected sites. Animal experiments revealed that CuTe@SA-PVA NF/G has good anti-infection effects and promotes wound healing. The transcriptomics results further revealed that CuTe@SA-PVA NF/G promoted wound healing through potent antimicrobial activity, modulation of the inflammatory response, and stimulation of angiogenesis and cell proliferation. This study successfully developed a CuTe@SA-PVA NF/G wound dressing with specific killing effects on Gram-negative bacteria, providing a promising approach for the clinical treatment of specific Gram-negative bacterial infections.