A brief strategy for the preparation of silk fibroin-copper sulfide-based electrospun nanofibrous membranes with photothermal antimicrobial properties to accelerate the infected wound healing

Bacterial infections often hinder the wound-healing process. Antibiotics are commonly used to eradicate bacteria, but long-term use can lead to the development of drug-resistant bacteria. Photothermal therapy (PTT) is a promising technology that utilizes a photothermal agent (PTA) to convert near-infrared radiation into heat, which can eliminate bacteria and has the advantages of being highly effective, controllable, and low drug resistance. In this study, we obtained silk fibroin-copper sulfide nanoparticles(SF/CuS NPs) in situ with excellent photothermal responsive properties by a green synthesis strategy using silk fibroin proteins as biological templates. Then, the SF/CuS NPs were mixed with PVA solution, and the photothermal nanofiber membrane (PVA-SF/CuS) was prepared using the electrostatic spinning technique. The synthesized SF/CuS NPs endowed the nanofiber membrane with excellent photothermal sterilization properties. In addition, the constructed PVA-SF/CuS nanofibrous membranes had good cytocompatibility and haemocompatibility. Meanwhile, in vivo experiments confirmed that PVA-SF/CuS nanofibrous membrane could inhibit the expression of pro-inflammatory factor (IL-6), promote the expression of angiogenic factor (VEGF), and accelerate collagen deposition and neovascularization under near-infrared light irradiation, which could then promote the healing of infected wounds. Thus, the PVA-SF/CuS nanofiber membrane provides a new candidate material for treating bacterially infected wounds.