Self-assembled Janus structure nanofiber membranes for skin wound healing: Synergistic photothermal and chemical antibacterial strategies

With the aging global population and a progressive annual rise in chronic diseases, the incidence of chronic skin trauma has increased significantly. Chronic skin wounds, which often remain unhealed for extended periods, are highly susceptible to bacterial infections. Consequently, the use of antibacterial dressings has become a crucial strategy for preventing and managing such infections. These dressings not only serve as a physical barrier protecting wounds from external contaminants, but also regulate the healing microenvironment, promote tissue regeneration, and accelerate the healing process. In this study, we designed a wound dressing with Janus structure by electrospinning technology. The inner layer consists of hydrophilic cellulose acetate (CA) incorporated with polylysine (ε-PL) to maintain a moist, bacteriostatic environment, while the outer layer is composed of hydrophobic polycaprolactone (PCL) integrated with tannic acid (TA)-modified black phosphorus (BP) to prevent microbial adhesion. The combination of the antibacterial activity of ε-PL and the photothermal effect of TA-modified BP (TABP) endows the Janus nanofiber membrane with a potent synergistic antibacterial capability. In vitro experiments demonstrate that the dressing exhibits excellent surface wettability and permeability, enhanced mechanical strength, potent antibacterial activity, and mild photothermal effects that help alleviate inflammatory responses. This Janus nanofiber membrane represents a promising strategy for enhancing and accelerating wound healing.