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 . • A Janus-structured nanofiber membrane fabricated via electrospinning. • Featuring an inner hydrophilic layer absorbing wound exudate and maintaining a moderately moist environment. • With an outer hydrophobic layer as a protective barrier against external contaminants. • Exhibit excellent photothermal performance under near-infrared irradiation. • Enabling heat-triggered release of antibacterial agents and achieving a synergistic antibacterial effect.