Antibacterial gradient-enhanced Janus self-pumping membrane for effective biofluid management and wound healing

Optimal wound healing requires a sterile, moderately moist environment. Effective biofluid management is particularly crucial in infected skin defects, where complete drainage is essential for tissue repair. However, current dressings are largely designed for superficial injuries and fail to provide efficient fluid evacuation in deep wounds. In this study, we developed an antibiotic-loaded PAN/PCL dual-gradient Janus membrane comprising a hydrophobic macroporous outer layer, a hydrophilic microporous inner layer, and an intermediate transition layer. The membrane enables efficient self-pumping and unidirectional biofluid transport in superficial wounds. When curled into drainage strips, it enhances biofluid enrichment and supports gravity-resistant drainage in deep wounds. The superhydrophobic layer minimises cellular adhesion, reducing secondary trauma upon dressing removal. Sustained release of the incorporated antibiotic ensures prolonged antibacterial activity. In comparison with conventional clinical dressings, this Janus drainage system reduced local bacterial load by two orders of magnitude in a murine abscess model, significantly accelerating wound healing. Owing to its active drainage capacity, antibacterial efficacy, anti-adhesion properties, and biosafety, this system shows considerable potential for clinical management of infected wounds.