Multifunctional Janus nanofibrous membrane with unidirectional water transport and pH-responsive color-changing for wound dressing.

Chronic wounds often produce a significant volume of exudate, posing a substantial obstacle to healing. Consequently, there is a pressing demand for a versatile dressing capable of effectively managing exudate in chronic wounds. In this context, a Janus smart dressing is proposed, featuring unidirectional water transport and a pH-responsive color-changing for exudate management and wound monitoring. The dressing's mechanisms for unidirectional water transport and color changing are elucidated. The Janus dressing consists of a polyacrylonitrile (PAN)/sodium polyacrylate (SPA)/anthocyanin (An) hydrophilic layer with antioxidant and pH-sensitive functions and a poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) hydrophobic layer, enabling unidirectional exudate drainage without reverse osmosis. Studies indicate that the Janus dressing exhibits excellent air permeability, moisture permeability, mechanical properties, cytocompatibility, and antioxidant performance while promptly responding to color variations in solutions of varying pH levels. In vivo studies demonstrated the excellent wound healing ability of Janus PHBV-PAN/SPA/An membrane. Consequently, this study provides a promising solution to develop wound dressings that can effectively manage excessive wound exudate and dressing changes.