An Environmentally Responsive Poly(Lactic Acid)‐Based Fibrous Membrane With In‐Situ Monitoring and Antibacterial Properties

The integration of real‐time wound monitoring and therapeutic functions represents a promising strategy for advancing next‐generation wound dressings. Herein, we propose a simple and scalable dip‐coating approach to functionalize electrospun poly(lactic acid) (PLA) fibrous membranes with an α‐lipoic acid (α‐LA)‐based supramolecular hydrogel. The resulting composite membrane (PLANFM/LA) exhibits a remarkable water‐induced transparency transition, with visible‐light transmittance switching from nearly opaque (~0.2%) in the dry state to highly transparent (up to 65%) in the hydrated state, enabling non‐invasive visual monitoring of the wound environment. The introduction of the α‐LA hydrogel endowed the membrane with excellent antioxidant and broad‐spectrum antibacterial activities, with DPPH and ABTS radical scavenging rates reaching 92.5% and 95.8%, respectively, at an α‐LA content of 50%, and bactericidal efficiencies against Staphylococcus aureus ( S. aureus ) and Escherichia coli ( E. coli ) increasing from 38.6% and 44.7% at 10% α‐LA to over 85% at higher α‐LA contents. In vitro studies further demonstrate significantly enhanced fibroblast proliferation and migration, with the cell migration rate increasing from ~24% to ~55%. Meanwhile, the membrane surface wettability is effectively regulated, transitioning from hydrophobic (water contact angle, WCA≈121.4°) to highly hydrophilic (WCA≈36.4°), accompanied by substantially improved mechanical flexibility (elongation at break up to 79%). Overall, by integrating water‐responsive transparency for real‐time wound visualization with antioxidant activity, broad‐spectrum antibacterial performance, improved mechanical flexibility, and favorable cytocompatibility, PLANFM/LA overcomes the limitation of conventional dressings that mainly provide passive wound coverage but lack simultaneous monitoring and therapeutic functions. This multifunctional design offers a promising non‐invasive strategy for advanced wound management.