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. Highlights Flexible PLA/hydrogel composite prepared via simple dip-coating. Brittle-to-ductile transition achieved with 79% elongation. Hydrogel acts as a plasticizer, ensuring strong interfacial adhesion. Integrates flexibility, antibacterial properties, and water-responsive transparency. A strategy to toughen and functionalize brittle biopolymer membranes.