Biomimetic trilayer gradient nanofibrous membrane with hydration-induced network formation for directional exudate Management

The development of unidirectional liquid-transporting membranes is crucially important for chronic wound exudate management. However, maintaining high pumping efficiency under continuously moist conditions remains challenging. A biomimetic trilayer gradient nanofibrous membrane featuring gradients in wettability, fiber diameter, and hydration behavior was fabricated by electrospinning. Upon contact with liquid, the crosslinked hydrophilic fibers undergo rapid hydration-induced swelling and form a hydrated network, accompanied by changes in the state of water within the membrane The TPU-containing transition layer provides structural support to the hydrated hydrophilic phase, while its intermediate wettability facilitates liquid conduction across the layered membrane. The unidirectional transport index of the trilayer membrane reaches up to 1250%, indicating efficient unidirectional liquid transport with suppressed reverse water permeation. Furthermore, after water absorption, the membrane exhibits a tensile strength of 8.46 MPa and an elongation at break of 424%, demonstrating favorable wet-state mechanical robustness under the tested conditions. This strategy, which integrates moisture regulation with structural reinforcement, offers a new approach to designing fiber-based membrane for efficient exudate management.