Bioinspired Janus Micro/Nanofibrous dressings for unidirectional exudate management and real-time colorimetric monitoring in chronic wounds.

Chronic wounds present significant challenges due to persistent inflammation and exudate accumulation. Inspired by nature's sophisticated fluid-manipulation architectures, an integrated Janus micro/nanofibrous dressing for synergistic unidirectional exudate management and real-time colorimetric infection monitoring was developed. This smart dressing integrates a pH-responsive hydrophilic viscose outer layer with a hydrophobic polyurethane nanofibrous inner layer. By covalently immobilizing pH-sensitive dyes onto the viscose fibers, a leach-proof chromatic response "biological traffic light" that visually monitors wound status was achieved. The structural and wettability gradients within the Janus architecture generate a localized Laplace pressure difference, enabling autonomous, unidirectional exudate transport to prevent maceration. Beyond superior fluidic control, the smart dressing provides a non-invasive diagnostic window by exhibiting distinct color shifts in response to pH variations. Furthermore, the smart dressing maintains an optimal healing microenvironment through excellent air/vapor permeability, mechanical integrity, and cytocompatibility. In vivo evaluations confirm that this Janus dressing significantly accelerates tissue regeneration. This bioinspired sense-and-treat dressing offers a sophisticated strategy for the next generation of intelligent chronic wound care.