Bioinspired "liquid-solid" biphasic dressing with exudate-gating transport, defense-attack antibacterial activity,...

The management of heavily exuding infected wounds is complicated by excessive exudates, persistent bacterial colonization, and secondary trauma during dressing changes. Here, we develop a bioinspired "liquid-solid" biphasic dressing designed to address these challenges simultaneously. This dressing integrates a hylarana guentheri mucus-inspired medical antibacterial oil (guest phase) within a concave nanofiber membrane that mimics the structure of octopus suckers (host phase). This unique architecture enables an exudate-triggered self-adaptive gating mechanism, where the oil-filled concaves act as pressure-deformable gates. High hydrostatic pressure from excess exudate opens the gates for unidirectional transport, while low pressure maintains a closed state, thus dynamically regulating moisture and creating an optimal healing environment. The integrated oil, infused with thymol, establishes a synergistic "defend-and-attack" antibacterial barrier, preventing biofilm formation and neutralizing planktonic E. coli and S. aureus. The same oil layer provides a low-adhesion interface, enabling nearly painless dressing changes with minimal peeling force. In an infected wound model, the dressing accelerates healing, suppresses inflammatory cytokine expression, and reduces bacterial burden. This "liquid-solid" strategy offers a promising paradigm for developing next-generation smart biomaterials for complex wound care.