Bioinspired "liquid-solid" biphasic dressing with exudate-gating transport, defense-attack antibacterial activity, and anti-adhesion property for exuding infected wound therapy.

Abstract

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 <i>E. coli</i> and <i>S. aureus</i>. 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.