Multifunctional hierarchical porous structured aerogel as a self-pumping dressing for enhanced wound healing

Ideal dressings for chronic wounds should efficiently manage excessive exudate while preventing wound infection. Although existing three-dimensional dressings with interconnected porous networks enable rapid fluid absorption, they generally lack the capacity for unidirectional fluid transmission, especially for viscous fluids. To address these limitations, a cationic waterborne polyurethane emulsion was first prepared via the prepolymer emulsification method. Based on this emulsion, a multifunctional aerogel featuring hydrophilic hierarchical nano-micro porous channels was proposed by programming ice-crystal growth behavior using a dynamic ice-templating strategy. This unique gradient-structured aerogel functioned like an intelligent pump, facilitating swift unidirectional transport of viscous fluids up to 60 mPa·s within ~5.7 s. Simultaneously, its gradient stiffness network dissipated stress effectively through elastic energy storage, achieving outstanding mechanical performance (compression for 500 cycles). Furthermore, the aerogel showed intrinsic cationic long-lasting antimicrobial characteristics, demonstrating exceptional antibacterial activity (>99.9%) against E. coli and S. aureus. In vivo studies confirmed that the aerogel considerably enhances wound healing through effective exudate management, infection prevention, and tissue regeneration.