Synergistic strategy constructed hydrogel-aerogel biphase gel (HAB-gel) with self-negative-pressure exudate absorption, M2 macrophage-polarized and antibacterial for chronic wound treatment

Chronic wound healing is a major and unmet challenge, due to contamination of exudate, bacterial infection and non-healing symptoms, having become urgent an problem to be solved. Developing multifunctional dressings capable of efficiently absorbing exudate by forming self-micro-negative pressure, effectively antibacterial and inducing immune regulation, would be a promising strategy for wound healing. Herein, the hydrogel-aerogel biphase gel (HAB-gel) dressing consisted of PVA grafted with PAM and bio-based polyurethane was prepared to generate synergistic therapeutic effects through removing exudates, antibacterial properties and immune regulation. The PVA grafted with PAMs features generating self-negative pressure to absorb deep exudate by aerogel phase, providing a comfortable microenvironment for wound healing, moreover, the capacities of liquid absorption and retention are enhanced by hydrogel phase, preventing wounds from exudate contamination. The incorporation of beta-cyclodextrin (beta-CD) in the constructed polyurethane (LPU) endows the HAB-gel materials with excellent antibacterial properties after being loaded with polyhexamethylene biguanidine (PHMB). Furthermore, the HAB-gel dressing can accelerate the macrophage polarization into anti-inflammatory M2 via the hydrogen sulfide (H2S) generation, angiogenesis promotion and collagen deposition in periwound tissue. Overall, this novel strategy for synergistic treatment of chronic wounds, provides a promising method for the management of tissue regeneration disorders.