Composite antibacterial hydrogels based on two natural products pullulan and ε-poly-l-lysine for burn wound healing

Antibacterial hydrogels as burn wound dressings are capable of efficaciously defending against bacterial infection and accelerating burn wound healing. Thus far, a large plethora of antibacterial hydrogels have adopted numerous components and intricate preparation processes, yet restricting their practical industrialization applications. Simple and effective preparation methods of antibacterial hydrogels are hence urgently needed. Herein, an easy but efficacious strategy with the employment of two natural products pullulan and ε-poly-l-lysine (ε-PL) was designed to fabricate composite antibacterial hydrogels for burn wound healing for the first time. The hydrogel crosslinking networks were formed through amidation reactions between carboxylated pullulan derivative (CP) and ε-poly-l-lysine hydrochloride (ε-PL·HCl). The resulting hydrogels possessed high transparency, porous structures, tunable gelation time and gel content, relatively low swelling ratios, appropriate self-degradability, proper mechanical properties, strong in vitro bacteriostatic activities, non-cytotoxicity, capacities of facilitating cell migration and excellent hemocompatibility. In the infected burn model of mice, the hydrogels were observed to display prominent in vivo antibacterial activities and enable the acceleration of burn wound healing. We opine the simply and effectively prepared antibacterial hydrogels as promising dressings for burn wound recovery have broad industrialization prospects.