Mussel-Inspired Hydrogel with Potent in Vivo Contact-Active Antimicrobial and Wound Healing Promoting Activities

Open wounds (e.g., burns and trauma) are always challenged by various opportunistic bacteria. There is an urgent need for developing novel wound dressing that is able to prevent bacterial infection and promote the healing simultaneously. Herein, we developed a new type of antimicrobial hydrogels for the open wound healing through imitating a facile mussel-inspired catechol/polyamine chemistry. This hydrogel was prepared using catechol (CT) and ϵ-poly-l-lysine (EPL) by oxidative cross-linking directly in the open air at room temperature. This nonleaching CT/EPL hydrogel not only exhibited excellent contact-active antimicrobial activities against Gram-negative bacteria Escherichia coli (E. coli) and Gram-positive "superbug" methicillin-resistant Staphylococcus aureus (MRSA) but also inhibited the biofilm formation in vitro. Moreover, the animal burn wound model study clearly validated the in vivo anti-infective property of CT/EPL hydrogel against MRSA infection. More importantly, the CT/EPL hydrogel possessed low cytotoxicity and enhanced cell migration in vitro. A full-thickness cutaneous wound model study revealed that CT/EPL hydrogel upregulated the expression of vascular endothelial growth factor (VEGF) and reduced the production of the pro-inflammatory cytokines, thus promoted the wound healing. These findings suggested that the CT/EPL hydrogel have great potential as a wound dressing for preventing bacterial infection and accelerating healing of open wounds.