Thermoresponsive Self-Healing Zwitterionic Hydrogel as an In Situ Gelling Wound Dressing for Rapid Wound Healing

It is highly desired yet challenging to fabricate biocompatible injectable self-healing hydrogels with anti-bacterial adhesion properties for complex wounds that can autonomously adapt to different shapes and depths and can promote angiogenesis and dermal collagen synthesis for rapid wound healing. Herein, an injectable zwitterionic hydrogel with excellent self-healing property, good cytocompatibility, and antibacterial adhesion was developed from a thermoresponsive ABA triblock copolymer poly[(N-isopropyl acrylamide)-co-(butyl acrylate)-co-(sulfobetaine methacrylate)]-b-poly(ethylene glycol)-b-poly[(N-isopropyl acrylamide)-co-(butyl acrylate)-co-(sulfobetaine methacrylate)] (PZOPZ). The prepared PZOPZ hydrogel exhibits a distinct thermal-induced sol–gel transition around physiological temperature and could be easily applied in a sol state and in situ gelled to adapt complex wounds of different shapes and depths for complete coverage. Meanwhile, the hydrogel possesses a rapid self-healing ability and can recover autonomously from damage to maintain structural and functional integrity. In addition, the CCK-8 and 2D/3D cell culture experiments revealed that the PZOPZ hydrogel dressing shows low cytotoxicity to L929 cells and can effectively prevent the adhesion of Staphylococcus aureus and Escherichia coli. In vivo investigations verified that the PZOPZ hydrogel could increase angiogenesis and dermal collagen synthesis and shorten the transition from the inflammatory to the proliferative stage, thereby providing more favorable conditions for faster wound healing. Overall, this work provides a promising strategy to develop injectable zwitterionic hydrogel dressings with multiple functions for clinic wound management.