Core-shell chitosan microsphere with antimicrobial and vascularized functions for promoting skin wound healing

It is imperative to develop a wound dressing that can effectively treat bacterial infection in the wound location and speed up wound healing. In this study, chitosan (CS) microspheres with a core–shell structure were prepared using high-voltage electrostatic drop technology. The antimicrobial polypeptide (PonG1) and bFGF, were encapsulated in the core of the CS microsphere. The preparation of CS microspheres was studied by changing the parameters. The surface morphology of CS microspheres and the release quantities of PonG1 and bFGF were observed and detected. In vivo experiments were conducted to study the neovascularization and anti-inflammatory abilities of bFGF and PonG1. The repair ability of CS microspheres was evaluated using a rat model of full-thickness skin wound. Both bFGF and PonG1 exhibited slow release from the CS microspheres within 14 days. In vivo experiments showed that CS microspheres containing PonG1 (3 mg/ml) and bFGF (300 μg/ml) had the best neovascularization and anti-inflammatory effects. CS microspheres containing both bFGF and PonG1 had the strongest ability to repair skin wound. CS microspheres with antimicrobial and vascularized functions can be used as dressings for the repair of hard-to-heal wounds.