Zinc-loaded human serum albumin methacryloyl microspheres with growth factors release for infected wound healing

Bacterial infection is one of the main causes of delayed wound healing. Hence, the development of antimicrobial dressings with good biocompatibility has high clinical significance and social value. The natural macromolecule, serum albumin, has superior biocompatibility, low immunogenicity, and a good drug-carrying capacity. In this study, human serum albumin (HSA) was modified with methacrylic anhydride to obtain photo-crosslinking properties. Then, the photo-crosslinking HSA was applied to produce homogenized microspheres (HMS) through the nitrogen elution-assisted microfluidic technique and ultraviolet light. Effective loading of vascular endothelial growth factor (VEGF) was achieved by utilizing the adsorption of HSA onto zinc ions and their crosslinking with His-tagged VEGF. The prepared HMS-Zn@VEGF exhibited broad-spectrum antibacterial activity and simultaneously exerted proangiogenic effects in vitro, effectively promoting the healing of infected wounds in rats. In vivo experiments using rats showed that HMS-Zn@VEGF promoted the deposition of collagen around the wound, improved the local inflammatory response, and promoted angiogenesis. In conclusion, our prepared HMS-Zn@VEGF microspheres have good biocompatibility, antimicrobial properties, and angiogenic ability, which can be used for infected wound healing.