Electrospun SF/PHBV nanofibers loaded with berberine as a bioactive wound dressing: Accelerating diabetic wound healing and alleviating hypertrophic scar

The development of innovative wound dressings that can accelerate diabetic wound healing and alleviate hypertrophic scar has aroused intensive attraction in the clinics. In this study, the nanofibrous wound dressings constructed with a blend of silk fibroin (SF) and poly-3-hydroxybutyric acid-co-3-hydroxyvaleric acid (PHBV) were designed and fabricated. Meanwhile, berberine (BBR) were loaded in the SF/PHBV nanofibers to enhance the pharmacological effects. Firstly, material characterisation and biological characteristics of SF/PHBV-BBR dressings were investigated. The addition of BBR didn't change the mechanical properties and biocompatibility of SF/PHBV nanofiber dressings. Then in vitro experiment proved that SF/PHBV-BBR nanofiber dressings obviously decreased the releases of inflammatory factors TNF-alpha and IL-6, inhibited inflammatory proteins COX-2 and iNOS expression, and also suppressed oxidative stress responses of activated macrophages. Subsequently, in vivo study showed that SF/PHBV-BBR nanofiber dressings with high dose of BBR significantly promoted the healing of diabetic wounds in mice by significantly enhancing wound closure rates, accelerating angiogenesis, and improving collagen matrix deposition. Additionally, SF/PHBV-BBR obviously alleviated scar hyperplasia in rabbit by inhibiting fibroblast activation mediated by transforming growth factor-(31 (TGF-(31)/Smad3 pathway. Our study offered a promising alternative dressing materials for the treatment of hard-to-heal diabetic wounds and hypertrophic scars.