Sustained release of EGF/bFGF growth factors achieved by mussel-inspired core–shell nanofibers with hemostatic and anti-inflammatory effects for promoting wound healing

Developing wound dressings with high-effective antibacterial activity, rapid hemostasis and accelerated wound healing are urgently needed in clinical wound treatment. Herein, in terms of coaxial electrospinning and mussel-inspired chemistry, a multifunctional polydopamine modified core–shell nanofiber membrane loaded with antibacterial quaternary ammonium salt grafted sulfonated chitosan (QAS-SCS) and bioactive EGF/bFGF in the core layer was constructed for hemostasis and promoting wound healing. The coaxial nanofibers exhibited excellent hydrophilicity, thermal stability, and suitable mechanical strength and stretchability match human skin. The incorporation of QAS-SCS in the coaxial nanofibers led to efficient inherent antibacterial activity, with bacteria inhibition rate of 95.15 ± 0.77% and 93.63 ± 1.44% against S. aureus and E. coli, respectively. The biocompatibility of nanofibers was studied through hemocompatibility and cell compatibility tests. In mouse full-thickness skin defect model, together with sustained release of dual growth factors (EGF/bFGF) achieved by core–shell structure, the multifunctional nanofibers were revealed to suppress the release of inflammatory cytokines, and reduce inflammation response, and enhance collagen deposition, and promote angiogenesis as well as hair follicles regeneration at the injury site, and finally accelerate wound healing. Overall, the as-prepared coaxial nanofibers simultaneously incorporated with QAS-SCS and EGF/bFGF provide an alternative strategy for skin wound repair.