Design of 3D polycaprolactone/ε-polylysine-modified chitosan fibrous scaffolds with incorporation of bioactive factors for accelerating wound healing

Electrospun nanofibrous scaffolds show great application potentials for wound healing owing to their effective simulation of extracellular matrix (ECM). Three-dimensional (3D) nanofibrous dressings exhibit relatively high specific surface areas, better mimicry of native ECM, adjustable hydrophilicity and breathability, good histocompatibility, enhanced wound healing, and reduced inflammation. In the present work, we designed the 3D polycaprolactone/ε-polylysine modified chitosan (PCL/PCS) nanofibrous scaffolds by an electrospinning and gas foaming process. Then, gelatin and heparin (Gel/Hep) were assembled onto the surface of PCL/PCS nanofibers by electrostatic adsorption, and vascular endothelial growth factors (VEGFs) were also synchronously incorporated into Gel/Hep layer to form a multifunctional 3D nanofibrous scaffold (PCL/PCS@Gel/Hep+VEGF) for accelerating wound healing. The as-fabricated 3D PCL/PCS@GEL/Hep+VEGF nanofibrous scaffold showed excellent antibacterial ability, hemocompatibility and biocompatibility in vitro and wound healing ability in vivo. Immunological analysis showed that the as-fabricated nanofibrous scaffold inhibited inflammation at the wound sites while promoting angiogenesis during the wound healing process. STATEMENT OF SIGNIFICANCE: The electrospun 3D fibrous scaffolds using polycaprolactone/ε-polylysine modified chitosan (PCL/PCS) have been fabricated as backbone for mimicking the extracellular matrix (ECM). Gelatin and heparin (Gel/Hep) were wrapped onto the surface of PCL/PCS fibers by electrostatic adsorption and vascular endothelial growth factors (VEGFs) were also synchronously incorporated into surface Gel/Hep layer to form multifunctional 3D fibrous scaffolds. The as-fabricated multifunctional 3D fibrous scaffolds with good antibacterial ability and biocompatibility have been used as dressings for accelerating wound healing by inhibiting inflammation at the wound sites while promoting angiogenesis during the wound healing process.