PCL/ Hyaluronan /EGF Nanofiber Scaffolds For Wound Healing

Electrospining technology has been used in many fields since it’s invention. Nanofibrous scaffolds prepared by this method due to its similar spatial structure to the extra-cellular matrix of cells are widely used in the field of tissue engineering. A large area of skin wounds, especially whole cortical trauma is still one of the major ailments, how can accelerate healing and reduce scarring the surface remains a clinical problem facing. In this study, a novel wound dressing composed of nanofibers was made through emulsion electrospun. Hyaluronan(HA) and epidermal growth factor(EGF) were embedded into nanofibrous scaffolds to accelerate wound healing and reduce scar formation. This study contains detailed contents as follows:① Emulsions were prepared by water in oil system, wherein the oil phase was prepared by dissolved solvent PCL and HA in chloroform(TCM) and formic acid(FA), the aqueous phase is an aqueous solution of epidermal growth factor(EGF). PC L / HA / EGF nanofibrous scaffold was prepared by electrospinning, meanwhile, prepared PCL, PCL / HA as controls. Scanning electron microscope(SEM) and transmission electron microscopy(TEM) were used to characterize the scaffold surface morphology and fiber core-shell structure; Fourier transform infrared spectroscopy(FTIR) and photoelectron spectroscopy were performed to detect the chemical composition of materials; Using a contact angle measuring instrument to detect material hydrophilicity; The release rates of HA and EGF were determined by enzyme-linked immunoabsorbent assay.② The immortalized human epidermal cells(Ha Ca T) and human skin fibroblasts(FEK4) were seeded on PC L, PCL / HA, PCL / HA / EGF three different nanofibrous scaffolds, then using MTS assay to evaluation cell proliferation ability; The cell infiltration evaluation experiment was performed using a modified Transwell system in 24-well plate. The results showed that nanofibrous scaffolds have a good biocompatibility, EGF can significantly promote the proliferation of both cells, HA and EGF synergistically can promote FEK4 cell migration into the internal bracket.③ The gene expression levels of Collagen-, Collagen-Ⅲ and transformation growth factor(TGF-β1) were detected by q-PCR after the FEK4 cells cultured on PCL, PCL/HA, PCL/HA/EGF nanofibrous scaffolds for 1 day, 5 days and 10 days.④ A full- thickness skin wound was created on the dorsal of SD rat. Then PCL, PCL/HA and PCL/HA/EGF nanofibrous scaffolds were implanted on the injury site. The wound healing degree was determined by measuring the wound size after surgery for 1 week, 2 weeks and 4 weeks. Meanwhile, the full- thickness defect dorsum skin was excised to make paraffin sections. Finally, the HE staining was performed to evaluation the structure of regenerated skin.Our research results demonstrated that: nanofibrous scaffolds fabricated by emulsion electrospun had a stable homogeneous surface structure, obviously stable core-shell structure and good biocompatibility. HA and EGF could efficiently released from the scaffolds to enhance cell proliferation and migration so that the wound healing process could be accelerated and the scar formation could be reduced. Overall, our results demonstrate that scaffold PCL/HA/EGF can be a promising wound dressing applied in clinical.