P34HB Ultrafine Fiber Slow-release System Based On Cell-electrospinning Induces Stem Cell Osteogenesis In Vivo

Objective:Explore the effect of P34 HB filaments sustained-released L-ascorbic acid2-magnesium phosphate(ASP),?-glycerophosphate(GP)and dexamethasone(DEX)based on cell electrospinning on the osteogenic differentiation of human umbilical cord mesenchymal stem cells in vivo influences.Methods:The bioactive scaffold was prepared by double-nozzle C-ES.The nozzle head 1is a coaxial nozzle,the shell is P34 HB,and the core is L-ascorbate 2-phosphate magnesium,?-sodium glycerophosphate and dexamethasone.The nozzle head 2 is a polyvinylpyrrolidone(PVP)loaded human umbilical cord mesenchymal stem cells(h UCMSCs).Dual nozzle rotation made the cells/fibers evenly distributed,and a certain thickness of fibrous scaffolds were collected in the medium for culture.According to whether the scaffolds contained Cells or induced components,the scaffolds were divided into four groups: cell electrospun P34 HB fibrous scaffolds containing ASP,GP and DEX(P34HB-ASP-GP-DEX-Cells,P-AGD-Cells);P34HB fiber stent containing ASP,GP and DEX(P34HB-ASP-GP-DEX,P-AGD);P34HB stent(P-induced,P-I)and simple P34 HB stent(P)were Induced by osteogenic induction medium.In vitro and in vivo experiments were conducted to verify the osteogenic induction ability of cellular fibrous scaffolds.The osteoinduction ability of cellular fibrous scaffolds was verified by in vitro and in vivo experiments.Results:The uniform distribution of h UCMSCs inside and outside the fibrous scaffold was observed by light microscopy and scanning electron microscopy.Crystals of dexamethasone,?-sodium glycerophosphate and L-ascorbate 2-phosphate magnesium were uniformly distributed in the interior of the fibers.X-ray diffraction(XRD)analysis showed that the incorporation of the three inducers improved the crystallinity of the fibers and the mechanical properties of the fibers.Dexamethasone sustained-release lasted for 2 months and L-ascorbate 2-phosphate magnesium sustained-release lasted for 1 month.Good biocompatibility was observed with live/dead staining.Meanwhile,calcein,type I collagen,osteopontin(OPN)and alkaline phosphatase staining proved that the bioactive scaffold had a good effect on osteogenic differentiation of h UCMSCs.Eight weeks after implantation of the bioactive scaffold into the leg muscle of rabbits,a large amount of new bone was formed inside the biological scaffold.Conclusion:Discarded blood is a major hospital waste,and the disposal of discarded blood consumes a lot of resources.In this study,we successfully prepared three-dimensional structure-like materials from discarded blood using electrospinning within a short timeframe.The preliminary study results showed that this method and material had great development potential in the tissue engineering field,and the good biocompatibility and physical properties of the material may allow it to become an ideal choice for application for skin wounds and the induced membrane technique for bone defects.