Preparation And Application Of Neurogenic Bone Repair Materials

In daily life,bone defects caused by limb trauma,degenerative lesions or tumor resection are very common.When the size of bone defect exceeds the critical size,it cannot heal spontaneously.Therefore,to repair the damaged bone tissue,clinical intervention and artificial bone materials are very necessary.Hydroxyapatite(HA)is the main mineral in natural bone.We choose nano hydroxyapatite(n HA)as the base material to overcome the problem of low strength and poor toughness of large HA or micro ha.Collagen(Col)is the main component of mammalian connective tissue and contributes to cell adhesion;The main function of chondroitin sulfate(CS)in bone tissue is to coordinate the attachment of osteoblasts and indirectly participate in the formation of bone tissue;Basic fibroblast growth factor(b FGF)can induce neurogenesis and enhance nerve survival and growth.Then,the composite nanofibers doped with n HA,Col and CS were prepared by electrospinning technology.The b FGF/Col/CS layer was assembled on the surface of the composite by layer(LbL)self-assembly technology.Through Fourier transform infrared spectroscopy,scanning electron microscopy and simulated body fluid mineralization experiments,we characterized and verified that the scaffolds have the basic physical and chemical properties of bioactive materials,and are expected to have the potential to promote bone repair.Mouse bone marrow mesenchymal stem cells(BMSCs)were selected as experimental seed cells,and through a series of biological experiments at the cellular and molecular levels,including alkaline phosphatase(ALP)activity detection,Western blot(WB)and quantitative real-time PCR(q RT-PCR),It is proved that the bioactive scaffold can promote the osteogenic differentiation and mineralization of BMSCs.After verifying the bone inducibility of the composite,we still use BMSCs as seed cells,first induce them to differentiate into neural precursor cells,and then prove that the composite scaffolds containing col,CS and b FGF in the experimental group can promote the differentiation of BMSCs into neural cells by immunofluorescence examination(IE),q RT-PCR and gene sequencing,And this behavior can promote bone repair at the defect.Finally,we established an animal experimental model of critical defect of mouse skull,and detected the defect of mouse skull four weeks after operation by Micro-CT.The photos and data results also verified the experimental conclusions obtained in the earlier stage.In conclusion,the bioactive scaffolds prepared in this experiment can coordinate the osteogenic differentiation and neural differentiation of BMSCs.The synchronous regulation of osteogenesis and neurogenesis is helpful to the clinical treatment of critical bone defects and has a good prognosis,which also shows that the composite nanofibers prepared in this paper have high research potential in the field of bone tissue engineering.