Effect Of Hydroxyapatite Combined With Collagen And Multi Walled Carbon Nanotubes On Bone Defect Repair

Objective: The repair of bone defect has always been a hot topic in the field of medicine.The bone defect caused by trauma,infection and tumor needs a lot of bone tissue repair.In recent years,bone tissue engineering has become the main way to repair bone defects.Bone tissue engineering includes three elements: seed cells with osteogenic potential,growth factors regulating osteogenic induction of cells,and scaffold materials providing basic framework.Scaffold material is the key factor of bone tissue engineering,which promotes the adhesion and growth of seed cells,provides the environment for cell adhesion,growth,proliferation and differentiation,plays a key role in tissue construction,and is an important research content of tissue engineering.Different materials have different properties.The purpose of this study is to select the best materials for combination.Methods: Hydroxyapatite / collagen / MWCNT scaffolds were prepared by freeze-drying technology.The porosity,water absorption,compressive tensile strength and biocompatibility of the scaffolds were measured.The effects of collagen and MWCNT on the biological properties of scaffolds were discussed.The pore size of scaffolds and the adhesion and growth of cells on the scaffolds were measured by scanning electron microscopy 。 In addition,the critical bone defect model of rats was used to repair the skull defect with cell scaffold complex,and the formation of bone was observed.Results: The results showed that hydroxyapatite / collagen / MWCNT scaffolds had a porous network structure,the fibers were arranged in a regular and orderly way,and there was no gap on the surface of the fibers,and the fiber spacing and diameter were uniform.Scanning electron microscopy showed that the cells grew well on the hydroxyapatite / collagen / MWCNT scaffolds,and adhered closely to the surface of the scaffolds and micropores At the same time,the secretory extracellular matrix was filamentous around the cell.The results of CT showed that compared with the control group,the rat model of hydroxyapatite / collagen / MWCNT composite scaffold had better results of bone tissue repair.The results of histological staining showed that hydroxyapatite / collagen / MWCNT scaffolds had good biocompatibility,no obvious infiltration of inflammatory tissue,the scaffolds had been completely degraded,and a large number of new bone formation could be seen in the defect of rat model.Conclusion: Hydroxyapatite / collagen / MWCNT composite scaffolds with uniform pores and moderate pore size are suitable for the adhesion and growth of BMSCs.They have good mechanical properties and good cell compatibility.They can be used as scaffold materials for bone tissue engineering.