Preparation Of NHAC/PLA Bone Repair Materials By 3D Printing And Its Performance Study

In recent years,the incidence of bone defects has increased year by year.At present,bone transplantation has become the most demanded graft after blood transfusion,and it is increasing gradually.At present,the main method used in clinical treatment of bone defects is bone transplantation,and the bone materials used for transplantation are mainly autogenous bone,allogeneic bone and artificial bone.Autologous bone transplantation needs to take bone from other parts of the patient,which will cause secondary injury;allogeneic bone transplantation can easily lead to immune rejection and infection of other diseases carried by the donor of the upper bone.Because of the above problems with autogenous bone and allogeneic bone repair materials,it is very important to study artificial bone repair materials with good biocompatibility.In this paper,Nano Hydroxyapatite / Collagen(nHAC)and polylactic acid(PLA)are used to prepare the filament for 3D printing artificial bone material,and using fused deposition modeling(FDM)3D printer for the preparation of bone repair restoration.Use proteinase K to degrade the bone repair restoration,analyze the change of weightlessness rate,and analyze the change of its microstructure by SEM;Cultivate MC3T3-E1 cells and draw their growth curve,then co-culture nHAC / PLA with MC3T3-E1 cells,and observe the adhesion and proliferation of cells on the material through a microscope;According to GB / T16886 Biological Evaluation of Medical Devices,L929 cells were used to study the cytotoxicity of bone repair restorations;Bone repair restorations were co-cultured with MC3T3-E1 cells to detect the ALP activity of the cells and the total protein secreted by the cells to study the in vitro osteogenic effect of the bone repair restorations,and observe the cell-to-material interaction by SEM;Using piglets as animal experimental models,bone repair restorations were implanted into animal bone defect sites to study the in vivo osteogenesis effect of nHAC / PLA bone repair restorations.The final results show that the nHAC / PLA composite filament prepared in this paper and the 3D printed bone repair restoration have good degradation performance,good cell adhesion and cell compatibility,no obvious cytotoxicity,and it can promote MC3T3-E1 cells ALP secretion and cell proliferation,after implanting it in animals,it has obvious bone repair effect.