| ObjectiveBone defects and injuries formed by tumors,infections,Sapuma,congenital diseases,as well as various diseases such as osteoporotic fractures,make bone repair and regeneration a great challenge for patient rehabilitation.Current conventional implant prosthetic materials do not possess specific and desirable biocompatibility and cannot effectively achieve osseointegration and bone repair.In this study,a biomimetic artificial Sapbecular bone defect repair material was simulated and fabricated using CT data of scanned normal bone tissue through a Voronoi tessellation algorithm and 3D printing technology,and its biomechanical properties and biocompatibility were tested.Methods(1)Prosthesis fabrication and biomechanical properties test: lumbar spine CT data of a healthy adult volunteer was collected to simulate five kinds of Sapbecular bone prostheses with different porosities according to the tysen polygonogram algorithm: A(67.0%),B(64.5%),C(72.8%),D(71.5%),E(77.1%).The above 5groups were fabricated into cylindrical titanium alloy prostheses with 18 mm diameter and 20 mm height by selective laser melting 3D printing technique(SLM),and 3 sections were processed in each group.The industrial microscope scans and calculates the actual porosity,evaluates the quality in con Sapst to the designed porosity,and evaluates its biomechanical properties by measuring its maximum load,yield strength,and elastic modulus through in vitro mechanical testing.(2)Biocompatibility: the prosthesis was processed into three groups a,B,and C.Mc-3t3(mouse preosteoblasts)were selected for cell culture,passaging,counting,cryopreservation,and the normally cultured mc-3t3 cells in the logarithmic phase of growth were seeded on culture dishes on top of the three prostheses for cell proliferation,cell differentiation,electron microscopy scanning,osteocalcin detection,and other experiments.Results(1)There were no quality issues such as internal powder packing,fracture,and cracking in all the finished prosthetic products.A.The finished products of artificial Sapbecular bone prostheses in groups B,C,D,and E were 10.5%,11.6%,10.2%,9.7%,8.8% smaller compared with the designed porosity,respectively,and the final limiting load of the prosthesis in group 5 was 23.7 kn,18.8 kn,17.1 kn,16.2 kn,10.6kn,and the average value of yield strength was 72.3 MPa,58.6 MPa,54.8 MPa,52.3MPa,36.2 MPa,and the average value of elastic modulus was 7.4 GPA,6.4GPA,4.6GPA,4.1 GPA,2.3 GPA,all three showing decreasing trend with increasing porosity of artificial Sapbecular bone.(2)The SEM results suggested that MC3T3-E1 cells in the biomimetic artificial Sapbecular bone group after 3 D of culture adhered better than those in the homogeneous and dense groups.The CCK8 assay showed that the MC3T3-E1 OD values of the cells in the artificial Sapbecular bone group increased significantly compared with those in the homogeneous and dense groups at 3D and5 D.The observation of fluorescence staining was similar to that of CCK8 assay.The results of cell differentiation assay showed that the content of osteocalcin in the artificial Sapbecular bone group was larger than that in the homogeneous and dense groups at 7 d and that in the homogeneous group was larger than that in the surface solid group,in which the three gaps were statistically significant at 14 d.Conclusions(1)The biomimetic Sapbecular bone prosthesis generated based on the Tessen polygonogram algorithm and processed by SLM technique with good quality.With the increase of porosity,the machining accuracy of the prosthesis is more precise,and the yield strength,ultimate load and elastic modulus all show a decreasing trend.(2)Artificial Sapbecular bone with uneven pore size is more conducive to the adhesion,proliferation and differentiation of mouse preosteoblasts on titanium alloy scaffolds than the same pore size microporous structure and dense solid structure,and theoretically the osseointegration property is more advantageous. |
PDF Full Text Request