| Ti-6Al-4V titanium alloy has good application prospects because of its good mechanical properties,especially in the load-bearing part of large bone defects.The customized porous titanium alloy scaffold design can match the host bone in size and contour shape,providing a good spatial environment for the growth of host tissue cells.In addition,and the elastic modulus of its overall structure can be adjusted to close to biological bone by changing pore spacing and strut size,so as to promote the integration of bone and material.However,titanium alloy is inert material with poor biocompatibility.The most effective method is to modify its surface.Hydroxyapatite(HA),the main inorganic component of human and animal bones,can improve the bioactivity and biocompatibility of titanium alloy surface by coating technology.Design of hydroxyapatite coating test bed and controller were prepared respectly.The UG8.0 software was used for 3D modeling,and a special test bed for hydroxyapatite coating was manufactured.The controller with parameter Settings can make the lifting device realize automatic steeping lifting movement of the sample.The process of hydroxyapatite coating,the morphology and properties of the coating on titanium alloy surface were studied.Triethyl phosphite and calcium nitrate were used to prepare solution,which can obtain pure HA when the solution was deal with in aged 50 h and process conditions of 700 ℃ sintering temperature,and obtained higher XRD diffraction intensity.According to the confocal microscope,the Ra value of titanium alloy substrate prepared by 3D printing after HA coating was12.336μm.In addition,the bonding strength of the coating is related to the roughness of the titanium alloy substrate.It can be seen from SEM scanning electron microscope that the bonding strength of the 3D-printed titanium alloy and hydroxyapatite is stable,no peeling phenomenon occurs,and the coating is uniform with few cracks.The optimization and mechanical properties of customized titanium alloy artificial bone scaffolds with complex surface profile structure were studied.26 kinds of artificial bone scaffolds 3D models with different structures were established byusing UG8.0 software,and their static structures were analyzed by ANSYS.On this basis,the structure of the artificial bone scaffold was further optimized,and the analysis showed that the stress of the scaffold had a great relationship with the direction and distribution of the column.After optimization,it was found that the size of the hole spacing and diameter of the column had a great impact on the overall mechanical properties of the scaffold,and that the column and the beam with approximate perpendicular,same spacing and diameter can have better mechanical properties.The biological properties of titanium alloy scaffolds were studied.Through animal experiments and medical cytotoxicity test of the scaffolds,it was found that the titanium alloy and its HA coating samples were non-toxic to cells,and the coating samples had obvious advantages in cell growth.The results of X-ray examination showed that the scaffolds of both specifications did not promote the growth of bone tissue,and the scaffolds with small mesh holes filled with cancellous bone had obvious fibrous tissue growth.But both served as load-bearing support,providing a reference for the subsequent selection of composite bone induction materials. |
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