Design,Preparation,Material Characterization And Biological Activity Of 3D Printed Porous Titanium Scaffolds

Objective:In this study,macro porous pure titanium scaffolds were prepared by digital simulation design and 3D printing technology,and their mechanical properties were tested;Micro nano porous coatings were prepared on the surface of macroporous scaffolds by micro arc oxidation technology to form scaffolds with macro micro multi-level porous structure.The materials were characterized and the biological activities were preliminarily explored,providing a theoretical basis for the construction of bionic mandibular cortical bone scaffolds.Methods:1.Two kinds of porous pure titanium scaffold models with diamond structure and simple cubic structure are designed by using CAD software.The titanium scaffold is printed by selective laser melting(SLM)3D printing technology.The diamond structure is marked as Ti dia and the simple cubic structure is marked as Ti Cu.The relative error rate of the actual porosity of the scaffold is measured by density method.2.The elastic modulus of the scaffold was measured by static three-point bending experiment.Compared with the mechanical properties of human mandibular cortical bone,the mechanical properties of porous pure titanium scaffold were analyzed.3.The Ti-DIA and Ti-CU scaffolds were treated by micro arc oxidation,and the micro arc oxidation coating was prepared on the surface and inside of the scaffolds.The prepared scaffolds were recorded as Ti-DIA-MAO and Ti-CU-MAO respectively.The surface morphology,element composition,crystalline phase and wettability of porous titanium scaffolds before and after micro arc oxidation treatment were detected by SEM,EDS,XRD and contact angle experiment.4.MC3T3-E1 cells were co cultured with four groups of scaffolds before and after micro arc oxidation in vitro.CCK-8 cell proliferation test was used to detect the toxicity of scaffold materials and the proliferation ability of loaded cells,and to explore the biological activity of scaffold materials.Results:1、The porous scaffolds printed in 3D by SLM technology have regular shape,simple diamond structure,clear cubic structure and obvious holes,which basically meet the design requirements.In addition,in the determination of porosity,the relative error rate of porosity is less than 20%,and with the increase of rod diameter,the measured value of porosity is closer to the design value.2.、 The three-point bending experiment shows that in the diamond group structure,the larger the rod diameter of the scaffold with the same porosity,the smaller the elastic modulus and bending strength.The cubic structure scaffold as the control group also shows better mechanical properties.Although there are differences in the mechanical properties of the four porous scaffolds,they are all suitable for the mechanical properties of human mandibular cortical bone.3 、 SEM showed that micro nano porous structure coating appeared on the surface of porous titanium scaffold after micro arc oxidation treatment.EDS showed that the coating surface was composed of Ti,O,Si and P elements.XRD showed that the crystal structure of the surfaces of Ti-DIA and Ti-DIA-MAO materials was Ti.The contact angle experiment showed that the contact of the materials after micro arc oxidation treatment was small and significantly reduced.Micro arc oxidation technology improved the hydrophilic properties of titanium surface.4 、 CCK-8 experiment showed that the scaffolds before and after micro arc oxidation treatment were not toxic,and the scaffolds after micro arc oxidation treatment were more conducive to the early adhesion and proliferation of cells.Conclusion:Through 3D printing and micro arc oxidation technology,the titanium scaffolds with macro microporous multi-level pore structure were successfully prepared.The porous titanium scaffolds with diamond structure and simple cubic structure were compatible with the mechanical properties of human mandibular cortical bone.The macroporous titanium scaffolds formed by micro arc oxidation are conducive to the adhesion and proliferation of MC3T3-E1 cells,and have good biological activity.This study provides some reference for the design and preparation of bionic mandibular cortical bone scaffold.