SLM制备径向梯度多孔钛/钽的力学性能及生物相容性

Mechanical Properties and Biocompatibilities of Radially Graded Porous Titanium/Tantalum Fabricated by Selective Laser Melting

利用增材制造技术制作仿天然骨的径向梯度多孔钛/钽骨科植入物具有广阔的前景。基于三周期极小曲面(triply minimal surfaces,TPMS)建模法建立了平均孔隙率为70%的圆柱型径向梯度孔隙结构,孔隙率由中轴线(90%)向圆周面(30%)逐渐降低。利用激光选区熔化(selected laser melting,SLM)工艺制作径向梯度多孔钛/钽。光学显微镜,扫描电镜,Micro-CT检测结果共同显示,SLM径向梯度多孔钛/钽的孔隙结构与设计特征一致。SLM工艺制作的径向梯度多孔钛/钽的孔隙率分别为73.18%与68.18%。力学测试结果表明,梯度多孔钛/钽的弹性模量分别为(3.96±0.20)与(3.47±0.25)GPa,抗压强度分别为(90.83±3.35)与(93.27±1.24)MPa。梯度多孔钛/钽的弹性模量与抗压强度分别显著高于均匀多孔钛/钽(孔隙率为70.11%的均匀多孔钛弹性模量为(2.34±0.48)GPa,抗压强度为(67.63±1.33)MPa,孔隙率为65.39%的均匀多孔钽弹性模量为(1.69±0.50)GPa,抗压强度为(68.56±0.41)MPa)。体外细胞相容性实验证明,径向梯度多孔钛/钽均具有良好的生物相容性,适合间充质干细胞与肌肉细胞的粘附生长。SLM工艺制作的径向梯度多孔钛/钽比均匀多孔钛/钽具有与天然骨组织更相近的结构与性能,是理想的骨缺损修复替代物。

Radially graded porous titanium/tantalum orthopedic implants fabricated by additive manufacturing technology have golden prospects.A cylindrical radially graded porous scaffold with an average porosity of 70%was built by the triply minimal surfaces(TPMS)modeling methods,and the porosity gradually decreases from the central axis(90%)to the circumferential surface(30%).Selected laser melting(SLM)process was used to fabricate this scaffold.Optical microscopy,scanning electron microscopy,and Micro-CT results show that the SLM titanium/tantalum is consistent with the design models.The porosities of the SLM radially graded porous titanium/tantalum are 73.18%and 68.18%,respectively.The mechanical test results show that the elastic modulus of radially graded porous titanium/tantalum are(3.96±0.20)and(3.47±0.25)GPa,respectively,and the compressive strength are(90.83±3.35),(93.27±1.24)MPa respectively.Both of them are significantly higher than those of homogeneous porous titanium/tantalum.(homogeneous porous titanium with an average porosity of 70.11%has an elastic modulus of(2.34±0.48)GPa and a compressive strength of(67.63±1.33)MPa;homogeneous porous tantalum with a porosity of 65.39%has an elastic modulus of(1.69±0.50)GPa and a compressive strength of(68.56±0.41)MPa).In vitro cytocompatibility experiments show that both radially graded porous titanium and tantalum have good biocompatibility and they are suitable for the adherent and growth of mesenchymal stem cells and muscle cells.The radially graded porous titanium/tantalum fabricated by the SLM process has more similar structure and properties to natural bone tissue than homogeneous porous titanium/tantalum,and both of them are ideal substitutes for bone defect repairing.