Naghavi Seyed Ataollah, Tamaddon Maryam, Marghoub Arsalan, Wang Katherine, Babamiri Behzad Bahrami, Hazeli Kavan, Xu Wei, Lu Xin, Sun Changning, Wang Liqing, Moazen Mehran, Wang Ling, Li Dichen, Liu Chaozong
Institute of Orthopaedic & Musculoskeletal, Division of Surgery & Interventional Science, University College London, Royal National Orthopaedic Hospital, Stanmore, London HA7 4LP, UK.
Department of Mechanical Engineering, University College London, London WC1E 7JE, UK.
Bioengineering (Basel). 2022 Sep 24;9(10):504. doi: 10.3390/bioengineering9100504.
Additive manufacturing has been used to develop a variety of scaffold designs for clinical and industrial applications. Mechanical properties (i.e., compression, tension, bending, and torsion response) of these scaffolds are significantly important for load-bearing orthopaedic implants. In this study, we designed and additively manufactured porous metallic biomaterials based on two different types of triply periodic minimal surface structures (i.e., gyroid and diamond) that mimic the mechanical properties of bone, such as porosity, stiffness, and strength. Physical and mechanical properties, including compressive, tensile, bending, and torsional stiffness and strength of the developed scaffolds, were then characterised experimentally and numerically using finite element method. Sheet thickness was constant at 300 μm, and the unit cell size was varied to generate different pore sizes and porosities. Gyroid scaffolds had a pore size in the range of 600-1200 μm and a porosity in the range of 54-72%, respectively. Corresponding values for the diamond were 900-1500 μm and 56-70%. Both structure types were validated experimentally, and a wide range of mechanical properties (including stiffness and yield strength) were predicted using the finite element method. The stiffness and strength of both structures are comparable to that of cortical bone, hence reducing the risks of scaffold failure. The results demonstrate that the developed scaffolds mimic the physical and mechanical properties of cortical bone and can be suitable for bone replacement and orthopaedic implants. However, an optimal design should be chosen based on specific performance requirements.
增材制造已被用于开发各种用于临床和工业应用的支架设计。这些支架的机械性能（即压缩、拉伸、弯曲和扭转响应）对于承重骨科植入物而言至关重要。在本研究中，我们基于两种不同类型的三重周期极小曲面结构（即类螺旋体和菱形）设计并通过增材制造制备了多孔金属生物材料，这些结构模仿了骨的机械性能，如孔隙率、刚度和强度。然后，使用有限元方法对所制备支架的物理和机械性能，包括压缩、拉伸、弯曲和扭转刚度及强度进行了实验和数值表征。板材厚度恒定为300μm，通过改变单位晶胞尺寸来生成不同的孔径和孔隙率。类螺旋体支架的孔径范围为600 - 1200μm，孔隙率范围为54 - 72%。菱形结构的相应值分别为900 - 1500μm和56 - 70%。两种结构类型均通过实验验证，并使用有限元方法预测了广泛的机械性能（包括刚度和屈服强度）。两种结构的刚度和强度均与皮质骨相当，从而降低了支架失效的风险。结果表明，所制备的支架模仿了皮质骨的物理和机械性能，可适用于骨替代和骨科植入物。然而，应根据具体性能要求选择最佳设计。
