Department of Mechanical Engineering, 9 Engineering Drive 1, #07-08 Block EA, National University of Singapore, 117575, Singapore.
Singapore Institute of Manufacturing and Technology, 73 Nanyang Drive, 637662, Singapore.
Biomater Adv. 2022 Jun;137:212829. doi: 10.1016/j.bioadv.2022.212829. Epub 2022 Apr 28.
Lattice structures are widely used in orthopedic implants due to their unique features, such as high strength-to-weight ratios and adjustable biomechanical properties. Based on the type of unit cell geometry, lattice structures may be classified into two types: strut-based structures and sheet-based structures. In this study, strut-based structures (Cubic & Octet) and sheet-based structure (triply periodic minimal surface (TPMS) gyroid) were investigated. The biomechanical properties of the three different Ti6Al4V lattice structures fabricated by selective laser melting (SLM) were investigated using room temperature compression testing. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to check the 3D printing quality with regards to defects and quantitative compositional information of 3D printed parts. Experimental results indicated that TPMS gyroid has superior biomechanical properties when compared to Cubic and Octet. Also, TPMS gyroid was found to be less affected by the variations in relative density. The biocompatibility of Ti6Al4V lattice structures was validated through the cytotoxicity test with human osteoblast-like SAOS2 cells. The debris generated during the degradation process in the form of particles and ions is among the primary causes of implant failure over time. In this study, Ti6Al4V particles with spherical and irregular shapes having average particle sizes of 36.5 μm and 28.8 μm, respectively, were used to mimic the actual Ti6Al4V particles to understand their harmful effects better. Also, the effects and amount of Ti6Al4V ions released after immersion within the cell culture media were investigated using the indirect cytotoxicity test and ion release test.
晶格结构由于其独特的特性，如高强度重量比和可调节的生物力学特性，在骨科植入物中得到了广泛的应用。根据单元胞几何形状的类型，晶格结构可以分为两种类型：基于杆的结构和基于片的结构。在本研究中，研究了基于杆的结构（立方和八面体）和基于片的结构（三重周期性极小曲面（TPMS）胞元）。通过室温压缩试验研究了通过选择性激光熔化（SLM）制造的三种不同 Ti6Al4V 晶格结构的生物力学性能。扫描电子显微镜（SEM）和能谱（EDX）用于检查 3D 打印质量，包括缺陷和 3D 打印零件的定量成分信息。实验结果表明，与立方和八面体相比，TPMS 胞元具有更好的生物力学性能。此外，TPMS 胞元受相对密度变化的影响较小。通过与人类成骨样 SAOS2 细胞的细胞毒性试验验证了 Ti6Al4V 晶格结构的生物相容性。在降解过程中以颗粒和离子形式产生的碎片是随着时间的推移导致植入物失效的主要原因之一。在本研究中，使用具有球形和不规则形状的 Ti6Al4V 颗粒来模拟实际的 Ti6Al4V 颗粒，以更好地了解它们的有害影响。此外，还通过间接细胞毒性试验和离子释放试验研究了在细胞培养介质中浸泡后释放的 Ti6Al4V 离子的量和作用。
