Waygood J, Murch G E, Fiedler T
Centre for Mass and Thermal Transport in Engineering Materials, School of Engineering, The University of Newcastle, Callaghan, NSW, 2308, Australia.
J Mater Sci Mater Med. 2015 Sep;26(9):229. doi: 10.1007/s10856-015-5560-x. Epub 2015 Sep 3.
This paper addresses the mechanical behavior of robocast PCL-Bioglass(®) scaffolds. These structures can be used as 3rd generation implants in tissue engineering to support the regrowth of damaged tissue, in particular bone. After successful tissue regeneration the scaffolds slowly dissolve leaving no foreign material permanently inside the body. However, to avoid mechanical separation from surrounding tissue they must exhibit similar mechanical properties. The present study introduces a detailed numerical study focusing on the determination of effective mechanical material properties, their anisotropy, and mechanical degradation due to scaffold resorption. In order to accurately capture the complex scaffold geometry, micro-computed tomography scans of actual samples are conducted. The resulting three-dimensional data are directly converted into finite element calculation models. Numerical compressive tests of these unmodified models are repeated for three perpendicular directions to investigate mechanical anisotropy, after which the effect of scaffold degradation due to exposure to body fluid is simulated. To this end, two different resorption models, namely surface erosion and bulk degradation, are applied to the micro-computed tomography data. The modified geometry data are then converted into calculation models and numerical compression tests then allow the prediction of the mechanical properties of partially resorbed scaffolds.
本文探讨了机器人铸造聚己内酯-生物玻璃（®）支架的力学行为。这些结构可作为组织工程中的第三代植入物，以支持受损组织尤其是骨骼的再生。在组织成功再生后，支架会缓慢溶解，不会在体内永久留下任何异物。然而，为避免与周围组织发生机械分离，它们必须表现出相似的力学性能。本研究引入了一项详细的数值研究，重点在于确定有效的机械材料性能、其各向异性以及由于支架吸收导致的力学降解。为了精确捕捉复杂的支架几何形状，对实际样品进行了微观计算机断层扫描。所得的三维数据直接转换为有限元计算模型。对这些未修改的模型在三个垂直方向上重复进行数值压缩试验，以研究力学各向异性，之后模拟由于暴露于体液导致的支架降解的影响。为此，将两种不同的吸收模型，即表面侵蚀和整体降解，应用于微观计算机断层扫描数据。然后将修改后的几何数据转换为计算模型，随后的数值压缩试验可预测部分吸收的支架的力学性能。
