Department of Mechanical Engineering, Texas Tech University, Lubbock, TX, 79409, USA.
Department of Mechanical Engineering, Texas Tech University, Lubbock, TX, 79409, USA.
Comput Biol Med. 2021 Nov;138:104913. doi: 10.1016/j.compbiomed.2021.104913. Epub 2021 Oct 1.
Bone tissue engineering approaches have recently begun considering 3D printed lattices as viable scaffold solutions due to their highly tunable geometries and mechanical efficiency. However, scaffold design remains challenging due to the numerous biological and mechanical trade-offs related to lattice geometry. Here, we investigate novel tetragonal unit cell designs by independently adjusting unit cell height and width to find scaffolds with improved tissue growth while maintaining suitable scaffold mechanical properties for bone tissue engineering. Lattice tissue growth behavior is evaluated using a curvature-based growth model while elastic modulus is evaluated with finite element analysis. Computationally efficient modeling approaches are implemented to facilitate bulk analysis of lattice design trade-offs using design maps for biological and mechanical functionalities in relation to unit cell height and width for two contrasting unit cell topologies. Newly designed tetragonal lattices demonstrate higher tissue growth per unit volume and advantageous stiffness in preferred directions compared to cubically symmetric unit cells. When lattice beam diameter is fixed to 200 μm, Tetra and BC-Tetra lattices with elastic moduli of 200 MPa-400 MPa are compared for squashed, cubic, and stretched topologies. Squashed Tetra lattices demonstrated higher growth rates and growth densities compared to symmetrically cubic lattices. BC-Tetra lattices with the same range of elastic moduli show squashed lattices tend to achieve higher growth rates, whereas stretched lattices promote higher growth density. The results suggest tetragonal unit cells provide favorable properties for biological and mechanical tailoring, therefore enabling new strategies for diverse patient needs and applications in regenerative medicine.
骨组织工程方法最近开始考虑 3D 打印晶格作为可行的支架解决方案，因为它们具有高度可调的几何形状和机械效率。然而，由于与晶格几何形状有关的众多生物学和机械权衡，支架设计仍然具有挑战性。在这里，我们通过独立调整单元胞高度和宽度来研究新颖的四方单元胞设计，以找到具有改善组织生长的支架，同时保持适合骨组织工程的支架机械性能。使用基于曲率的生长模型评估晶格组织生长行为，并用有限元分析评估弹性模量。实现了计算效率高的建模方法，以便使用设计图针对两种对比单元胞拓扑的单元胞高度和宽度来对晶格设计权衡进行批量分析，以实现生物学和机械功能。与立方对称单元胞相比，新设计的四方晶格在单位体积内具有更高的组织生长和有利的各向异性刚度。当晶格梁直径固定为 200 μm 时，比较了弹性模量为 200 MPa-400 MPa 的 Tetra 和 BC-Tetra 晶格的压扁、立方和拉伸拓扑结构。与对称立方晶格相比，压扁的 Tetra 晶格表现出更高的生长速率和生长密度。在相同弹性模量范围内的 BC-Tetra 晶格表明，压扁的晶格往往具有更高的生长速率，而拉伸的晶格则促进更高的生长密度。结果表明，四方单元胞提供了生物和机械定制的有利特性，因此为满足不同患者需求和再生医学中的应用提供了新的策略。
