ETH Zurich, Zurich, Switzerland.
Biomech Model Mechanobiol. 2018 Oct;17(5):1481-1495. doi: 10.1007/s10237-018-1040-9. Epub 2018 Jun 6.
Experiments have demonstrated biological tissues grow by mechanically sensing their localized curvature, therefore making geometry a key consideration for tissue scaffold design. We developed a simulation approach for modeling tissue growth on beam-based geometries of repeating unit cells, with four lattice topologies considered. In simulations, tissue was seeded on surfaces with new tissue growing in empty voxels with positive curvature. Growth was fastest on topologies with more beams per unit cell when unit cell volume/porosity was fixed, but fastest for topologies with fewer beams per unit cell when beam width/porosity was fixed. Tissue filled proportional to mean positive surface curvature per volume. Faster filling scaffolds had lower permeability, which is important to support nutrient transport, and highlights a need for tuning geometries appropriately for conflicting trade-offs. A balance among trade-offs was found for scaffolds with beam diameters of about [Formula: see text] and 50% porosity, therefore providing the opportunity for further optimization based on criteria such as mechanical factors. Overall, these findings provide insight into how curvature-based tissue growth progresses in complex scaffold geometries, and a foundation for developing optimized scaffolds for clinical applications.
实验已经证明,生物组织通过机械感知其局部曲率来生长,因此几何形状是组织支架设计的关键考虑因素。我们开发了一种模拟方法,用于对基于梁的重复单元细胞的几何形状进行组织生长建模,考虑了四种晶格拓扑结构。在模拟中,组织在具有正曲率的空体素中生长的表面上播种。当固定单元体积/孔隙率时,每个单元中梁数较多的拓扑结构的生长速度最快,但当固定梁宽/孔隙率时,每个单元中梁数较少的拓扑结构的生长速度最快。组织按单位体积的平均正表面曲率填充。更快填充的支架具有更低的渗透性,这对于支持营养物质运输很重要,这凸显了需要适当地调整几何形状以平衡相互冲突的权衡。对于直径约为[公式:见文本]和孔隙率为 50%的支架,在权衡之间找到了平衡,因此为进一步优化提供了机会,优化的标准可以是机械因素等。总的来说,这些发现为理解基于曲率的组织在复杂支架几何形状中的生长过程提供了深入的了解,并为临床应用开发优化的支架奠定了基础。