Dias Marta R, Guedes José M, Flanagan Colleen L, Hollister Scott J, Fernandes Paulo R
IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal.
Scaffold Tissue Engineering Group, University of Michigan, 3412 GGB, 2350 Hayward, Ann Arbor, MI 48109-2125, USA.
Med Eng Phys. 2014 Apr;36(4):448-57. doi: 10.1016/j.medengphy.2014.02.010. Epub 2014 Mar 11.
In bone tissue engineering, the scaffold has not only to allow the diffusion of cells, nutrients and oxygen but also provide adequate mechanical support. One way to ensure the scaffold has the right properties is to use computational tools to design such a scaffold coupled with additive manufacturing to build the scaffolds to the resulting optimized design specifications. In this study a topology optimization algorithm is proposed as a technique to design scaffolds that meet specific requirements for mass transport and mechanical load bearing. Several micro-structures obtained computationally are presented. Designed scaffolds were then built using selective laser sintering and the actual features of the fabricated scaffolds were measured and compared to the designed values. It was possible to obtain scaffolds with an internal geometry that reasonably matched the computational design (within 14% of porosity target, 40% for strut size and 55% for throat size in the building direction and 15% for strut size and 17% for throat size perpendicular to the building direction). These results support the use of these kind of computational algorithms to design optimized scaffolds with specific target properties and confirm the value of these techniques for bone tissue engineering.
在骨组织工程中，支架不仅要允许细胞、营养物质和氧气的扩散，还要提供足够的机械支撑。确保支架具有合适性能的一种方法是使用计算工具来设计这样的支架，并结合增材制造技术，按照最终优化的设计规格制造支架。在本研究中，提出了一种拓扑优化算法，作为设计满足质量传输和机械承载特定要求的支架的技术。展示了通过计算获得的几种微观结构。然后使用选择性激光烧结制造设计好的支架，并测量制造支架的实际特征，并与设计值进行比较。有可能获得内部几何形状与计算设计合理匹配的支架（在构建方向上，孔隙率目标的误差在14%以内，支柱尺寸误差为40%，喉部尺寸误差为55%；在垂直于构建方向上，支柱尺寸误差为15%，喉部尺寸误差为17%）。这些结果支持使用这类计算算法来设计具有特定目标性能的优化支架，并证实了这些技术在骨组织工程中的价值。
