Relationship between the morphological, mechanical and permeability properties of porous bone scaffolds and the underlying microstructure
Relationship between the morphological, mechanical and permeability properties of porous bone scaffolds and the underlying microstructure
复制标题
多孔骨支架的形态、力学和渗透性能与底层微观结构之间的关系
DOI：
10.1371/journal.pone.0238471
复制
发表时间：
2020-09-01
期刊：
影响因子：
3.7
通讯作者：
Zhu, Hanxing
中科院分区：
文献类型：
--
作者：
Lu, Yongtao;Cheng, LiangLiang;Zhu, Hanxing
骨支架是目前广泛使用的主要骨替代材料之一。然而，存在许多骨支架微结构拓扑结构，当为特定应用设计支架时，仍不清楚使用哪种拓扑结构。本研究旨在揭示骨支架微结构驱动性能的机理，从而为支架设计提供指导。建立了5种TPMS(Diamond、Gyroid、Schwarz P、Fischer-Koch S和F-RD)支架和3种传统支架(Cube、FD-Cube和Octa)的有限元模型。通过力学分析，采用周期边界条件下的有限元单胞模型，计算了支架的有效压缩和剪切弹性模量。采用4×4×4有限元模型，通过计算流体力学(CFD)分析计算支架的渗透性。结果表明，在所研究的支架中，费歇尔-科赫-S基支架的表面积体积比最高。力学分析表明，弯曲变形占主导地位的结构(如钻石、陀螺体、施瓦茨P)具有较高的有效剪切模数。以拉伸变形为主的结构(如Schwarz P、Cube)具有较高的有效压缩模数。对于所有支架，当支架孔隙率变化相同时，支架相对剪切模数的相应变化大于相对压缩模数的变化。计算流体力学分析表明，简单直孔结构(如立方体)比复杂孔道结构(如S)具有更高的渗透率。本研究的主要贡献在于系统地研究了支架性能与底层微结构之间的关系，从而为骨支架的设计提供了一些指导，例如，在要求高表面积体积比的情况下，建议使用费歇尔-科赫-S基支架。
Bone scaffolds are widely used as one of the main bone substitute materials. However, many bone scaffold microstructure topologies exist and it is still unclear which topology to use when designing scaffold for a specific application. The aim of the present study was to reveal the mechanism of the microstructure-driven performance of bone scaffold and thus to provide guideline on scaffold design. Finite element (FE) models of five TPMS (Diamond, Gyroid, Schwarz P, Fischer-Koch S and F-RD) and three traditional (Cube, FD-Cube and Octa) scaffolds were generated. The effective compressive and shear moduli of scaffolds were calculated from the mechanical analysis using the FE unit cell models with the periodic boundary condition. The scaffold permeability was calculated from the computational fluid dynamics (CFD) analysis using the 4×4×4 FE models. It is revealed that the surface-to-volume ratio of the Fischer-Koch S-based scaffold is the highest among the scaffolds investigated. The mechanical analysis revealed that the bending deformation dominated structures (e.g., the Diamond, the Gyroid, the Schwarz P) have higher effective shear moduli. The stretching deformation dominated structures (e.g., the Schwarz P, the Cube) have higher effective compressive moduli. For all the scaffolds, when the same amount of change in scaffold porosity is made, the corresponding change in the scaffold relative shear modulus is larger than that in the relative compressive modulus. The CFD analysis revealed that the structures with the simple and straight pores (e.g., Cube) have higher permeability than the structures with the complex pores (e.g., Fischer-Koch S). The main contribution of the present study is that the relationship between scaffold properties and the underlying microstructure is systematically investigated and thus some guidelines on the design of bone scaffolds are provided, for example, in the scenario where a high surface-to-volume ratio is required, it is suggested to use the Fischer-Koch S based scaffold.