The mechanical environment of the chondrocyte: a biphasic finite element model of cell-matrix interactions in articular cartilage
The mechanical environment of the chondrocyte: a biphasic finite element model of cell-matrix interactions in articular cartilage
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DOI：
10.1016/s0021-9290(00)00105-6
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发表时间：
2000-12-01
影响因子：
2.4
通讯作者：
Mow, VC
中科院分区：
文献类型：
--
作者：
Guilak, F;Mow, VC
软骨细胞外基质的机械压缩对软骨细胞的代谢活性具有显著影响。然而，在宏观的“组织”水平和微观的“细胞”水平的应力-应变和流体流场之间的关系还没有完全理解。基于现有的实验数据的变形行为和生物力学特性的关节软骨和软骨细胞，一个多尺度的双相有限元模型的软骨细胞作为一个球形夹杂物嵌入细胞外基质的软骨植块。在细胞水平的机械环境被认为是随时间变化的和不均匀的，和软骨细胞和细胞外基质的弹性特性的大的差异（类似于3个数量级）的结果在应力集中在细胞-基质边界和应变和扩张（体积变化）在细胞水平的近两倍的增加，相比于宏观水平。与软骨细胞或细胞外基质的不同性质的狭窄的“细胞周基质”的存在显着改变了软骨细胞内的主应力和应变幅度，这表明细胞周基质的功能生物力学作用。这些研究结果表明，即使在简单的压缩载荷条件下，软骨细胞受到一个复杂的局部力学环境，包括拉伸，压缩，剪切和流体压力。了解细胞外基质中的局部应力和应变场是解释软骨外植体培养模型中机械信号转导研究的重要一步。(C)2000爱思唯尔科技有限公司版权所有。
Mechanical compression of the cartilage extracellular matrix has a significant effect on the metabolic activity of the chondrocytes. However, the relationship between the stress-strain and fluid-flow fields at the macroscopic "tissue" level and those at the microscopic "cellular" level are not fully understood. Based on the existing experimental data on the deformation behavior and biomechanical properties of articular cartilage and chondrocytes, a multi-scale biphasic finite element model was developed of the chondrocyte as a spheroidal inclusion embedded within the extracellular matrix of a cartilage explant. The mechanical environment at the cellular level was found to be time-varying and inhomogeneous, and the large difference (similar to 3 orders of magnitude) in the elastic properties of the chondrocyte and those of the extracellular matrix results in stress concentrations at the cell-matrix border and a nearly two-fold increase in strain and dilatation (volume change) at the cellular level, as compared to the macroscopic level. The presence of a narrow "pericellular matrix" with different properties than that of the chondrocyte or extracellular matrix significantly altered the principal stress and strain magnitudes within the chondrocyte, suggesting a functional biomechanical role for the pericellular matrix. These findings suggest that even under simple compressive loading conditions, chondrocytes are subjected to a complex local mechanical environment consisting of tension, compression, shear, and fluid pressure. Knowledge of the local stress and strain fields in the extracellular matrix is an important step in the interpretation of studies of mechanical signal transduction in cartilage explant culture models. (C) 2000 Elsevier Science Ltd. All rights reserved.