Shape of chondrocytes within articular cartilage affects the solid but not the fluid microenvironment under unconfined compression.
Shape of chondrocytes within articular cartilage affects the solid but not the fluid microenvironment under unconfined compression.
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DOI：
10.1016/j.actbio.2015.10.035
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发表时间：
2016-01
影响因子：
9.7
通讯作者：
Torzilli PA
中科院分区：
文献类型：
--
作者：
Guo H;Torzilli PA
关节软骨中软骨细胞的代谢活性与其特定区域的形状以及周围细胞外基质（ECM）的组成和机械特性密切相关。然而，细胞形状影响 ECM 微环境对机械载荷的响应的机制尚未阐明。在无侧限应力松弛过程中，使用 ECM 浅层和深层区域不同形状软骨细胞的双相多尺度有限元模型研究了这种关系。对于浅表区的软骨细胞，增加细胞的初始纵横比（长度/高度）会增加加载阶段软骨细胞和细胞周基质（PCM）的变形和固体应力；对于深部软骨细胞，细胞形状对固体微环境的影响取决于时间和变量。然而，对于浅层和深层软骨细胞，细胞形状不影响流体压力和流体剪切应力。这些结果表明，关节软骨中软骨细胞的力传导可能是通过固相而不是液相来调节的，并且浅层固体微环境中的高应力和变形可能对于软骨细胞的区域特异性生物合成活性至关重要。双相多尺度计算分析表明，维持细胞形状对于调节组织工程结构中软骨细胞的微环境和代谢活动至关重要。
Metabolic activity of the chondrocytes in articular cartilage is strongly related to their zone-specific shape and the composition and mechanical properties of their surrounding extracellular matrix (ECM). However the mechanisms by which cell shape influences the response of the ECM microenvironment to mechanical loading is yet to be elucidated. This relationship was studied using a biphasic multiscale finite element model of different shaped chondrocytes in the superficial and deep zones of the ECM during unconfined stress relaxation. For chondrocytes in the superficial zone, increasing the cell’s initial aspect ratio (length/height) increased the deformation and solid stresses of the chondrocyte and pericellular matrix (PCM) during the loading phase; for chondrocytes in the deep zone the effect of the cell shape on the solid microenvironment was time and variable dependent. However, for superficial and deep zone chondrocytes the cell shape did not affect the fluid pressure and fluid shear stress. These results suggest that mechanotransduction of chondrocytes in articular cartilage may be regulated through the solid phase rather than the fluid phase, and that high stresses and deformations in the solid microenvironment in the superficial zone may be essential for the zone-specific biosynthetic activity of the chondrocyte. The biphasic multiscale computational analysis suggests that maintaining the cell shape is critical for regulating the microenvironment and metabolic activity of the chondrocyte in tissue engineering constructs.