Changes in proteoglycan synthesis of chondrocytes in articular cartilage are associated with the time-dependent changes in their mechanical environment
Changes in proteoglycan synthesis of chondrocytes in articular cartilage are associated with the time-dependent changes in their mechanical environment
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DOI：
10.1016/0021-9290(95)00103-4
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发表时间：
1995-12-01
影响因子：
2.4
通讯作者：
Mow, VC
中科院分区：
文献类型：
--
作者：
Bachrach, NM;Valhmu, WB;Mow, VC
进行外植体加载实验以研究加载持续时间对蛋白聚糖合成的影响。研究发现，施加 0.1 MPa 的压缩载荷 10 分钟会刺激蛋白聚糖的合成，而施加相同的载荷 20 小时则会抑制蛋白聚糖的合成。这种双峰反应表明，随着时间的推移，细胞对不同的机械刺激做出反应。因此，开发了一个理论模型来描述软水合组织（例如关节软骨）内的细胞在组织加载时感知的机械环境。使用双相理论将细胞建模为嵌入并附着在具有不同材料特性的双相细胞外基质中的流体-固体内含物。开发了一种适用于任何轴对称负载配置的解决方法，前提是细胞半径 a 相对于组织高度 h 较小（即 h/a 远大于 1）。然后针对受限压缩配置提出了该夹杂问题的封闭式解析解。该模型的结果表明，细胞内部和周围的机械环境是时间依赖性的且不均匀的，并且可能受到细胞和细胞外基质之间的特性差异的显着影响。
Explant loading experiments were conducted to investigate the effect of load duration on proteoglycan synthesis. A compressive load of 0.1 MPa applied for 10 min was found to stimulate proteoglycan synthesis, while the same load applied for 20 h suppressed synthesis. This bimodal response suggests that the cells are responding to different mechanical stimuli as time progresses. A theoretical model has therefore been developed to describe the mechanical environment perceived by cells within soft hydrated tissues (e.g. articular cartilage) while the tissue is being loaded. The cells are modeled, using the biphasic theory, as fluid-solid inclusions embedded in and attached to a biphasic extracellular matrix of distinct material properties. A method of solution is developed which is valid for any axisymmetric loading configuration, provided that the cell radius, a, is small relative to the tissue height, h (i.e. h/a much greater than 1). A closed-form analytical solution for this inclusion problem is then presented for the confined compression configuration. Results from this model show that the mechanical environment in and around the cells is time dependent and inhomogeneous, and can be significantly influenced by differences in properties between the cell and the extracellular matrix.