Determination of the Poisson's ratio of the cell: recovery properties of chondrocytes after release from complete micropipette aspiration
Determination of the Poisson's ratio of the cell: recovery properties of chondrocytes after release from complete micropipette aspiration
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DOI：
10.1016/j.jbiomech.2004.11.006
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发表时间：
2006-01-01
影响因子：
2.4
通讯作者：
Guilak, F
中科院分区：
文献类型：
--
作者：
Trickey, WR;Baaijens, FPT;Guilak, F
关节软骨中的软骨细胞经常因关节的动态载荷而受到压缩和恢复。先前的研究研究了使用微孔抽吸技术研究软骨细胞的弹性和粘弹性，但是为了计算细胞的特性，这些研究通常认为细胞与泊松比为0.5的比率不可压缩。这项研究的目的是通过将理论建模与完全细胞抽吸的实验测量和从微管释放相结合，来测量软骨细胞的泊松比和恢复性能。从非稳定性和骨关节炎软骨中分离出的软骨细胞被完全吸入微孔，并允许达到机械平衡。然后将细胞从微型移液器中挤出，并在整个实验过程中测量细胞体积和形态。通过有限元分析模拟该实验过程，将软骨细胞建模为可压缩的两种模式粘弹性固体或双相粘弹性材料。通过将实验数据拟合到理论上预测的细胞反应中，确定了泊松的比率和细胞的粘弹性恢复特性。发现非骨关节炎软骨的软骨细胞比率为0.38，骨关节炎软骨细胞为0.36（没有显着差异）。骨关节炎软骨细胞在完全抽吸后显示出恢复时间的增加。与以前的假设相反，这些发现表明软骨细胞是可压缩的，与以前的研究一致，该研究表明细胞体积变化伴随着细胞外基质的压缩。 （c）2004 Elsevier Ltd.保留所有权利。
Chondrocytes in articular cartilage are regularly subjected to compression and recovery due to dynamic loading of the joint. Previous studies have investigated the elastic and viscoelastic properties of chondrocytes using micropipette aspiration techniques, but in order to calculate cell properties, these studies have generally assumed that cells are incompressible with a Poisson's ratio of 0.5. The goal of this study was to measure the Poisson's ratio and recovery properties of the chondrocyte by combining theoretical modeling with experimental measures of complete cellular aspiration and release from a micropipette. Chondrocytes isolated from non-osteoarthritic and osteoarthritic cartilage were fully aspirated into a micropipette and allowed to reach mechanical equilibrium. Cells were then extruded from the micropipette and cell volume and morphology were measured throughout the experiment. This experimental procedure was simulated with finite element analysis, modeling the chondrocyte as either a compressible two-mode viscoelastic solid, or as a biphasic viscoelastic material. By fitting the experimental data to the theoretically predicted cell response, the Poisson's ratio and the viscoelastic recovery properties of the cell were determined. The Poisson's ratio of chondrocytes was found to be 0.38 for non-osteoarthritic cartilage and 0.36 for osteoarthritic chondrocytes (no significant difference). Osteoarthritic chondrocytes showed an increased recovery time following full aspiration. In contrast to previous assumptions, these findings suggest that chondrocytes are compressible, consistent with previous studies showing cell volume changes with compression of the extracellular matrix. (c) 2004 Elsevier Ltd. All rights reserved.