Quantification and significance of fluid shear stress field in biaxial cell stretching device
Quantification and significance of fluid shear stress field in biaxial cell stretching device
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DOI：
10.1007/s10237-010-0255-1
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发表时间：
2011-07
影响因子：
3.5
通讯作者：
M. Thompson;Stuart Abercrombie;C. Ott;F. Bieler;G. Duda;Y. Ventikos
中科院分区：
文献类型：
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作者：
M. Thompson;Stuart Abercrombie;C. Ott;F. Bieler;G. Duda;Y. Ventikos
一个广泛使用的市售系统的机械敏感性的调查适用于双轴应变场的细胞培养上的一个顺应性的有机硅基板膜拉伸在一个中心柱。除了预期的基质应变外，该装置还为培养的细胞提供流体流动环境。为了解释使用该装置的实验与体内和临床情况的相关性，必须对基质和流体环境进行分析。虽然以前的工作已经详细的基板应变，流体剪切应力，骨细胞是已知的敏感，是未知的。因此，构建了一个流体结构相互作用计算流体动力学模型，该模型结合了一种有限元技术，该技术能够捕获柱和硅树脂基底膜之间的接触，泵控制压力施加到该硅树脂基底膜的下侧。使用直径为10 μ m的荧光微球进行了流动验证实验。流体剪切应力随着半径沿着在柱上的基底膜近似线性地增加，峰值位于靠近柱边缘处。刺激频率和培养基粘度的变化影响流体剪切应力大小的成比例变化（峰值流体剪切应力在0.09-3.5 Pa范围内变化），对时间和空间分布的影响较小。预测和测量的径向流动模式之间获得了良好的协议。这些结果表明，重新解释以前的数据，使用该设备，包括潜在的强大的作用，流体剪切应力在mechanosensitivity。
A widely used commercially available system for the investigation of mechanosensitivity applies a biaxial strain field to cells cultured on a compliant silicone substrate membrane stretched over a central post. As well as intended substrate strain, this device also provides a fluid flow environment for the cultured cells. In order to interpret the relevance of experiments using this device to the in vivo and clinical situation, it is essential to characterise both substrate and fluid environments. While previous work has detailed the substrate strain, the fluid shear stresses, to which bone cells are known to be sensitive, are unknown. Therefore, a fluid structure interaction computational fluid dynamics model was constructed, incorporating a finite element technique capable of capturing the contact between the post and the silicone substrate membrane, to the underside of which the pump control pressure was applied. Flow verification experiments using 10-μm-diameter fluorescent microspheres were carried out. Fluid shear stress increased approximately linearly with radius along the on-post substrate membrane, with peak values located close to the post edge. Changes in stimulation frequency and culture medium viscosity effected proportional changes in the magnitude of the fluid shear stress (peak fluid shear stresses varied in the range 0.09–3.5 Pa), with minor effects on temporal and spatial distribution. Good agreement was obtained between predicted and measured radial flow patterns. These results suggest a reinterpretation of previous data obtained using this device to include the potential for a strong role of fluid shear stress in mechanosensitivity.