Sotoudeh M, Jalali S, Usami S, Shyy J Y, Chien S
Department of Bioengineering and Institute for Biomedical Engineering, University of California, San Diego, La Jolla 92093-0412, USA.
Ann Biomed Eng. 1998 Mar-Apr;26(2):181-9. doi: 10.1114/1.88.
The objective of this study is to design a new apparatus to allow the control of the magnitude and frequency of dynamic stretch applied uniformly to cells cultured on a silicon elastic membrane. The apparatus is designed to produce equi-biaxial dynamic stretches with area changes ranging from 0% to 55% and frequencies ranging from 0 to 2 Hz. Homogeneous finite strain analysis using triangles of markers was performed to compute the symmetric two-dimensional Lagrangian strain tensor on the membrane. Measurements of strain in both static and dynamic conditions showed that the shear component of the strain tensor (Erc) was near zero, and that there was no significant difference between radial (Err) and circumferential (Ecc) components, indicating the attainment of equi-biaxial strain. Bovine aortic endothelial cells were transiently transfected with a chimeric construct in which the luciferase reporter is driven by TPA-responsive elements (TRE). The transfected cells cultured on the membrane were stretched. The luciferase activity increased significantly only when the cells were stretched by 15% or more in area. Cells in different locations of the membrane showed similar induction of luciferase activities, confirming that strain is uniform and equi-biaxial across the membrane.
本研究的目的是设计一种新装置，以控制均匀施加于培养在硅弹性膜上的细胞的动态拉伸的幅度和频率。该装置旨在产生等双轴动态拉伸，面积变化范围为0%至55%，频率范围为0至2Hz。使用标记三角形进行均匀有限应变分析，以计算膜上对称的二维拉格朗日应变张量。静态和动态条件下的应变测量表明，应变张量的剪切分量（Erc）接近零，径向（Err）和周向（Ecc）分量之间没有显著差异，表明实现了等双轴应变。用一种嵌合构建体瞬时转染牛主动脉内皮细胞，其中荧光素酶报告基因由佛波酯反应元件（TRE）驱动。在膜上培养的转染细胞被拉伸。仅当细胞面积拉伸15%或更多时，荧光素酶活性才显著增加。膜不同位置的细胞显示出相似的荧光素酶活性诱导，证实整个膜上的应变是均匀且等双轴的。
