Development of In Vivo Vascular Endothelial Cellular Nano-mechanics Measurement System

1.导论：参与内皮细胞微动和细胞间隙的血管内皮细胞纳米/微观力学是动脉粥样硬化形成的关键因素。为了测量培养细胞的微运动，Giaever和Keese(Natural 366,591-2,1993)发展了一种形态生物传感器，称为电细胞-底物阻抗传感系统(ECIS)。该系统的优点是，细胞到细胞和细胞到基质的距离的定量估计可以分别和实时地进行。在本研究项目中，我们尝试将ECIS系统应用于在体内皮细胞的纳米力学测量。研究结果：初步建立了用于电化学阻抗谱测量的平行板式流室。利用该测量系统，我们对培养的牛内皮细胞进行了反映细胞单层屏障功能的阻抗值的测量，并在sta…下获得了与正常测量系统相同的值。更多的抽搐症状。我们还检测了培养的牛内皮细胞对流体剪切力的反应。对内皮细胞施加2pA切应力后，阻抗值即刻增大。在30min至1h时，阻抗值逐渐降低，成功地测量了内皮细胞对流体剪应力的纳米/微细机械响应。然而，在用于ECIS测量的流动室原型中，无法观察到细胞的形态。因此，我们改装了流动室来观察细胞的形态。对于这一改进，我们还重建了电极阵列和放大器之间的连接器。作为改进的结果，我们成功地测量了细胞单层的电阻抗，同时观察了细胞的形态，并尝试构建了用于ECIS测量的管式流动室。然而，将电极蒸发到管的内表面上存在技术上的困难。因此，用于ECIS测量的管式流室的建造一直没有成功。较少

1. Introduction : Vascular endothelial cell nano/micro-mechanics that are involved in the endothelial cell micro-motion and cellular gaps are the key factors in atherogenesis. For the micro-motion measurement of the cultured cells, Giaever and Keese (Nature 366, 591-2, 1993) developed a morphological biosensor named Electric Cell-substrate Impedance Sensing (ECIS) system. The advantage of this system is that quantitative estimation of cell-to-cell and cell-to-substrate distances can be performed separately and in real time. In this research project, we tried to apply ECIS system to measure nano-mechanics of endothelial cells in vivo.2. Research results : We constructed the parallel plate type flow chamber for ECIS measurement as the first step. Using this measurement system, we measured the electrical impedance value, that reflects the barrier function of the cell monolayer, of cultured bovine endothelial cells and obtained the same value measured in normal measurement system under sta … More tic condition. We also examined the response of cultured bovine endothelial cells to fluid shear stress. After applying 2Pa shear stress to endothelial cells, immediate increase of impedance value was observed. After 30 min to 1h, the impedance value was gradually decreased.We successfully measured the nano/micro-mechanical response of endothelial cells to fluid shear stress. However, the cell morphology could not observe in the prototype of the flow chamber for ECIS measurement. Therefore, we modified the flow chamber to observe the cell morphology. For this modification, we also reconstructed the connector between the electrode array and the amplifier. As the results of this modification, we successfully measured the electrical impedance of cell monolayer with observation of cell morphology simultaneously.We also tried to construct the tube type flow chamber for ECIS measurement. However, there is the technical difficulty in evaporating the electrodes onto the inner surface of the tube. Therefore, the construction of the tube type flow chamber for ECIS measurement has not been succeeded. Less