Linz Georg, Djeljadini Suzana, Steinbeck Lea, Köse Gurbet, Kiessling Fabian, Wessling Matthias
DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52074 Aachen, Germany; RWTH Aachen University, Aachener Verfahrenstechnik-Chemical Process Engineering, Forckenbeckstrasse 51, 52074, Aachen, Germany.
Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, 52074 Aachen, Germany.
Biosens Bioelectron. 2020 Oct 1;165:112345. doi: 10.1016/j.bios.2020.112345. Epub 2020 Jun 2.
We describe an impedance-based method for cell barrier integrity testing. A four-electrode electrical impedance spectroscopy (EIS) setup can be realized by simply connecting a commercial chopstick-like electrode (STX-1) to a potentiostat allowing monitoring cell barriers cultivated in transwell inserts. Subsequent electric circuit modeling of the electrical impedance results the capacitive properties of the barrier next to the well-known transepithelial electrical resistance (TEER). The versatility of the new method was analyzed by the EIS analysis of a Caco-2 monolayer in response to (a) different membrane coating materials, (b) two different permeability enhancers ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) and saponin, and (c) sonoporation. For the different membrane coating materials, the TEERs of the standard and new protocol coincide and increase during cultivation, while the capacitance shows a distinct maximum for three different surface materials (no coating, Matrigel®, and collagen I). The permeability enhancers cause a decline in the TEER value, but only saponin alters the capacitance of the cell layer by two orders of magnitude. Hence, cell layer capacitance and TEER represent two independent properties characterizing the monolayer. The use of commercial chopstick-like electrodes to access the impedance of a barrier cultivated in transwell inserts enables remarkable insight into the behavior of the cellular barrier with no extra work for the researcher. This simple method could evolve into a standard protocol used in cell barrier research.
我们描述了一种基于阻抗的细胞屏障完整性测试方法。通过简单地将商用筷子状电极（STX-1）连接到恒电位仪上，就可以实现四电极电阻抗谱（EIS）设置，从而监测培养在Transwell小室中的细胞屏障。对电阻抗结果进行后续电路建模，可得出屏障的电容特性以及广为人知的跨上皮电阻（TEER）。通过对Caco-2单层细胞进行EIS分析，来分析这种新方法的通用性，该分析针对以下情况：（a）不同的膜包被材料；（b）两种不同的通透性增强剂乙二醇双（2-氨基乙醚）-N,N,N',N'-四乙酸（EGTA）和皂苷；（c）声孔效应。对于不同的膜包被材料，标准方案和新方案的TEER值在培养过程中一致且升高，而电容对于三种不同的表面材料（无包被、基质胶和I型胶原蛋白）呈现出明显的最大值。通透性增强剂会导致TEER值下降，但只有皂苷会使细胞层的电容改变两个数量级。因此，细胞层电容和TEER代表了表征单层细胞的两个独立特性。使用商用筷子状电极来获取培养在Transwell小室中的屏障的阻抗，能够让研究人员在无需额外工作的情况下深入了解细胞屏障的行为。这种简单的方法可能会发展成为细胞屏障研究中使用的标准方案。
