Electrical and optical characterization of thrombin-induced permeability of cultured endothelial cell monolayers on semiconductor electrode arrays

Impedance spectroscopy and phase-contrast microscopy are combined to monitor the electrical and morpho-logical properties of human umbilical vein endothelial cell monolayers. The cells were cultured on optically transparent indium-tin-oxide (ITO) semiconductor electrode arrays coated with collagen IV, and the effect of the inflammatory mediator thrombin on monolayer permeability was monitored in real time. ITO electrodes provide several advantages for these kinds of experiments, because they are optically transparent, polarizable and highly sensitive due to the absence of insulating oxide layers. A qualitative correlation between the thrombin-induced gap formation and the electrical parameters of the cell layer is established.