Bioimpedance Analysis of Epithelial Monolayers After Exposure to Nanosecond Pulsed Electric Fields

Exposures to pulsed electric fields (PEFs) are known to affect cell membranes and consequently also cell-cell interactions as well as associated characteristics. Bioimpedance analysis offers direct and non-invasive insights into structural and functional changes of cell membranes and extracellular matrices through a rigorous evaluation of electrical parameters. Accordingly, the multi-frequency impedance of confluent monolayers of rat liver epithelial WB-F344 cells was monitored in situ before and after exposure to nanosecond PEFs. The results were fitted by two Cole models in series to obtain the Cole parameters for the monolayer. For an interpretation of the results, dielectric parameters were correlated with changes of the TJ-protein zonula occludens (ZO-1) and the paracellular permeability of the monolayer. Cole parameters, in general, change as a function of pulse number and time. The findings demonstrate that impedance analysis is an effective method to monitor changes in cell-cell contacts and paracellular permeability and relate them to exposure parameters.