27.09 -01.10.2021 | 56th Congress of the European Societies of Toxicology (EUROTOX)
Conference Venue: Virtual Event
Go to the Conference website here
Dr. Elena Dragicevic (Nanion Technologies GmbH) will present the following poster:
"High-content multi-frequency impedance cell monitoring for label-free and time-resolved cell toxicity analysis of various cell types"
Impedance readouts from cell-covered, planar gold-film electrodes give profound insights into cell morphology, contractility, proliferation and cytotoxicity of various cell phenotypes, in a label-free fashion. The method offers a crucial advantage over standard, mostly endpoint, cytotoxicity assays as cells can be continuously monitored, even over prolonged periods of time. Advanced information content is obtained by using multi-frequency impedance readouts as they allow zooming in on changes in membrane topography, cell-cell or cell-matrix junctions deconvoluting the complex whole cell response, such as to G-protein-coupled receptor (GPCRs) activation. The multi-frequency readout allows selecting the most sensitive frequency for a particular application or cell type. Here, impedance spectra were calculated and data acquired with CardioExcyte96 impedance recording system, for HeLa, HEK293 and CHO cells to demonstrate cell-type specific differences under stationary conditions. Single frequency recordings have been performed to investigate drug induced hepatic toxicity as well as monitoring in vitro breast cancer recurrence and cardiotoxic effects of anticancer drugs on pluripotent stem cell-derived cardiomyocytes.
Frequency-dependent impedance data reveal individual drifts of the most sensitive frequency, i.e. of the maximal responses indicating cell type specific changes in cell junctions and proliferation dynamics. The expected concentration dependent toxicity was observed for DMSO, Escin and Triton-X showing decreasing impedance values with exposure time and drifting of the maximal responses to lower frequencies. GPCR-mediated signal transduction was investigated by applying the endogenous agonist in dose-response studies or receptor-independent agents.
Single-frequency impedance data were performed on hepatocytes and liver sinusoidal endothelial cells (LSECs) from two donors. The initial results showed that LSECs and hepatocytes respond differently to typical hepatic compounds (acetaminophen and imipramine). Moreover, these drugs had similar pharmacological IC50 values in impedance recordings compared to the intracellular ATP measurements. Additionally, we have used single-frequency impedance measurements to monitor chronic changes (500h) in confluency and viability of murine mammary carcinoma cells. Intrinsic dose dependent effects of anticancer drug mix CAF were identified and consistent with other methods, such as image-based live-cell analysis. The implication of same anticancer drug mix was tested on pluripotent stem cell-derived cardiomyocytes. CAF or doxorubicin long-and short-term implications on cell viability were observed.
In summary, single and multi-frequency impedance data allow for a non-invasive continuous monitoring of cells with the option to zoom in on certain cell aspects or to tailor the readout to individual cell types for improved data interpretation.