Journal article
Interdependence of initial cell density, drug concentration and exposure time revealed by real-time impedance spectroscopic cytotoxicity assay
Department of Micro- and Nanotechnology, Technical University of Denmark1
Nanoprobes, Department of Micro- and Nanotechnology, Technical University of Denmark2
Bioanalytics, Department of Micro- and Nanotechnology, Technical University of Denmark3
Molecular Windows, Department of Micro- and Nanotechnology, Technical University of Denmark4
Polytechnic University of Milan5
University of Genoa6
Colloids and Biological Interfaces, Department of Micro- and Nanotechnology, Technical University of Denmark7
We investigated the combined effect of the initial cell density (12 500, 35 000, 75 000, and 100 000 cells cm−2) and concentration of the anti-cancer drug doxorubicin on HeLa cells by performing timedependent cytotoxicity assays using real-time electrochemical impedance spectroscopy. A correlation between the rate of cell death and the initial cell seeding density was found at 2.5 μM doxorubicin concentration, whereas this was not observed at 5 or 100 μM.
By sensing the changes in the cell–substrate interaction using impedance spectroscopy under static conditions, the onset of cytotoxicity was observed 5 h earlier than when using a standard colorimetric end-point assay (MTS) which measures changes in the mitochondrial metabolism. Furthermore, with the MTS assay no cytotoxicity was observed after 15 h of incubation with 2.5 μM doxorubicin, whereas the impedance showed at this time point cell viability that was below 25%.
These results indicate that impedance detection reveals cytotoxic events undetectable when using the MTS assay, highlighting the importance of combining impedance detection with traditional drug toxicity assays towards a more in depth understanding of the effect of anti-cancer drugs on in vitro assays.
Moreover, the detection of doxorubicin induced toxicity determined with impedance under static conditions proved to be 6 times faster than in perfusion culture.
Language: | English |
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Publisher: | The Royal Society of Chemistry |
Year: | 2015 |
Pages: | 3623-3629 |
ISSN: | 13645528 and 00032654 |
Types: | Journal article |
DOI: | 10.1039/c5an00097a |
ORCIDs: | Zor, Kinga , Andresen, Thomas Lars , Heiskanen, Arto and Emnéus, Jenny |