Comprehensive Characterization of the Interaction between Pulsed Electric Fields and Live Cells by Confocal Raman Microspectroscopy

This study reports a comprehensive analysis of the effect of 100 mu s electric pulses on the biochemical composition of live cells using a label-free approach, confocal Raman microspectroscopy. We investigated different regions of interest around the nucleus of the cells and the dose effect relationship related to different electric pulse parameters. We also extended the study to another cell type. Membrane resealing was monitored by pulsing the cells in reversible or irreversible electropermeabilization condition at different temperatures. Our results confirmed a previous publication showing that proteins and lipids were highly impacted by the delivery of electric pulses. These chemical changes were similar in different locations around the cell nucleus. By sweeping the field magnitude, the number of electric pulses, or their repetition rate, the Raman signatures of live cells appeared to be related to the electropermeabilization state, verified by Yo-Pro-1 uptake. We also demonstrated that the chemical changes in the Raman signatures were cell-dependent even if common features were noticed between the two cell types used.