During electroporation (EP), short electric pulses increase cells permeability, thus leading to emphasized material transfer to cells like drugs and genes or intracellular molecules extracted from cells. One can find EP daily utilized in biotechnology, food industry and medicine. However, during pulsing metal ions get released from anode electrode and cause contamination of electroporated sample with these metal ions leading to changes in medium pH, cell viability, quench fluorescence of fluorophores etc. [1]. Scientist demonstrated that electrodes made from alloys, like aluminum, copper, contaminate samples with metal ions more significantly compared to stainless steel or more inert electrodes [2]. Moreover, it was determined that release of metal ions depend on electric pulse parameters [3]. However, we were unable to find titanium electrodes being used for EP. Here we compare stainless steel to titanium electrodes impact on cell electropermeabilization, gene electrotransfer, viability and pore resealing in regards to changing pulse duration and intensity, but maintaining the same pulse power.
Chinese hamster ovarian (CHO) cells were electroporated between titanium or stainless-steel electrodes with 0,1, 0,5 and 1 ms duration high voltage (HV) electric pulses. Flow cytometry was used to measure the amounts of cells that were permeabilized or irreversibly electroporated by determining number of propidium iodide (PI) positive cells (PI+). Transfection was performed using pEGFP-N1 plasmid and measured using flow cytometry 24 hours after EP. Cell viability was evaluated using colorimetric MTS assay 24 hours after treatments.
Results revealed that titan and stainless-steel electrodes give nearly identical amount of permeable CHO cells after EP. Similar tendencies were noticed measuring gene electrotransfer and pore resealing efficacies and cell viability cells electroporated between titanium electrodes gave similar results as cells electroporated between stainless-steel electrodes.
Overall, EP of CHO cells with different duration of 0.1 ms, 0.5 ms and 1 ms HV pulses bearing the same power output revealed no significant difference in results using titan either stainless-steel electrodes concerning electropermeabilization, gene electrotransfer, pore resealing efficacies and cell viability. Our data emphasize that using titanium electrodes for EP one may expect the same results as using stainless-steel electrodes.