Enhancing Cell Viability and Efficiency of Plasmid DNA Electrotransfer Through Reducing Plasma Membrane Permeabilization.

Abstract

Pulsed electric field has been widely used to facilitate molecular cargo transfer into cells. However, the cell viability is often decreased when trying to increase the electrotransfer efficiency. We hypothesize that the decrease is due to electropermeabilization of cell membrane that disrupts homeostasis of intracellular microenvironment. Thus, a reduction in the membrane permeabilization may increase the cell viability. Different compounds were supplemented into the pulsing buffer prior to electrotransfer for reduction of cell membrane damage. Extent of the damage was quantified by leakiness of the membrane to a fluorescent dye, calcein, preloaded into cells. At 24 hours post electrotransfer, cell viability and electrotransfer efficiency were quantified with flow cytometry. The cell viability could be substantially increased by supplementation of either type B gelatin or bovine serum albumin (BSA), without compromising the electrotransfer efficiency. The supplementation also decreased the amount of calcein leaking out of the cells, suggesting that the improvement in cell viability was due to the reduction in electrotransfer-induced membrane damage. Data from the study demonstrate that type B gelatin and BSA can be used as inexpensive supplements for improving cell viability in electrotransfer.