Significance of Treatment Energy in Cell Electropermeabilization

Abstract

The effect of applied electrical energy on cell survival and permeabi-lization of the plasma membrane under in vitro conditions were examined. Cell viability was measured with a colony-forming assay, permeabilization of the plasma membrane by means of propidium iodide (PI) uptake. Cells were exposed to five regimens of electrical treatment parameters. For a given voltage, applied electrical energy was the same for all regimens. In all applied regimes, cell survival was comparable. The differences in PI uptake between applied regimens were significant. The highest percentage of stained living cells (76%) was observed with four long pulses (200 μs) with a repetition frequency of 0.5 Hz at 200 V. At regimens with higher numbers of shorter pulses, the percentage of stained living cells was considerably lower. According to our results, total applied electrical energy is not a determinant parameter for drug uptake and cell survival under in vitro conditions.

Key Words:

• Electropermeabilization
• Electrochemotherapy
• Treatment energy