Pulsed Electromagnetic Field Assisted in vitro Electroporation: A Pilot Study.

Vitalij Novickij,Rūta Kananavičiūtė,Dovilė Pamedytytė,Eglė Lastauskienė,Damijan Miklavčič,Lilija Kalėdienė,Jurij Novickij,Audrius Grainys

doi:10.1038/srep33537

Abstract

Electroporation is a phenomenon occurring due to exposure of cells to Pulsed Electric Fields (PEF) which leads to increase of membrane permeability. Electroporation is used in medicine, biotechnology, and food processing. Recently, as an alternative to electroporation by PEF, Pulsed ElectroMagnetic Fields (PEMF) application causing similar biological effects was suggested. Since induced electric field in PEMF however is 2–3 magnitudes lower than in PEF electroporation, the membrane permeabilization mechanism remains hypothetical. We have designed pilot experiments where Saccharomyces cerevisiae and Candida lusitaniae cells were subjected to single 100–250 μs electrical pulse of 800 V with and without concomitant delivery of magnetic pulse (3, 6 and 9 T). As expected, after the PEF pulses only the number of Propidium Iodide (PI) fluorescent cells has increased, indicative of membrane permeabilization. We further show that single sub-millisecond magnetic field pulse did not cause detectable poration of yeast. Concomitant exposure of cells to pulsed electric (PEF) and magnetic field (PMF) however resulted in the increased number PI fluorescent cells and reduced viability. Our results show increased membrane permeability by PEF when combined with magnetic field pulse, which can explain electroporation at considerably lower electric field strengths induced by PEMF compared to classical electroporation.

Highlights

Electroporation is a phenomenon occurring due to exposure of cells to Pulsed Electric Fields (PEF) which leads to increase of membrane permeability
We showed that the single sub-millisecond magnetic field pulses up to 9 T do not cause membrane permeabilization of yeast cells or the effect is beyond the detection ranges of the Propidium Iodide (PI) fluorescence microscopy
We believe that the result was due to low dB/dt, low induced electric field value during the single magnetic field pulse

Summary

Introduction

Electroporation is a phenomenon occurring due to exposure of cells to Pulsed Electric Fields (PEF) which leads to increase of membrane permeability. As an alternative to electroporation by PEF, Pulsed ElectroMagnetic Fields (PEMF) application causing similar biological effects was suggested. As an alternative method to electroporation by Pulsed Electric Fields, cell membrane permeabilization by Pulsed ElectroMagnetic Field (PEMF) was suggested, which causes biological effects similar to electroporation[43,44,45,46,47]. The introduction of the PEMF offers a non-invasive method and an impedance-independent pulse parameters protocols, since the electric field is induced in the target sample by time-varying electromagnetic field, which allows achieving contactless permeabilization[45]. In case of the conventional electroporation the voltage breakdown between the electrodes can occur which, is eliminated completely during electroporation by PEMF

Methods

Results

Conclusion