Study of the transmembrane potential distribution of cell pairs in a microfluidic device using polymer obstacles to initiate electrofusion

¹ École Normale Supérieure de Cachan, CNRS, Laboratoire Systémes et Applications des Technologies de l’Information et de l’Énergie, UMR 8029, 94235 Cachan cedex, France
² University Paris-Sud, CNRS, Institut d’Électronique Fondamentale, UMR 8622, 91405 Orsay cedex, France
³ École Normale Supérieure de Cachan, CNRS, Laboratoire de Biologie et Pharmacologie Appliquée, UMR 8113, 94235 Cachan cedex, France

^a e-mail: bruno.lepioufle@satie.ens-cachan.fr

Received: 26 September 2012
Revised: 4 February 2013
Accepted: 7 February 2013
Published online: 11 April 2013

Abstract

In this paper, we investigate the different parameters that affect the distribution of the transmembrane potential of cells brought into contact before electrofusion in a miniaturized fluidic device. In particular, we discuss the deviation of the effective transmembrane voltage compared to the one predicted by Schwan’s law. The application of electric field pulses to biological cells induces a transmembrane potential which leads to cell permeabilization. Electrofusion occurs when several cells are brought into contact while they are electropermeabilized. Nevertheless, we show that in this case, the mutual presence of cells interferes on Schwan’s equation. Consequently, the transmembrane voltage at the cell contacting point is drastically reduced, which is not favorable for an electrofusion in smooth conditions, as the applied voltage needs to be increased to compensate this phenomenon. We show that the introduction of polymer obstacles reverses this trend, as the high electric field region is focused on the fusion zone. To confirm the theory we developed, quantitative biological experiments are presented in which murine melanoma cells were paired and fused in both conditions (with and without obstacles).