title: How medium osmolarity influences dielectrophoretically assisted on-chip electrofusion.
abstract: Cells submitted to an electric field gradient experience dielectrophoresis. Such a force is useful for pairing cells prior to electrofusion. The latter event is induced by the application of electric field pulses leading to membrane fusion while cells are in physical contact. Nevertheless, the efficiency of dielectrophoretic pairing and electrofusion of cells are highly dependent on medium properties (osmolarity and conductivity). In this paper, we examine the effect of medium osmolarity on volume, viability and electrical properties of cells. Then we characterize in real time the impact of electropermeabilization of cells on their dielectrophoretic response. To do so, a microfluidic device, inducing particular field topologies is used. These real time observations are correlated to numerical analysis of the Clausius-Mossotti factor. Taking into account the identified changes, an electrofusion protocol adequate to the optimal medium (100 mOsm, 0.03 S/m) is defined. Up to 75% simultaneous binuclear rapid electrofusions were achieved and monitored with average membrane fusion duration lower than 12s.
authors.affiliation: Ecole Normale Supérieure de Cachan, CNRS, BIOMIS-SATIE, UMR 8029, 61 avenue du Président Wilson, 94235 Cachan Cedex, France; Univ Paris-Sud, CNRS, Institut d'Electronique Fondamentale, UMR 8622, Bat. 220, Rue André Ampère, 91405 Orsay Cedex, France. Electronic address: feriel.hamdi@satie.ens-cachan.fr.
authors.forename: Feriel Siham
authors.initials: FS
authors.lastname: Hamdi
authors.affiliation: Ecole Normale Supérieure de Cachan, CNRS, BIOMIS-SATIE, UMR 8029, 61 avenue du Président Wilson, 94235 Cachan Cedex, France. Electronic address: olivier.francais@satie.ens-cachan.fr.
authors.forename: Olivier
authors.initials: O
authors.lastname: Français
authors.affiliation: Univ Paris-Sud, CNRS, Institut d'Electronique Fondamentale, UMR 8622, Bat. 220, Rue André Ampère, 91405 Orsay Cedex, France. Electronic address: elisabeth.dufour-gergam@campus-paris-saclay.fr.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Dufour-Gergam
authors.affiliation: Ecole Normale Supérieure de Cachan, CNRS, BIOMIS-SATIE, UMR 8029, 61 avenue du Président Wilson, 94235 Cachan Cedex, France. Electronic address: bruno.lepioufle@satie.ens-cachan.fr.
authors.forename: Bruno
authors.initials: B
authors.lastname: Le Pioufle
mesh_terms: D000818:Animals; D002459:Cell Fusion / Q000379:methods*; D045744:Cell Line, Tumor; D048430:Cell Shape; D048429:Cell Size; D002470:Cell Survival; D018274:Electroporation; D006801:Humans; D051379:Mice; D046210:Microfluidic Analytical Techniques; D009997:Osmotic Pressure
keywords: Dielectrophoresis; Electrofusion; Electropermeabilization; Lab-on-chip; Microfluidic