Electropermeabilization of mammalian cells. Quantitative analysis of the phenomenon

Abstract

Transient membrane permeabilization by application of high electric field intensity pulses on cells (electropermeabilization) depends on several physical parameters associated with the technique (pulse intensity, number, and duration). In the present study, electropermeabilization is studied in terms of flow of diffusing molecules between cells and external medium. Direct quantification of the phenomenon shows that electric field intensity is a critical parameter in the induction of permeabilization. Electric field intensity must be higher than a critical threshold to make the membrane permeable. This critical threshold depends on the cell size. Extent of permeabilization (i.e., the flow rate across the membrane) is then controlled by both pulse number and duration. Increasing electric field intensity above the critical threshold needed for permeabilization results in an increase membrane area able to be permeabilized but not due to an increase in the specific permeability of the field alterated area. The electroinduced permeabilization is transient and disappears progressively after the application of the electric field pulses. Its life time is under the control of the electric field parameters. The rate constant of the annealing phase is shown to be dependent on both pulse duration and number, but is independent of electric field intensity which creates the permeabilization. The phenomenon is described in terms of membrane organization transition between the natural impermeable state and the electro-induced permeable state, phenomenon only locally induced for electric field intensities above a critical threshold and expanding in relation to both pulse number and duration.

Effective treatment of cutaneous and subcutaneous malignant tumours by electrochemotherapy

“…One possible reason for this low response rate is the difficulty of some drugs to cross the cell membrane and reach their intracellular site of action. The application of short and intense electric pulses can reversibly permeabilize membranes of all living cells, including mammalian, bacterial, yeast and plant cells Neumann et al, 1989;Rols and Teissie, 1990;Orlowski and Mir, 1993). These electric pulses have been used in vitro to introduce drugs, foreign DNA and other exogenous molecules into cells .…”

Fast kinetics studies of Escherichia coli electrotransformation

“…This is observed through the light emission of the luciferin-luciferase complex which occurs in the external medium after pulsing the bacterial suspension [12]. This process takes place within about 1 min and is associated with the transient permeant state of the membrane organization (elcctropermeabilization) [16]. If ATP was able to leak out, it was predicted that other cytoplasmic molecules and ions should also be able to cross the membrane.…”

Involvement of a Rac1-Dependent Macropinocytosis Pathway in Plasmid DNA Delivery by Electrotransfection

“…[33][34][35][36] One of the most popular mechanisms, known as the "pore theory," states that, when electric-field-induced transmembrane potential exceeds a certain threshold, transient pores will form in the plasma membrane, [37][38][39][40][41][42] allowing extracellular molecules to enter cytoplasm through diffusion, electrophoresis, and/or electro-osmosis. 43 Thus, the technique has also been called electroporation in the literature. 17 Although the "pore theory" may explain how small molecules enter cells, it has failed to explain cellular uptake of larger biopolymers, especially pDNA.…”