How electric fields pierce cell membranes

Publication of the Chemistry Laboratory in the journal PNAS on March 7, 2023. Communication of the CNRS-INC on March 28, 2023.

Electroporation consists of perforating the cell membrane with an electric field to pass a therapeutic substance through it. A team from the Chemistry Laboratory (CNRS/ENS de Lyon/Claude Bernard Lyon 1 University) and their colleagues from the University of Freiburg im Breisgau have published in the journal PNAS some essential elements for understanding this widely used but still little understood phenomenon.

Why does a pore open when a high-enough electric field is applied to a lipid bilayer? Scarcity of data from experiments designed to probe this important phenomenon has so far precluded a clear answer to the question. Here, we report results from electropermeation experiments on black lipid membranes assembled from different mixtures of a common lipid, 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC), and its hydroperoxidized form POPC-OOH. By carefully identifying pore formation events, we were able to quantify the influence of the applied electric field and of the hydroperoxidation degree on the frequency of pore opening. Our results disagree with the standard model of pore formation and bring a significant insight into the factors controlling pore opening under an electric field.

Reference : Activation energy for pore opening in lipid membranes under an electric field . Eulalie J. Lafarge, Pierre Muller, André P. Schroder, Ekaterina Zaitseva, Jan C. Behrends and Carlos M. Marques. PNAS, March 7, 2023.
DOI : 10.1073/pnas.2213112120