Effects of a Pulse Electric Field on Electrofusion of Giant Unilamellar Vesicle (GUV) -Jurkat Cell (Measurement of Fusion Ratio and Electric Field Analysis of Pulsed GUV-Jurkat Cell)

Abstract

Electrofusion of Giant Unilamellar Vesicle (GUV) and living cell is a gentle method to deliver membrane impermeable cryo-/lyo-protective molecules into living cell for cryo-/lyopreservation. In this method, cellular fusion is believed to be triggered by the irreversible electical breakdown of the membrane at contact region. Nevertheless, as the time change of the membrane potential distribution during an electric pulse is still not clear, the length and strength of electric pulse are hardly designed. In this study, the GUV-Jurkat electrofusion ratios under various pulse strength and length were measured. In addition, we calculated the time change of membrane potential distribution of a deformed GUV-Jurkat pair during the electric field application by a finite element method (FEM)-electric field analysis. The measured cellular and GUV's electric properties and a GUV-Jurkat profile were used for the analysis to validate the quantitative calculation results. Both results of experiment and calculation suggested that; 1) GUV-Jurkat should be stretched for the electrofusion, 2) whole contact region of membrane should breakdown at the same time to process electrofusion, 3) after applying an electric field for around 1μsec, membrane potential in contact region becomes homogeneous, 4) after applying an electric field for around 10μsec, membrane potential is relaxed, 5) the irreversible electric breakdown is around 3V.