Effect of surfactant polyoxyethylene glycol (C12E8) on electroporation of cell line DC3F

Surfactant polyoxyethylene glycol (C12E8) decreases the voltage required for irreversible electroporation in planar lipid bilayers. In our study the effect of non-cytotoxic concentration of C12E8 on cell membrane reversible and irreversible electroporation voltage was investigated in DC3F cell line. Cell suspension was exposed to a train of 8 electric pulses of 100 μs duration, repetition frequency 1 Hz and amplitudes from 0 to 400 V at electrode distance 2 mm. The effect of C12E8 on the reversible and irreversible electroporation was investigated. We found that C12E8 decreases the voltage necessary for irreversible electroporation but has no effect on reversible electropermeabilization. Cell membrane fluidity measured by electron paramagnetic resonance spectrometry, using the spin probe methylester of 5-doxyl palmitate was not significantly changed due to the addition of C12E8. Based on this we conclude that the main reason for the observed effect were not the changes in the membrane fluidity. As an alternative explanation we suggest that C12E8 induced anisotropic membrane inclusions may stabilize the hydrophilic pore, by accumulating on a toroidally shaped edge of the pore and attaining favorable orientation.