Analysis of intense, subnanosecond electrical pulse-induced transmembrane voltage in spheroidal cells with arbitrary orientation.

Self-consistent evaluations of the transmembrane potential (TMP) and possible membrane electroporation in spheroidal cells arising from an ultrashort, high-intensity pulse are reported. The present study couples the Laplace equation with Smoluchowski theory of pore formation, and uses double-shell models. It is shown that the response of prolate spheroids is faster than that of the sphere, with the outer membrane reaching its steady-state value in about 2 mus. The simulation result also shows that the TMP across an inner organelle could exceed the value across the plasma membrane at least over the first 0.4 mus or so, indicating a possibility of intracellular, electromanipulation of cells. The TMP induced by pulsed external voltages is predicted to be higher in oblate spheroids in comparison to both spherical and prolate spheroidal cells. This occurs due to flattening of the surface area.