Analysis of the Electric Field-Dependent Current During Electroporation Pulses

When delivered across a cell, certain pulsed electric fields can cause an increase in the cell membrane permeability through a biophysical process known as electroporation. The current signals during the electric pulses could be used as a method for noninvasive electroporation measurement because of the sharp change in the conductivity of cells due to electroporation. To add to the existing knowledge on electroporation current signals under different pulse parameters, we undertook a study in which the electric current across the cells was recorded during electroporation pulses. The experimental current response to a pulsed electric field consisted of three stages: a) a rapid initial increase followed by b) an exponential decrease and then c) a monotonic increase. The rise time of the current signals was not affected by the intensity of the electric field or the number of pulses. However, the time at which the current increased again, deemed the electroporation onset time, shortened as the electric field became more intense and as the number of pulses increased. The transient conductivity change rate, defined to describe the electroporation degree during the pulse, increased under a higher electric field strength. However, the transient conductivity change rate first decreased and then gradually increased with additional pulses. This work may provide insight into the change in current during real-time electroporation detection.