Blumlein configuration for high-repetition-rate pulse generation of variable duration and polarity using synchronized switch control.

Blumlein generators are used in different applications such as radars, lasers, and also recently in various biomedical studies, where the effects of high-voltage nanosecond pulses on biological cells are evaluated. In these studies, it was demonstrated that by applying high-voltage nanosecond pulses to cells, plasma membrane and cell organelles are permeabilized. As suggested in a recent publication, the repetition rate and polarity of nanosecond high-voltage pulses could have an important effect on the electropermeabilization process, and consequently, on the observed phenomena. Therefore, we designed a new Blumlein configuration that enables a higher repetition rate of variable duration of either bipolar or unipolar high-voltage pulses. We achieved a maximal pulse repetition rate of 1.1 MHz. However, theoretically, this rate could be even higher. We labeled endocytotic vesicles with lucifer yellow and added propidium iodide to a cell suspension for testing the cell plasma membrane integrity, so we were able to observe the permeabilization of endocytotic vesicles and the cell plasma membrane at the same time. The new design of pulse generator was built, verified, and also tested in experiments. The resulting flexibility and variability allow further in vitro experiments to determine the importance of the pulse repetition rate and pulse polarity on membrane permeabilization -- both of the cell plasma membrane as well as of cell organelle membranes.