Pulse generators for pulsed electric field exposure of biological cells and tissues

This paper describes three pulse generators: a spark gap switched coaxial cable, a spark gap switched Blumlein, and a solid state modulator, developed for applying ultrashort electrical pulses to biological materials in culture. Recent research has shown that ultrashort pulsed electric fields can induce apoptosis in biological cells, and that pulses as short as 10 ns with field amplitude greater than 1 MV/m cause membrane phospholipid rearrangement and activation of the effector enzymes of apoptosis. Pulses of very short duration use only tens of mJ per mL per pulse to induce apoptosis and other intracellular effects without causing thermal trauma. The pulse generators discussed here, each of a different topology, deliver ns pulsed electric fields (nsPEF) to cells in liquid suspension, and can be modified to drive electrodes for external, surgical, or endoscopic treatment of tissues in situ.