History of electroporation

Abstract

Electroporation phenomena can be traced back to the eighteenth century when red spots on human animal skin (Lichtenberg figures) were observed in the areas where electric fields were applied. Once the cause of this phenomenon was understood and control over the parameters that produce electric fields was achieved, a quick adoption of the use of pulsed electric fields to kill microbes was seen in the area of food and water sterilization. Biomedical applications soon followed where electric fields began to be used to control movement of biological material: cells were brought in close proximity and fused together through membrane destabilization (electrofusion), DNA material was introduced into cells through transient pores in the membrane (electrogenetherapy), and chemotherapeutic drugs were directly delivered to cells (electrochemotherapy). These applications fall under the energy regime known as reversible electroporation in which temporary cell membrane destabilization is achieved. Irreversible electroporation (IRE) uses an energy regime much higher than that of reversible electroporation and induces cell death via various mechanisms. Since the postulation that IRE can be used to ablate substantial volumes in such a manner that it does not induce significant traditional thermal damage, it has been widely investigated moving from in vitro studies, to in vivo animal studies, and finally to human patients through clinical trials. Its nonthermal mechanism to induce cell death makes it an attractive modality to safely treat unresectable tumors.