What is electroporation?
All living things are built from cells. Each cell is surrounded by a plasma membrane. Plasma membrane consists of a lipid bilayer in which proteins are embedded to allow for transport of molecules and ions. The main function of the plasma membrane is shielding the cell from the environment. It is also involved in maintaining homeostasis, regulating communication between cells, in cell adhesion, ion conductivity, and cell signaling.
Under normal conditions, cells have a negative resting transmembrane voltage of a few tens of mV. When biological cells are exposed to short high-voltage pulses, the absolute value of the resting transmembrane potential increases several-fold. A very high electric field is induced in the plasma membrane, and electroporation occurs. Presumably, pores are formed in the lipid bilayer through which the transport of ions and molecules can occur. Molecules which normally do not enter the cell or exit it, can go across the plasma membrane. Because the pores are extremely small (several nm in diameter), we cannot see them with conventional optical methods. However, they were predicted by molecular dynamics simulations and observed indirectly via electrical measurements and fluorescent dyes. If after electroporation cells recover, it is called reversible electroporation. If the damage is too severe and cells die, either due to membrane destruction or disruption of homeostasis, it is called irreversible electroporation.
Figure: Kotnik et al., 2012