What Is Electroporation?

Electroporation (Electroporation), also known as electrotransfection , uses a high-intensity electric field to instantly increase the permeability of the cell membrane, thereby absorbing foreign molecules in the surrounding medium. This technology can introduce nucleotides, DNA and RNA, proteins, sugars, dyes and virus particles into prokaryotic and eukaryotic cells. Electrotransformation is a valuable and effective alternative to other physical and chemical transformation methods.

Electroporation or electroosmosis is

Lipid bilayer mechanics

Electroporation allows cells to introduce highly charged molecules, such as DNA that does not passively diffuse through the core of a hydrophobic bilayer. This phenomenon indicates that the mechanism is the formation of nano-scale water-filled holes on the membrane. Although both electroporation and dielectric breakdown are caused by the application of an electric field, the mechanisms involved are fundamentally different. During dielectric breakdown, the barrier material is ionized, creating a conductive path. The change in material is therefore chemical. In contrast, during electroporation, lipid molecules are not chemically changed, but simply move their position, open a pore, and act as a conductive pathway through a double layer when acting as water.

Electroporation is a dynamic phenomenon that depends on the local transmembrane voltage at each point on the cell membrane. It is generally believed that for a given pulse duration and shape, a specific transmembrane voltage threshold exists for the performance of the electroporation phenomenon (from 0.5V to 1V). This leads to the definition of the electric field magnitude threshold ( _Eth ) of electroporation. In other words, only the cells in the area where E Ë are electroporated. If the second threshold (E _ir ) is reached or exceeded, electroporation will damage the viability of the cell, which is irreversible electroporation (IRE).

The theoretical arrangement of lipids in hydrophobic (top) and hydrophilic (bottom) pores is shown in Figure 2.

Electroporation is a multi-step process with several different stages. First, short electrical pulses must be applied. Typical parameters are 300-400 mV, and the time to cross the membrane is less than 1 ms (note: the voltages used in battery experiments are usually much higher, because they are used to span large distances of large volumes of solution, so they cross the actual membrane The resulting field is only a small part of the bias applied). When this potential is applied, the membrane is charged like a capacitor and migrates through the ions in the surrounding solution. Once the critical field is reached, rapid local rearrangements occur in the lipid morphology. The resulting structure is considered a "pre-hole" because it is not conductive but quickly results in conductive holes. The evidence for the existence of these front pores comes mainly from the "flicker" of the pores, which indicates a transition between conductive and insulating states. It has been proposed that these pre-made pores are small (~ 3) hydrophobic defects. If this theory is correct, the transition to a conductive state can be explained by rearrangement at the edges of the pores, where the lipid heads fold to form a hydrophilic interface. Finally, these conductive holes can heal, reseal the double layer or expand, and eventually break. The conclusions drawn here depend on whether the critical defect size is exceeded, which in turn depends on the applied field, local mechanical stress, and the edge energy of the double layer ^[4] .