Electroporation physical Transfection

Electroporation physical Transfection

Subject: Science and Technology

Context: a team of researchers from IIT-Madras, in collaboration with scientists from the UK and Taiwan, have achieved a signal breakthrough in doing transfection.

Concept:

Transfection is the process of introducing foreign genetic substances such as nucleic acids into cells, is often needed for gene research and therapy.

Single-cell transfection techniques (SCTT) provide a better understanding of the interactions between molecules and organelles, which can help in the development of therapeutics and diagnostic tools.

There are three ways of doing transfection.

A) Biological, in which the desired genetic material is introduced into a virus. The virus is then used as a truck to take the material inside the cell. It is an Easy method, but there are undesirable side-effects as it could trigger an immuno-response from the body or set off harmful genetic mutations.

B) Chemical method attaches the shipment (carrier) to the positive ions of certain chemicals (cationic polymer, cationic amino acids) and they get attracted to the negatively charged cell membrane. This is tough, because it have to match the chemicals to the type of cell, or else the ‘transfection efficiency’ will be low.

C) Physical is gaining ground. Here again, there are different techniques, such as micro-injection, biolistics and electroporation.

1. Micro-injection is straightforward injection but demands high skill and is laborious.
2. ‘Biolistics’, or biological ballistics, is expensive as it needs equipment for mixing the shipment material with gold and shooting it into the cell using a gene-gun.
3. Electroporation, a more fancied technique, involves applying an electric field to the cell, so that its permeability increases — the holes in its walls get bigger, so that our shipment passes through. For this, it needs extremely small electrodes (at least one thousandth of an mm)

Electroporation, The researchers fabricated a very precise array of nano-electrodes with the help of advanced micro/ nanofabrication techniques.

 The gap between two nano-electrodes was 70 nanometers and the interspace between an array of nano-electrodes was 5 micrometers. The electric pulse creates temporary hydrophilic (water-loving) pores, through which the desired cargo could be slipped in. In the experiment, the researchers used their device to deliver into a cell material such as cell-impermeable dyes, quantum dots (nano crystals that can ferry electrons) and plasmids (a kind of DNA).

Advantages,

• With Nano-electrodes, the voltage applied is small (4V to 6V) and, because of this, the cell lives longer (3 to 4 days).
• The voltage needed is large enough to kill the cell within minutes after the cargo gets in the smaller Nano-electrode surface area, the electrolysis effect was almost negligible, which enhanced cell viability
• Also, with Nano-electrodes it is possible to choose where to puncture holes in the cell membrane. This brings in two advantages.
• Can deny the entry of other unwanted materials into the cell. Two, you can do parallel transfection of multiple drugs and see how they interact.
• This Nano device provides a spatial and temporal dosage control technique, offering high transfection efficiency and cell viability.
• This technology is a significant breakthrough in transfection techniques, which can aid drug research.