Aptamers can be made up from peptide chains  or out of nucleic acids (DNA and RNA bases: adenine, guanine, thymine and cytosine and uracil) made into short chains of nucleotides called oligonucleotides . For this activity the focus is on nucleic acid aptamers.

Aptamers are being researched and developed to be used as nanomedicine for cancer treatment as they can act like antibodies and can bind with specificity to receptors. The DNA within the aptamer isn’t binding with DNA on the cell receptor, but instead forming bonds between the binding site of the aptamer which folds into a 3D structure and the molecules on the receptor .

These bonds can be quite strong depending on the kind of 3D structure the aptamer forms and the kind of receptor on the cell.  If these receptors are specific to a cancer cell type this has the potential to create targeted cancer treatment.

Nucleic acids have a diameter of 2.5 nanometres so aptamers are a form of nanotechnology. Because they are nano sized they can get into various tightly packed cell masses much more easily than larger molecules such as antibodies, making them great at targeting tumour masses .

Because aptamers resemble the same material we have in our cells and the nucleus, they have low immunogenicity- ability of a substance to set off a defensive immune system reaction in the body , this makes them preferable to using antibodies to direct cancer cell targeting as antibody use has a greater potential to set off an immune system reaction.

​

Aptamers can go by other names such as ligands which are molecules that bind to a metal ion  or chemical antibodies because they are chemically made versions of antibodies.

Aptamer’s are a relatively new technology, only discovered in the 1990’s. This was a chance observation by scientists who were working with HIV viruses, noticing small segments of a RNA that would attach to some proteins strongly . This was of interest and so further research into the use of small single stranded DNA or RNA has been investigated; to this current day it has great theoretical potential use to create targeted cancer cell treatment .

The reason why this isn’t currently used clinically in cancer treatment is because it is a relatively new technology and as a result, still has to go through many tests and laboratory and clinical trials before it is allowed to become a clinical treatment which takes many years to complete .  Nucleic acids can also be easily made into 3D shapes as they can bend and fold into shapes, like origami, so they can also form capsules . These can be an incredibly useful tool when utilised for nanomedicine to treat cancer  as a drug can be housed inside the capsule until the capsule degrades, releasing the drug inside the target cell.