18 April 2016

Origami from synthetic DNA

Origami Medicine

Marina Astvatsaturyan, "Search"

Synthetic DNA can help in solving the problem of targeted drug delivery inside the body; the proposed method is based on the principle of DNA origami. New Scientist writes about this (Artificial DNA folds into parcels that can survive inside us – VM).

The advantage of the described approach to the creation of DNA origami is the stability of the final structure. For the first time, strands of artificial genetic material have been folded into three-dimensional shapes of the desired shape, and such packaging can be used to transfer and deliver medicines to the right place in the body.

Natural nucleic acids, DNA and RNA, perform many biological functions – from information storage to catalysis. About 10 years ago, biochemists found a new application for these filamentous molecules – DNA origami. Long strands of DNA can be designed in such a way that they will fold into nanoscale two- and three-dimensional structures capable of carrying, among other things, drugs.

The problem is that the DNA and RNA constructed by scientists are not very stable inside the body due to protective enzymes that recognize and break down foreign nucleic acid, and therefore the origami DNA structures are at risk of disintegration before they do their job. British scientists Alex Taylor (Alex Taylor) and Philip Hollinger (Philipp Hollinger) from the Laboratory of Molecular Biology of the Medical Research Council (MRC Laboratory of Molecular Biology) in Cambridge, already known for their experiments on the creation of synthetic, or xenonucleic, acids, have shown that the problem of instability can be overcome by introducing elements unusual to it into the DNA sequence.

Xenonucleic acids, which Taylor and Hollinger reported recently (in the article Nanostructures from Synthetic Genetic Polymers – VM) in the European Journal of Chemical Biology (ChemBioChem), differ from natural nucleic acids by sugars, which together with phosphates form the backbone of DNA molecules holding nitrogenous bases: in xenonucleic acids, it consists of synthetic molecules.

Drawing from an article in ChemBioChem – VM

With a certain configuration, the synthetic backbone of xenonucleic acid promotes stronger bonds within a pair of nucleotide bases than those that hold them against each other in natural DNA, and this reduces the likelihood of splitting the molecule when ingested.

To control the shape of the new molecules, Taylor and Hollinger created two matrices of xenonucleic acids, thanks to which synthetic DNA can take the form of either a tetrahedron or an octahedron. In order to test which of the two forms is more stable, the scientists immersed the synthesized molecules in blood serum samples at body temperature. Eight days later, the xenonucleic acid was still intact, while the tetrahedron synthesized from elements of natural DNA disintegrated in two days.

Portal "Eternal youth" http://vechnayamolodost.ru  18.04.2016

Found a typo? Select it and press ctrl + enter Print version