"Stealth nanoparticles" for cancer diagnosis and drug delivery
Bioengineers have created artificial viruses based on DNA
Alexander Khramov, Infox.ru
Scientists have synthesized nanoparticles that are similar in structure to viruses. Such objects are "invisible" to the immune system and in the future may be useful in the diagnosis of cancer and the treatment of a number of diseases.
This is stated in an article by American specialists from Harvard University published in the journal ACS Nano (Steven D. Perrault and William M. Shih, Virus-Inspired Membrane Encapsulation of DNA Nanostructures To Achieve In Vivo Stability).
Not so long ago, Harvard scientists developed a technology that allows using DNA as a building material in the creation of nanoparticles. Due to the interaction between complementary nitrogenous bases arranged in a certain order, DNA can independently fold into a three-dimensional structure of a given shape.
The authors of the article have improved this technology and created an artificial "virus" based on a DNA particle that can freely circulate through the body. They surrounded the octahedrons of DNA (their diameter is only 50 nanometers) with a membrane consisting of two layers of phospholipids. Such a membrane is fixed to the nanoparticle using 60 "handles", also consisting of single-stranded DNA segments.
Figure from the article in ACS Nano – VM
In nature, a lipoprotein membrane is present in some large viruses, such as influenza and herpes viruses. These viruses "cut out" the lipoprotein membrane from the membrane of the host cell, which serves as a place of their reproduction. As a result, the immune system does not recognize foreign objects in them. A similar effect was observed in the case of DNA particles: when scientists provided them with a shell, the immune system of mice began to react to them 2 orders of magnitude weaker.
On the left is a photo of a virus with a lipoprotein envelope, on the right is its artificial analogue.
Photo: Steven Perrault/Harvard's Wyss Institute
According to the authors of the article, if certain proteins are inserted into the shell of artificial viruses, they will find certain types of cells in the body, for example, cancer cells. This will help diagnose malignant tumors at the earliest stages. In addition, artificial viruses will also be useful for the point delivery of drugs to the affected organs.
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