How to grow nanoparticles for MRT-imaging inside a cell?

Newswise — It so happened that we tried to visit every major conference in our country where neurothematics was presented. This year, we visited “Optogenetics +” in the northern capital, which was held at the Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, and the Volga Neuroscience conference, which was held near Nizhny Novgorod and was organized by NI Lobachevsky State. Nizhny Novgorod University. And ahead of us is the XXIV Congress of the Pavlovian Russian Physiological Society! We decided to tell you about the most interesting reports that were presented at all these forums, without waiting for the full printed versions of these studies. We start with a very interesting method of genetic coding of iron nanoparticles, precisely for MRT-tomography in cells.

Magnetic nanoparticles have recently become very popular in biomedicine. For example, magnetic iron oxide nanoparticles can be used as contrast for T2 mode in MRT. They are less toxic and can be changed for intravenous injection after receiving the dispersoid. There is another interesting way to use them for MRT: labeling cells embedded in the body. However, this method has two drawbacks. First, cells can get rid of nanoparticles with the help of exocytosis. On the other hand, if the embedded cells divide, the concentration of nanoparticles in them also decreases.

There is another interesting option: to encode them genetically directly in the cell: the protein ferritin can deposit up to 3 thousand atoms – and what else do you need to do MRT? However, the nanoparticles obtained in this way are amorphous and low magnetic. At the “Optogenetics+” conference, researchers from Pirogov Russian National Research Medical University proposed an original way of “packaging” the stem cells of the farm.

To do this, you also need to encode the bacterial protein encapsulin in the cells. These specific proteins can store up to 30,000 iron atoms. The authors of the report spoke not only theoretically: with the help of a lentivirus, they obtained a cell line of mesenchymal stem cells in which the Fermi carrier protein, enzyme ferroxidase and bacterial encapsulation were expressed. Transmission electron microscopy showed that the iron dioxide nanoparticles did indeed grow inside the cells, and the authors were able to demonstrate the basic ability to detect such genetically modified cells using MRT after they were injected into the body.

The material was prepared with the financial support of the Russian Ministry of Education and Science within the framework of the federal project “Promotion of Science and Technology”.