Aptamers are small (usually, including from 20 to 100 nucleotides, "letters" of DNA) single chain molecules with the structure similar to that of nucleic acids, these molecules can, in a specific manner, be bound with different target molecules. Essentially, aptamers are nucleotide analogs of antibodies, molecules produced by the immune system, however to obtain them is easier and cheaper. Due to their properties, aptamers are in high demand in targeted drug delivery; the drugs in this case will directly hit the target without damaging other organs. However, to create an effective medical drug it is necessary to know its spatial structure, mechanism of action and target.

This research was carried out with the participation of the scientists from the Kirensky Institute of Physics KSC SB RAS and Krasnoyarsk State Medical University at the small angle scattering station of the Kurchatov synchrotron radiation source which was opened in 2018.

During the work, the scientists studied DNA-aptamers which have the ability to bind with cells of glioblastoma, aggressive malignant brain tumor. The method of small angle X-ray scattering allowed constructing a three dimensional map of electron density distribution for this molecule. Based on this map the scientists were able to make molecular modeling of the spatial structure of the aptamer.

As a result, the scientists managed to determine the structure of the aptamer which is suitable for the application in neurosurgery, in particular, for effectively visualizing malignant cells of glioblastoma during the operation. In the future, scientists will be able to create similar DNA aptamers for other types of tumor cells. In general, the obtained results will allow creating effective medical drugs for targeted drug delivery.