A new invention from LNBE: A high-precision, next-generation diagnostic system simultaneously detecting a number of cancer markers

Researchers of LNBE are going to patent their invention, a diagnostic system for simultaneous detection of several disease biomarkers in blood samples. The application for a patent on A Method for Fabrication of Arrays of Microbeads Optically Encoded with Fluorescent Nanocrystals and Carrying Capture Biomolecules on Their Surface by R. S. Bilan, junior researcher, I. R. Nabiev, leading scientist of LNBE, and coauthors has recently been registered at the Center for Information Technologies and Systems of Executive Authorities (CITS).

Nano-bioengineering systems for diagnosing diseases, mainly oncological ones, have been among the main fields of LNBE's research and development activity since its foundation. A new breakthrough in this area has been a long-felt need of medicine, because, on the one hand, the mortality rate due to cancer is growing and, on the other hand, state-of-the-art therapeutic and surgical technologies could save tens of thousands of lives if the disease were diagnosed at a sufficiently early stage.

Detection of cancer markers, i.e., tumor antigens or antibodies against them, in patients' blood samples by means of specific probes containing a capture molecule (an antibody to the marker) and a fluorescent label has proved to be a promising strategy for early diagnosis. In diagnostic systems developed in LNBE, these labels are fluorescent semiconductor nanocrystals (quantum dots, QDs). QD fluorescence is much brighter than that of organic fluorophores used earlier, they are stable to photobleaching, and they have two unique properties: (1) the color of QD fluorescence is determined by their size and can be varied throughout the optical spectrum, from infrared to ultraviolet, and (2) the QD light absorption spectrum is very wide, so that fluorescence of QDs of different colors can be excited using one and the same source. The use of nanocrystals as fluorophores makes the diagnostic systems substantially more sensitive than the best currently available prototypes. Moreover, by using QDs of different colors in the diagnostic systems, one can obtain a practically unlimited variety of unique combinations, which, when selectively bound with specific capture molecules, would allow a whole set of markers to be detected in a single biological sample.

This is precisely what the authors of the invention have done. Microscopic polymer beads serve as the basis of the diagnostic system; in these beads, layers of QDs of different colors are separated from one another by layers of polymer (in order to avoid resonance energy transfer between nanocrystals of different sizes), and capture molecules are attached to the surface of the microbeads. The first experiments with these microbeads have demonstrated the possibility of simultaneous detection of three cancer markers. Now that the feasibility of this principle has been proved experimentally, the number of detected biomarkers will be increased. Furthermore, such detecting systems will make it possible to diagnose not only cancer, but also other diseases.

This project of LNBE is supported by the Federal Research and Development Target Program of the Ministry of Education and Science of the Russian Federation (https://xpir.ru/conference2015/theses/14.578.21.0054).


Regina S. Bilan, junior researcher (reginchg@gmail.com)

Laboratory of Nano-Bioengineering,
Moscow Engineering Physics Institute
31 Kashirskoe shosse, 115409 Moscow, Russian Federation


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