Chip COVID
A unique biosensor will detect an infection in ten minutes
The proposed technique will also make it possible to create drugs for antiviral therapy
Maria Nedyuk, Izvestia
Russian scientists are developing a unique rapid diagnostic system COVID-19, which promises to be the fastest in the country. The whole analysis will take only ten minutes. Biotechnologists have modeled peptide molecules similar in structure to the "entrance gate" of the coronavirus into human cells. If there are viruses in the sample, they will "cling" to the peptides, and with the help of an optical device, you can immediately see their bright glow. Also, the created molecules are planned to be used in antiviral therapy – ointments and sprays made on their basis will not allow the pathogen to enter the body, as they will "capture" the spikes of the virus and deprive them of the opportunity to attach to human epithelial cells.
Laboratory on a chip
Scientists of the St. Petersburg State Electrotechnical University "LETI" are developing an innovative system for rapid diagnosis and treatment of COVID-19 using peptides spatially complementary (suitable as a lock and key) to the coronavirus spike. The fact is that when infected with SARS-CoV-2, it is adsorbed on the cell surface with the help of spikes through the ACE-2 receptor, which is present in the cells of the lungs and other organs and is the "entrance gate" for the coronavirus. Then the pathogen penetrates into the cell and starts the processes of forming its copies by introducing its own RNA into the genetic apparatus of the cell. As a result, the cell turns into a small "factory" for assembling new coronavirus virions.
LETI specialists came to the conclusion: for inactivation of the pathogen and for express analysis for its presence, oligopeptide molecules (compounds representing short chains of amino acids of very small size) are needed. – Izvestia), which have a spatial structure complementary to the spikes of the coronavirus as well as ACE-2. A biochip with such molecules will allow to "bind" SARS-CoV-2, and promptly identify it, and at the same time block the virus, depriving it of the ability to attach to the receptor of human cells, the presenter told Izvestia Researcher at LETI, Candidate of Physical and Mathematical Sciences Tatiana Zimina. Using the Protein-3D computer program created at the university, scientists modeled two suitable amino acid sequences.
– One of them contains only eight amino acid residues. It can be used as a solution in a diagnostic biochip," explained Tatiana Zimina. – The second reaches 15 amino acid residues, which will provide even greater binding strength of the sequence to the spike of the virus. Thus, the second peptide will almost completely bind all groups involved in the interaction of the SARS-CoV-2 coronavirus with ACE-2.
The fastest
Now scientists are testing both sequences and developing a prototype of the biochip platform. In case of successful tests, the new test system will be the fastest in Russia - it will be able to identify the coronavirus in just ten minutes. The high speed of analysis is achieved through the use of microelectronics technologies that minimize all manual operations (preparation of the drug, mixing of reagents), and the process of finding the virus using a chip is fast and automated. In addition, such systems are mobile and do not require special premises.
– Experiments using such peptide biochips are unknown to us, – Tatiana Zimina noted in a conversation with Izvestia. – Our methodology is as follows. Since the virus is located in the epithelium, sputum or a smear from the throat or nose is needed for analysis. On a chip made of glass or polymer the size of a slide, there is an inlet tank with a solution where a sample is placed for analysis. The chip is inserted into the reader, where the solution passes by the sites with peptides.
If there are viruses in the sample, they will "cling" to the peptides. And with the help of an optical device, you can immediately see their bright glow. Registration of attached proteins on such a biochip is carried out using an optical method also developed at LETI.
Scientists emphasize that the developed peptides can also be used in antiviral therapy. If you bring them closer to the virus, they "capture" its spikes and inactivate the pathogen. As a result, it will not attach to the epithelial cells. Such molecules can be included in the composition of products for external use. They can be used in the form of an aerosol, powder or ointment for the nose for both therapeutic and preventive purposes.
Promising development
Peptide interactions are a promising technology, Alexander Lukashev, director of the Institute of Medical Parasitology, Tropical and Vector-Borne Diseases named after E.I. Marcinovsky Sechenov University (a university participating in the 5-100 project), told Izvestia.
– In the future, this method may form the basis of portable sensors that detect the virus in real time in crowded places. The use of human receptor analogues will ensure the detection of even mutant forms of the virus (which is not guaranteed when using antibodies), since it is the interaction with the receptor that determines the pathogenesis of the disease. Of course, the development of COVID-19 therapy using this method is a matter of a more distant perspective, since there is still a significant amount of testing to be done," the scientist stressed.
The described method looks interesting in theory, and there are a number of scientific articles in world-renowned journals about the possibility of using the spatial features of the SARS-CoV-2 virus, Stanislav Stravnov, deputy head of the laboratory for the analysis of population health indicators and digitalization of healthcare at MIPT, told Izvestia.
– However, there is a natural question why the principles known before the COVID-19 pandemic did not lead to a revolution in the treatment of other viral infections, for example, the human immunodeficiency virus, – the expert noted.
Scientists from LETI have a long way to go from testing a hypothesis to introducing effective technology into clinical practice. The experts themselves say that the entire test cycle up to certification by Rospotrebnadzor will take from eight to ten months. LETI specialists are working on the fastest test system and a cure for coronavirus together with the Research Institute of Influenza of the Ministry of Health of the Russian Federation, the Research Institute of Especially Pure Biological Products, the St. Petersburg Research Institute of Epidemiology and Microbiology named after Pasteur.
Without restrictions, but in a mask
Recently, the chief pulmonologist of the Ministry of Health of the Russian Federation Sergey Avdeev said that many misunderstand the essence of easing restrictions imposed due to the coronavirus pandemic in the country. In a conversation with journalists, he noted that today there is a clear decrease in new cases of coronavirus: "This is, of course, a big step towards reducing the size of the pandemic. Nothing significant is happening on a national scale yet: we can say that today we have some success in the fight against coronavirus infection, and this is due to the lifting of restrictions," he said in an interview with TASS.
However, according to the doctor, an increase in the number of contacts between people after the removal of a number of restrictive measures may lead to new cases of infection.
– The most important thing here is the very events that doctors, Rospotrebnadzor, and the media talk about so much. We must keep a social distance, wear masks, and gloves indoors. All this will reduce the risks of a negative scenario," Avdeev said.
Earlier, WHO representatives announced that Russia was reaching a plateau on coronavirus. Domestic experts say that this is natural and the number of infected will decrease.
– The theory of epidemiology teaches that after the peak of morbidity, the plateau stage should be reached, and then the number of newly ill people will gradually begin to decrease, – Maria Orlova, senior researcher at the Institute of X-Vio of TSU, told Izvestia.
As of June 14, 528,964 cases of coronavirus have been confirmed in Russia, 280,050 people have recovered, 6948 have died from a new infection. The total number of people infected with coronavirus in the world by the morning of June 14 exceeded 7.76 million people. The pandemic has spread to 188 countries. This is evidenced by the data of the Johns Hopkins University project.
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