Magnetic nanoparticles for Covid-19 testing in practical applications

Miniature particles with a magnetic core and a thin silica shell on the surface to isolate viral RNA developed by scientists at the Regional Centre of Advanced Technology and Materials (RCPTM), the Faculty of Science, are now being translated into commercial applications. Commercial companies have already purchased first batches of the magnetic balls for diagnostic purposes. Nanoparticles are an important part of the new Covid-19 testing technology designed at the Institute of Organic Chemistry and Biochemistry (IOCB) of the Czech Academy of Sciences, whose help was fundamental at the time of the culminating coronavirus pandemic.

The development of the testing protocol was a response to the lack of commercial test kits at a time of the coronavirus crisis. RCPTM’s researchers responded quickly to the demand of colleagues at IOCB. Thanks to extensive experience with research into nanomaterials for biomedical applications, they prepared, within a couple of days, a new type of magnetic nanoballs, dozens of nanometers in size, with a suitably modified surface to isolate nucleic acids.

“Silicon dioxide, which coats magnetic nanoparticles, has a great ability to bind nucleic acids. Owing to the vast surface of the nanoparticles, large amounts of viral RNA can effectively get captured on them. Such bound RNA molecules can be easily isolated by the method of PCR, using an external magnet for diagnostics purposes,” described the principle of nanoballs Radek Zbořil from RCPTM.

The team from Olomouc can produce the nanoparticles in bulk. “In one cycle, we are able to prepare more than 100 grams, which is enough for around 100,000 tests on Covid-19. This is a technologically undemanding synthesis. That way, we can increase the capacity by an order of magnitude,” explained Ivo Medřík, who was involved in the development of nanoparticles.

According to Pavel Šácha from IOCB, the isolation of viral RNA was the bottleneck of the whole process of preparing the new technology. “At the time of the coronavirus crisis, RNA isolation kits manufactured abroad were not available, so we looked elsewhere for suitable magnetic particles capable of binding viral RNA. Nanoparticles from RCPTM have proved to be the best: they have a rapid response to the magnetic field, a large capacity for RNA binding and can be prepared in large quantities,” said Šácha, who coordinated the design of the new test protocol.

Successful verification of the technology was carried out by the National Institute of Public Health in Prague, as well as in hospitals in Motol and Na Bulovce, or in academic workplaces including CEITEC, Brno; BIOCEV, Prague; IMTM, Olomouc. The National Reference Laboratory for Influenza of the National Institute of Public Health tested the IOCB–RCPTM RNA isolation kits and compared them with sets designed to isolate nucleic acids produced by the world’s leading suppliers —Roche and ThermoFisher Scientific. “The IOCB–RCPTM RNA isolation kit showed equal efficiency in isolating ribonucleic acids. As part of the validation of the recommended procedure, all steps and reagents were individually verified against series of variously diluted inactivated SARS-CoV-2,” said Helena Jiřincová from the National Institute of Public Health in Prague.

“The results confirmed that our magnetic particles are comparable to commercial materials in terms of the efficiency of viral RNA isolation. They are therefore fully prepared for transfer to applications, taking into account the production capacity and lower production costs. The whole development of the new isolation kits for diagnostics of Covid-19 is, to my mind, a prime example of effective collaboration among academic workplaces. At the same time, it is a demonstration of their ability to translate lab results into application in an extremely short time,” said Zbořil.

Domestically developed kits will be able to assist with diagnosis during potentially further waves of the disease, not just in the Czech Republic. “We believe that if we find a manufacturer, there will be a possibility of supplying the RNA insulation kits to other countries,” concluded Pavel Šácha. IOCB is in negotiations with several manufacturers to grant a licence for know-how and production of the isolation kits; pending their closure, production for the Czech and Slovak markets will be provided by an IOCB’s subsidiary IOCB Tech. Palacký University Olomouc ensures the production and supply of magnetic balls to isolate viral RNA.