Shydlovska O. Antiviral activity of cerium dioxide nanoparticles and nanobiocomposites based on it

The research work for gaining the scientific degree candidate of biological sciences (Doctor of Philosophy) in specialty 03.00.06 – virology. – D.K. Zabolotny institute of microbiology and virology of NAS of Ukraine, Kyiv, 2018. The dissertation is devoted to the study of antiviral properties of cerium dioxide nanoparticles (CDN) in comparison with gold nanoparticles (GN), iron oxide nanoparticles (ION) and complex nanoparticles with lanthanum (LSMON). Also, the dissertation is devoted to the study of the properties of nanoparticles to form nanobiocomposites with biomolecules such as interferon (IFN), tumor necrosis factor (TNF), and components of the anti-influenza vaccine. In the research, we carried out a comprehensive and systematic study of the antiviral and antioxidant activity, cytotoxicity, and genotoxicity of metal nanomaterials. The cerium dioxide nanoparticles and iron oxide nanoparticles demonstrated higher cytotoxicity on tumor cell lines than on primary and normal cells. We found the most effective and safe concentrations for studied nanometals. Also, we established that the most effective as an antiviral preparation is cerium dioxide nanoparticles. It decreases the logarithm of vesicular stomatitis virus titer on 2.3-4.5 LG in diapason of concentrations equal to 1.0 nm-1.0 mM. The antiviral activity of iron oxide nanoparticles and complex nanoparticles with lanthanum equal to 50% of living cells. The gold nanoparticles demonstrated antiviral activity only under the influence of the illumination. In the research, we showed the effectiveness of using cerium dioxide nanoparticles like an antioxidant. The cerium dioxide nanoparticles decrease the nitrite-ion production in primary and normal cells in 5-8 times. In the same time, these nanoparticles increase the nitrite-ion production in tumor cells in 8-9 times. Obtained data can be the key to the explanation of the possible mechanism of nanoparticles action. In the dissertation, we showed the possibility of cerium dioxide nanoparticles to form nanobiocomposites with some biomolecules. Thus, we created the nanobiocomposite with interferon and cerium dioxide nanoparticles (IFN-CDN). We established the certainty of the nanobiocomposite formation with the method of dynamic light scattering (DLS). The application of the interferon modifying with cerium dioxide nanoparticles causes the significant and prolonged respond of mice interferon system in comparison with non-modified interferon. The mice injected with nanobiocomposite IFN-CDN have the serum interferon level 8 times higher than mice injected with non-modified interferon. We first created the nanobiocomposite with tumor necrosis factor and cerium dioxide nanoparticles (TNF-CDN) and established the certainty of the nanobiocomposite formation with the method of DLS. Also, the optimal conditions for its obtaining have been worked out. The ability of CDN has been shown to increase the activity of the recombinant TNF-alpha in the tumor cell lines by 15-20%. Also, we studied the possibility of using the CDN as an adjuvant for the vaccine. We demonstrated on Vaxigrip vaccine the ability to form the nanobiocomposites with CDN with DLS method. The application of the Vaxigrip vaccine modified with non-stabilized CDN is in 5 times more effective than the non-modified vaccine and vaccine modified with citrate-stabilized CDN. The application of the Vaxigrip vaccine modified with non-stabilized CDN is accompanied with the prolonged activation (up to 9 weeks after vaccination) of the humoral immune response. The obtained results in the dissertation demonstrated the high antiviral activity of cerium dioxide nanoparticles in comparison with other nanomaterials. Cerium dioxide nanoparticles potentiate the activity of the recombinant interferon and the recombinant tumor necrosis factor. Also, the CDN may act as an effective adjuvant for the Vaxigrip vaccine. The obtained data open the prospect of CDN study in order to create highly effective antiviral therapy.