Investigation of Nonlinear Optical Properties of Quantum Dots Deposited onto a Sample Glass Using Time-Resolved Inline Digital Holography

We report on the application of time-resolved inline digital holography in the study of the nonlinear optical properties of quantum dots deposited onto sample glass. The Fresnel diffraction patterns of the probe pulse due to noncollinear degenerate phase modulation induced by a femtosecond pump pulse were extracted from the set of inline digital holograms and analyzed. The absolute values of the nonlinear refractive index of both the sample glass substrate and the deposited layer of quantum dots were evaluated using the proposed technique. To characterize the inhomogeneous distribution of the samples’ nonlinear optical properties, we proposed plotting an optical nonlinearity map calculated as a local standard deviation of the diffraction pattern intensities induced by noncollinear degenerate phase modulation.publishedVersionPeer reviewe

Investigation of oncolytic potential of vaccine strains of yellow fever and tick-borne encephalitis viruses against glioblastoma and pancreatic carcinoma cell lines

Introduction. Flaviviruses, possessing natural neurotropicity could be used in glioblastoma therapy using attenuated strains or as a delivery system for antitumor agents in an inactivated form. Objective. To investigate the sensitivity of glioblastoma and pancreatic carcinoma cell lines to vaccine strains of yellow fever and tick-borne encephalitis viruses. Materials and methods. Cell lines: glioblastoma GL-6, T98G, LN-229, pancreatic carcinoma MIA RaCa-2 and human pancreatic ductal carcinoma PANC-1. Viral strains: 17D yellow fever virus (YF), Sofjin tick-borne encephalitis virus (TBEV). Virus concentration were determined by plaque assay and quantitative PCR. Determination of cell sensitivity to viruses by MTT assay. Results. 17D YF was effective only against pancreatic carcinoma tumor cells MIA Paca-2 and had a limited effect against PANC-1. In glioblastoma cell lines (LN229, GL6, T98G), virus had no oncolytic effect and the viral RNA concentration fell in the culture medium. Sofjin TBEV showed CPE50 against MIA Paca-2 and a very limited cytotoxic effect against PANC-1. However, it had no oncolytic effect against glioblastoma cell lines (LN229, T98G and GL6), although virus reproduction continued in these cultures. For the GL6 glioblastoma cell line, the viral RNA concentration at the level with the infection dose was determined within 13 days, despite medium replacement, while in the case of the LN229 cell line, the virus concentration increased from 1 × 109 to 1 × 1010 copies/ml. Conclusion. Tumor behavior in organism is more complex and is determined by different microenvironmental factors and immune status. In the future, it is advisable to continue studying the antitumor oncolytic and immunomodulatory effects of viral strains 17D YF and Sofjin TBEV using in vivo models

New Hybrid Compounds Combining Fragments of Usnic Acid and Thioether Are Inhibitors of Human Enzymes TDP1, TDP2 and PARP1

Tyrosyl-DNA phosphodiesterase 1 (TDP1) catalyzes the cleavage of the phosphodiester bond between the tyrosine residue of topoisomerase 1 (TOP1) and the 3′ phosphate of DNA in the single-strand break generated by TOP1. TDP1 promotes the cleavage of the stable DNA–TOP1 complexes with the TOP1 inhibitor topotecan, which is a clinically used anticancer drug. This article reports the synthesis and study of usnic acid thioether and sulfoxide derivatives that efficiently suppress TDP1 activity, with IC50 values in the 1.4–25.2 μM range. The structure of the heterocyclic substituent introduced into the dibenzofuran core affects the TDP1 inhibitory efficiency of the compounds. A five-membered heterocyclic fragment was shown to be most pharmacophoric among the others. Sulfoxide derivatives were less cytotoxic than their thioester analogs. We observed an uncompetitive type of inhibition for the four most effective inhibitors of TDP1. The anticancer effect of TOP1 inhibitors can be enhanced by the simultaneous inhibition of PARP1, TDP1, and TDP2. Some of the compounds inhibited not only TDP1 but also TDP2 and/or PARP1, but at significantly higher concentration ranges than TDP1. Leader compound 10a showed promising synergy on HeLa cells in conjunction with the TOP1 inhibitor topotecan

Self-Assembled Particles Combining SARS-CoV-2 RBD Protein and RBD DNA Vaccine Induce Synergistic Enhancement of the Humoral Response in Mice

Despite the fact that a range of vaccines against COVID-19 have already been created and are used for mass vaccination, the development of effective, safe, technological, and affordable vaccines continues. We have designed a vaccine that combines the recombinant protein and DNA vaccine approaches in a self-assembled particle. The receptor-binding domain (RBD) of the spike protein of SARS-CoV-2 was conjugated to polyglucin:spermidine and mixed with DNA vaccine (pVAXrbd), which led to the formation of particles of combined coronavirus vaccine (CCV-RBD) that contain the DNA vaccine inside and RBD protein on the surface. CCV-RBD particles were characterized with gel filtration, electron microscopy, and biolayer interferometry. To investigate the immunogenicity of the combined vaccine and its components, mice were immunized with the DNA vaccine pVAXrbd or RBD protein as well as CCV-RBD particles. The highest antigen-specific IgG and neutralizing activity were induced by CCV-RBD, and the level of antibodies induced by DNA or RBD alone was significantly lower. The cellular immune response was detected only in the case of DNA or CCV-RBD vaccination. These results demonstrate that a combination of DNA vaccine and RBD protein in one construct synergistically increases the humoral response to RBD protein in mice

Efficacy of Pneumococcal Polysaccharide Conjugate Vaccine (13-valent, Adsorbed) in Patients with Systemic Juvenile Idiopathic Arthritis Treated with Genetically Engineered Biologic Drugs (Tocilizumab or Canakinumab): Prospective Cohort Study

Background. Immunological potency of 13-valent pneumococcal vaccine (PCV-13) in children with systemic juvenile idiopathic arthritis (SJIA) is still unstudied. Estimates of the genetically engineered biologic drugs (GEBD) effects on pneumococcal vaccination results also remain controversial.Objective. The aim of the study was to explore the PCV-13 efficacy in patients with SJIA and who is on treatment with monoclonal antibodies against interleukin 6 receptor (tocilizumab) and interleukin 8 receptor beta (canakinumab).Methods. The study included patients under the age of 18 with SJIA in remission or active form of disease vaccinated with PCV-13. The vaccine was administered in single dose of 0.5 ml intramuscularly in patients on treatment with GEBD or 3 weeks before GEBD administration for the first time (for patients with active disease). Vaccination was considered effective at achievement of the minimum protective level of antibodies to capsular polysaccharide of pneumococcus (anti-SPP IgG; ≥ 7 U/ml) or increase of anti-SPP IgG level ≥ 2 times in 4 weeks after vaccination. The anti-SPP IgG levels were measured with enzyme immunoassay.Results. The study included 53 patients (27 girls) in remission of SJIA and 25 (16 girls) in active disease. Median age was 13.3 and 10.8 years respectively. Tocilizumab/canakinumab was administrated in 43/10 and 18/7 patients respectively. Minimum significant anti-SPP IgG level and two-fold increase in anti-SPP IgG level were recorded in 49/53 (92%) and 32/53 (60%) patients with SJIA in remission, as well as in 22/25 (88%) and 18/25 (72%) patients in active disease respectively. PCV-13 immunological potency in patients with SJIA in remission and in active disease (in those who were initially administrated and who did not receive GEBD) did not differ.Conclusion. PCV-13 vaccination allows to achieve protective antibodies level in most of the patients with SJIA in children population regardless of the disease stage and the history of GEBD administration