Tannin-albumin particles as stable carriers of medicines

Background: The effectiveness of a drug is dependent on its accumulation at the site of therapeutic action, as well as its time in circulation. The aim of the research was the creation of stable albumin/tannin (punicalagin, punicalin) particles, which might serve for the delivery of medicines. Methods: Numerous chromatographic and analytical methods, docking analyses and in vivo testing were applied and used. Results: Stable tannin-albumin/medicine particles with a diameter of ∼100 nm were obtained. The results of in vivo experiments proved that tannin-albumin particles are more stable than albumin particles. Conclusion: Based on the experiments and docking analyses, these stable particles can carry an extended number of medicines, with diverse chemical structures.

SARS-CoV-2 Detection by Extraction-free qRT-PCR for Massive and Rapid COVID-19 Diagnosis During a Pandemic

Introduction/Objective

COVID-19 pandemic severely impacted the healthcare and economy on a global scale. It is widely recognized that mass testing is an efficient way to contain the spread of SARS-CoV-2 infection as well as aid in the development of informed policies for disease management. Here we optimized two different protocols for qRT- PCR with direct samples and systematically compared them with the laboratory standard qRT-PCR detection assay.

Methods/Case Report

RNA samples from 270 subjects collected in two phases at 2020-2021. The groups consisted from positive (n = 240) and negative (n = 30) samples. We compared the performance of qRT-PCR in direct heat- inactivated (95 °C for 5 min, H), heat-inactivated and pelleted (95 °C for 5 min and centrifuged for 10 min at 12,000 g, HC) against standard laboratory protocol for SARS-CoV-2 qRT-PCR (targeting ORF1ab and N genes). Accuracy, sensitivity, and specificity for PCR assays were calculated using caret and epiR packages available in the R software environment for statistical computing. The Wilcoxon matched rank test was used to compare differences in Ct values.

Results (if a Case Study enter NA)

Our study suggests that HC samples show higher accuracy for SARS-CoV-2 detection PCR assay compared to direct H (89 % (95 % CI: 80–95 %) vs 83 % (95 % CI: 74–91 %) of the detection in RNA). The median ΔCt was lower by 1.55 and 2.29 cycles (Wilcoxon signed-rank test p = 0.0018 and < 0.0001 for ORF1ab and N genes, accordingly) in HC samples compared to H samples.

Conclusion

Our results suggest that purified RNA provides more accurate results; heat-inactivated and pelleted sample testing with qRT-PCR showed a slight drop in accuracy. However, the latter could also help to significantly increase testing capacity. Switching to the direct sample testing is justified if the number of tests is doubled at least.

Eutrophication leads to the formation of a sulfide-rich deep-water layer in Lake Sevan, Armenia

Lake Sevan is a meso-eutrophic water body, which was severely impacted by anthropogenic level decrease, pollution and eutrophication during the last century. Starting in the 1970s, these processes resulted in the formation of an oxygen-depleted hypolimnion during summer-autumn stratification of the lake. In this work, we demonstrate for the first time that eutrophication of the lake leads not only to the full depletion of oxygen and nitrate in the hypolimnion but as well to the presence of sulfate-reducing microorganisms and toxic hydrogen sulfide. Concentrations of hydrogen sulfide in the hypolimnion of Major and Minor Sevan in October were as high as 9 and 39 μM, respectively. In October 2019, 66 % of lake's bottom was covered by sulfidic waters, while the fraction of sulfidic water volume reached 19 %. Values of δ³⁴S for hypolimnetic sulfide are lower by only 7-12 ‰ compared to epilimnetic sulfate, while δ³³S values of sulfide are similar to the δ³³S values of sulfate. These isotopic fingerprints are not consistent with microbial sulfate reduction as the sole source of hydrogen sulfide in the hypolimnion. We attribute the formation of a sulfidic deep-water layer to a combination of microbial sulfate reduction in the water column and diffusion of hydrogen sulfide from the sediments.