Silver containing sorbents: Physicochemical and biological properties

New silver containing sorbents, based on mineral carriers, such as alumina and silica systems with a meso- and macro- porous structure, have a higher mechanical resistance and, hydrophilic and hydrophobic chemical composition of the surface. These sorbents are easy to find and relatively inexpensive, compared to their known equivalents. They are furthermore characterised by high specific surface and simple preparation, whilst the addition of silver considerably increases their antiseptic activity. The results of research of the physical, chemical and biological properties of the developed substances, as well as bio-comparability of sorbents with biological tissues, are presented in this paper. The modified material acts simultaneously as the carrier for active substances to the area of therapeutic application and as a sorbent used to remove toxic agents from such areas. This approach led us to modify the sorbent, and prolong the delivery of substances such as silver, as an effective antibacterial and antimycotic agent

Surface abundances of light elements for a large sample of early B-type stars - IV. The magnesium abundance in 52 stars - a test of metallicity

From high-resolution spectra a non-LTE analysis of the MgII 4481.2 A feature is implemented for 52 early and medium local B stars on the main sequence (MS). The influence of the neighbouring line AlIII 4479.9 A is considered. The magnesium abundance is determined; it is found that log e(Mg) = 7.67 +- 0.21 on average. It is shown that uncertainties in the microturbulent parameter Vt are the main source of errors in log e(Mg). When using 36 stars with the most reliable Vt values derived from OII and NII lines, we obtain the mean abundance log e(Mg) = 7.59 +- 0.15. The latter value is precisely confirmed for several hot B stars from an analysis of the MgII 7877 A weak line. The derived abundance log e(Mg) = 7.59 +- 0.15 is in excellent agreement with the solar magnesium abundance log e_sun(Mg) = 7.55 +- 0.02, as well as with the proto-Sun abundance log e_ps(Mg) = 7.62 +- 0.02. Thus, it is confirmed that the Sun and the B-type MS stars in our neighbourhood have the same metallicity.Comment: 9 pages, 6 figures. Has been accepted for publication at MNRA

Estimation of acute toxicity of a drug based on the complex of lithium citrate, polymethylsiloxane, aluminum oxide

Research Institute of Clinical and Experimental Lymphology has developed an innovative drug based on a complex of lithium citrate, polymethylsiloxane and aluminum oxide (LOAP). Lithium-based drugs are effective in treating bipolar disorders. However, the toxic effects of lithium cause a “narrow therapeutic window”, which limits its clinical use. The creation of the drug LOAP was aimed at creating a prolonged form with a slow release of lithium to reduce toxic properties and use lithium citrate as an active pharmacological agent. At the moment, the lithium complex has no analogues. The purpose of the study was to study the parameters of acute toxicity of the LOAP. Material and methods. When studying acute toxicity, drugs were administered once intragastrically to mice and rats at doses of 12000, 10000, and 5000 mg/kg. Results. A single administration of drugs intragastrically through a probe in the maximum possible doses to mice and rats did not cause the death of animals and did not cause a locally irritating effect on the gastric mucosa. LOAP can be assigned to hazard class 4 (GOST 12.1.007-76)

STUDYING THE POSSIBLE MUTAGENIC PROPERTIES OF NEW MEDICINE ON THE BASIS OF COMPLEX LITHIUM CITRATE, ALUMINUM OXIDE AND POLYMETHILSILOXANE

Aim of the study was to investigate the possible mutagenic properties of a new drug based on a lithium-containing substance – a complex of lithium citrate, polymethylsiloxane and aluminum oxide. Material and methods. Methods for testing mutagenicity using chromosomal aberrations in the bone marrow cells of CBA mice and somatic recombination in Drosophila melanogaster were used. Results. It was shown that a single intragastric administration of drug at a dose of 5000 mg/kg and a fivefold course of administration at a dose of 400 mg/kg to CBA mice did not increase the level of cytogenetic disorders in bone marrow cells. The study of the lithium complex drug in a somatic mosaicism test revealed that the preparation at a dose of 2000 mg/kg does not increase the frequency of mutations in Drosophila melanogaster. Conclusion. A single intragastric administration of the studied drug at a dose of 5000 mg/kg and its course administration (400 mg/kg × 5) do not increase the level of cytogenetic disorders in the bone marrow cells of CBA mice. In the somatic recombination (mosaicism) test system on D. melanogaster, no increase in the appearance of mutant setae and spots on the body and head was observed when using yellow and singed markers. The results of the study indicate that the studied drug does not have mutagenic properties

COMPARATIVE ELECTRON-MICROSCOPIC AND MICROBIOLOGICAL INVESTIGATION OF SILVER PROTEINATE PREPARATIONS

The purpose of this work was a comparative study of the particle sizes of commercial preparations of colloidal silver by the method of electron microscopy, in connection with the characteristics of specific antimicrobial activity of the preparations under the same conditions. Four commercial preparations of colloidal silver were investigated: Vitargol Forte (manufactured by NPC «Elusan»), Protalor (manufactured by OOO «Esko-Farm», Armenia), Sialor (manufactured by PFK «Obnovlenie»). Protargol (prescription drugstore) served as the drug of comparison. Material and methods. The silver particle sizes in the preparations were determined by high-resolution transmission electron microscopy using a JEM 2010 electron microscope (JEOL, Japan) with a resolution of 0.14 nm at an accelerating voltage of 200 kV. The antimicrobial activity of the silver protein preparations was studied by a standard serial dilution method in liquid nutrient media and diffusion method using bacterial cultures of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Results and discussion. Vitargol Forte, manufactured using advanced technology, is the most fine-dispersed and monodisperse preparation. The preparation of standard classical Protargol, prepared in pharmacy conditions, was the most coarsely dispersed and polydispersed. The conclusion. The dependence of antimicrobial activity of the preparation on the size of its silver particles was shown. Of the four investigated preparations of silver proteinate, the smallest particle size was in the Vitargol Fort preparation. The same drug showed the highest bactericidal and bacteriostatic activity