A. A. Ostroushko

Studies on the possibility of introducing iron-molybdenum buckyballs into an organism by electrophoresis

The fundamental possibility of transporting polyoxometalate with a Mo72Fe30 keplerate structure through the skin of animals (rats) is shown; the efficiency of such transport significantly increases upon applying an electric field (electrophoresis). The experiments have been performed on separate rat skin specimens and directly on laboratory animals. The optimum operating conditions for electrophoresis are selected, and the absence of changes in the biochemical parameters used in the clinical laboratory diagnostics for estimating the functional state of the heart, liver, kidneys, and pancreas after the impact of the above-specified polyoxometalate on the organism of animals in experimental conditions is established.

Study of acute and subacute action of iron-molybdenum nanocluster polyoxometalates

There were no significant deviations from the norm in the functional state of the liver, kidneys, and pancreas in the study of the acute toxicity of iron-molybdenum buckyballs intended for targeted drug delivery. No accumulation of nanoparticles or deviation from the norm in any investigated parameter was detected in the study of subacute toxicity.

Behavior of associates of keplerate-type porous spherical Mo72Fe30 clusters with metal cations in electric field-driven ion transport

It has been demonstrated that the keplerate-type porous spherical Mo72Fe30 cluster is stable upon association with multicharged metal cations (calcium, lanthanum) in aqueous solutions. The behavior of Mo72Fe30 keplerate associates with lanthanum ions attests to the possibility of transfer of such associates in electric field-induced transport of cationic forms, in particular, upon electrophoretic delivery in living systems. Lanthanum ions can be used as labels for monitoring polyoxometallate transfer in different media.

Changing the content of histone proteins and heat-shock proteins in the blood and liver of rats after the single and repeated administration of nanocluster iron-molybdenum polyoxometalates

The effect of nanocluster iron-molybdenum polyoxometallates (POMs) on the content of histone proteins and heat shock proteins in rat blood and liver after single and repeated administration had been investigated. It is found that the introduction of POMs was not accompanied by a decrease in the number of histone proteins in blood lymphocytes, which may indicate a lack of gene expression of proinflammatory factors. An increase in the content of the heat shock protein Hsp60 and Hsp70 in the liver is revealed, and the degree of increase depended on the nanoparticles exposition. The assumptions about the absence of a lymphocytes proinflammatory phenotype and the heat shock proteins protective effect are confirmed with the continuation of normal functional-state liver parameters during all periods of polyoxometalates exposure.

On the possibility of controlling the hydrophilic/hydrophobic characteristics of toroid Mo138 nanocluster polyoxometalates

The possibility of changing the hydrophilic (polar) surfaces of toroid nanocluster polyoxomolibdates to hydrophobic (nonpolar) surfaces via the modification of Mo138 nanoclusters by surfactant molecules (dodecylpyridinium chloride) as a result of the interaction between these compounds in solutions is demonstrated. Benzene and methanol are used as molecular probes (indicators of the condition of nanocluster surfaces). Comparative characteristics of the equilibrium sorption of benzene and methanol vapors on the initial and modified surfaces of the solid polyoxometalate, and data on the sorption of organic molecules on the surfaces of Rhodamine B-modified nanoclusters of the toroid (Mo138) and keplerate (Mo132) types are obtained.

Features of thermophotoinitiated degradation of nanocluster polyoxomolybdate Mo132 and its polymer-containing composites

An EPR spectroscopy study was made into the simultaneous effect of intense degradation factors (UV radiation, elevated temperature) on nanocluster porous polyoxomolybdate Mo132 of the Keplerate type in the solid state and also into the behavior of film composites including water-soluble nonionogenic polymers (polyvinylpyrrolidone, polyethylene glycol) under the action of these factors. The effect of mutual stabilization of polyoxometalate and polymer components in the studied composites was detected.

Iontophoretic transport of associates based on porous Keplerate-type cluster polyoxometalate Mo 72 Fe 30 and containing biologically active substances

The possibility of iontophoretic transport through the native membranes of biologically active substances (vitamin B1 and insulin) associated with porous clusters Mo72Fe30 polyoxometalate of the Keplerate type is demonstrated for the first time in an experimental setup. The diffusion coefficient is estimated. The possibility of transferring Keplerate ions with a protective coating of biocompatible polymer polyvinylpyrrolidone is also shown.

Enthalpy of mixing of porous nanocluster polyoxometalates of keplerate-type Mo 72 Fe 30 with polyvinyl alcohol and polyethylene glycol

The interaction between porous spherical nanocluster polyoxometalate and water-soluble nonionic polymers (polyvinyl alcohol and polyethylene glycol) in the compositions of film is studied via calorimetry. The concentration dependences of the enthalpies of these processes are obtained using calculations based on the thermodynamic cycle.

Influence of iron-molybdenum nanocluster polyoxometalates on the apoptosis of blood leukocytes and the level of heat-shock proteins in the cells of thymus and spleen in rats

We have studied the influence of iron-molybdenum nanocluster polyoxometalates on the organism of animals (rats) in order to determine the correlation between the exposure and changes at the cellular level in the blood and immune system. Single and repeated administrations of polyoxometalates lead to an increase in the amount of cells containing heat-shock proteins (HSPs) HSP60 and HSP70 not only in the spleen but also in the thymus, despite the blood–thymus barrier. The enhancement of both early and late apoptosis in leukocytes after the administration of 30 doses of polyoxometalates may result from the disruption of homeostasis in immunopoietic organs. No changes in the blood parameters indicative of inflammatory process or anemia are observed at any exposure. The increased level of HSPs in the cells of thymus and spleen and the absence of changes indicative of inflammation in the blood leucocytes, apparently, support the viability of cells in studied organs, since no morphological disruptions are found in the thymus and the spleen.

Effect of Silver Nanoparticles on the Sorption Characteristics of La 1 − x Ag x MnO 3 ± y

The effect silver nanoparticles have on the sorption characteristics of perovskite lanthanum manganite relative to methanol, benzene, and hexane vapors is studied by means of gravimetric equilibrium interval sorption. The state of silver particles is investigated using spectroscopic tools. Sorption data are compared to the catalytic activity in deep oxidation reactions of organic compounds over lanthanum manganite-based catalysts.