[Superparamagnetic Cobalt Ferrite Nanoparticles "Blow up" Spatial Ordering of Double-stranded DNA Molecules].

The formation of cholesteric liquid-crystalline dispersions formed by double-stranded DNA molecules, handled by positively charged superparamagnetic cobalt ferrite nanoparticles, as well as action of these nanoparticles on DNA dispersion, are considered. The binding of magnetic nanoparticles to the linear double-stranded DNA in solution of high ionic strength (0.3 M NaCl) and subsequent phase exclusion of these complexes from polyethylene glycol-containing solutions lead to their inability to form dispersions, whose particles do possess the spatially twisted arrangement of neighboring double-stranded DNA molecules. The action of magnetic nanoparticles on DNA dispersion (one magnetic nanoparticle per one double-stranded DNA molecule) results in such "perturbation" of DNA structure at sites of magnetic nanoparticles binding that the regular spatial structure of DNA dispersion particles "blows up"; this process is accompanied by disappearance of both abnormal optical activity and characteristic Bragg maximum on the small-angle X-ray scattering curve. Allowing with the fact that the physicochemical properties of the DNA liquid-crystalline dispersion particles reflect features of spatial organization of these molecules in chromosomes of primitive organisms, it is possible, that the found effect can have the relevant biological consequences.

Magnetofection of human somatic cells with magnetite and cobalt ferrospinel nanoparticles.

Superparamagnetic nanoparticles varying by their chemical composition and synthesis method were used to transfer DNA into somatic cells under the influence of constant magnetic field (method of magnetofection). Magnetite particles obtained by mechanochemical synthesis ensured higher expression of the marker gene GFP (evaluated by fluorescence intensity of the cell lysate) then particles of ferric oxide obtained by chemical co-precipitation and cobalt ferrospinel particles obtained by the mechanochemical method.

Contractile reactions of guinea pig airway smooth muscles in the presence of stannum oxide nanosized particles.

Contractile reactions of the guinea pig airway smooth muscles in the presence of stannum dioxide nanosized particles were studied. Contractile reactions to cholinergic and histaminergic stimulation were potentiated by inhalations of nanoparticle aerosol and by exposure of isolated smooth muscle segments to nanoparticle suspension.

[Influence of nanosize particles of cobalt ferrite on contractile responses of smooth muscle segment of airways].

Contractile responses of airways segments of porpoises inhaling nanopowder CoFe2O4 were stidued by means of a mechanographic method. Inhalation of the nanosize particles of CoFe2O4 in vivo and in vitro testing the nanomaterial on isolated smooth muscles led to potentiation histaminergic, cholinergic contractile activity in airways of porpoises and to strengthening of adrenergic relaxing answers. Nanosize particles vary amplitude of hyperpotassium reductions in smooth muscle segments of airways similarly to the effect of depolymerizing drug colchicine.

Study of DNA interaction with cobalt ferrite nanoparticles.

Interaction of cobalt ferrite nanopowder and nucleic acid was investigated. Superparamagnetic cobalt ferrite nanoparticles (6-12 nm) were prepared by mechanochemical synthesis. Structure of the nanopowder was characterized using X-ray diffraction. It was shown that cobalt ferrite nanoparticles were associated with ssDNA and dsDNA in Tris-buffer resulting in bionanocomposite formation with mass weight relation nanoparticles: DNA 1:(0.083 +/- 0.003) and 1:(0.075 +/- 0.003) respectively. The mechanism of interaction between a DNA and cobalt ferrite nanoparticles was considered basing on the whole set of obtained data: FTIR-spectroscopy, analyzing desorption of DNA from the surface of the particles while changing the chemical content of the medium, and on the modeling interaction of specific biomolecule fragments with surface of a inorganic material. It was supposed that the linkage was based on coordination interaction of the phosphate groups and oxygen atoms heterocyclic bases of DNA with metal ions on the particle surface. These data can be used to design specific magnetic DNA-nanoparticles hybrid structures.

Effect of nanodisperse ferrite cobalt (CoFe2O4) particles on contractile reactions in guinea pigs airways.

The effect of nanopowder CoFe(2)O(4)on contractile responses of smooth-muscle segments of guinea pigs airways was studied by mechanography. Both in vivo inhalation of nanopowder aerosol or in vitro application of nanopowder to isolated airway segments increased the amplitude of contractile responses to histamine and potentiated the dilatory reaction to adrenergic salbutamol.

Colony-forming activity of unipotent hemopoietic precursors under the effect of nanosized ferrites in a constant magnetic field in vitro.

We studied in vitro effect of ferrimagnetic nanoparticles in a dose of 3 mg/liter (10 maximum permissible concentrations) on colony-forming capacity of bone marrow granulocytic and monocytic precursors in a constant magnetic field at magnetic field intensity of 200 Oe. We tested powders obtained by the methods of electrical explosion of conductors (magnetite and a mixture of hematite with magnetite) or mechanochemical synthesis (cobalt ferrite). According to electron microscopy, size of particles was within 6-65 nm. Specific effect of nanopowders on functional properties of hemopoietic and stromal cells were demonstrated; this effect was not related to dissolution of these powders, but had a complex nature. It depends on the size and magnetic characteristics of powder particles, the route and dose of administration, and the presence of external magnetic field. It was emphasized that in multicellular systems a reaction of committed hemopoietic precursors mediated via cells (factors) of microenvironment cannot be excluded, the state of this system varying in different individuals and under different conditions. Our data open new vistas for the creation and targeted use of nanosized materials and technologies for individual therapy in the context of personalized medicine.

[Biochemical plasma parameters in rats during intravenous injection of magnetite nanopowder].

Nanotechnology is now recognized as a priority area of researches. Despite its rapid development, the literature contains a paucity of evidence for the effect of nanoparticles on the biochemical plasma parameters of experimental animals. This paper determines the biochemical parameters reflecting the functional state of the rat vital organs. Intravenous administration of a standardized Fe3O4 nanopowder solution has shown reversible changes in the biochemical parameter of plasma.