Том 13, № 7-8 (2018)

This paper describes a method for synthesizing single-wall carbon nanotubes (SWCNTs) and preparing a functional enzyme-carbon nanotube complex possessing antioxidant properties via the immobilization of superoxide dismutase on SWCNTs. spectrophotometry has shown that the inhibition of adrenochrome formation was accelerated by an increased added concentration of this enzyme-carbon nanotube complex. This indicates the successful immobilization of superoxide dismutase and functional activity of the superoxide dismutase (SOD)–SWCNT complex, which can be used in nanomedicine for delivering active SOD to tissues and cells.

The structure of nanocomposites based on opal matrices with different types of filling of structural voids is investigated. It is shown that the order in which tetrahedral and octahedral voids in the opal matrix are filled with various substances affects the X-ray diffraction pattern in the small angle region. On the basis of neutron diffraction, small angle X-ray scattering, and transmission electron microscopy data, models are proposed for filling the voids. The structural parameters of ordered nanocomposites based on opal matrices of different compositions are determined.

In this work, the relations between the parameters of the structure of epoxy nanodisperions and nanocomposites and a complex of physicomechanical properties of epoxynanocomposites upon the distribution of nanoparticles on nano- and microlevels are established. It is shown that the morphology of epoxy nanocomposites and the size of agglomerates in an epoxy oligomer are almost unchanged during hardening upon the transition of a binder from liquid to solid state (matrix) both on the nanolevel (to ~100 nm) and on the microlevel (to ~390 nm). It is found for the first time that the optimal physicochemical properties are achieved for nanodispersions and nanocomposites only upon the formation of agglomerates of nanoparticles 150–200 nm in size in the structure of epoxynanocomposites.

Conjugates of gold nanoparticles with two isolated tularemia microbe antigens, a protective antigen complex and a glycosylated protein complex, are used to obtain anti-tularemia sera and to vaccinate animals. A conjugate of gold nanoparticles with the glycosylated protein complex during the subcutaneous immunization of mice is more effective than the unconjugated antigen, which is evident from the increase in protectiveness and antibody titers. The use of conjugates of both antigens with gold nanoparticles during the immunization of rabbits makes it possible to obtain sera with a high titer of specific antibodies (1/64–1/128 titer in the diffusion precipitation reaction and 1/5120–1/10240 in the reaction of indirect hemagglutination) during a relatively short period of time and with minimal antigen consumption (1.8–10 mg). The use of immunoglobulins extracted from sera during the enzyme-linked immunosorbent assay makes it possible to detect Francisella tularensis cells of different subspecies in the amount of (5.2 ± 0.5) × 10⁵ MC/mL with 100% specificity for heterologous strains at a concentration of 10⁸ MC/mL, which enables their subsequent application in the production of preparations for the diagnostics of tularemia.

The strong dependence of cytotoxicity of Keggin heteropoly acids [XM₁₂O₄₀]^n–, X = Si or P, M = Mo and W, n = 3 or 4 on chemical composition is demonstrated using the example of human embryo fibroblast cells based on the results of diagnostics using impedance monitoring, scanning electron microscopy, and measurements of visible cell sizes. The explanation of this dependence based on the role of hydrolytic stability of multiply charged anions in the development of cytotoxicity of these compounds is suggested. The results make it possible to suggest a new mechanism for the development of selectivity of polyoxometalate cytotoxicity relative to the studied cells. The differentiated cytotoxic activity of polyoxometalates relative to oncogenic cells is predicted.

A mathematical model describing optical nanosensors, the principle of action of which is based on an increase in the hydrodynamic diameters of functionalized nanoparticles (conjugates) under the influence of an analyte, is constructed. The formation of shells from analyte molecules around conjugates and the aggregation of conjugates to dimers at the expense of “bridges” represented by analyte molecules are considered. Antibodies capable of association with antibody footprints (epitopes) on analyte molecules are considered receptors, which are used for the functionalization of nanoparticles. The input parameters of the model are the sizes and concentrations of conjugates, kinetic constants of association and dissociation of receptors with epitopes, number of receptors per conjugate, and the concentration of the analyte. The model makes it possible to estimate the ranges of defined concentrations, as well as detect the limits during the development of nanosensors for specific analytes and optimizing parameters of these sensors, including the required incubation time for a mixture of conjugates with an analyte.

The possibility of obtaining direct Pickering emulsions by means of self-organization on the oil/water interface of commercial titanium dioxide by the structure modification of rutile and anatase is studied. The stability of emulsion to coalescence is estimated microscopically. The surface properties of hydrophilic anatase nanoparticles are investigated to develop a way to partially hydrophobize their surface with molecules of n-octadecylphosphonic acid. The conditions of modifying titanium dioxide nanoparticles are chosen for the formation of stable Pickering emulsion.

Complexes of spherical gold nanoparticles with antibodies, obtained by direct adsorption and indirect (nanoparticle–anti-species antibody–specific antibody) interaction, were studied. The binding processes for nanoparticle-labeled antibodies in immunochromatographic analysis (ICA) and competitive detection of low molecular weight analytes are considered. Based on the developed mathematical model, the advantages of indirect labeling of antibodies are shown; the parameters determining the gain in the detection limit between two kinds of systems are characterized. The obtained complexes of gold nanoparticles with antibodies were used for the development of ICA for antibiotics. The reached detection limit of ampicillin ICA is 100 ng/mL for direct labeling and 16 ng/mL for indirect; in the case of tetracycline, these values are equal to 4.2 and 1.3 ng/mL, respectively.

The aim of this work is to study the possibility of removing antimicrobial peptides arenicin-1 and tachyplesin-1 from aqueous solutions using new highly hydrophobic nanomaterials—carbon nanotubes (CNTs) Taunit-M. Two types of CNTs, respectively, functionalized and nonfunctionalized with–COOH groups are studied. The RP HPLC method is used for the quantification of peptides in solutions before and after the sorption on the CNTs. It is revealed that tachyplesin-1 and arenicin-1 are actually not adsorbed on nonfunctionalized CNTs. A theoretical calculation of specific hydrophobicity and aliphatic index shows that both peptides have poorly expressed hydrophobic properties, and this can explain lack of their adsorption. On the contrary, using functionalized CNTs makes it possible to remove up to 89% of arenicin-1 and 92% of tachyplesin-1 from the solution. A comparative study of adsorption of the antimicrobial peptide tachyplesin- 1 on nonfunctionalized activated carbons and functionalized CNTs shows that the amount of peptide adsorbed on activated carbons is about three times less than that absorbed on CNTs. It is assumed that the high adsorption capacity of the functionalized CNTs toward the studied peptides results from the functionalization of the sorbent surface with the–COOH groups capable of forming ionic bonds with free–NH₂ groups of peptides. This shows the prospects for using functionalized CNTs as sorbents for the removal of toxic preparations of peptide origin from aqueous solutions.