Nanotechnologies in Russia最新文献

An original method is developed for producing organic-based graphene ink by the micromechanical exfoliation of graphite in 1-methyl-2-pyrrolidone (NMP), followed by the isolation of graphene particles by changing the solvent and stabilization with ethylcellulose. It is shown that the yield of graphene particles by micromechanical exfoliation in NMP is more than 2 times higher than the same parameter when using dimethylformamide (DMF) as a solvent. Organic-based graphene inks can be used as antibacterial and anti-corrosion coatings with high adhesion and low imperfection. The studies show the high bactericidal efficiency of graphene ink, which amounts to 98.1–99.9% using the example of Pseudomonas aeruginosa and Staphylococcus epidermidis. At the same time, for the developed ink, the reduction in contamination is 2–3 orders of magnitude, which characterizes the developed composite as an effective antibacterial agent.

It is shown that the viscosity of lamellar liquid crystals in the system lecithin–avocado oil–tea tree oil–water in the shear rate range of 0.01–1.0 s^–1 increases with increasing CuO concentration from 0.01 to 0.3 wt % when introduced as spherical nanoparticles with a diameter of 92 ± 3 nm and submicron cylindrical particles with a diameter of 151 ± 9 nm and a length of 268 ± 36 nm, while the shape of the flow curves does not change. The range of changes in the viscosity (compared to the sample without particles) at temperatures of 25 and 37°С is from 1.1 to 2.1 times for spherical nanoparticles and from 1.6 to 2.9 times for submicron cylindrical nanoparticles. When introducing spherical Al₂O₃ nanoparticles with an average diameter of 84 ± 32 nm and needle-shaped ZnO nanoparticles (diameter 37 ± 6 nm and length 302 ± 77 nm), similar results are obtained: the viscosity increased by 1.1–2.0 times compared to the sample without nanoparticles. In contrast to nanoparticles, the introduction of CuO microparticles (diameter 31.2 ± 3.6 μm) has virtually no effect on the viscosity of the composition.

The concept of “3Rs” (refinement, reduction, and replacement) has become widespread in toxicological studies. 3D cell models are a further development of traditional 2D models. In the current study, 3D models of the human respiratory system consisting of BEAS-2B bronchial epithelial cells and MRC5-SV40 lung fibroblasts are developed. The results of studying the toxicity of carbon nanotubes (CNTs) using advanced 3D models demonstrate the absence of proapoptotic and profibrogenic effects at concentrations corresponding to the reference exposure level. However, starting at a CNT concentration of 20 μg/mL, well above concentrations corresponding to the reference exposure level, signs of oxidative stress are detected in the cell models. 3D cell models can be recommended as a more objective screening method for assessing the toxicity of CNTs when moving from traditional in vitro experiments to in vivo studies.

In order to create new high efficient anticancer drugs for photodynamic therapy (PDT) the triple complexes on the basis of the zero-valent selenium (Se⁰) nanoparticles, graft copolymer (Cell-graft-PMAA) and photosensitizer-fotoditazin (FD) with various priority of introduction of the components have been synthesized and studied. The comparative studies of the spectral and morphological characteristics of the triple complexes (Cell-graft-PMAA/SeNPs) (the 1st method) and (Cell-graft-PMAA/FD/SeNPs) (the 2nd method) with the similar characteristics of FD and double complexes of the variable composition (SeNPs/Cell-graft-PMAA, SeNPs/FD and Cell-graft-PMAA/FD) were carried out by means of UV/IR spectroscopy, luminescence and atomic force microscopy. By means of the UV spectroscopy it was demonstrated that the value of the optical density in the range of PDT wavelength (Q-range) is higher in the triple systems by 30–40% compared to free FD and luminescence intensity in the Q-range for these nanosystems is in excess of 6 times compared to the intensity for FD.

The adhesion, proliferation, differentiation, and other types of interaction of a cell culture with synthetic biocompatible matrices completely depend on the type of cells, as well as on the structure, filling, and surface of the matrix itself. The results of studying the proliferation of HEK293T cells on polylactide matrices of various architectures are presented. An estimate of the rate of cell proliferation is obtained for oriented and nonoriented spongy and nonwoven fibrous matrices, as well as composite polylactide matrices with collagen and chitosan.

The features of resistive switching in memristors based on crystalline aluminum nitride with a wurtzite structure, grown under technology developed at the National Research Center “Kurchatov Institute” are studied.

The review covers the main stages in the development and achievements of surface-enhanced Raman scattering (SERS), the fiftieth anniversary of which we celebrate in 2024. Modern theoretical views on the SERS effect, a retrospective of the substrates and materials used, and expansion of the range of studied compounds and objects are presented. Using the example of the most important and interesting applications of SERS spectroscopy, the achievements of the last decade are considered; its role in modern surface chemistry, nanotechnology, bioanalysis and bioimaging methods is shown.

The development of miniature autonomous power sources for personal electronics and the Internet of things is one of the urgent tasks of modern science. A promising direction in this area is powering such devices by harvesting and converting the mechanical energy of the environment into electrical energy. This study investigates the ability of nitrogen-doped carbon nanotubes (N-CNTs) to convert and store mechanical energy into electrical energy to create piezoelectric nanogenerators. It is shown that N-CNTs under conditions of constant vibration noise generate a surface potential and a corresponding current of about 33 nA throughout the entire exposure time without a tendency to decrease in current value. It is established that a potential barrier is formed at the boundaries of the side wall of N-CNTs with bamboo-like bridges, which allows the storage of a piezoelectric charge induced during nanotube deformation. This fact opens up wide opportunities for creating a miniature power source based on N-CNTs, combining the possibility of converting and accumulating mechanical energy of the environment.

For the purpose of imaging hydrophilic drugs, aggregates of gentamicin and vinorelbine with carbocyanine dyes fluorescing in the near-infrared region of the spectrum and a laurate ion as a counterion are obtained. To isolate the aggregates, precipitation from an aqueous solution of components is used. The size of the aggregates with gentamicin range from 200 to 600 nm; with vinorelbine, from 400 to 1000 nm; the surface ζ potential varies in the range of –15…–5 mV. The aggregates are sorbed by the subcutaneous fatty tissue, muscle, bone, and endothelial tissues of chickens. In the future, the resulting aggregates can be used to visualize drug delivery to the tissues of living organisms.

Spherical GNPs of various sizes (10–30 nm), obtained by the reduction of chloroauric acid with ascorbic acid, are used to obtain conjugates with native and biotinylated antibodies (Ab, bAb). The process of the formation of nanoagglomerates of GNP-bAb conjugates with the participation of free streptavidin (Stvd) in a solution is studied in the range of stoichiometric ratios [Stvd] : [GNP] from 0 : 1 to 3200 : 1. Using the dynamic-light-scattering method, it is shown that at a 19–50-fold excess of free Stvd relative to GNPs in a solution, GNP-bAb conjugates form nanoagglomerates with an effective diameter 1.5–3 times larger than the size of the initial conjugate. The efficiency of the interaction of a detection reagent prepared from a GNP-bAb conjugate in the presence of various concentrations of free Stvd in a lateral flow with Stvd or bAb absorbed on a membrane is studied. It is shown that the color intensity of the reaction zones undergoes a significant change in the region of the ratio of the concentrations of GNP-bAb and Stvd, corresponding to the formation of nanoagglomerates, and depends on the composition and size of the resulting complex and the presence in its composition of Stvd molecules or biotin residues available for binding with the absorbed component. On the basis of mathematical modeling of the proposed kinetic mechanism for the formation of GNP complexes with the participation of biotin-streptavidin interaction, the predominant formation of nanoagglomerates consisting of two or three GNPs linked by Stvd molecules is shown. The use of such nanoagglomerates as a label in a lateral immunoassay can lead to a several-fold reduction in the detection limit of the assay.