Nanotechnologies in Russia最新文献

Aptamers, short oligonucleotides, are capable of high-affinity binding to targets due to their unique structure. Shortening the aptamer while maintaining the active site will increase the affinity and reduce the cost of synthesis. Using the example of the aptamer LC-224, a method for rational optimization of its length and verification of the validity of the developed approach is tested. The use of computer modeling and small-angle X‑ray scattering shows the possibility of optimizing the aptamer structure by removing nucleotides that do not participate in binding to the target. It is shown that truncation of the aptamer does not reduce the affinity and specificity of the DNA aptamer. Thus, theoretical and experimental studies demonstrate successful experience in optimizing the structure of a DNA aptamer by shortening it without compromising its affinity and specificity for its target.

Abstract

Using a small oscillating load (continuous stiffness measurement, CSM), in addition to the main quasi-static load, we determine the hardness, Young’s modulus, storage and loss moduli, mechanical loss coefficient ((tan delta )), and the plasticity characteristics in various components of the nanostructure and microstructure of pine (Pinus sylvestris) and spruce (Picea abies) wood. The contribution of structures of different scales to the ratio of the viscoelastic properties of early and late wood in the composition of one annual ring is determined. The plasticity characteristic δ_А is determined, and the influence of an additional oscillating load on the dynamic parameters of wood is assessed.

Abstract

The aim of the work is to evaluate the effect of gold nanoparticles with a surface modified with fucose (Au-Fuc), lactose (Au-Lac), and galactose (Au-Gal) residues on the functional activity and expression of the transporter protein P-glycoprotein (Pgp). The work is performed using Caco-2 and HEK293 cells, which are incubated for 2 and 8 h with solutions of Au-Fuc, Au-Lac, and Au-Gal in a nutrient medium (450 and 300 µg/mL, 700 and 490 µg/mL, and 400 and 250 μg/mL, respectively). The amount of Pgp on the membranes of the Caco-2 cells is determined by the western blot method. The Pgp activity is assessed by the accumulation of fexofenadine Fex (150 µM) in cells by high-performance liquid chromatography (HPLC) with mass detection. Au-Fuc and Au-Gal do not change the amount of Pgp; Au-Lac increases the transporter level by 1.9 and 1.8 times upon 2 and 8 h of incubation respectively. Au-Fuc, Au-Lac, and Au-Gal increase the Pgp content in cells upon 8 h of incubation by 2.6, 3.5, and 5.3 times, which indicates a decrease in Pgp activity. When particles are incubated with HEK293 cells, no increase in the Fex levels are detected, which indicates the absence of a nonspecific increase in membrane permeability. Thus, the tested gold nanoparticles reduce the functional activity of Pgp in vitro.

Abstract

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.

Abstract

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.

Abstract

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.

Abstract

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.

Abstract

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.

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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.

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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.