Nanotechnologies in Russia最新文献

Biosensors have long been an integral part of analytical laboratory equipment. Some developments have already been commercialized and mass produced for field-test analysis. The best-known biosensors at the moment are those for glucose determination, which are both disposable and long lasting. The use of biosensors for the early diagnosis of diseases would bring medicine to a qualitatively new level, allowing for the more accurate detection of a disease and its individual stages, the adjustment of treatment, and the monitoring of various parameters and biochemical indicators of health in the process of both treatment and during sports training. New electrode modifications, the application of new nanomaterials, the development of new analysis schemes, and the miniaturization of signal processing devices significantly expands the analytical capabilities of the developed biosensors. This paper presents new directions in the development of biosensors for the determination of both traditional markers of the human physiological state (glucose, lactate, etc.) and infectious pathologies (viral, cancerous, etc. diseases), wearable and implantable devices, as well as combined devices for simultaneous diagnostics and drug delivery.

Novel polyurethane-based composite materials filled with silver sub-microparticles in different concentrations (1, 5, and 10 wt %) are produced. The properties of the initial and composite materials are studied by modern structural and physical–chemical methods. Significant differences in the electrical and mechanical properties of native polymer matrices with identical chemical composition are revealed. The quality of the filler distribution in the matrix is evaluated and the fractal structure of silver particle agglomerates in the polyurethane matrix is established. The effect of a conductive filler (silver) on the electrical characteristics (conductivity and permittivity) of the material is studied. Composite materials based on polyurethanes can be considered as promising for dielectric elastomer actuators in soft robotics, due to enhancement of the dielectric permittivity while maintaining the mechanical properties.

Unbranched polyamines perform a number of regulatory functions in the cell: they participate in the control of transcription and translation, modulate the activity of certain enzymes, and play an active role in maintaining calcium homeostasis. The intracellular level of polyamines is tightly regulated, and its alterations can lead to the development of a variety of pathologies. Thus, polyamines and their derivatives are both potential therapeutic agents and targets for therapy. In this work the effect of nonbranched polyamines with different structures on the energy parameters of rat-liver mitochondria is investigated. The effect of polyamines on the respiratory chain, their involvement in the activity of the nonspecific mitochondrial permeability transition pore, and their effect on ATP synthesis by mitochondria are shown.

Damage to skin and subsequent wound healing are complex multistage biological processes that are inextricably linked with almost any human activity. That is why the search for biodegradable, inexpensive, and accessible materials to create wound dressings that are effective in healing and biocompatible continues. This work shows the influence of the properties of porous materials based on chitosan on the processes of incorporation and release of C-phycocyanin (C-PC), which is obtained from the biomass of the cyanobacteria Arthrospira platensis in in vitro experiments. Thus, the entry efficiency of C-PC exceeds 90% for sponges obtained from both studied chitosans, but the profiles of the incorporation process curves differ significantly. Furthermore, the maximum load capacity is 171.75 ± 1.47 and 184.03 ± 3.64 mg/g for chitosan sponges with different degrees of deacetylation. Evaluation of the C-PC release from the porous matrix also reveals significant differences. Within 24 h, more than 80 and 65% of the loaded C-PC is released from the chitosan sponges, depending on the degree of deacetylation of the initial sponge material. As a result of the studies, it is established that by correctly selecting the characteristics of the initial chitosans, it is possible to optimize the process of C-PC release from porous wound dressings.

Hybrid electrically conductive materials were obtained by the synthesis of a polyaniline-based conductive layer on fibrous matrices. Nonconductive nonwoven fabrics with fibers 0.5–13.5 μm in diameter were produced by electrospinning from solutions and melts of a number of commodity polymers. The influence of the surface properties of the initial matrices on the polyaniline synthesis process and electrophysical characteristics of the hybrid conductive materials was studied. It was shown that for highly hydrophobic matrices synthesis of the conductive layer occurs only on the upper layers of fibers, which causes much lower conductivity (10^–4 S/cm and less) compared to wettable matrices, where synthesis occurs over the entire volume of the nonwoven fabric, and conductivity reaches 5 × 10^–2 S/cm.

A promising strategy for combating pathologies associated with oxidative stress is the use of mitochondria-targeted drugs. One of them is the positively charged tetrapeptide SS-20, which is able to penetrate into mitochondria. The effect of SS-20 on isolated supercoupled rat-liver mitochondria is studied. It is shown that SS-20 decreases hydrogen peroxide production, inhibits the opening of the nonspecific Ca²⁺/Pi-dependent mitochondrial pore, does not exhibit uncoupling activity, does not inhibit mitochondrial respiration, and does not reduce their membrane potential. In the aerobic yeast Dipodascus magnusii, SS-20 reduced the level of oxidative stress in yeast and prevented prooxidant-induced mitochondrial fragmentation.

Recording the activity of brain neurons opens up many possibilities for both diagnosing diseases and expanding human capabilities. Classic metal electrodes are inevitably rejected by nervous tissue due to their physical properties, and hence have a number of significant limitations in use. Hydrogels may be more suitable materials for this role, since they make it relatively easy to achieve the required properties by simply combining different polymers. This work presents an electrically conductive hydrogel based on poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS), carrageenan (CRG), and polyvinyl alcohol (PVA), which has already proven itself as a stable and biocompatible material. This series of experiments on C57Bl/6 mice demonstrates its feasibility as an electrocorticography electrode.

The results of determination of the static permittivity of individual red blood cells (RBCs) and their membranes by dc-electrostatic force microscopy are presented. This method is based on a quantitative analysis of the cross-sectional profiles of experimental electrostatic images. A model of electrostatic interaction between the cantilever tip and a biological cell of disk shape is proposed. The obtained permittivity of individual RBCs agrees well with published data. Calculation of the permittivity by the effective medium approximation for RBCs is performed for comparison with the mean value of the RBC permittivity of our model.

Selenium-containing nanoscale systems stabilized with alkyldimethylamine oxide are obtained. Based on computer quantum-chemical modeling, it is established that alkyldimethylamine oxide is the optimal stabilizer. During optimization of the synthesis technique, the optimal concentrations of the components are established: C (selenous acid) = 0.3536 mol/L, C (alkyldimethylamine oxide) = 0.0339 mol/L, C (ascorbic acid) = 0.0992 mol/L. This sample is examined using the transmission-electron-microscopy method. The stability of the sample is established in the concentration range of NaCl, BaCl₂, and FeCl₃ salts up to 0.5 mol/L, and Na₂SO₄ and K₃PO₄ salts up to 0.1 mol/L, as well as in the pH range from 8 to 12.

The biomass of phototrophic microorganisms (cyanobacteria and microalgae) is widely used in the food, feed, and pharmaceutical industries. Extracts from the biomass of microalgae and cyanobacteria, as well as various groups of compounds (lipids, peptides, polysaccharides, pigments, etc.) have a wide range of biological activity, which makes microalgae and cyanobacteria a very promising source of a wide variety of new bioactive molecules for inclusion in cosmetic formulations to combat the signs of aging, in sunscreens, bleaching agents, wound-healing preparations, etc. This review focuses on the use of phototrophic microorganisms in cosmetic products based on their biological activity.