Nanotechnologies in Russia最新文献

Silver nanoprisms are promising agents for both diagnostic and therapeutic applications in photoinduced hyperthermia of tumors within the transparency window of biological tissues. However, one of the primary challenges in utilizing silver nanoparticles in biological systems is their instability in physiological environments. To address this issue, a comprehensive comparative analysis of various stabilizing coatings was conducted to develop an effective stabilization method for nanoprisms intended for biomedical applications. The results demonstrated that among the tested polymers, a sulfhydryl derivative of polyethylene glycol provided the most effective stabilization for the nanoprisms while preserving the localized surface plasmon resonance effect. Furthermore, the synthesized nanoprisms showed significant potential for biovisualization. Specifically, the technique of intravital optical tomography effectively visualized body tissues using fluorescently labeled nanoprisms. This advancement paves the way for the application of these colloid-stable nanoprisms as agents for bioimaging and photothermal therapy.

Parkinson’s disease is a chronic neurodegenerative disease that is based on mitochondrial dysfunction. One of the factors in the development of Parkinson’s disease is aggregation of the α-synuclein protein, which makes it a strong biomarker of the disease. α-Synuclein itself is a neuronal protein involved in dopamine transport, but its overexpression or mutations negatively affect cellular homeostasis. Since the disease is complex, identifying the role of mitochondrial dysfunction in its pathogenesis is an important task, and many different models are being developed to study the intracellular features of the disease. The use of yeast seems to be a promising strategy for studying pathologies of this kind. The effect of α-synuclein expression in Yarrowia lipolytica yeast on the mitochondrial morphology and sensitivity to oxidative stress induced by a prooxidant is considered. It is shown that α-synuclein expression leads to the fragmentation of yeast mitochondria and reduces the tolerance of yeast cells to induced oxidative stress.

Currently, technologies based on the use of electrode systems implanted in the head interacting with the human brain are under active development. Such systems are used both for stimulation of the brain in various diseases and as full-fledged neural interfaces. Electrodes in this case are one of the key elements, since they provide contact with the nervous tissue. Recently, considerable attention has been paid to polymer electrodes and, in particular, hydrogels due to the fact that they have mechanical properties close to body tissues and can carry various functional molecules. At the same time, the electrical conductivity of polymer electrodes is lower than that of metal or carbon materials. In this regard, this work provides an overview of publications in this area and notes the most promising trends. Also, based on the publications reviewed, it is noted that an important task for such electrodes remains their miniaturization. It is concluded that despite their shortcomings, electrodes based on polymer hydrogels are an extremely promising system for creating invasive neural interfaces.

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.

Polyvinylpyrrolidone (PVP) is a biocompatible and hemocompatible polymer that has found wide application in many fields, including in the production of toothpastes. Having some structural features similar to those of proteins, it has great potential for use in the medical field. PVP is not a biodegradable polymer, which is why its widespread use inevitably leads to the question of how the different molecular weight of the polymer, which depends on the synthesis conditions and molar mass, affects the environment. Phytotoxicity assessment can be used to systematically assess potential toxic reactions.

Nanodispersions based on silver nanoparticles (Ag⁰) are synthesized In the presence of polymer complexones (copolymers of N-vinylpyrrolidone (VP) with p-methacryloylaminobenzoic (MABA-Na) and p-methacryloylaminosalicylic acid (MASA-Na)). The spectral and morphological characteristics of the nano-dispersions are investigated using ultraviolet (UV) spectroscopy and atomic force microscopy (AFM); the minimum energy (E_g) of electron transfer from the valence band to the conduction band of the metal is estimated; and the influence of the nature of the chelate unit on the band gap E_g, as well as on the size of spherical nanoparticles is shown. The reduction of silver ions in water in the presence of copolymers VP-MABA-Na and VP-MASA-Na, due to fairly good screening, makes it possible to obtain spherical nanostructures with a diameter not exceeding 200 nm. In the case of Ag⁰/VP-MASA-Na, massive dense oval-shaped aggregates are formed, which consist of small densely packed nanostructures. The silver-containing dispersions Ag⁰/VPрMABA-Na and Ag⁰/VP-MASA-Na tested against E. coli, P. aeruginosa, and S. aureus bacteria show pronounced antimicrobial activity, significantly superior to the activity of the reference drug, Protargol.

The structure of rat-heart mitochondria and mitochondrial membrane preparations is studied using cryoelectron tomography. It is found that pseudocrystalline clusters formed by densely packed proteins exist between the inner and outer membranes. Using subtomogram averaging, the structure of these clusters is obtained and it is shown that they are formed by tens or even hundreds of densely packed octamers of mitochondrial creatine kinases (mCK). In intact mitochondria, mCK octamers form a single membrane-parallel layer in which they are tightly coupled to the outer and inner membranes, as well as to each other. On membrane fragments in which there is no compression of the intermembrane space, the supramolecular mCK clusters are organized differently: they form two layers in which there are fewer contacts with the membrane, but more protein–protein contacts. In addition, bilayer clusters generally lack curvature and are larger in size, which is indicative of their increased rigidity and possible role in stabilizing the membrane when it is damaged. The obtained results are discussed in the context of previously known data on the functional role, structure, and location of creatine kinases in mitochondria.

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.