s. V. Valueva

Russian Academy of Sciences | RAS · IMC

Amphiphilic molecular brushes, i.e. graft copolymers (graft-CP), with a hydrophobic polyimide main chain and hydrophilic side chains of polymethacrylic acid at a high degree of polymerization m of the side chains and their grafting density, can be used as nanocontainers for the targeted delivery of drugs/agents. In this work, silver nanoparticles (...

Selenium (Se0) nanoparticles are stabilized with water-soluble polymers containing ionogenic groups of the different signs, namely, poly(N,N,N-trimethylammonium)ethyl methacrylate iodide (polycation) and sodium polystyrenesulfonate (polyanion). A comprehensive comparative study of the resulting selenium-containing nanodispersions by the UV–visible...

The morphology, optical, and molecular-conformation characteristics of amphiphilic molecular brushes with a polyimide main chain and poly(methacrylic)acid acid side chains loaded with the second-generation photosensitizer Radachlorine ® or a biogenic element (selenium in the zero-valence form Se 0) nanoparticles are studied using atomic force micro...

The optical and morphological characteristics of polymer molecular brushes with the polyimide backbone and polymethacrylic acid side chains, and also of binary nanosystems based on the molecular brushes and Radachlorine®, a photosensitizer of second generation, were studied. The brushes had the same backbone and approximately equal molecular mass o...

An original method for the synthesis of copper-containing nanosystems for biomedical applications using hydrazine hydrate as a reducing agent, intermediate stage of formation of complex ion [Cu(NH3)4]2+, which allows to obtain Cu0 nanoparticles without impurities of oxides has been developed. As a macromolecular hydrophilic stabilizer copolymer of...

Atomic-force (AFM) and transmission electron microscopy (TEM) were used for determination of the morphological and dimensional characteristics of hybrid polymer nanosystems (HPNS) based on nanoparticles (NPs) of zero-valent selenium and zero-valent silver stabilized by zosterin and methylcellulose (MC). The possibility of controlling the morphologi...

An original method for the synthesis of copper-containing nanosystems for biomedical applications using hydrazine hydrate as a reducing agent was developed. The process involves intermediate formation of the [Cu(NH3)4]²⁺ complex ion, which ensures the formation of Cu⁰ nanoparticles without oxide impurity. The 2-deoxy-2-methacrylamido-D-glucose copo...

The morphological, dimensional, and spectral characteristics of hybrid polymeric nanosystems based on nanoparticles of zero-valent selenium and silver stabilized with zosterin and methylcellulose are determined by methods of atomic-force microscopy, dynamic light scattering, and UV-vis spectroscopy. The possibility of changing the morphological par...

The molecular conformation and spectroscopic and kinetic characteristics of hybrid selenium-containing nanosystems based on different kinds of biocompatible polymer stabilizers are determined via UV spectroscopy, static/dynamic light scattering, and flow birefringence at a Se⁰ : polymer weight ratio of ν = 0.1. It is shown that the structure of pol...

The sizes and spectral characteristics of hybrid nanosystems (HNSes) based on zero-valent silver or selenium nanoparticles (NPs) stabilized with different biocompatible polymer stabilizers (BPSes) (cationic polyelectrolyte (poly-N,N,N,N-trimethylmethacryloyloxyethylammonium methyl sulfate), methyl cellulose, Zosterine, and polyvinylpyrrolidone) are...

The morphology, structure, and optical properties of polymeric compositions based on a natural sorbent Zosterin, methyl cellulose (MC), and a Poviargol (silver-containing preparation) are studied via atomic force microscopy (AFM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and X-ray diffraction (XRD). AFM studies show s...

The molecular-conformal, morphological, and kinetic characteristics of selenium-containing nanosystems (NSs) based of biocompatible polymer matrices of different origins modified Se⁰ nanoparticles for the Se⁰ : polymer mass ratio ν = 0.1 have been analyzed using static and dynamic light scattering methods, UV spectroscopy, flow birefringence, and a...

Morphological and spectral characteristics of hybrid nanosystems (NSes) based on mono- and bimetallic silver and platinum nanoparticles (NPs) stabilized by a cationic polyelectrolyte (CP), poly-N,N,N,N-trimethylmethacryloyloxyethylammonium methylsulfate, are determined via static/dynamic light scattering, UV spectroscopy, and atomic force microscop...

Nanosystems based on zero-valent selenium and biocompatible polymer stabilizers (polyvinylpyrrolidone with molecular weight (MW) Мw = (10–55) × 10³, poly-N,N,N,N-trimethylacryloyloxyethylammonium methylsulfate with Мw = (30–250) × 10³ and polyethylene glycol with Мw = (1–40) × 10³) are studied by means of static and dynamic light scattering, and th...

The morphology and electrical properties of biogenic selenium-containing nanosystems based on polyelectrolyte complexes (PECs) were examined using AFM, Kelvin Probe Force and electron microscopy methods. It has been found, that prepared nanostructures significantly differed in their morphological types and parameters. In particular, multilayers cap...

Selenium-containing nanosystems based on biocompatible polymer stabilizers (PS) polyvinylpyrrolidone (M w = (10–55) × 103) and poly-N,N,N,N-trimethylmethacryloyloxyethylammonium methyl sulfate (M w = (30–13 000) × 103) are studied by means of light scattering and UV spectrophotometry in the range of the saturated adsorption capacity of selenium nan...

The kinetic, structural, and morphological studies showed that the composition of polyelectrolyte complexes (PECs) and the selenium/PEC mass ratio affected the formation of biogenic selenium-containing nanosystems and their structural and morphological properties.

The use of a photodynamic therapy (PDT) is hampered in some cases by the inability to create a sufficient concentration of photosensitizer (PS) in a tumor or the inability to deliver effectively laser radiation in some localization of malignant neoplasms. A number of nosological forms of the primary tumor and its metastases (in brain, peripheral pa...

The structure and morphology of hybrid nanosystems based on selenium and zinc-selenide nano-particles stabilized by water-soluble polymers—polyvinylpyrrolidone and polymethacrylic acid, are studied by methods of atomic force microscopy (AFM), high-resolution electron microscopy, transmission and scanning electron microscopy (TEM and SEM), X-ray pho...

Water-soluble polymers poly- N-methacryloyloxyethyl- N,N,N-trimethylammonium methyl sulfate and poly(methacrylic acid) are found on the basis of spectral, thermophysical, structural, and morphological studies to form stable complexes with Photodithazine photosensitizer.

The structural-morphological parameters of hybrid nanosystems, which are promising as photosensitizers (PS) for photodynamic therapy (PDT), are comparatively studied by atomic force microscopy (AFM), ultraviolet (UV) spectroscopy, photoluminescence (PL) and dynamic light scattering. The nanosystems are nanoparticles of zinc selenide (ZnSe) prepared...

В работе проводится анализ экономических связей белорусско-российско-украинского приграничья (БРУП) в контексте интеграционных процессов в рамках СНГ и ТС/ЕЭП. Дается комплексная оценка потенциала приграничного сотрудничества. Исследуются приграничные торговые, производственные, инвестиционные и миграционные связи, рассматривается взаимодействие ре...

Selenium-containing biogenic nanosized systems based on polymer stabilizers (PSts) of different natures are obtained. A comparative investigation of the kinetic parameters of self-organization and the dimensional characteristics of forming nanostructures and their shapes is performed by means of light scattering, UV spectrophotometry, atomic force...

Morphological characteristics and electronic structures of platinum-containing nanosystems obtained during a redox reaction in water medium at different concentrations of a stabilizing polymer and platinum were studied by atomic-force microscopy (AFM), X-ray photoelectron spectroscopy, and dynamic light scattering. It was shown that individual and...

Selenium-containing nanosystems based on nonionic polymers (polyvinylpyrrolidone, oxyethyl cellulose), a cationic polyelectrolyte (poly-N,N,N,N-trimethylmethacryloyloxyethylammonium methyl sulfate), and anionic polyelectrolytes (poly-2-acrylamido-2-methylpropanesulfonic and polymethacrylic acids) were studied.

The size characteristics and formation kinetics of selenium-containing nanosystems based on various polymeric matrices (nonionic polymers: polyvinylpyrrolidone, oxyethylated cellulose; cationic polyelectrolyte: poly-N,N,N,N-trimethylmethacryloyloxyethylammonium methyl sulfate; anionic polyelectrolytes: poly-2-acrylamido-2-methylpropanesulfonic acid...

Comparative studies of the morphological characteristics of selenium- and platinum-containing nanostructures were performed by molecular optics methods. The nanostructures were based on an ionogenic polymeric stabilizer, poly-N,N,N,N-trimethylmethacryloyloxyethylammonium methyl sulfate, and a non-ionogenic polymeric stabilizer, oxyethylcellulose. S...

The morphology and thermodynamic characteristics of nanostructures formed as a result of the reduction of the selenium ion in a selenite-ascorbate redox system in water solutions of polymethacrylic acid were studied by molecular optics and atomic-force microscopy. The dependence of the morphology of the selenium-containing nanostructures on the mas...

Selenium-containing nanostructures of rigid-chain polymers with close molecular masses were studied by flow birefringence (FB) and static and dynamic light scattering at a fixed selenium to polymer mass ratio ν = 0.1 in solution. The group of polymers under study included the cationic polyelectrolyte poly-N,N,N,N-trimethylmethacryloyloxyethylammoni...

The formation of DNA complexes with polycations of different structure (homopolymers: N,N-dimethylaminoethyl and methylsulfate salt of N,N,N-trimethylaminoethylmethacrylate, along with a copolymer of N,N-dimethylaminoethyl methacrylate with N-methacryloylaminoglucose) in water-salt solutions, was studied by the method of static and dynamic light sc...

Macroinitiators containing β-diketonate fragments were prepared by copolymerization of styrene with cobalt(II) 5-Formation and morphological characteristics of selenium-containing nanostructures formed by reduction of selenious acid with ascorbic acid in the presence of ionic or nonionic polymeric stabilizer in aqueous solutions were studied by met...

The Mark-Kuhn-Houwink relationship was obtained for solutions of poly-N-methacryloyloxy-ethyl-N,N,N-trimethylammonium methyl sulfate in 1 M NaNO3 from the light scattering and viscometric data. The Kuhn segment length for this polymer was estimated.

The systems show the adsorption of considerable numbers of hydroxyethylcellulose HEC macromolecules on selenium nanoparticles with the formation of a supermolecular close-packed nanostructure for form close to spherical. As the mass fraction of selenium in solution increases up to ν = 0.1, there is a considerable increase in Mw for the nanostructur...

Optical and spectral methods were used to study nanostructures formed in the reduction of ionic selenium in the selenite-ascorbate redox system in aqueous solutions of polyvinylpyrrolidone, a physiologically active polymer. The weight ratio between the selenium: polymer complex components (ν) was varied over a wide range (ν = 0.01−0.2). The adsorpt...

Several optical methods were used to study nanostructures formed in the reduction of selenium ions in the selenite-ascorbate redox system in an aqueous solution of the poly-N,N,N,N-trimethylmethacryloyloxyethylammonium methyl sulfate polycation. The relaxion between the molecular weight of the polymeric matrix, which varied over a wide range, M w =...

Nanostructures formed during the reduction of ionic selenium in the selenite-ascorbate redox system in an aqueous solution of bovine serum albumin (BSA) were studied using static and dynamic light scattering and flow birefringence. It was established that this process results in the formation of stable aggregates of selenium nanoparticles that adso...

The sorption and desorption of poly(vinylpyrrolidone)-Se0 (PVP-Se0) nanoparticles on gel films of cellulose Acetobacter xylinum (CAX) are investigated. It is revealed that the hydrodynamic radius R h of PVP-Se0 nanoparticles decreases from 57 nm in the initial solution (without CAX gel films) to 25 nm after the sorption of nanostructures on gel fi...

Nanostructures arising from the reduction of ionic selenium by a selenite-ascorbate redox system in aqueous solutions of oxyethyl cellulose, methyl cellulose, and carboxymethyl cellulose have been studied by using a set of optical methods (flow birefringence and static and dynamic light scattering) and viscometry. The adsorption of a substantial am...

Selenium nanoparticles were synthesized in aqueous solutions of polyelectrolyte complexes of sodium dodecyl sulfate, and the size and morphology of the forming nanostructures were determined.

The formation of zero-valence selenium nanoparticles through the reduction of selenious acid by ascorbic acid or mercaptoethanol in an aqueous solution of a random acrylic acid-N,N-(dimethylamino)ethyl methacrylate copolymer with M w = 20 × 106 was studied. Using the methods of molecular optics, it was first shown that this process yields nanostruc...

A new method of preparing hyperbranched poly (L-lysine) was developed. This method includes the catalytic removal of a N ε-carbobenzyloxy blocking group from N ε-carbobenzyloxy-L-lysine-N- carboxyanhydride by hydrogen in the presence of an activated palladium. Under similar conditions, hyperbranched poly(amino acids) containing residues of glutamic...

Nanostructures arising from reduction of ionic selenium by a redox system selenite-ascorbate in an aqueous solution of the polycation poly(N,N,N,N- trimethylmethacryloyloxyethylammonium methyl sulfate) were studied using a set of optical methods (static and dynamic light scattering and flow birefringence). It was shown that, within a wide range of...

Structuring processes that occur in dilute aqueous-saline solutions of poly(2-acrylamido-2-methylpropanesulfonic acid) on zero-valence selenium nanoparticles composites were studied by polarized light scattering in terms of the Debye-Stein theory. It was shown that the formation of these nanostructures in solution is accompanied by an increase in t...

A study was made of formation of selenium nanoparticles in water from reduction of sodium selenite with ascorbic acid in the presence of polyacrylic and polymethacrylic acids.

Nanostructures arising from the reduction of an ionic selenium in the presence of an anionic polyelectrolyte, poly(2-acrylamido-2-methylpropanesulfonic acid), and an anionic surfactant, sodium dodecyl sulfate, were studied for the first time using a set of optical methods (static and dynamic light scattering, polarized light scattering, flow birefr...

The nanostructures formed by reduction of Se(IV) in the selenite-ascorbate redox system in an aqueous solution of supermacromolecular polycation, poly[trimethyl(methacryloyloxyethyl)ammonium] methyl sulfate, were studied by static and dynamic optical scattering and flow birefringence.

Se nanoparticles were formed through the reduction of selenious acid with ascorbic acid without any polymer and in the presence of poly(vinylpyrrolidone) (PVP). The first system afforded a sol of Se with an initial hydrodynamic radius of particles of 170 nm that was instable to aggregation. When the synthesis was performed in a polymer solution, th...

Acryloylmorpholine homopolymers were synthesized by radiation-chemical and material polymerization. Light scattering and viscometry data were used to establish the relation between the intrinsic viscosity in DMF and the molecular mass of the polymer in water, which can be described by the Mark-Kuhn-Houvink equation [η] = 1.8 × 10 -2 M w0.67. The re...

Two previously unknown phenomena were observed in studying the reduction of selenious acid with ascorbic acid in an aqueous hydroxyethyl cellulose solution: (1) formation of nanoparticles of amorphous Se0 with uniform particle size distribution and mean particle radius of 15 4 nm and (2) adsorption of more than 3000 macromolecules on these nanopart...

Poly(vinylcaprolactam) and its copolymers with acrylic acid of various compositions exhibiting different molecular conformational characteristics were prepared by radiation-induced polymerization. The effect of the synthesis conditions on the characteristics of the resultant copolymers of N-vinylcaprolactam and special features of the conformationa...

Aqueous-salt semidilute solutions of a high-molecular-weight polyelectrolyte, poly-2-acrylamido-2-methylpropanesulfonic acid, were studied by flow birefringence and light scattering methods at varied ionic strength of the medium.

The flow birefringence and polarized light scattering techniques were applied to study semidilute water-salt solutions of a high-molecular-mass (Mw = 6 × 106) flexible-chain polyelectrolyte, the copolymer of 2-acrylamido-2-methylpropanesulfonic acid with acrylamide, at different ionic strengths of the medium (I = 1 and 0.1 mol/l). It was shown that...

Two procedures for synthesis of water-soluble poly-N-methacryloyloxyethyl-N,N,N-trimethylammonium methyl sulfate are compared. Synthesis occurred by the radical mechanism with the Co(III)-glycine system and with acid catalytic initiation. The effect of the initiator nature and the reaction conditions on the course of polymerization was studied.

Dilute aqueous-salt solutions of macromolecular flexible-chain polyelectrolyte, poly-2-acrylamido-2-methylpropanesulfonic acid, were studied by the method of flow birefringence, viscometry, and light scattering. The degrees of the form asymmetry p of poly-2-acrylamido-2-methylpropanesulfonic acid macromolecules determined by this method for ionic s...

Molecular-conformation properties of water-soluble polymers based on salts of dimethylaminoethyl methacrylate and 2-acrylamido-2-methylpropanesulfonic acid, prepared under conditions of radical initiation with the Co(III)-glycine redox system and with acid-catalytic initiation, were studied in comparison with those of the polymers based on salts of...

The aqueous-saline dilute solutions of high-molecular-mass flexible polyelectrolytes, salts of poly(2-methacryloyloxyethyltrimethyl ammonium) (M w = 9.6 × 10 6) and 2-acrylamido-2-methylpropanesulfonic acid copolymer with acrylamide (M w = 6 × 10 6) were studied by flow birefringence, viscometry, and light scattering. It was found that, in the regi...

The structural and molecular-conformational characteristics of water-soluble polymers based on ammonium salts of vinyl monomers produced by radical polymerization with the use of the redox system Co(III)-glycine and acid-catalytic initiation were studied. For the polymers studied the molecular-conformation parameters are analyzed in comparison with...

DNA interaction with cis-diaminodichloroplatinum (cis-DDP in solutions of different ionic strength was studied by flow birefringence, viscometry, circular dichroism. Though cis-DDP is not an electrolyte, electrostatic interactions are important for binding of cis-DDP with DNA probably for transporting cis-DDP to a macromolecule. The charges aqua-co...

Sodium poly(2-acrylamido-2-methylpropane sulfonate) (M=3.6×106) in aqueous solutions with a variable acetone content was examined using light scattering, flow birefringence, diffusion, and viscosimetry. As the weight fraction of acetone in solution increases, the macromolecules sustain a reversible transition from the random coil conformation to th...

A high-molecular-mass polyelectrolyte poly(dimethylaminoethyl methacrylate) with Mw=28×106 was examined in water-acetone solution with a varying weight fraction γ of acetone using dynamic birefringence, light scattering, and viscometry. Concentration dependences of reduced viscosity, reduced optical anisotropy, and Rayleigh light scattering were st...

Molecular characteristics (Mw, A2, 〈R2〉w1/2, Kunh segment A, [η]) of poly-2-acrylamide-2-methylpropane sulfonic acid and its copolymers with acrylamide in water-salt solutions have been studied by light scattering and viscometry methods. Viscosity was measured for various values of the ionic strength I and pH of the medium. Content of SO3- groups i...