Publications by authors named "Riabtseva A"

A key challenge in the development of forward osmosis (FO) technology is to identify a suitable draw solute that can generate a large osmotic pressure with favorable water flux while being easy to recover after the FO process with a minimum of energy expenditure. While the CO- and thermo-responsive linear poly(,-dimethylallylamine) polymer (l-PDMAAm) has been reported as a promising draw agent for forward osmosis desalination, the draw solutions sufficiently concentrated to have high osmotic pressure were too viscous to be usable in industrial operations. We now compare the viscosities and osmotic pressures of solutions of these polymers at low and high molecular weights and with/without branching.

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This study reports a dose-dependent pro-apoptotic action of synthetic cannabimimetic -stearoylethanolamine (NSE) on diverse cancer cell lines, including multidrug-resistant models. No antioxidant or cytoprotective effects of NSE were found when it was applied together with doxorubicin. A complex of NSE with the polymeric carrier poly(5-(tert-butylperoxy)-5-methyl-1-hexen-3-yn-co-glycidyl methacrylate)-graft-PEG was synthesized.

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Aim: To study whether water formulation of the complex of 4-thiazolidinone derivatives with a PEG-containing polymeric nanocarrier enhances their pro-apoptotic action towards rat glioma C6 cells.

Methods: Mechanisms of antineoplastic effects of 4-thiazolidinone derivatives were investigated in vitro with rat glioma C6 cells. Cell nativity, cell cycling pattern, and Annexin V expression were evaluated and DNA damage was estimated by DNA comet analysis.

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Background: Development of biocompatible multifunctional polymeric drug carriers is crucial in modern pharmaceutics aimed to create "smart" drugs. The high potential of the PEGylated comb-like polymeric nanocarrier (PNC) in delivering both traditional and experimental drugs to tumor cells in vitro and in vivo has been demonstrated previously. In the present study, we investigated the general toxicity of polyethylene glycol (PEG) processed with both covalent and non-covalent attachments of PEG to compose a comb-like polymer that behaves like a simple chain of n monomers decorated with swollen side chains.

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The synthesis of defined triphilic terpolymers with hydrophilic, lyophilic, and fluorophilic blocks is an important challenge as a basis for the development of multicompartment self-assembled structures with potential for, e.g., cascade catalysis and multidrug loading.

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We report on the physicochemical properties and self-assembly behavior of novel efficient pH-sensitive nanocontainers based on the Food and Drug Administration-approved anionic polymer Eudragit L100-55 (poly(methacrylic acid-co-ethyl acrylate) 1:1) and nonionic surfactant Brij98. The features of the interaction between Eudragit L100-55 and Brij98 at different pH values and their optimal ratio for nanoparticle formation were studied using isothermal titration calorimetry. The influence of the polymer-to-surfactant ratio on the size and structure of particles was studied at different pH values using dynamic light scattering and small-angle X-ray scattering methods.

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The aim of this study was to measure the activity of enzymes which reflect cardiotoxic action in rats of novel synthetic 4-thiazolidone derivatives--3882, 3288 and 3833 that demonstrated antineoplastic effect in vitro towards 60 lines of human tumor cells tested in the framework of the program of screening new anticancer drugs at the National Cancer Institute (USA). Such action of these compounds was compared with the effect of well known anticancer agent doxorubicin and after conjugation of all above mentioned substances with new polyethylenglycol-containing polymeric comb-like carrier that was synthesized by the authors. Among the biochemical indicators of cardiotoxic action of anticancer agents, activity of the following enzymes in rat blood serum showed to be the most informative: creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransterase.

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Severe toxic side effects and drug resistance are the major limitations of doxorubicin (Dox), one of the most potent anticancer agents in clinical use. Nanocarrier preparations offer the opportunity to overcome these drawbacks, which is reflected in the clinical approval of two liposomal Dox preparations. Additionally, there are many attempts to enhance the activity of Dox against multi-drug resistant (MDR) cancer cells.

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Ruthenium anticancer drugs belong to the most promising non-platinum anticancer metal compounds in clinical evaluation. However, although the clinical results are promising regarding both activity and very low adverse effects, the clinical application is currently hampered by the limited solubility and stability of the drug in aqueous solution. Here, we present a new nanoparticle formulation based on polymer-based micelles loaded with the anticancer lead ruthenium compound KP1019.

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The aim of the study was to evaluate the possibility to reduce the doxorubicin toxic effects by its immobilization with N-stearoylethanolamine (NSE) on nanocarier polyethylene glycol. The studied parameters of the doxorubicin toxicity were: the level of creatinine in the mice blood plasma and activity of alanine aminotransferase and aspartate aminotransferase in the blood plasma of mice. The activity of catalase superoxide dismutase, glutathione peroxidase and intensity of lipid peroxidation was determined in the tissues of the heart, kidneys and liver.

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Development of novel nanoscale functionalized carriers is nowadays one of the most urgent problems in cancer treatment. The aim of our study was to compare the antineoplastic effect of free doxorubicin and its complex with a nanoscale polymeric carrier towards HTC116 colorectal carcinoma cells. It was established that application of the complex of poly(5-tret-butylperoxy)-5-methyl-1-hexene-3-in-co-glycydyl metacrylat)-graft-polyethyleneglycol (poly(VEP-GMA-PEG)-graft-PEG), where VEP--5-tret-butylperoxy)-5-methyl-1-hexene-3-in; GMA--glycydyl metacrylat; graft-PEG--graft-polyethyleneglycol accordingly, functionalized with phosphatidylcholine for doxorubicin delivery increased 10 times the efficiency of cytotoxic action of this drug, as compared wich such efficiency in case of the action of free doxorubicin.

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The antioxidant effects of N-stearoylethanolamine (NSE) in the nanocomplex composition and in suspension are shown on the model of intoxication by doxorubicin in conditions of development of the Lewis carcinoma in the heart, kidneys and liver tissue and in the blood plasma of female mice. The NSE suspension reduces the level of urea in the blood plasma of mice with the Lewis carcinoma, which growth was revealed as a result of introduction of doxorubicin. Under introduction of nanocomplex the amount of urea remains at the level of that in the intact mice.

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The results of sclera investigations from the positions of morphology, physiology, biomechanics and control-system theory, are summarized. The morphological evidence was obtained supporting the physiological hypothesis stating that the specific anatomical organization and spatial displacement of elastic fiber-containing scleral layers against one another, are the key elements in formation of the individual level of intraocular pressure (IOP) in man both under normal and pathological conditions. It was shown that the elastic fibers outlined the collagen lamallae in of scleral internal layers.

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A total of 178 patients aged 53 to 78 years with advanced and progressive primary open angle glaucoma have undergone a hypotensive operation. It is shown that it is beneficial for the patients to combine medication with ultratonotherapy of eyelid region for restoration of hydro- and hemodynamics in the operated eye; to give an impact on the projection of the cortical sight centers for activation of trophic and neuroregulatory mechanisms of visual functions. Such a combined approach improves the course of the postoperative period and prolongs remission in glaucomatous atrophy of the visual nerve.

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The paper presents a procedure and results of use of electrostimulation, magnetic therapy, and electrophoresis during treatment for accommodation cramp and in the prevention of myopia in children and adolescents. Data that characterize the dynamics and stability of achieved results are given.

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The paper deals with a complex procedure for rehabilitation of children with congenital blepharoptosis, which includes the multilevelled impact on the concerned central and peripheral links of the neuromuscular apparatus by using magnetic laser therapy and electrostimulation.

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A device BIK for active suppression of infection has been used against Herpes virus infection type 1 and 2 in 72 patients with keratouveitis. The immunological and genotypic monitoring show that patients with herpetic keratouveitis after BIK treatment have lower titers of antiherpetic antibodies, normal cellular and humoral immunity, weaker viremia and reduced quantity of viral material in corneal tissue. This positive effect persisted for 8-12 months.

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Seventy-one patients with optic nerve abnormalities of different origin were treated using transconjunctival electrostimulation of the eyeball with electrodes positioned in the ciliary body projection. A positive effect was attained, particularly manifest in the acute period of optic nerve diseases (neuritis, anterior ischemic neuropathy) and in involvement of the optic nerve in glaucoma patients. The results were assessed from the principal parameters of visual function, intraocular pressure, data of hydrodynamic and electrophysiological studies.

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It is shown that the measurement of diluted solutions surface tension of normal tears and tears at different eye pathologies (cataract, glaucoma before and after operation) gave identical results. It is interpreted as a normal function of the lacrimal gland at these pathologies.

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The capacity of myeloperoxidase which is the product of polymorphonuclear leucocytes to induce the lens opacity was studied in young and old rabbits. It was found that the injection of myeloperoxidase solution into anterior chamber of the eye causes the irreversible lens opacification in old rabbits, not in young ones. Light microscopy of the lens section has shown the following alterations: the local thickening of the anterior capsule, disorderly accumulation of epithelial cells, formation of so-called "bladder cells" under the lens epithelium.

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Exchange plasmapheresis was used in correction of the immune homeostasis in 5 patients with sympathetic ophthalmia. The inflammatory process ceased in all the cases. Exchange plasmapheresis resulted in improvement of the blood supply to ocular vessels, of intraocular vessel function, and of metabolic processes in the external layers of the retina.

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