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1
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THE FORMATION OF HYDROGELS BASED ON CHITOSAN AND ITS WATER-SOLUBLE DERIVATIVES

100%
Il’ina A. V., Shagdarova B. T., Lunkov A. P., Varlamov V. P.
Progress on Chemistry and Application of Chitin and its Derivatives
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2020
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vol. 25
5 - 15
EN
This review considers articles on the formation of hydrogels based on chitosan as well as succinylated and quaternized chitosan derivatives. They are synthesized using low toxicity reagents, under ordinary conditions (low production costs). Chitosan derivatives are soluble in an extended range of pH values and characterized by mucoadhesiveness, bioavailability and biodegradability, which extends the potential of their medical applications. One of the most important properties of chitosan and its derivatives is the ability to form hydrogels. Depending on the nature of the bonds that occur during formation, hydrogels are divided into chemically or physically crosslinked, or a mixture of the two. Chemically crosslinked gels have covalent bonds, while physically crosslinked gels are formed by noncovalent interactions, for example, ionic. Mixed hydrogels have both types of crosslinking.
2
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EXPRESS ANALYSIS OF CHITOSAN AND ITS DERIVATIVES BY GEL ELECTROPHORESIS

100%
Konovalova M., Shagdarova B. T., Zubov V., Svirshchevskaya E.
Progress on Chemistry and Application of Chitin and its Derivatives
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2019
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vol. 24
84 - 95
EN
Chitosan is one of the most promising polymers for biomedical applications due to its unique properties, such as its biocompatibility, low toxicity, biodegradation, and the presence of reactive amino and hydroxyl groups. Analysis of physicochemical properties of chitosan and its derivatives is a time-consuming process and requires expensive equipment and large amounts of the sample. This paper proposes a method for express analysis of the molecular weight (MW), the degree of deacetylation (DD), the substitution degree (SD), and the charge of chitosan and its derivatives using agarose gel electrophoresis under acidic and neutral conditions with Coomassie staining. Positively charged chitosan samples required acidic Tris Acetate-EDTA (TAE) buffer to move in the gel. The electrophoretic mobility of chitosan depended on MW, DD, SD, and the chitosan charge. Based on the dependences obtained by the proposed method, the MW and DD of commercial chitosan samples were determined. Express analysis of chitosan and its derivatives in agarose gel can be used to monitor the reactions of chitosan modification and to analyse samples with unknown characteristics.
3
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CELL BINDING AND PENETRATION OF QUATERNIZED CHITOSAN DERIVATIVES

100%
Zubareva A. A., Shagdarova B. T., Varlamov V. P., Svirshchevskaya E. V.
Progress on Chemistry and Application of Chitin and its Derivatives
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2016
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vol. 21
217-223
EN
Chitosan (Ch) is an attractive biopolymer with multiple reactive groups. However it is poorly soluble at neutral pH. Quaternization improves its solubility and permits the development of various positively charged drug delivery systems. The aim of this work was to study the solubility, toxicity, cell binding, and penetration of 20 kDa chitosan with 9, 40, 58 and 98% of quaternary ammonium group substitution (ChQ1 to ChQ4 accordingly). We showed that ChQ with substitution degree >40% was soluble in a wide pH range. Unexpectedly ChQ2 and ChQ3 were more toxic to cells than Ch, ChQ1 and ChQ4. Higher toxicity of ChQ was found against macrophage like cell line RAW264.7 than against epithelial cells MiaPaCa-2. All ChQ, in contrast to unmodified Ch, easily bound and penetrated the cells with the highest uptake by ChQ4. Thus, quaternized chitosan derivatives can be used for biomedical applications.
4
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THE EFFECT OF CHITOSAN HYDROLYSATE ON THE FUNGI ALTERNARIA SOLANI, FUSARIUM SOLANI AND RHIZOCTONIA SOLANI IN VITRO

100%
Shagdarova B. T., Karpova N. V., Il’ina A. V., Varlamov V. P.
Progress on Chemistry and Application of Chitin and its Derivatives
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2021
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vol. 26
200-209
EN
Chitosan hydrolysate was obtained using nitric acid; the prevailing fraction had a molecular weight of 30 kDa and a deacetylation degree of 95%. The effect of chitosan hydrolysate when added to potato dextrose agar (PDA) in different concentrations (0.5, 1, 1.5, 2, 4, 6 and 8 mg/mL) was studied on the growth of the fungi Alternaria solani Sorauer, Fusarium solani (Mart.) Sacc. and Rhizoctonia solani J.G. Kühn. A. solani was the most sensitive to the addition of chitosan hydrolysate to PDA in radial growth experiments. On days 3 and 7 of incubation, the antifungal activity of the phytopathogen growth was 69%-92% and 69%-88%, respectively, in the concentration range of 0.5-2 mg/ml.
5
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THE INHIBITION OF HUMAN PLATELET AGGREGATION BY A LOW-MOLECULAR WEIGHT CHITOSAN

88%
Drozd N. N., Logvinova Y. S., Shagdarova B. T., Il’ina A. V., Varlamov V. P.
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vol. 23
55 - 65
EN
Chitosan derivatives were obtained by chemical (MW of 6 kDa, DD 99% - Ch6/99; MW13 kDa, DD 98% - Ch13/98) and enzymatic (MW of 5 kDa, DD 85% - Ch5/85; MW of 10 kDa, DD 85% - Ch10/85) depolymeri-sation of chitosan with a MW of 334 and 1000 kDa. Chitosan derivatives (almost identical MW pairs and different DD) possessed insignificant an-ticoagulant activity, did not promote human platelet aggregation and re-duced ADP or collagen-induced platelet aggregation. The studied sam-ples at a concentration of 2 mg/ml reduced the aggregation of platelets more than twice induced in 2x10-6M and 1x10-5M concentrations; at weak activation in 2x10-6M, the Ch10/85 sample was the most effective. The Ch6/99 and Ch13/98 samples were 20 times more effective at the inhibi-tion of collagen-induced platelet aggregation than the Ch10/85 sample. The latter can be explained by the greater value of positive charge (DD) and polydispersity (Mw/Mn) of chitosan samples obtained by chemical de-polymerisation
6
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FORMATION AND CHARACTERIZATION OF SUCCINOYL CHITOSAN PARTICLES LOADED WITH WARNERIN

76%
Shagdarova B. T., Ilyina A. V., Lopatin S. A., Korobov V. P., Lemkina L. M., Varlamov V. P.
Progress on Chemistry and Application of Chitin and its Derivatives
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2015
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vol. 20
246-253
EN
This study aims to obtain nanoparticles based on succinoyl chitosan loaded with Warnerin (War-SCNPs), low molecular weight cationic peptide. The nanoparticles of succinoyl chitosan (SCNPs) were prepared by salt coacervation method, and Warnerin loading efficiency on SCNPs was reached 75% in the optimum conditions, particularly, ration (SCNPs : peptide) was equal to (1.75 : 1, μg / ml ). Formed War-SCNPs were stable, had a weak electric charge from (-4.4) to (-14,6) mV. Determining of SCNPs size showed that a main fraction of SCNPs had the size of 160 nm, and after the peptide sorption War-SCNPs size increased up to 330 nm. The experimental data of this study will likely impact War-SCNPs use as therapeutic delivery systems of the peptide to be administered parenteral.
7
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THROMBORESISTANT SILICON PLATES MODIFIED WITH CHITOSAN AND HEPARIN BY THE LAYER-BY-LAYER ASSEMBLY METHOD

64%
Drozd N. N., Shagdarova B. T., Zhuikova Y. V., Il’ina A. V., Vasiliev M. N., Vasilieva T. M., Hein A. M., Varlamov V. P.
Progress on Chemistry and Application of Chitin and its Derivatives
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2019
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vol. 24
5 - 22
EN
Fifteen samples of silicone plates (PlateSi, area=12 cm2), with surfaces modified layer-by-layer with chitosan and unfractionated heparin, were obtained. The sample surfaces were pre-treated by cold oxygen plasma in a planar-type plasma chemical reactor with 50 W power before coating with layered polysaccharides. Pre-treatment was carried out in two alternative operation modes of the reactor, namely in the plasma etching mode and in the reactive-ion etching mode. Thromboresistance was assessed in vitro in contact with human blood. The thromboresistant silicon plates, modified layer-by-layer (3, 5, 7, and 9 bilayers) with chitosan, with molecular weights of 65 kDa, increased with the increase in the number of layers, up to 5. An increase in the duration of thromboresistance was observed in layer-by-layer modification of the surface of the plates with chitosan with a molecular weight of 200 kDa or with quaternized chitosan with a molecular weight of 200 kDa. Some samples of highly thromboresistant, modified PlateSi contributed to the adhesion of platelets and the haemolysis of red blood cells to a lesser extent than untreated silicon plates. The three most promising samples of modified PlateSi were selected.
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