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Searching for a preparation that would meet all the requirements for modern adjuvants remains a matter of critical importance for specific immunoprophylaxis. Much information is available now on chitosan positive effect, including its effect on the immune response. The article provides results of the preclinical tests for different affordable chitosan-based products. For the test purposes, we took the following three products manufactured by LLC Bioprogress (Shchelkovo, Russia): water-soluble chitosan (succinate) – 2% solution edible chitosan (water-soluble) – 2% solution; edible chitosan (acid-soluble) – 2% solution, as well as antirabies vaccine RABIKOV manufactured by Shchelkovo Biocombinat (Russia). Immunogenic properties of chitosan-based products were tested in 85–100-day-old female white laboratory mice weighing 21–35 g. The animals were divided into 37 groups (6 mice in each group). Chitosan-based products were administered subcutaneously or intramuscularly, either together with the anti-rabies vaccine or without it. Animals from the control groups received either saline solution or the vaccine only. There was also a group of intact animals. The experiment demonstrated that the water-soluble chitosan (succinate) administered subcutaneously, acid-soluble edible chitosan (at a concentration of 1:64 and more), and water-soluble edible chitosan (at a concentration of 1:108) administered subcutaneously and intramuscularly increase the level of post-vaccination anti-rabies antibodies. Thus, the tested chitosan-based products do not have any negative impact on the laboratory animals and have immunogenic properties.

Background: A pressing issue in modern purulent surgery is the growing number of microbial strains resistant to antibiotics. One of the strategies to address this issue is to develop novel wound dressings (WD) with incorporation of antiseptics that can prevent or reduce infection without conventional antibiotics.Objective: To compare the efficacy of chitosan-based WD with immobilized antiseptics and their combinations in in vitro and in vivo experiments.Materials and methods: We conducted a multistage randomized controlled in vitro and in vivo study investigating samples of chitosan-based WD with incorporated antiseptics (polyhexanide, octenidine dihydrochloride, povidone-iodine, and a combination of polyhexanide and octenidine) in international concentrations and diluted. The antimicrobial activity of antiseptics was evaluated in vitro by broth microdilution and disk diffusion methods. Staphylococcus aureus and Escherichia coli were used as reference cultures. For in vivo experiments, we formed experimental purulent wounds of soft tissues in laboratory animals (male rats weighing 300±50 g) according to our own method and treated the wounds with the investigated WD. The dynamics of the wound process was assessed by clinical and cytological data, as well as intravital ultrasonography findings.Results: Depending on the prolongation of time to maintain an effective concentration in the wound and minimal irritating effect on the tissue, we ranked antiseptic agents as follows: polyhexanide>octenidine>povidone-iodine. The combination of polyhexanide and octenidine did not demonstrate the expected synergistic effect; however, it had a positive therapeutic effect on the wound comparable to that of other antiseptics used alone. The comprehensive assessment of the wound process showed that WD with immobilized polyhexanide demonstrated the best wound healing and antiseptic effect. Reliable signs of wound healing with further positive dynamics were observed by day 7. It was almost 2 times faster compared with other experimental samples.Conclusions: Chitosan is a promising material to be used as a chemically inert matrix for programmed delivery of various drugs, including antimicrobial drugs, into the wound. The studied WD with immobilized antiseptics did not demonstrate a pronounced cytotoxic and depressing effect on processes of soft tissue remodeling and, on the contrary, significantly reduced the time of wound transition to the proliferation phase.

Background. The study of the interaction of protein - sericin from the cocoons of the silkworm Bombix mori with chitosan Tenebrio molitor (T.m) and the determination of the properties of complex compounds based on them is relevant in the field of polymer chemistry. Purpose: to isolate chitosan from chitin of larvae (T.m) and sericin from cocoons of the silkworm Bombix mori, to study their structure. Methodology. Sericin extracted from cocoon shells, chitin from Tenebrio molitor larvae, the reaction of chitin deacetylation to obtain chitosan. The structure is confirmed by IR spectroscopy. Originality. The interaction, pH of the medium and optical density of solutions of sericin and chitosan (T.m) were studied. The factors influencing the course and direction of the reaction were revealed. Findings. An effective method for obtaining chitosan from chitin (T.m) was developed. In the presence of chitosan (T.m) and sericin, a complex was obtained and its IR spectra were analyzed. [ABSTRACT FROM AUTHOR]

In modern conditions, the increase in the yield of agricultural crops is provided not by expanding the areas of their cultivation, but mainly by introducing advanced technologies. The most effective strategy for this purpose is the development of genetically resistant and productive cultivars in combination with the use of a variety of plant protection products (PPPs). However, traditional, chemical PPPs, despite their effectiveness, have significant drawbacks, namely, pollution of environment, ecological damage, toxicity to humans. Recently, biological PPPs based on natural compounds have attracted more attention, since they do not have these disadvantages, but at the same time they can be no less effective. One of such agents is chitosan, a deacetylation product of chitin, one of the most common polysaccharides in nature. The high biological activity, biocompatibility, and safety of chitosan determine the breadth and effectiveness of its use in medicine, industry, and agrobiology. The review considers various mechanisms of action of chitosan as a biopesticide, including both a direct inhibitory effect on pathogens and the induction of plant internal defense systems as a result of chitosan binding to cell surface receptors. The effect of chitosan on the formation of resistance to the main classes of pathogens: fungi, bacteria, and viruses has been shown on a variety of plant objects. The review also discusses various ways of using chitosan: for the treatment of seeds, leaves, fruits, soil, as well as its specific biological effects corresponding to these ways. A separate chapter is devoted to protection products based on chitosan, obtained by its chemical modifications, or by means of combining of a certain molecular forms of chitosan with various substances that enhance its antipathogenic effect. The data presented in the review generally give an idea of chitosan and its derivatives as very effective and promising plant protection products and biostimulants.

Background. Injuries of various origins with damage to parenchymal organs remain one of the urgent issues of emergency surgery, despite all the achievements of medical science of the first quarter of the XXI century. One way to improve the quality of treatment for patients with this pathology consists in developing new wound dressings or modifying the properties of existing ones. Hemostatic efficacy is claimed to be one of the main requirements for such dressings.Objective. To perform a comparative analysis of the efficacy of the developed biodegradable wound dressings based on chitosan in the treatment of experimental wounds of parenchymal organs.Methods. The study involved laboratory animals (male rabbits weighing 2900 ± 150 g) to form experimental wounds of parenchymatous organs. The methodology involved wounding the liver via internal method, with the creation of a tissue defect of a given volume, or forming a linear incised wound with fixed parameters followed by application of a developed wound dressing. In the control group of animals, a collagen hemostatic sponge was used as a wound dressing. The animals used in the experiment were kept in accordance with GOST 33044-2014 “Principles of good laboratory practice”. The experiment involved studying the properties of two samples of wound dressings developed on the basis of modified Chitosan Soft (Ch-S) and Chitosan Hard (Ch-H) chitosan, having different properties due to their different structural parameters. The applied ultrasound control of the experimental wound area, with visualization of the samples of the investigated material in the process of biodegradation, enabled the features of the wound process to be studied in more detail. Statistical processing of the study results was carried out by methods of variational statistics, including the calculation of mean values (M), standard errors of mean values (± m). The criterion of the level of statistical significance considered a value of p

Chitosan (CS) with a viscosity-average molecular weight of 200 kDa and a deacetylation degree of 82 mol%, produced by Bioprogress Ltd. (RF) has been used in this work. Aqueous solutions of enantiomeric salt complexes of CS with L- and D-aspartic acid (AspA) have been obtained at an equimolar CS:AspA ratio, in terms of amino groups. Powders of CS·L-(D-) AspA salts have been isolated from the corresponding solutions by evaporation of water and stored in a desiccator at zero humidity. It has been established that under such conditions a water-soluble salt form of the polymer with lamellar light beige particles 0.05–1.0 mm in size is formed. Using the methods of elemental analysis, IR and NMR spectroscopy, and X-ray diff ractometry, the chemical interaction of CS with L-(D-)AspA in aqueous solution and condensed state has been evaluated, and the chemical structure and supramolecular ordering of these enantiomeric salts have been studied. It has been established that, according to the classifi cation of K. Ogawa et al., the formula unit CS·L-(D-)AspA corresponds to non-hydrated salts of type I, in which water molecules are replaced by acid anions. IR spectroscopy confi rmed the donor--acceptor polymer–acid interaction and revealed a developed system of intermolecular and intramolecular contacts. One- and two-dimensional NMR spectroscopy showed the interaction of pairs of atomic nuclei between H3–H6 of the polymer and 2Hβ or Hα of the acid, H1 or H2 and Hα, H1 and H3–H6, due to the spatial proximity of protons in repeating monomer units, in the “bend” chain segments removed along the chain, and in neighboring macromolecules. For CS·L-AspA, additional resonances have been identifi ed between H2 and H3–H6 of the polymer, for CS·D-AspA these have been between H1 or H2. X-ray diff ractometry has revealed a highly ordered orientation of macrochains and a high crystallinity degree, untypical for CS salts. The salt complex CS·D-AspA, in contrast to CS·L-AspA, is characterized by a smaller amount of crystallization water, a more ordered supramolecular structure, and a more developed system of intermolecular and intramolecular contacts.

The results of a study of the luminescent dynamics of combined aqueous-alcoholic solutions of extracts of red viburnum (Viburnum opulus L.) fruits with chitosan and gold nanoparticles at different oxygen concentrations were presented. The search for natural sources of photosensitizers is an urgent task. The sensitive analytical methods, in particular luminescence, with amplification of the analytical signal as a result of the generation of plasmons in nanoparticles of noble metals, have been used in this work. An additional studies under the conditions of plasmon energy generation showed a significant changes in the dynamics of optical spectra with variations in oxygen concentration in solutions. The spectral-temporal dynamics was investigated with complete oxidation of vitamin C in the studied system. The main method for recording the dynamics of interaction of Viburnum opulus L. flavonoids with oxygen molecules is the luminescent method. Luminescence spectra were measured by means of Fluorolog-3 optical system (Horiba, Japan). Methods of absorption analysis (Shimadzu spectrophotometer, Japan) were also used in the work. The nanosecond luminescence lifetimes of the extracts were measured in the multichannel photon counting mode using a picosecond NanoLED-405L nanoled by means of Fluorolog-3 spectral setup. Microsecond lifetimes were recorded when excited by a pulsed Xe lamp. For the synthesis of gold nanoparticles, the method of laser ablation of a metal plate of gold in distilled water was used. Laser ablation was performed at the LQ929 installation of Solar Laser System (Belarus). A plasmonic effect of amplification of the optical absorption density and luminescence intensity was detected. The kinetics of luminescence quenching of Viburnum opulus L. extract with chitosan under the influence of gold nanoparticles, close to diffusion, was studied. The oxygen concentration at which the flavonoids of the extract are oxidized was spectrally determined. Under the oxygen concentration changing, the dependences of changes in the luminescence intensity of the extract with chitosan at the wavelengths of registration of luminescence spectra were established. When oxygen was doped into all solutions, the spectral and kinetic features of luminescence attenuation with maxima at wavelengths of 480 and 580 nm were detected and investigated. It was established that the lifetime of luminescence at a registration wavelength of λ = 480 nm varies depending on the concentration of gold nanoparticles and the concentration of oxygen molecules and it is the nanosecond spectral region (3–4 ns). It was shown that luminescence at a wavelength of 580 nm is due to the oxidized form of quercetin which is a part of the Viburnum opulus L. flavonoids, appeared at a high oxygen concentrations. Long-lived chemiluminescence at a wavelength of 580 nm with time decay of 15 μs as a result of radical processes involving molecular oxygen and extract molecules was recorded. The spectral methods presented in this paper, as well as a method for determining of quercetin as a result of oxygen oxidation of flavonoids of red viburnum fruits, can be used in the field of biophysics, biotechnology and chemical analysis.

Background. Vanadium is toxic both in the form of cations and anions, which requires control of its presence and concentration in media. The development of methods for its determination is relevant. Purpose. To develop a method for detecting vanadium (V) ion by the luminescent property of a carbon dot based on chitosan and melamine. Methodology. 1.0 ml of a solution of carbon dots and a standard solution of ammonium vanadate, distilled water are introduced into the cuvette and the absorption and luminescence spectra are measured (Horiba Duetta, Japan). Originality. A sensitive luminescent method for detecting vanadium ions using carbon dots synthesized on the basis of chitosan and melamine has been developed. Findings. Luminescent determination of V(V) using carbon dots has been implemented. The luminescence intensity was determined at λ=448 nm at the carbon point and 423 nm in the V(V) complex, which indicates the extinction of luminescence with the formation of the complex. The alkalinity of the medium was controlled. [ABSTRACT FROM AUTHOR]

The method presents obtaining hydrosoluble graft copolymer of complicated structure based on сhitosan, acrylamide (AM), sodium 2-acrylamido-2-methylpropane sulfonic (АМPS-Na) in order to obtain fl ocсulant which is resistant to salt of transition metals and heat temperature, and in order to use it as a reagent for oil production processes. The obvious advantages of this copolymer can be attributed to its biodegradation due to inclusion of a biopolymer into the composition of the copolymer, which is important for the preservation of ecology, and effi ciency of its synthetic analogues. The graft copolymerization acrylamide and sodium 2-acrylamido-2-methylpropane sulfonic onto active sites of chitosan has been performed under condition of high concentration monomers in nitrogen atmosphere using combined initiator system of complex composition under the following order monomers [АА]>[АМПС-Na]. Kinetic study of graft copolymerization has been carried out using thermometry methods. Attempts have been made to describe mathematically the reaction of graft monomers АM and АМPS-Na onto chitosan. The IR spectra analysis of copolymers has been carried out. The study of reaction rate and molecular characteristics of synthesized copolymers has been conducted under changing concentration of chitosan, monomers, ratio components of the initiator system and reaction temperature during synthesis. It has been determined that the averaged energy activation of copolymerization reaction was in the range of reaction temperature 10–25°С. Molecular composition and proposed structure of the grafted copolymers have been determined by the results of viscosity and sedimentation analysis. The results of this study allow to obtain grafted copolymers with specifi ed properties and structure to use them in such areas as sewage and industrial water treatment and mineral industry.

Polymeric flocculants are used to accelerate the separation of solid and liquid phases in the treatment of drinking water and wastewater. Recently, much attention has been paid to flocculants, both synthetic and biobased, due to their advantages for wastewater treatment processes. Flocculants have many advantages such as biodegradability, non-toxicity, the ability to undergo various chemical modifications, and wide availability from renewable sources. This article provides a review of synthetic and biobased flocculants and lists their potential applications in water treatment. Based on the up-to-date data, a new approach is proposed for searching for modified and grafted flocculants, flocculation mechanisms, test methods, and factors influencing this process. Particular attention is paid to flocculants based on chitosan and its derivatives, since they are cheap and environmentally friendly materials used in industrial practice.

The continuous emergence of new pathogens and the evolution of microbial drug resistance make it absolutely necessary to develop innovative, effective vaccination strategies. Use of nasal vaccination can increase convenience, safety, cause both local and systemic immune reactions. Intranasal administration nevertheless has a number of shortcomings that can be overcome by using the latest achievements of pharmaceutical science. One of the aspects of such solution may be the use of systems for the production of intranasal vaccines in situ polymer compositions that provide a directed sol-gel transition controlled by the physiological conditions of the nasal cavity. At the same time, the gelation of the administered dose in contact with the nasal mucosa involves prolonged exposure of the drug at the injection site, greater mucoadhesion, counteraction to mucociliary clearance, modified and more complete release. A number of both foreign and domestic manufacturers produces polymers such as chitosan, gums, polyoxyethylene and polyoxypropylene block copolymers (poloxamers, proxanols), carbomers. For effective pharmaceutical development of new intranasal IBD delivery systems corresponding to the QbD concept, not only the knowledge of the range of excipients is necessary, but also simple, accessible, and reproducible methods for determining indicators that define the critical parameters of such delivery systems. In accordance with the conducted scientific search, the main indicators of standardization of in situ intranasal systems were identified: temperature and time of gel formation, gel strength, rheological characteristics, mucoadhesion, release, nasal mucociliary clearance time.

Background. An urgent problem of natural gas purification is the creation of an adsorbent on a local raw material base, of which interest is attracted by zeolites created using template additives that provide their predetermined functional properties. Purpose: to study a two-stage approach to the synthesis of nanostructured crystalline type A zeolite with the inclusion of chitosan gel crosslinked with glutaraldehyde as a template in the process, solving the problem of removing the chitosan template from the structure of the resulting zeolite.. Methodology. The use of the hydrothermal method in the sol-gel process of synthesizing nanostructured crystalline zeolite type A. The use of SEM, EMF, X-ray diffraction, nitrogen porosimetry to determine the structural characteristics, the study of CO2 adsorption-desorption on the resulting nanozeolite. Originality. Nanostructured crystalline type A zeolite was synthesized by a two-stage method. Chitosan crosslinked with glutaraldehyde was used as a template. To remove the chitosan template from the aluminosilicate, the product was treated with hydrogen peroxide. Findings. Nanostructured crystalline type A zeolite was synthesized, its physicochemical characteristics were studied, incl. no pore shrinkage, crystallinity, CO2 adsorption. [ABSTRACT FROM AUTHOR]

The research purpose was to develop and study biocatalysts based on papain associates with chitosan nanoparticles. We obtained medium and high molecular weight chitosan nanoparticles, both with and without ascorbic acid . When the papainna-noparticles complexes with ascorbic acid were formed, the catalytic activity of the enzyme increased by 3 % for medium molecular weight chitosan and by 16 % for high molecular weight chitosan. After 168 hours of incubation in 0.05 M of Tris-HCl buffer (pH 7.5) at 37 °C, the free enzyme retained 15 % of its catalytic activity, whereas its associates with chitosan nanoparticles exhibited ~ 30 %. The papain complex with chitosan nanoparticles and ascorbic acid exhibited 40 % of the enzyme catalytic activity. We simulated the bonds and interactions within the chitosan-ascorbic acid-papain complex. The proposed biocatalysts have high prospects for effective use in cosmetology, biomedicine, and pharmacy.

Nanotechnologies using biopolymers are widely used in biomedical applications. In this work, nanocomposite hydrogels based on natural (chitosan, carboxymethylcellulose) and synthetic (polyvinyl alcohol) polymers with silver nanoparticles for application to a textile carrier have been developed. Carboxymethylcellulose dialdehyde and boric acid were used as crosslinking reagents in the creation of hydrogels. Physicochemical properties (sorption capacity in unilateral contact with the model medium, degree of swelling, vapor permeability, capillarity) of hydrogel coatings on a textile carrier, and the kinetics of the drugs release (lidocaine, dioxidine) included in the hydrogels were determined. It is shown that materials with a two-layer coating are characterized by higher sorption properties relative to saline and a longer release of drugs than materials with a single-layer coating. The release of drugs from the two-layer coatings occurs in two stages with a maximum release within two days. The obtained textile materials with a film nanocomposite hydrogel coating can be used as dressings in the treatment of wounds.

Extrusion can be considered not only as an effective technology for processing agricultural raw materials into feed and food products, but also as a thermo-mechanical method for modification of the chemical properties of biopolymers. Carbohydrates are the most represented class of organic compounds in raw materials processed by the agro-industrial complex. The assessment of the influence of the processing factor on the final physicochemical and technological properties of various types of carbohydrates included in the chemical composition of raw materials or used as mono-ingredients is an actual task for the food industry. The review considers the issues of extrusion modification of starch in terms of the difference in the properties of amylose and amylopectin as well as the presence of lipids and organic acids in the reaction system. Processes of macromolecular degradation, gelatinization, esterification and the formation of new chemical bonds in dependence on the conditions of extrusion and the composition of mixtures are discussed. The results of studies of the influence of extrusion cooking on the changes in the physicochemical properties of non-starchy polysaccharides, cellulose, araboxylans, inulin, pectin, chitosan, and gums of various origins are presented. It has been shown that extrusion and varying of its operating regimes can significantly affect the nutritional value of extrudates including changing the glycemic index, inactivating antinutritional factors, or increasing their content in extrudates.

The purpose of the research was to develop and study biocatalysts based on ficin associates with chitosan nanoparticles. We obtained medium and high molecular weight chitosan nanoparticles with the addition of ascorbic acid and without it.The zeta potential of all types of nanoparticles was 0 mV. The associates of ficin and chitosan nanoparticles formed with the addition of ascorbic acid exhibited higher proteolytic activity. While determining the stability of the associates of chitosan and ficin nanoparticles, we noticed a decrease in the proteolytic activity of the samples within seven days. Medium and high molecular weight chitosan nanoparticles obtained using ascorbic acid differed significantly in size from the nanoparticles produced without ascorbic acid. The proposed biocatalysts have high prospects for use in cosmetology, biomedicine, and pharmacy.

This research aims to identify the optimum concentration of chitosan solution and the effectiveness of chitosan as a biocoagulant in shrimp-washing wastewater on three types of water quality parameters, i.e., color, turbidity, and total dissolved solids (TDS). By employing the jar test method, the coagulation-flocculation test was performed by adding chitosan doses of 0 ppm (control), 50 ppm, 100 ppm, 150 ppm, 200 ppm, and 250 ppm, respectively. The effectiveness of chitosan was measured by calculating the percentage decrease in color, turbidity, and TDS parameters in the treated shrimp-washing wastewater samples. The statistical analysis results indicated that the treatment had a significant effect on the three types of parameters, with the obtained optimum concentration of chitosan solution of 200 ppm. The effectiveness of chitosan in reducing color (84%), turbidity (83%), and TDS (54%).

Introduction. Smart food packaging that alerts consumers to spoilt food by changing color is based on affordable and biodegradable raw materials. The research objective was to develop films from anionic polysaccharides and anthocyanin pigment that can be used as a freshness indicator of minced fish. Study objects and methods. The study featured frozen black currant berries (Ríbes nígrum), polysaccharide-based anthocyanin films, and minced fish. Extracts of anthocyanin pigment and films based on agar, kappa-carrageenan, chitosan, starch, and anthocyanin pigments were analyzed by IR spectroscopy. Results and its discussion. Anionic polysaccharides, i.e. agar and kappa-carrageenan, demonstrated good film-forming properties. Films based on 1.5% agar and 2% kappa-carrageenan showed elasticity, resilience, plasticity, and sufficient resistance to mechanical deformation. Neutral polysaccharide starch and cationic polysaccharide chitosan appeared to have no such qualities. An IR spectral analysis revealed chemical interactions between polysaccharide and anthocyanin molecules. It indicated the electrostatic nature of the polyelectrolyte complexes of the anthocyanin pigment with anionic polysaccharides. A film based on 1.5% agar fortified with anthocyanin pigment was used as a test-system for analyzing the quality of fish. The minced fish samples were wrapped in the anthocyanin film and left for 2–7 min to register the color change of the film. When the anthocyanin film came in contact with fresh fish, the color of the film did not change even after prolonged contact. When the film came into contact with spoilt fish, the color of the film began to change after 2 min of contact. When the contact time reached 7 min, the film turned blue. Conclusion. The type of polysaccharide and the interaction between polysaccharides and anthocyanin pigment had a significant effect on film formation. Anionic polysaccharides demonstrated the best results. Electrostatic interactions between anionic polysaccharides and anthocyanin pigments produced stable polyelectrolyte complexes. The new smart films were able to determine the quality of minced fish.

Background. Wounds of various aetiology are among the most frequent traumatic injuries. A prospective route to improve treatment of this nosology is the development of novel or advancement of the already on-stage dressing materials.Objectives. A comparative experimental assay of novel chitosan-based wound dressings in the healing of soft tissue wounds of different genesis using ultrasound to control biodegradation of the developed dosage form.Methods. Soft tissue wounds were modelled in experimental animals, conventional and lineage male rats, 275 (± 25) g body weight, and male rabbits, 2,900 (± 150) g weight, using a proprietary methodology (Patent on invention RU No. 2703709 dated 23 August, 2018).Two wound dressing samples selected as most promising and applicable in large-volume soft tissue aseptic wounds were tested in the final step of experiment. Ultrasound imaging of the model wound area during the sample material biodegradation was used to control the wound process in more detail. At all steps of experiment, animal models were handled in compliance with GOST 33044-2014 “Principles of Good Laboratory Practice”.Histomorphological assays were carried out with common protocols. Variation statistics was used for the data analysis, including the mean (M) and standard mean error (± m) estimation. The level of statistical significance was p < 0.05.Results. The animal assays and comprehensive evaluation of the obtained data revealed a high healing efficacy of chitosan-based wound coatings. The analyses of wound dressing samples have confirmed their predesigned properties: scaffold stability, capillarity, biodegradability and matrix capacities for the carried drug delivery.Additionally, ultrasound was proved effective to estimate dynamics of the coated wound healing and biopolymer biodegradation processes.Conclusion. The developed chitosan-based wound dressings exhibited efficacy in an experimental model of the soft tissues wound process.The use of ultrasound to study dynamics of the wound process and coating biodegradation provided an adequate congruence between the imaging and tissue histomorphology data, as well as the structure and properties of coating material.

It was established that at the cathodic treatment of titanium in aqueous dimethyl sulfoxide solutions of sodium molybdate, containing phosphoric acid, at the potential of the cathodic incorporation of sodium (Ec = − 2.6 V) in the potentiostatic mode, the composition formed on the electrode surface layer depended not only on the composition of the solution, but also on the volume ratio of the aqueous electrolyte solution and the organic solvent (dimethyl sulfoxide).

Background. Research is underway to obtain three-component interpolyelectrolyte complexes (IPECs) of chitosan with polyanions and polyampholytes. The presence of a surface charge in the macromolecule of three-component IPECs can effectively immobilize oppositely charged particles. Purpose: obtaining stable three-component interpolyelectrolyte complexes based on Bombyxmori chitosan and studying their physicochemical properties. Methodology. We used conductometric titration, DLS, Litesizer and other research methods. Originality.Three-component interpolyelectrolyte complexes based on natural macromolecules have been obtained and their hydrodynamic parameters have been studied. Findings.The compositions and hydrodynamic dimensions of three-component complexes of chitosan were revealed. It has been established that at pH 6.3 binary complexes of chitosan/Na-CMC interact with collagen at 1:0.75:0.01 wt. ratio, where the sum of the surface charge of the complex is equal to zero. The hydrodynamic particle sizes of ternary IPECs vary from 98 to 132 nm. [ABSTRACT FROM AUTHOR]

The adsorption and dilatational rheological characteristics (the elasticity and viscosity modulus) of chitosan lactate at the liquid-gas interface are investigated by the oscillating drop shape method. The dependences of the dynamic and equilibrium surface tension on the concentration of chitosan lactate in solution have been determined. It was found that the dependences obtained are similar to those for surface-active high-molecular weight compounds. The dependences of the surface elasticity and viscosity of chitosan lactate on the oscillation frequency and concentration have been studied. It has been shown that chitosan lactate is capable of forming elastic adsorption layers with the values of the viscoelastic modulus comparable to that of protein biopolymers.

Strawberries (Fragaria ananassa) belong to short-term berries. Many technologies are used to extend its shelf life. One of the current technologies is the use of pretreatment of berries with polysaccharide solutions before refrigerated storage. This treatment makes it possible to reduce weight loss and improve the overall quality of berries by forming a protective barrier film on their surface. The purpose of this study was to investigate the effectiveness of chitosan strawberries pre-treatment while storing it in a refrigerated chamber using a modified gas atmosphere. To achieve the purpose, strawberries were treated with 0,05 %; 0,2 %; 0,5 % aqueous solutions of low molecular weight chitosan were stored in a refrigerator at t 0 + 2 °C using polyethylene bags of 30 microns thickness. Unprocessed berries were used as a control. All experimental studies were performed in triplicate. According to the research results it was found that the weight loss of treated berries was 1,48 – 5,11 % and in the control 11,35 %. The mass fraction of sugars at the end of storage in the treated berries was (2,2–2,6 %), which is 0,2–0,6 times higher than in the control.. The content of ethyl alcohol is fixed in all samples. In the control variant, it was 0,87 %, and in the samples the treatment was from 0,57 – 0,8 % According to the results of the tasting evaluation, the best performance was in the sample with a concentration of 0,5 % Pretreatment of strawberry berries with aqueous solutions of low molecular weight chitosan has a positive effect on the quality of strawberry berries and can be used as an effective tool in the storage of berries

Providing the population with high-quality and safe food products is a priority task for the Russian Federation food industry. One of the methods for solving the problem is creation of alternative, harmless antibacterial compositions using natural components.The aim of the research is to study the antibiotic action of the natural chitosan bacteriostat and its derivatives against Proteus bacteria. The objects of the research are high molecular weight chitosan, low molecular weight chitosan, chitosan succinate, Proteus vulgaris 222 pure culture.The article presents the results of the research of using the solutions of high molecular weight, low molecular weight chitosan and chitosan succinate at a concentration of 1% as an antibacterial agent in relation to a pure laboratory strain of Proteus vulgaris in various concentrations of 1 cm3.The maximum initial concentration of Proteus vulgaris cells in the product has been established, which is suppressed by 1% chitosan solutions. The growth of the inhibitory effect of the studied antibiotic substances with an increase in exposure has been shown.

In the work, the kinetics of the release of vitamin E and polyphyte oil from capsules was studied using synthetic and natural systems. The release of active ingredients was monitored on a Cary 50 Cons UV spectrophotometer equipped with CaryWinUV software. The kinetics of the release of vitamin E from capsules stabilized with sodium caseinate and then coated with chitosan shows a sustained prolonged release of 20% of vitamin E within 1 h, within 5 h about 45% is released, within 48 h about 80%. It was found that the efficiency of capsulation of vitamin E is higher than that of polyphyte oil, the release of vitamin E is more delayed and prolonged in comparison with polyphyte oil. The release of vitamin E from capsules stabilized with a synthetic system polymer-surfactant / vitamin E) chitosan) polystyrene sulfonate PSS was also investigated. It was determined that the release of vitamin E from capsules stabilized by a synthetic system (polymer-surfactant and coated with two layers of oppositely charged polyelectrolyte by the Layer-by-Layer method) is prolonged, within 1 h - 23% of vitamin E is released, 70% - within 12 h and 100% - within 80 h. [ABSTRACT FROM AUTHOR]

The data on the experimental study of the efficacy of the gel wound dressings based on chitosan and calcium alginate containing bioactive substances from marine hydrobionts with complex therapeutic action (sulfated polysaccharides from brown algae, hydrolyzed bivalves, peptides from nerve ganglia of cephalopods) are described. The model of thermal burns complicated by Staphylococcus aureus infection was used. Planimetric and bacteriological investigations revealed pronounced wound healing and antibacterial effects of the gel coating. The gel containing sulfated polysaccharides from brown algae showed the highest wound healing activity.

Cherry fruits are appreciated because they contain vitamins, a unique blend of phenolic compounds and anthocyanins. However, term of their consumption is limited by the period of their maturation, so today we are looking for new storage technologies. The purpose of the research conducted during 2016−2019 years on the basis of L.P. Simirenko Pomology Experimental Station of the National Academy of Agrarian Sciences of Ukraine, was to determine the effect of pre-treatment with chitosan solutions (1 %)and with chitosan(1 %) with salicylic acid (100 mg/l) to change the content of ascorbic acid, tannins and coloring matter, and antioxidant activity of the cherry fruit Alpha and Artemenko Pamiat varieties during storage. As a result of research was identified, that during the storage of fruits cherries the content of ascorbic acid decreases to 41 and 47,4 %; tannins and coloring matter - to 14,1−14,9 % and antioxidant activity to 39−41 %. Using the pre-treatment of the cherry fruit by a solution of chitosan, the loss of ascorbic acid content are reduced to 36,1−33,3 %; tannins and coloring matter to 9,4−12,2 %; and antioxidant activity 28−30 % The lowest losses were observed for cherry fruits treated by solution of chitosan with salicylic acid, in the content of ascorbic acid to 18,3−19,8 %, tannins and coloring matter to 8,2−9,5 %, and antioxidant activity 25−26 %. Between cherry fruit antioxidant activity and the content of tannins and coloring matter as well ascorbic acid were founded strong correlations with correlation coefficients r=0,93 r=0,98. The perspective of further research is studying the effect of pre-treatment by solution of chitosan with salicylic acid for the cherry fruits during storage and change their antioxidant composition.

The review focused on global trends in the development of scientific research and the practical applications of chitosan in food technology in recent years. Chitin and its derivative chitosan obtaining from the crustacean shells and the cell wall of fungi are among the most common biopolymers in the world. Chitosan is a polysaccharide discerned by a large number of unsubstituted amino groups. Featured properties of chitosan providing its high chemical and biological activities. Chitosan has various abilities as polycationite, film former, antimicrobial and antioxidant agent. Multifunctional properties open up broad prospects for the chitosan applications in various fields of technology, medicine and industry. The most attention in the review is paid to the works on extending food products shelf life with chitosan based primary edible film coatings and biodegradable packaging. At the same time chitosan applications as an emulsifier, a flocculant, as well as functional food additive, nutrient encapsulating material and dietary supplement are highlighted.

Aim. To experimentally evaluate the efficacy of multi-layer chitosan-based wound dressings developed for dental purposes.Materials and Methods. Over the period from 2018 to 2019, an experimental study was conducted to evaluate the efficacy of multi-layer chitosan-based wound dressings developed for dental practice. Two types of dressings (No. 1c and 2c), the central part of which was modified with the introduction of a 10% iodopyron solution, were compared with the widely-used wound dressings Alvostaz (NKF Omega-Dent LLC, Russia) and Gelatamp (Roeko, Germany). The work involved 26 male Chinchilla rabbits, ten months old and weighing 2500 (±50) g. Evaluation of the efficacy of the wound dressings under study was carried by modelling the conditions of both aseptic and purulent-inflammatory processes (a total of 8 series of experiments). In experiments modelling the purulent-inflammatory process, a Ps. aeruginosa bacterial culture at a concentration of 109 CFU/ml was introduced into the alveolar socket after tooth extraction, 3 days before the application of a wound dressing sample. The dressings under study were applied on the wound for the period of 7 days. During the observation postoperative period, the animals were provided with free access to water and food. The sampling of the material for the study was carried out in the operating room on day 7.Results. According to the experimental results, chitosan-based wound dressings (No. 2c in particular) demonstrated high efficacy in experiments on animals (rabbits). The developed wound dressings perform mechanical protection and exhibit fuse effects, as well as are characterized by biodegradability and the ability to deliver medical agents contained therein to the damaged tissue.Conclusion. The proposed chitosan-based wound dressings showed sufficient efficiency on the modelled wound process in the alveolar socket of an extracted tooth. Dressing No. 2c was recognised to be optimal for infected and purulent wounds. This dressing has a dense outer layer, which structure retains frame functions for a long time, thus providing proper drainage of the pathological focus. Dressing No. 1c was established to be promising in cases without inflammatory processes in the extracted tooth socket, where high adhesion to surrounding tissues is initially required for ensuring the tightness and preservation of a blood clot in the wound.

The aim of this work is to synthesise chitosan and N-vinylimidazole graft-copolymers of various compositions and to study the properties of their aqueous solutions. Chitosan and N-vinylimidazole graft-copolymers were obtained by solution polymerisation in the presence of a ceric ammonium nitrate redox initiator. The synthesised graft copolymers were characterised by FTIR to determine their compositions and the grafted side chains of poly-N-vinylimidazole were characterised by gel permeation chromatography to determine their molecular wights and polydispersity indices. It was established that the obtained products are characterised by high values of yield and grafting efficiency and low values of the polydispersity index. It was found that when the content of the N-vinylimidazole links is above 57 wt%, the synthesised graft copolymers are water-soluble. Aqueous solutions of the obtained copolymers were characterised using dynamic light scattering, transmission electron microscopy, and laser Doppler microelectrophoresis. The study showed that macromolecules of graft copolymers in aqueous solutions have stimuli-sensitive properties with respect to the medium reaction and at a concentration above 10–2 wt% are characterised by a tendency to self-association forming core-crown aggregates, the geometry of which depends on the molecular masses of the grafted chains. Associates of macromolecules in solutions are characterised by positive values of the electrokinetic potential, the values of which also depend on the medium reaction. Thus, it was found that the ceric ammonium nitrate initiator allows obtaining chitosan and N-vinylimidazole graft-copolymers showing stimuli-sensitive properties in aqueous solutions and prone to self-association at concentrations above 10–2 wt%.

The aim of this work was the investigation of the formation of structures in solutions of individual polymers, as well as their blends with each other in buffer solvents with different values of pH. In this study we used a sample of chitosan (degree of deacetylation ~ 84 %, M = 130,000), which is a polycation when dissolved, and polyvinyl alcohol (r = 1.25 g/cm3, M = 5000). Buffer systems based on acetic acid and sodium acetate with pH = 3.8, 4.25, and 4.75 were used as solvents. Viscosimetry was used to determine the intrinsic viscosity, the degree of structuring, and the Huggins constant. The Kriegbaum method was used to determine the nature of the aggregates formed by the blend of the studied polymers. In the course of the research, it was shown that an increase in the pH of the acetate buffer used as a solvent was accompanied by a compression of the macromolecular coil (a decrease in intrinsic viscosity values), a deterioration in the quality of the solvent (an increase in Huggins constant values), and an increase in the degree of polymer aggregation in a solution for chitosan polyelectrolyte. At the same time for a solution of polyvinyl alcohol the pH of the buffer practically did not affect the nature of the polymer-solvent interaction. It has been proved that polymer blends are characterized by an increase in aggregation processes and a decrease in the thermodynamic quality of the solvent in comparison with solutions of individual polymers. The size of the “combined” macromolecular coil, characterized by the intrinsic viscosity value for the polymer blend, which can be both above (buffer solvent with pH = 3.80) and below (buffer solvent with pH = 4.25 and 4.75) additive values, changed depending on the type of formed polymer-polymer aggregates (homo- or hetero-). It was established that the type of aggregates (homo- or hetero-) formed in solutions of polymer blends was determined not only by the thermodynamic quality of the used solvents, but also by the concentration of the polymers in the initial solutions

Introduction. The analysis of clinical experience for using biodegradable wound coating based on «HitoPran» chitosan in treatment of patients with burn trauma is presented.Background. Our work included an analysis of clinical experience for using a biodegradable wound coating based on «HitoPran» chitosan for surgical treatment in patients with local and common thermal burns.Material and Methods. A treatment analysis was conducted in 46 male and female patients, aged from 1 to 63 years with thermal burns on an area of 5 to 56% of the body surface. All injured were given surgical treatment in the complex with the use of low-temperature air plasma of arc discharge with atmospheric pressure in the conditions of our burn center in 2017–2018. Depending on the area and depth of the lesion, the patients were divided into two clinical groups: with local burns of II degree and area to 5% of the body surface and common burns of II and III degree and body surface 10% and more. In the course of early surgical treatment in patients with local border burns, the use of the wound coating «HitoPran» allows to achieve spontaneous epithelialization of wounds in dry environment after dermabrasion or escharotomy within the surface layers of dermis due to chitosan adhesion to the wound bottom, to reduce the number of dressings in the postoperative period. Covering skin grafts with perforation index 1:4 and 1:6 with wound «ChitoPran» coating in case of autodermoplasty in deep burn wounds provides satisfactory cellular epithelialization, reduces risk of regression of grafts, reduces consumption of wound coating and dressing material.Conclusion. Application of Russian modern biodegradable coatings based on «HitoPran» chitosan in complex treatment in patients with local and common burns with different depth allows to optimize local treatment of burn injuries, as well as to reduce the cost of used dressing material in comparison with foreign alternatives.

Extraction, transportation, transshipment and storage of oil lead to accidental pollution of soil with oil products. To solve this problem, the possibility of using organic waste produced by the Murmansk region for the remediation of oil-polluted soils in the Kola North has been studied. The study has been carried out for three months at temperatures from 10 to 18 °C simulating the temperature conditions of the summer months on the Kola Peninsula. The contaminated soil was collected outside of Murmansk borders and the zones of industrial pollution on the Kola Peninsula. The soil type is podzol. Pollution modeling has been carried out by introducing F-5 fuel oil into the soil. The following organic components have been used as reclamation agents: excess activated sludge from biological treatment facilities of the enterprise Murmanskvodokanal; Saccharomyces cerevisiae brewery sedimentary beer yeast of the Murmansk region; chitosan – a product of conversion of Kamchatka crab processing waste. Reclaimers have been applied in concentrations of 16, 20 and 20 g/kg of soil respectively. The effectiveness of reclaiming of fuel oil contaminated soils has been assessed during measuring the oil content by the fluorimetric method and the ecotoxicological phytotesting of the studied soil samples. At the end of the reclaiming period, the greatest decrease in the concentration of oil products (up to 62 %) is observed in samples with active sludge. In soil samples reclaimed by sedimentary yeast and chitosan, the decrease in concentration is 48.7 and 54.6 % respectively; at the same time, the level of soil self-purification is 22.6 %. The results of the experiment allow us to make a reliable conclusion about the effectiveness and feasibility of using excess activated sludge, sedimentary yeast and chitosan as remediation of oil-polluted soils.

A «green» method of obtaining gas separation composite membranes from cellulose solutions and its mixtures with chitosan in orthophosphoric acid is proposed for industrial use, and differs from the viscose method of producing cellophane and other known methods for producing cellulose gas separation membranes without gaseous emissions and wastewater. It is shown that new composite cellulose membranes on a viscose fabric substrate are characterized by high productivity and selectivity for O2/ N2 pairs, comparable to the values obtained for known membranes made of synthetic polymers, as well as increased mechanical strength. The developed composite membranes demonstrate an inverse selectivity for the CH4/CO2 pair, which is not typical for gas separation membranes described in the literature with cellulose-based selective layers.

The article investigates the aqueous solutions of food chitosan and glutaraldehyde to determine the feasibility of their use as components of an embolizing composition. It was shown on the basis of experimental flow curves, viscosity and velocity curves that test solutions have low viscosity and exhibit Newtonian flow behavior. The activation energy of viscous flow of the fluids was estimated in the temperature range of 25-37 °C within the Arrhenius - Frenkel - Eyring equation. It varies within a narrow range: 17-24 kJ/mol. When mixing the aqueous solutions of food chitosan and glutaraldehyde, chemical interaction of the solutes occurs. It is accompanied by an increase in viscosity and formation of a covalently crosslinked gel. Using a simple exponential equation the effective rate constant of the chemical process was calculated. It varies in a wide range: 1.9-82.7∙103 1/s. These values can be used when selecting an optimal region of food chitosan-glutaraldehyde ratios and concentrations of their aqueous solutions to generate embolizing agents. The conditions at which gel formation takes place over forty seconds were determined. Differential scanning calorimetry indicated a negligible thermal effect of food chitosan reaction with glutaraldehyde in the aqueous medium, which ensures no thermal burn during the formation of an embolus in the blood vessel in situ. As a result of the work elastic solid gels suitable for use as embolizing agents were obtained.

The paper considers the preparation of film materials based on the chitosan/polyhydroxybutyrate blend by the casting method. The combination of polysaccharide chitosan and polyester polyhydroxybutyrate gives the possibility to decrease the degradation rate and improve biomaterial mechanical characteristics. Acetic acid was used to dissolve biopolymer components. The paper presents compatibility study results for polymers in the blend composition. It was demonstrated that crystallization of polyhydroxybutyrate is suppressed by mixing with chitosan. In order to reduce the film coating solubility, we have studied the application possibility of ionic cross-linking with the help of calcium chloride. The effect of the calcium chloride content on the structure and morphology of the surface of the film compositions was studied by infrared spectroscopy and optical microscopy. Infrared spectroscopy showed that chemical cross-linking with calcium chloride occurs with the participation of carbonyl groups of polyhydroxybutyrate and hydroxyl groups of chitosan. It has been found that addition of more than 9% calcium chloride provides optically homogeneous surface of the film composition based on the chitosan/polyhydroxybutyrate blend. The obtained polymeric compositions of chitosan/polyhydroxybutyrate/CaCl2 have high perspectives for their further application in the development of medical materials.

The paper presents results of studying antigenicity and local tissue reaction in pigs immunized with the experimental PRRS vaccine produced on the basis of commercial SEPPIC (France) adjuvants with addition of water-soluble chitosan derivatives.

Strawberry (Fragaria ananassa) is among the most perishable berries and is vulnerable to physical injuries and fungal invasion. One of the main approaches to extend the storability of this perishable commodity is to apply edible coatings on the surface followed by cold storage. Edible coatings can be used as a protective barrier to reduce respiration, retard microbial growth and improve physical integrity be reinforcing the tender skin structure. The objective of the research was to the investigate the effect of chitosan treatment on weight loss, respiratory rate, pH and microbiological damage of strawberries during refrigerated storage. To achieve this goal berries were treated with 0,1; 0,3; 0,5% chitosan solution and storage at t 0+2°С for 14 days. Uncoated fruit were used as control samples. Strawberries that showed any sign of surface mycelia development were considered decayed. Results were expressed as percentage of infected strawberries. Results have shown that storage duration of strawberries in the control variant was 8 days, in the experimental variants was 14 days, which is 1,7 times longer. An important indicator of preservation is natural weight loss. The criteria for the end of storage was the weight loss no more than 5%. The experimental results show for strawberries in the control variant, the average weight loss on the 8th day of storage was (6,11%). The weight loss of treated berries were (2,88 – 4,81%). Chitosan treatment changer the respiration rate of strawberries. At the end of storage the respiration rate was (1,15 – 1,8%). Chitosan treatment berries had less damage to fungal diseases. Chitosan edible coatings can be an effective method to improve the quality and extending the shelf-life of strawberry. It approved to be good barrier, thus preventing the weight loss by evaporation and delaying microbiological damage

Background. Wastewater (alkaline) of various enterprises in significant quantities is contaminated with heavy metal cations, including Pb (II) ions. Lead is able to concentrate and accumulate in soil, sewage and groundwater, to accumulate in the human body, having a negative impact on the environment. In this regard, there is a need to develop environmentally and economically viable sorption methods for cleaning alkaline media. A promising sorbent is natural zeolite, which is also widespread in Kazakhstan. In the practice of zeolite modification, the method of modification with organic compounds with functional hydroxyl and amino groups is often used. This allows one to obtain a sorbent that combines the sorption properties of a zeolite and a modifier, for example, chitosan (C6H11O4N)n. Purpose. Investigation of the sorption process of Pb (II) cations in an alkaline medium by chitosan-modified zeolite. Methodology. When performing the work, physicochemical methods (IR, XRF, DTA, SEM) were used, the method of mathematical planning (orthogonal rotatable 3-factor experiment of the 2nd order, determination of Pb (II) was performed on AAS. Originality. A mathematical model of the sorption of Pb2+ cations by chitosan-modified zeolite from an alkaline medium has been developed. The general regularities of the process of sorption of Pb2+ cations by chitosan-modified zeolite from an alkaline medium are established. The determining factors in the process are lead concentration and temperature. Findings. The relationship between the influence of time, the concentration of Pb (II) cations and the process temperature on the sorption capacity of the sorbent was revealed. The sorption process of Pb2+ cations proceeds according to the ion-exchange type due to the exchange of H+ cations located in exchange positions in the zeolite structure. The high sorption ability of chitosan-modified (97-99.3%) zeolite is achieved due to the participation of the (C6H11O4N)n modifier, active in the process of ion exchange, of the acid centers of the zeolite and hydroxyl and amino groups. [ABSTRACT FROM AUTHOR]

Anti-influenza drugs and vaccines have a limited effect due to the high mutation rate of virus genome. The direct impact on the conservative virus genome regions should significantly improve therapeutic effectiveness. The RNA interference mechanism (RNAi) is one of the modern approaches used to solve this problem. In this work, we have investigated the antiviral activity of small interfering RNA (siRNA) against the influenza A/PR/8/34 (H1N1), targeting conserved regions of NP and PA. Polycations were used for intracellular siRNA delivery: chitosan’s derivatives (methylglycol and quaternized chitosan), polyethyleneimine, lipofectamine, and hybrid organic/non-organic microcapsules. A comparative study of these delivery systems with fluorescent labeled siRNA was conducted. The antiviral activity of three small interfering RNAs targeting the NP (NP-717, NP-1496) and PA (PA-1630) influenza A viruses genes was demonstrated, depending on the chosen carrier. The most effective intracellular delivery and antiviral activity were observed for hybrid microcapsules.

Objective: to conduct a clinical study of the effectiveness of the gel based on chitosan in skin care healthy people with different manifestations of signs of aging and patients with pigmented lesions of the skin of those aged 34 to 63 years. Material and Methods. The study was performed in the group of patients consisting of 10 people ranging in age from 34 to 63 years. They have been estimated by the following biophysical parameters: the moisture level and elasticity of the skin, the melanin content, the level of erythema, as well as the width and depth of wrinkles. Results. The application of hydrogel with chitosan marked hydration of the skin (in particular immediate increase in skin moisture immediately afterthe first application), reducing the depth and width of wrinkles, restoring elasticity and improving muscle tone. Conclusion. Course application of the hydrogel during the month allows you to obtain a lasting effect, OMO application.

In the work the hypothesis has been proposed explaining the features of the kinetics of chitin/chitosan alkali deacetylation reaction in highly concentrated solutions of sodium hydroxide, which almost completely stops after 30–60 min after the start of the reaction and does not provide a fully deacetylated product – chitosan. Analysis of the known publications explaining the observed decline in the deacetylation reaction rate has been executed, and some new experimental results confirming the authors' conclusions have been presented. It has been shown that water present in the reaction mixture renders the greatest influence on the kinetics of chitin deacetylation, and can lead to hydration as chitin molecules and ions alkalis as well. The hypothesis has been offered according to which in the reaction mixture there is the dynamic balance between hydrated alkali ions, molecules of chitin and formed acetate ion, which can shift depending on the concentration of the reacting particles. It has been suggested that in concentrated alkali solutions water is present almost entirely or partly in the form of hydrate shells of alkali ions, and to a lesser extent in the form of "free" water. Apparently, the limiting stage of the deacetylation reaction is the hydration of chitin macromolecules by water molecules, which are released during nucleophile replacing hydroxyl ions by acetyl radicals binding with chitin amino groups. Acetate ion is a product of the deacetylation reaction. Acetate ion hydration energy is less than hydration energy of hydroxyl ion, so the acetate ion is less hydrated, as a result some water is released. In these conditions, hydration of chitin macromolecules occurs in the local area around the chitin molecules, where the high water concentration is created after deacetylation. The alkali concentration in all reaction volume remains practically constant.

Objective of research: to study the mechanisms of induced tomato plant resistance to rootknot nematode Meloidogyne incognita and potato to cyst nematode Globodera rostochiensis.Materials and methods: The biogenic elicitors — chitosan and signal molecules — SA, JA for the modulation of immune plant responses were used. In experiment 1, tubers of potato cultivars Istrinskii (PCN-susceptibility) and Krinitsa (PCN-resistant), were treated with aqueous solutions of the immunomodulators at the specified concentrations. A low molecular weight soluble chitosan and acetylation degree of 15% and signal molecule — SA was used as an elicitor. In experiment 2, system tomato M. incognia was studied. Water solutions of chitosan, signal molecules: SA, JA were used for treatment of tomato seeds for 2 h and then the seeds were planted in sterile soil. The control plants were treated with water. Cultivation of plants was carried out by the standard technique. Plants were maintained in a greenhouse long enough for the nematodes to complete their life cycle. Development of nematodes in the processed plants estimated on morphophysiological and population characteristics. Biochemical indicators of roots and leaves of tomatoes estimated for 14 days after infection of plants. Previously identified major biochemical indicators of the plants in the genome that contain genes that determine the resistance of plants. The effects of biogenic elicitors on plant resistance were also evaluated by some metabolic changes related to natural plant resistance to tomato and potato to plant nematodes. These indicators were studied in clarifying mechanisms of induced resistance.Results and discussion: Biogenic elicitors induce systemic resistance of plants to plant parasitic nematodes — Meloidogyne incognita and Globodera rostochiensis (decrease in the parasitic invasion of the roots; an inhibition of the vital activity of the parasite; a decrease in fertility and the amount of agents sources (larvae and eggs) capable of infecting the plants). The addition of signal molecules (salicylic and jasmonic acid) to elicitors increased their activity as immunomodulators. In present investigation, the mechanisms of induced plant resistance nematode were studied. The data obtained suggest that the mechanisms natural and induced by biogenic elicitors tomato resistance to the nematode have the same origin. These features meet all requirements of the new generation of methods of plant protection and the use of biogenic elicitors to raise plant resistance to parasitic nematodes may be promising.

The article describes modern methods for producing one-, two-, and three-dimensional composite matrices for tissue engineering based on resorbable and non-resorbable polymers. Coagulation method for producing composite fibers based on chitosan and chitin nanofibrils, electrospinning method for composite nanofibers, lyophilization of chitosan solutions and their mixtures with nanoparticles to obtain three-dimensional porous matrices with increased stability of mechanical characteristics in aqueous media. The results of the study of the adhesion and kinetics of proliferation of stem and somatic cells of humans and animals on the developed matrices are presented. In vivo experiments have shown that materials in the form of fibers, films, tubular samples, and sponges can be used as implants for blood vessels, effective wound dressings. The article contains the results of the study of the kinetics of resorption of the studied materials in a living organism.

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To produce high quality products at modern enterprises of food industry it is necessary to establish effective systems of quality and safety such as HACCP. The paper presents a brief review of modern quality management systems of food products. This study deals with peculiarities of food safety management system when producing beverages stable to turbidity. Improvement of the system is considered in the framework of one of the principles of the concept of quality of beverages prone to turbidity. Implementation is performed by augmenting the implemented safety management system of the production process with additive critical control points. The quantitative content of the turbidity components of beverages is controlled with the designation of critical limits of their concentration and, actually, a processing aid in the technological chain. The necessity of additive critical control points at the stage of beer fermentation has been established. The HACCP worksheet for stable beer has been developed. Regarding the storage and preparation of chitosan the production program of mandatory preliminary actions when producing stable beer using chitosan has been proposed.

Chitosan-based adjuvants combine effectiveness, safety and economic feasibility and thus are quite promising for enhancement of influenza control via vaccination, however, problems of characterization and reproducibility remain unresolved; data on relations between physical-chemical characteristics (PCC) of the polymer and immunogenicity of chitosan-based adjuvants, as well as comparative evaluation with other adjuvants are needed. Groups of mice were immunized intramuscularly with inactivated influenza vaccines based on A/California/07/2009 (H1N1) strain with characterized adjuvants based on chitosan with varying PCC (molecular mass 700 and 10 kDa, deacetylation degree 85%; HMC and LMC, respectively) and its derivative (succinylated chitosan (SC)). Experimental formulations were also studied: an «oil-in-water» emulsion (ME) and a multi-component adjuvant (MS). Different adjuvants increased immunogenicity of the inactivated influenza vaccines by hemagglutinin inhibiting sera antibodies in varying patterns. HMC was more immunogenic than LMC, whereas SC even reduced immunogenicity of the vaccine. HMC was comparable to MS by immunogenicity, and LMC - to ME. PCC of chitosan and its derivatives play an important role in immunogenicity of the respective adjuvants, and perspective and characterized chitosan-based adjuvants are comparable or even more immunogenic than adjuvants from other groups.

Aim. Direct immunogenicity comparison of adjuvants from various sources and with different mechanisms of action for inactivated influenza vaccines. Materials and methods. Groups of mice were immunized intramuscularly twice with an inactivated whole-virion influenza vaccine based on A/ California/07/2009 X-179A (H1N1) strain. The following adjuvants were added to the vaccine (10 in total): aluminium hydroxide, oligonucleotide CpG, complete Freund’s adjuvant, poly(lactide-co-glycolide) microparticles, monophosphoryl lipid A and polyoxidonium, as well as 2 adjuvants based on characterized chitosan substances with different physical/chemical properties and 2 experimental complex formulations (a multi-component adjuvant and an oil-in-water emulsion based on squalene and tocopherol). Immunogenicity was determined by HAI and MN (MDCK) sera antibodies. Results. Different adjuvants increased immunogenicity of the vaccine against the homologous strain in varying patterns. Experimental complex formulations were the most immunogenic (antibody titer increase reached 48 - 96 times compared with unadjuvanted vaccines). Chitosan based adjuvants showed high immunogenicity. Not all the adjuvants significantly increased immunogenicity, and in some cases even an immunogenicity decrease was noted with the addition of certain adjuvants. Conclusion. Research and development of chitosan based adjuvants with characterization and standardization issues addressed, as well as complex adjuvants, both multi-component and emulsion based, are the most promising approaches that could lead to next generation vaccines against influenza and other human and animal infectious diseases.