Acid-soluble Chitosan Research Articles

Assessment of adsorption efficiency of Kaoline-Chitosan composite beads for removal of Ca and As from aqueous solution in lab-scale

Abstract In this study, Kaoline (CK) and Chitosan (CTS) including water-soluble CTS (WCTS) and acid-soluble CTS (ACTS), were synthesized from commercial materials to produce composite beads which were then employed as adsorbents to investigate the removal of Ca and As from aqueous solutions. Results showed that the adhesion and granular properties of CK-WCTS and CK-ACTS were different, which affected the adsorption efficiency. Specifically, when 0.3 g of adsorbent (i.e., CK-WCTS and CK-ACTS) was used to test with 30 ml aqueous solution containing 380 ± 50 mg/L Ca(II) during 2 hours, the CK-ACTS showed more effective (i.e., Ca(II) removal of 34.73%) as compared to CK-WCTS (i.e., only 2.08%). In the case of As(III) removal, 0.5 g of adsorbent (i.e., pure ACTS and CK-ACTS composite) was applied to test with 50 ml artificial aqueous As (III) solution of 500 ± 50 μg/L during 90 mins of operation. The CK-ACTS composite also showed better performance since the highest removal As efficiency of 72% could be obtained after a contacting time of 45 mins, as compared to that produced by pure ACTS (i.e. As removal of 42.42%). The SEM analysis was also conducted to compare the difference in morphology of pure ACTS and CK-ACTS composite.

Preparation of high water-retention biodegradable kidney tray from rice straw pulp

A biomedical pulp product, a hydrogel-coated high water-retention biodegradable kidney tray from rice straw pulp, was successfully prepared in a simple and environmentally friendly process. Response surface methodology (RSM) was applied to optimize the rice straw pulping condition. The optimum condition was investigated using influential parameters and the results were 17% active alkali, 21.15% sulfidity, and 120-min pulping time, resulting in a pulp yield of 38.56% and a delignification selectivity of 25.91%. This pulping condition effectively increased the cellulose proportion and the crystallinity of the pulp, while the lignin portion was decreased. The hydrogel was prepared by mixing acid-soluble chitosan solution and rice straw pulp suspension. Introducing the hydrogel into the kidney tray led to water retention for 5 h with no leak and swelling degree up to 500%. The kidney tray also showed a good level of biodegradation, indicated by changes in surface morphology and weight loss of the sample and also high tensile strength. Therefore, this research suggests that rice straw pulp has promising application in the development of biodegradable and high-strength biomedical pulp products such as pulp-based kidney trays.

Improving the technology for obtaining of low molecular weight chitosan under conditions of controlled enzymatic cleavage

Relevance. Annotation. Experimental data on improving the production technology of regulated enzymatic cleavage of chitosan to obtain its low-molecular derivatives are presented. Experimental studies were carried out in the conditions of the Department of Disease Diagnostics, Therapy, Obstetrics and Animal Reproduction of the Moscow State Academy of Veterinary Medicine and Biotechnology — MVA named after K.I. Skryabin and on the basis of the All-Russian Research and Technological Institute of the Biological Industry.Methods. Acid-soluble chitosan from king crab shell (MM 700 kDa, SDA 85%), chitosan succinate (MM 330 kDa, SZ 75.2%), low-molecular food chitosan (hydrochloride) (MM 50 kDa) were used as raw materials for obtaining new modifications of chitosan, gel chitosan (2% solution in 2% acetic acid) manufactured by Bioprogress LLC.Results. As a result of the experiment, the technological parameters of obtaining low-molecular chitosan by enzymatic hydrolysis were selected. The greatest decrease in the dynamic viscosity of chitosan was reliably observed in the pilot-industrial series II (by 29.3 times), and the pilot-industrial series I and III — by 6.9 and 10.6 times, respectively. As a result of enzymatic hydrolysis of chitosan in the pilot series II, it was possible to reduce the molecular weight from 700 to 24 kDa, and in series I and III — to 102 and 66 kDa. Based on the research results, a technological scheme for obtaining low-molecular-weight chitosan derivatives by enzymatic hydrolysis has been developed, tested and proposed for industrial use, technical conditions have been developed.

Effect of pH Variation on Cross-Linking of Water-Soluble and Acid- Soluble Chitosan with Sodium Tripolyphosphate and Gallium-67.

Chitosan is a cationic biopolymer obtained from deacetylating chitin, a natural compound present in crustacean shell, fungi and exoskeleton of insects. Chitosan involves various applications, including as drug and gene delivery systems, as wound dressing material and scaffolds for tissue engineering, agriculture, textile, food and feed nanotechnology, and in wastewater treatments. Chitosan-TPP particle has been figured out as the most important and stable nanoparticle for chitosan application in various fields. In this study, chitosan was chemically modified by sodium tripolyphosphate (TPP). Afterward, TPP-chitosan was radiolabeled with the gallium-67 radionuclide. The effect of several factors on labeling yield, such as chitosan solubility, acidity and concentration of TPPchitosan solution, and incubation time with gallium-67, were investigated. To prepare [67Ga] gallium-chitosan complex, chitosan (0.5 ml) was dissolved in 2.2 mCi of [67Ga] gallium chloride solution. The obtained solution was stirred for 5 min and then kept for 30 min at room temperature. The radiochemical purity and radiolabeling yield were measured via radiochromatography, which was performed by using a radio thin-layer chromatography (TLC) scanner instrument. To investigate the effect of chitosan kind and concentration on the labeling yield, two kinds of chitosan (acid-soluble chitosan and water-soluble chitosan) at two different concentrations (1% and 0.5%) and different pH were used. In addition, labeling efficiency and stability of the 67Ga-TPP-chitosan complex (acidic/water soluble chitosan) at both concentrations (0.5 and 1%) and at room temperature were assessed for 30, 45 and 60 min. The incubation time did not have any significant effect on labeling yield. The acidic soluble chitosan exhibited the highest radiolabeling yield at pH=9.3-10.4, while water-soluble chitosan showed the highest radiolabeling yield at pH > 5. Also, the prepared complex was stable in the final solution at room temperature and could even be used 24 hours after preparation for further application. Taken together, the TPP-modified water-soluble chitosan at the concentration of 0.5 % depicted the highest radiochemical yield (>95 %) in the optimized condition (pH= 6.2- 7.6). Therefore, TPP modified water-soluble chitosan can prove to be an effective carrier for therapeutic radionuclides in tumor treatment.

Combination of Polysaccharide Nanofibers Derived from Cellulose and Chitin Promotes the Adhesion, Migration and Proliferation of Mouse Fibroblast Cells.

Extracellular matrix (ECM) as a structural and biochemical scaffold to surrounding cells plays significant roles in cell adhesion, migration, proliferation and differentiation. Herein, we show the novel combination of TEMPO-oxidized cellulose nanofiber (TOCNF) and surface-N-deacetylated chitin nanofiber (SDCtNF), respectively, having carboxylate and amine groups on each crystalline surface, for mouse fibroblast cell culture. The TOCNF/SDCtNF composite scaffolds demonstrated characteristic cellular behavior, strongly depending on the molar ratios of carboxylates and amines of polysaccharide NFs. Pure TOCNF substrate exhibited good cell attachment, although intact carboxylate-free CNF made no contribution to cell adhesion. By contrast, pure SDCtNF induced crucial cell aggregation to form spheroids; nevertheless, the combination of TOCNF and SDCtNF enhanced cell attachment and subsequent proliferation. Molecular blend of carboxymethylcellulose and acid-soluble chitosan made nearly no contribution to cell culture behavior. The wound healing assay revealed that the polysaccharide combination markedly promoted skin repair for wound healing. Both of TOCNF and SDCtNF possessed rigid nanofiber nanoarchitectures with native crystalline forms and regularly-repeated functional groups, of which such structural characteristics would provide a potential for developing cell culture scaffolds having ECM functions, possibly promoting good cellular adhesion, migration and growth in the designated cellular microenvironments.

Содержание липидов в яйце при добавлении в рацион кур-несушек кислото- и водорастворимого хитозана

The studies were carried out on laying hens of the Ptichnaya cross at the age of 19 weeks. with an initial live weight of 1,67 kg for 1,5 months, who were given a complete mixed feed (recipe No. KK 1-58-59576, (OJSC Istra-Hleboprodukt) at 135 g/bird/day. The hens were divided into 4 groups: the 1st was the control group received BR without additives, the 2nd and 3rd received BR + acid-soluble chitosan (ASC) at 10 and 20 mg/kg of live weight, respectively, the 4th received BR + 20 mg kg/l of live weight of water-soluble chitosan succinate (WSCC). Inclusion in the diet of laying hens of both forms had practically no effect on the content of total lipids in the yolk. In the eggs of group 2 hens, the content of total lipids in relation to the control at the age of 30 weeks was higher by 10,3 %, at 52 weeks it was lower by 3 %, and at 65 weeks it was lower by 0,76 %. In the eggs of hens of the 3rd group, the content of lipids at the age of 30 weeks was higher than in the control samples of eggs by 12,8 %, at 52 weeks by 1,2 %, and 65 weeks no differences were found. WSCC had no effect on the content of phospholipids, and ASC increased their concentration (depending on the dose). At a lower dose, an increase in the level of phospholipids in the yolk in the 1,8 times. In the eggs of hens of the 2nd group, the concentration of phospholipids was higher than in the control ones at the age of 30 weeks. by 85 %, at 52 weeks by 51,6 %, and at 65 weeks by 50%. In the eggs of hens of group 3, the concentration of phospholipids was higher compared to the data of eggs of hens of the control group at the age of 30 weeks. by 36,5 %, at 52 weeks. by 8 % and 65 weeks – by 9,6 %. The introduction of ASC at a dose of 10 mg/kg of live weight into the diet of chickens was accompanied by a decrease in cholesterol content by 1,5 times, and WSCC at a dose of 20 mg – by 2 times. The content of polyunsaturated fatty acids in the eggs of laying hens between the control and experimental groups did not have significant differences and their values are within the established norms. When ASC was included in the diet of laying hens at a dosage of 20 mg/kg of live weight, a 15 % decrease in the amount of polyunsaturated fatty acids was observed, with an increase in the content of fatty acids of the ω-3 family in the whole egg by 24 %.

Feasibility study of the project of using own-produced mayonnaise at a public catering enterprise

The relevance of the issue considered in the paper follows from the current state of development of public catering, when the recipe components of industrial production (sauces, seasonings, marinades, semi-finished products, etc.) are replaced by products produced at the enterprises of the food industry. The technology and formulations of fat and oil products of emulsion nature - mayonnaise, enriched with biologically active additives with high nutritional and functional properties have been developed. The paper substantiates an approach to the feasibility study for the production of mayonnaise for functional purpose using acid-soluble chitosan, protein concentrate from sesame seeds and β-carotene at public catering establishments. On the basis of production and financial plans, analysis of project risks, an assessment of the economic efficiency from the introduction and implementation of the developed technological solutions was made. The production plan includes the following structural elements: the volume of capital investments, the capacity of the enterprise, the program for the production and sale of products, wages, the cost of fixed assets, the cost of production and sales of products. The financial plan included the volume of project financing, calculations of taxes, cash receipts and payments.

БІОТЕХНОЛОГІЧНІ ОСНОВИ ТЕХНОЛОГІЇ КОНСТРУЮВАННЯ «GREEN ARTICLE» ДЛЯ УПРАВЛІННЯ ХАРАКТЕРИСТИКАМИ БІОКЕРАМІЧНОГО ЗАХИСНОГО ШАРУ ШКАРАЛУПИ ЯЄЦЬ КУРЕЙ В ТЕХНОЛОГІЧНОМУ ПРОЦЕСІ ІНКУБАЦІЇ

Авторами теоретично обґрунтована та практично доведена ефективність застосування розробленого способу передінкубаційної обробки яєць з використанням біоміметичної технології «штучна кутикула» «ARTICLE» («ARTIficial cutiCLE») «GREEN ARTICLE» для поліпшення структурних і фізіологічних характеристик шкаралупи як біокерамічного захисного шару інкубаційних яєць, котра полягає в утворенні на поверхні яйця захисної плівки з суміші штучних і природних матеріалів, що регулює рівень газопроникності шкаралупи пташиного яйця. Захисна плівка являє собою полікомпонентне покриття для відновлення та посилення бар’єрних властивостей біокерамічних структур шкаралупи і шкаралупних мембран, якому притаманна біоцидна (антибактеріальна та антивірусна) активність, а також здатність оптимізувати газообмін ембріонів протягом інкубації та поліпшувати процеси обміну речовин ембріона і якість молодняка птиці. Метою нашої роботи була розробка технології передінкубаційної обробки курячих яєць «GREEN ARTICLE» з використанням захисних нанокомпозитних покриттів «Штучна кутикула», що були створені за біоміметичним принципом, для зниження контамінації патогенною мікрофлорою та підвищення виводимості яєць. Для проведення досліду було сформовано три партії яєць, котрі були отримані від курей-несучок Легорн білий, по 540 штук в кожній групі. В кожній партії був контроль і дослідна група. Інкубацію проводили в інкубаторі «Універсал» протягом 21 доби згідно методики. Першу групу яєць перед закладкою на інкубацію обробляли кислото розчинним хітозаном, другу – водорозчинним хітозаном, третю – водорозчинним хітозаном сукцинат. Рахували відсоток браку інкубації, вивід та виводимість курчат. Перед закладкою на інкубацію, а також на сьому та вісімнадцяту добу інкубації, перед перенесенням яєць у вивідну шафу, брали змиви з поверхні шкаралупи і досліджували їх на наявність мікробної контамінації. Доведено, що використання для передінкубаційної дезінфекції курячих яєць композиції на основі кислоторозчинного хітозана з додаванням надоцтової кислоти, пероксиду водню (H2O2) та наночасток металів (нанодисперсного діоксиду титану TiO2, оксиду заліза Fе2O3 та сульфату міді CuSO4), стимулює розвиток ембріонів та забезпечує підвищення виводимості яєць на 7,7 % відносно контролю. Технологія «GREEN ARTICLE» для передінкубаційної обробки яєць з використанням препарату «Штучна кутикула» призводить до значного зниження кількості патогенних мікроорганізмів на поверхні шкаралупи, що призводить до підвищення виводимості яєць.

INFLUENCE OF THE MODIFICATION TYPE OF CHITOSAN WITH CARBONYL-CONTAINING COMPOUNDS ON THE PROPERTIES OF FORMED FILM MATERIALS

The features of the modification of acid-soluble chitosan by carbonyl-containing compounds in solution and by the method of surface modification of molded materials are investigated. The dependence of the rheological properties of polysaccharide solutions on the structure of the hydrocarbon radical of the modifier is established. The formed films based on iminochitosans, obtained by the interaction of the polymer with aldehydes in a solution of acetic acid, have lower surface, hydrophobic, and strength characteristics compared to chitosan films. The possibility of biodegradation of the obtained materials, as well as the dependence of the mass loss of the samples on the HLB level, which can be used to create wound dressings with programmed degradation, is shown.

Comparison of acid and water-soluble chitosan doped fibrous cellulose hemostat wet laid nonwoven web for hemorrhage application

Fibrous hemostat was produced using wet laying technique comprising of acid and water soluble chitosan with fibrous cellulose. The hemostatic efficiency and their structural properties were evaluated using blood clotting time, whole blood adhesion and analytical characterization techniques. The maximum concentration of chitosan utilised for the production of nonwoven was 1.5 w/v % upon which increased the viscosity of the solution. The absorption of phosphate buffer solution was found to be 1117% for acid soluble chitosan based nonwoven whereas for water soluble chitosan based nonwoven was 997%. Increased red blood cells and platelets were found to be higher in acid soluble chitosan compared to water soluble chitosan based cellulose nonwoven. The blood clotting time for acid soluble chitosan nonwoven was found to be 166 s and water soluble chitosan nonwoven was 170 s. The developed hemostat have potential application in reducing blood loss and also inducing the blood coagulation pathway which was confirmed by the adhesion of platelets on to the surface of nonwoven web.

Содержание деценовых кислот в препаратах трутневого расплода и комбинированных препаратах на его основе

The drone brood contains a large number of substances with antioxidant activity. These substances require stabilization and strict adherence to storage conditions. Among these substances are unique decenoic acids, the content of which is an indicator of the quality of drone brood and products based on it. The ability of drone brood to reduce the manifestations of oxidative stress is shown. There are dietary supplements for food and drugs based on drone brood, which are used for a wide range of diseases. Together with drone brood, chitosan-containing products, propolis, royal jelly can be used. They enrich the composition with their own biologically active substances and affect the preservation of the biologically active substances of the drone brood. Promising are the products containing, in addition to the drone brood, a chitin-chitosan-melanin complex from bees, propolis, royal jelly. The chitin-chitosan-melanin complex in the amount of 5% in the composition of the adsorbent practically does not affect the preservation of decenic acids, while in the amount of 2% and 10% it somewhat worsens. The acid-soluble and water-soluble chitosan of marine crustaceans significantly worsens the preservation of decenoic acids in the product. Drone brood with royal jelly demonstrates a rather high content of decenoic acids. When propolis is introduced into the composition of the product, the content of decenoic acids increases according to the content of propolis.

A model for predicting microbiological and organoleptic indicators of salads during storage with the use of chitosan

The authors theoretically substantiated and experimentally confirmed the feasibility of using high-molecular acid-soluble chitosan (HAC), which inhibits the growth of microbial flora in the production of salads, to extend the expiration date of salads and ensure the quality and safety indicators of products during storage. The effect of «cold pasteurization» of HAC on the microflora of salads was established. Regression models were obtained that adequately describe the effect of HAC on the microbiological and organoleptic indicators of salads. A method for multi-criteria optimization of the technological mode of production of salads using chitosan according to microbiological and organoleptic indicators to extend their expiration date is proposed. A method for the introduction of HAC in the production of salads in the composition of the dressing – in the form of a 1 % solution in 3 % acetic acid. Salad dressing recipe using HAC was developed. The efficiency of the production technology of salads with the use of HAC was confirmed, which allows one to extend their expiration date at a storage temperature of (4 ± 2) °C from 12 to 78 h.

Wasted Ganoderma tsugae Derived Chitosans for Smear Layer Removal in Endodontic Treatment

The objective of this study is to investigate the synergistic effects of acid etching and metal-ion chelation in dental smear layer removal using wasted Ganoderma tsugae derived chitosans. The wasted Ganoderma tsugae fruiting body was used to prepare both acid-soluble fungal chitosan (FCS) and alkali-soluble polysaccharide (ASP). To explore the effective irrigant concentration for smear layer removal, a chelating effect on ferrous ions was conducted. Specimens of various concentrations of EDTA, citric acid, and polysaccharide solutions were reacted with FerroZine™ then the absorbance was examined at 562 nm by a UV-visible spectrophotometer to calculate their metal chelating capability. Twenty extracted premolars were instrumented and individually soaked in the solutions of 15 wt% EDTA, 10 wt% citric acid, 0.04 wt% ASP, 0.04 wt% FCS, and normal saline were randomly divided into five groups (N=4). Next, each tooth was cleaved longitudinally and examined by scanning electron microscopy (SEM) to assay the effectiveness of smear layer removal. The chelating capability for EDTA, FCS, and ASP showed no significant difference over the concentration of 0.04 wt% (p > 0.05). The SEM results showed that 0.04 wt% FCS solution was effective in smear layer removal along the canal wall. These results indicated that Ganoderma tsuage derived FCS in acid solutions could be a potential alternative as a root canal irrigant solution due to its synergistic effect.

The effect of different kinds of chitosans and cooking methods on the formation of heterocyclic aromatic amines in huso ( Huso huso ) fillet

The aim of the present survey was to investigate the effectiveness of different chitosans (oligosaccharide and acid soluble) and cooking methods (deep‐fat frying and barbecuing) on the formation of four potentially carcinogenic heterocyclic amines (PhIP, IQ, MeIQ, and MeIQx) in fish fillet of huso (Huso huso). The results demonstrated that chitosans imparted significantly (p ≤ .05) favorable characteristics on texture profile, cooking traits, and proximate composition in the fillet. Concerning heterocyclic aromatic amines (HAAs) compositions, PhIP (Non‐detected [Nd]—2.51 ng/g), IQ (Nd—0.62 ng/g), MeIQ (0.41–0.92 ng/g), and MeIQx (Nd—1.20 ng/g) were evaluated. The total HAA amounts in the barbecued samples were higher than the deep‐fat frying samples. The fried samples treated with 1% acid soluble chitosan had the highest inhibitory effect (68.09%) against HAA formation. Based on the results, chitosan could reduce the formation of HAAs in huso fillet in the deep‐fat frying fillet. PRACTICAL APPLICATIONS: Chitosan can be utilized in fish processing company to reduce HAA contents in them. In addition, chitosan can reinforce antioxidant and antimicrobial properties in them.

The infrared spectroscopy of chitosan films doped with silver and gold nanoparticles

Abstract This work presents the dependences of the absorption intensity of the acid-soluble chitosan biopolymer films in the infrared (IR) region of the spectrum on the concentrations of silver and gold nanoparticles (NPs) of different morphologies. The interaction mechanisms in the vibrational spectra overlapping area of the silver NPs and chitosan molecules (2500–3500 cm−1) were observed. The influence of the metal NPs on the dipole moments of the OH-, NH3 +- and CH-chitosan molecule group oscillations was established. This interaction leads to a linear increase of the IR absorption intensity with an increase of the silver nanoparticle concentration, synthesized by the citrate and borohydride methods. The presence of silver and gold ablative NPs in the chitosan films demonstrates the IR absorption intensity exponential decrease with the metal NPs’ concentrations.

FORMATION OF CONSUMPTION PROPERTIES OF SWEET PEPPER (CAPSICUM ANNUUM L.) SAUCE

The aim of the study is to form consumption properties of a green sweet pepper sauce with a balanced content of macro- and microelements. Due to the use of Xanthium strumarium and chitosan a new product has high organoleptic properties that attract a consumer and increase its competitiveness at the market. Sweet green pepper that relates to most valuable vegetable cultures as to food value and taste was chosen as a main component of a sauce. For giving it a necessary consistence and for decreasing a time of thermal processing, there was used chitosan. According to results of the conducted studies, it was established, that among studied types of chitosan, advantages as to forming a consistence belongs to food acid-soluble chitosan with particle sizes up to 0,5 mm in amount 0,5 %.For preserving the natural green color, pepper fruits were preliminarily processed in 1 % decoction of Xanthium strumarium at temperature 75ºС during 15 min. For increasing its food value, the recipe was added with spicy-aromatic vegetable raw materials: garlic, dill, parsley, celery. The sauce quality was formed by mathematical modeling using general criteria of optimization of organoleptic parameters. There were also determined specific criteria of optimization of the recipe composition taking into account their daily need. As a result of the conducted studies the composition of recipe components for the sauce was optimized: sweet pepper 80 %, garlic leaves – 5 %, parsley leaves,dill – 5 %, celery leaves – 5 %, salt – 1,5 %, sugar – 0,5 %, chitosan – 0,5 %. There were studied organoleptic parameters of the developed sauce, characterized by a pleasant bright-green color, homogenous paste-like consistence, pleasant taste and smell. The used stabilizing factors allowed to get the sauce with the increased content of essential factors of nutrition. They participate in the increase of protective forces of the organism, so allow to recommend them in prophylactic, child and dietary nutrition.

Combining electrospun nanofibers with cell-encapsulating hydrogel fibers for neural tissue engineering

A promising component of biomaterial constructs for neural tissue engineering are electrospun fibers, which differentiate stem cells and neurons as well as direct neurite growth. However, means of protecting neurons, glia, and stem cells seeded on electrospun fibers between lab and surgical suite have yet to be developed. Here we report an effort to accomplish this using cell-encapsulating hydrogel fibers made by interfacial polyelectrolyte complexation (IPC). IPC-hydrogel fibers were created by interfacing acid-soluble chitosan (AsC) and cell-containing alginate and spinning them on bundles of aligned electrospun fibers. Primary spinal astrocytes, cortical neurons, or L929 fibroblasts were mixed into alginate hydrogels prior to IPC-fiber spinning. The viability of each cell type was assessed at 30 min, 4 h, 1 d, and 7 d after encapsulation in IPC hydrogels. Some neurons were encapsulated in IPC-hydrogel fibers made from water-soluble chitosan (WsC). Neurons were also stained with Tuj1 and assessed for neurite extension. Neuron survival in AsC-fibers was worse than astrocytes in AsC-fibers (p < 0.05) and neurons in WsC-fibers (p < 0.05). As expected, neuron and glia survival was worse than L929 fibroblasts (p < 0.05). Neurons in IPC-hydrogel fibers fabricated with WsC extended neurites robustly, while none in AsC fibers did. Neurons remaining inside IPC-hydrogel fibers extended neurites inside them, while others de-encapsulated, extending neurites on electrospun fibers, which did not fully integrate with IPC-hydrogel fibers. This study demonstrates that primary neurons and astrocytes can be encapsulated in IPC-hydrogel fibers at good percentages of survival. IPC hydrogel technology may be a useful tool for encapsulating neural and other cells on electrospun fiber scaffolds.

Tartrate/tripolyphosphate as co-crosslinker for water soluble chitosan used in protein antigens encapsulation

In drug delivery research, several toxic chemical crosslinkers and non-toxic ionic crosslinkers have been exploited for the synthesis of microparticles from acetic acid soluble chitosan. This paper hypothesized the implementation of sodium potassium tartrate (SPT) as an alternative crosslinker for sodium tripolyphosphate (TPP) and SPT/TPP co-crosslinkers for synthesis of the microparticles using water soluble chitosan (WSC) for encapsulation of Bovine serum albumin (BSA) as a model protein, and Tetanus toxoid (TT) as a model vaccine. The crosslinking was confirmed by FT-IR, SEM with EDS. The XRD entailed molecular dispersion of proteins and thermal analysis confirmed the higher stability of STP/TPP co-crosslinked formulations. The resultant microparticles were exhibiting crosslinking degree (52–67%), entrapment efficiency (72–80%), particle size (0.3–1.7μm), zeta potential (+24 to 46mV) and mucoadhesion (41–68%). The superiority of SPT over TPP was confirmed by higher crosslinking degree and entrapment efficiency. However, co-crosslinking were advantageous in higher regression values for Langmuir adsorption isotherm, slower swelling tendency and extended 30days controlled in-vitro release study. TT release obeyed the Quasi-Fickian diffusion mechanism for single and cocrosslinked formulations. Overall, in crosslinking of chitosan as biological macromolecules, STP/TPP may be alternative for single ionic crosslinked formulations for protein antigen delivery.

Effect of chitosan and sodium alginate edible coatings on the postharvest quality of fresh-cut nectarines during storage

Introduction. The use of edible coatings could be a new technological alternative to maintain fruit quality during cold storage. The objective of this work was to determine the effects of different coatings, alone or in conjunc- tion, on the quality of fresh-cut nectarines during storage. Materials and methods. Nectarines (Prunus persica L.) cv. Big Top were studied under three different coatings: 2% acid-soluble chitosan, 1.5% sodium alginate, and a solution with 3% chitosan and 2% sodium alginate. Slices were then sealed in polyethylene plastic bags and stored at 4 ◦ C and 95% RH for 9 days. Titratable acidity, soluble solids content, firmness, weight loss, color, browning potential and polyphenol oxidase activity were determined. Yeasts and molds were also monitored. Results and discussion. Nec- tarine firmness was maintained equally in all analyzed groups. The color parameter L* showed a tendency to decrease with the increasing length of storage, with lower values in alginate- and alginate + chitosan-coated fruits. The chitosan coating decreased the metabolism activity of fruit during the cold storage without significant changes in the fruit quality (lightness and total soluble solid content). The chitosan coating also controlled the growth of microorganisms. Conclu- sion. The chitosan coating appears to be a promising preservation alternative and an effective method to improve the quality and shelf life of fresh-cut nectarines in marketing conditions.

Effects of Edible Coatings on Quality Maintenance of Fresh-cut Nectarines

The study was conducted to investigate the effects of edible coatings, alone or in conjunction, on overall postharvest quality of fresh-cut Orion nectarine under fresh-cut commercial storage conditions. Three different coatings were used: 2% acid-soluble chitosan, 1.5% sodium alginate and a solution with 1.5% chitosan and 1% sodium alginate. Fresh-cut nectarine slices firmness, color, soluble solids content, titratable acidity and polyphenol oxidase activity were measured. Also microorganism counts of yeasts and moulds were analized. The results indicated that treatments with alginate inhibited decrease in firmness, titratable acidity and delayed browning. Chitosan coating reduced microorganism counts of yeasts and moulds compared to control treatment. Furthermore alginate inhibited the activities of PPO throughout the storage period. Our study suggests that alginate coating treatment may be a promising method of maintaining fresh-cut nectarines quality and extending their postharvest life.