The Chitosan Implementation into Cotton and Polyester/Cotton Blend Fabrics

Chitosan is an environmentally friendly agent that is used to achieve the antimicrobial properties of textiles. Nowadays, the binding of chitosan to the textiles has been thoroughly researched due to the increasing demands on the stability of achieved properties during the textile care processes. Most crosslinking agents for chitosan are not safe for humans or environment, such as glutaric aldehyde (GA) and formaldehyde derivatives. Eco-friendly polycarboxyilic acids (PCAs) are usually used in after-treatment. In this work, chitosan powder was dissolved in citric acid with sodium hydrophosphite (SHP) as a catalyst. Standard cotton (CO) and polyester/cotton (PES/CO) fabrics were pretreated in 20% NaOH, similar to mercerization, in order to open the structure of the cotton fibers and hydrolyze polyester fibers, continued by finishing in the gelatin chitosan bath. Afterwards, the hot rinsing process, followed by drying and curing, closed the achieved structure. The main objective was to achieve durable antimicrobial properties to multiple maintenance cycles CO and PES/CO fabric in order to apply it in a hospital environment. The characterization of fabrics was performed after treatment, first and fifth washing cycles according ISO 6330:2012 by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR-ATR), electrokinetic analysis (EKA), by the determination of tensile properties and mechanical damage (wear), and the antimicrobial activity. The application of 20% NaOH led to the swelling and mercerization of cotton cellulose, and hydrolysis of polyester, resulting in better mechanical properties. It has been confirmed that the chitosan particles were well implemented into the cotton fiber and onto to the polyester component of PES/CO blend. The presence of chitosan was confirmed after five washing cycles, but in lower quantity. However, achieved antimicrobial activity is persistent.

Antibodies to enzymes of antioxidant system as a pathogenetic component of anemia in rheumatoid arthritis

Цель исследования - изучение антителообразования к супероксиддисмутазе, глутатионредуктазе, каталазе у больных ревматоидным артритом и выяснение их роли в патогенезе сопутствующей анемии. Методика. Проведено обследование 104 больных ревматоидным артритом с различной степенью активности процесса, формой и характером течения. Диагноз ревматоидного артрита ставился на основании клинико-лабораторного и инструментального обследования больных согласно системе диагностических критериев Американской ревматологической ассоциации, предложенной в 2010 году (ACR / EULAR). Выраженность анемии оценивали по уровню гемоглобина и количеству эритроцитов. Определение уровня антител проводили методом непрямого иммуноферментного анализа [ELISA тест] с использованием иммобилизированных магнитосорбентов, представляющих собой полиакриламидные гранулы, содержащие магнитный материал и перечисленные ферменты в качестве антигена. В качестве антигенов использовались коммерческие отечественные препараты: супероксиддисмутаза из эритроцитов человека (активность 30 Ед/мг), в исследованиях использовали фермент в рабочем разведении по белку - 100 мкг/мл, глутатионредуктаза (активность 340 Ед/мг) - 200 мг/мл по белку, каталаза (активность 380 Ед/мг) - 1,4 мг/мл по белку. Учитывая достаточную относительную молекулярную массу глутатионредуктазы и каталазы, иммобилизацию проводили методом эмульсионной полимеризации в потоке газообразного азота с включением магнитного материала. В связи с небольшой относительной молекулярной массой эритроцитарной фиксации супероксиддисмутазы иммобилизацию фермента проводили путем пришивки его молекулы глютаровым альдегидом к инертной полиакриламидной грануле, содержащей магнитный материал. «Чистые» антитела к ферментам получали с помощью соответствующего антигенного иммуносорбента. Источником специфических иммуноглобулинов служили сыворотки больных ревматоидным артритом с заранее определенным высоким титром антител (экстинция>0,2). После инкубации антигенного иммуносорбента и растворимой формы фермента с полученными антителами был проведен анализ изменения активности энзима. Статистическую обработку результатов проводили с использованием программных пакетов Statistica 6.0, Excel 5.0, Statgraphics 3.0, SPSS 12.0. Результаты. Выявлена зависимость между уровнем антител к супероксиддисмутазе, глутатионредуктазе и каталазе и активностью, течением и формой болезни. Полученные результаты свидетельствуют о повышении антителогенеза к этим ферментам по мере активизации патологического процесса. Выявленное снижение активности энзимов, связанное с выработкой антител к ним, происходит, очевидно, вследствие блокирования специфическими иммуноглобулинами активного центра фермента, являющегося одновременно и антигенной детерминантой. Об участии антител к ферментам в патогенезе анемии у больных ревматоидным артритом свидетельствует обратная корреляция между содержанием антител и уровнем гемоглобина. У больных ревматоидным артритом с умеренно выраженной анемией содержание антител было значимо выше, чем у пациентов без анемии, но ниже, чем у пациентов с тяжелой формой анемии. Заключение. Антитела к супероксиддисмутазе, глутатионредуктазе и каталазе являются одним из патогенетических факторов развития анемии и могут служить критерием тяжести заболевания. The aim was to study formation of antibodies to superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT) in patients with rheumatoid arthritis (RA) and to elucidate the role of the antibodies in development of anemia. Methods. The antibodies were determined by enzyme-linked immunosorbent assay (ELISA) using immobilized magnetic sorbents, polyacrylamide granules containing a magnetic substance and the enzymes (SOD, GR, CAT) as antigens. Antibody concentration was expressed in absorbance units. Rheumatoid arthritis was diagnosed based on clinical and instrumental evaluation of patients according to the criteria of the American College of Rheumatology (ACR/EULAR, 2010). Statistical analysis was performed using variation statistics, and results were expressed as mean±SEM. Central tendencies were compared using the Student’s test. Differences were considered statistically significant at p<0.05. ELISA was performed on blood serum from 104 rheumatoid arthritis patients with different disease activity. The following commercial reagents (Russia) were used as antigens: superoxide dismutase from human RBCs (30 U/mg), which was used in the study in a working protein dilution of 100 mcg/ml; glutathione reductase (340 U/mg) which was used in the study at a protein concentration of 200 mg/ml; and catalase (380 U/mg), which was used in the study at a protein concentration of 1.4 mg/ml. Since the relative molecular weights of glutathione reductase and catalase were sufficient, immobilization was performed by emulsion polymerization in a flow of gaseous nitrogen including a magnetic material. Due to a low relative molecular weight of SOD from RBCs this enzyme was immobilized by coupling to an inert polyacrylamide granule containing a magnetic material, using glutaric aldehyde. «Pure» antibodies to the enzymes were obtained using a respective antigen immunosorbent. Specific immunoglobulins were obtained from blood serum of rheumatoid arthritis patients with a known high antibody titer (extinction > 0.2). Enzymatic activity was analyzed following incubation of the antigen immunosorbent and soluble enzyme with the obtained antibodies. Results. Production of antibodies to the studied enzymes increased with increasing severity of the disease. The decrease in enzymatic activity associated with production of respective enzyme antibodies is apparently due to inhibition by specific immunoglobulins of the active center, which is also the antigenic determinant. Conclusion. Antibodies to SOD, GR, and CAT are pathogenetic factors in the development of anemia; they may serve as a criterion for disease severity.

Biocatalysts Based on Bacterial Strain Cells with Amidase Activity for Synthesis of Acrylic Acid from Acrylamide

A biocatalytic process for synthesis of acrylic acid was studied in the presence of Rhodococcus erythropolis 4-1 and Alcaligenes faecalis 2 strains with the pronounced amidase activity. The optimal pH of the process was 6–7 for R. erythropolis 4-1 and 7–7.5 for A. faecalis 2, optimal temperature 20–50 °C for both strains, optimal concentration of acrylamide 150 mM for R. erythropolis 4-1 and 250 mM for A. faecalis 2. At the stepwise addition of the substrate, the synthesis was more effective with A. faecalis 2 than with R. erythropolis 4-1. Freezing at –20 °C was shown preferable for storing the biocatalysts. The amidase activity of both humid and dry stored A. faecalis 2 cells immobilized on activated glutaric aldehyde and non-activated chitosan was not decreased.