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1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Белобров П.И., Воеводин В.А., Ерохин В.В., Львов Ю.М., Петушков В.Н., Пузырь А.П., Родионова Н.С.
Заглавие : Взаимодействие бактериальной люцефаразы с амфифильными молекулами в растворе, на поверхности воды и в пленках Ленгмюра-Блоджетт : научное издание
Коллективы :
Место публикации : Препр. - 1988. - N 92Б. - С. 1-28
ГРНТИ : 34.17.09
Предметные рубрики: БИОЛЮМИНЕСЦЕНЦИЯ
ЛЮЦИФЕРАЗА
СВОЙСТВА
БИОСЕНСОРЫ
BACTERIA LUCIFERASE
Р ОРЕ Т Е III SOLUTION WATER FILMS
В О Е О
Аннотация: Исследованы амфифильные свойства бакт. люциферазы в различных условиях и ее взаимодействие с длинноцепоч. алифатич. альдегидом и соответствующей жирной к-той. Методом малоуглового рассеяния рентген. лучей определены радиусы инерции фермента в р-ре и найдены зависимости их от состояния люциферазы. Исследована реология монослоев, полученных из белка, субстрата, продукта и их комбинаций со строго определенными соотношениями на поверхности различных субфаз. Соответствующие 'пи'-А изотермы показывают, что во всех случаях образуются твердые двумерные пленки, сжимаемость к-рых сильно зависит от соотношения компонент. Монослои перенесены на твердую подложку и получены мультислойные пленки на разных носителях. Рентгеновское исследование позволило определить ближний порядок в толстых пленках, к-рый также зависит от соотношения компонент. Метод позволяет конструировать регулярные неоднородности распределения люциферазы в монослое. Результаты электр. микроскопии чистых и смешанных ионо- и бислоев, перенесенных на твердые подложки, свидетельствуют в пользу микроэмульсионной модели амфифильности люциферазы. Получены ленгмюровские пленки с сохранением активности. Это открывает путь к новому поколению люциферазных твердотельных биосенсоров. Библ. 21
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2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Vlasov A..., Ralchenko V..., Gordeev S..., Zakharov D..., Vlasov I..., Karabutov A..., Belobrov P...
Заглавие : Thermal properties of diamond/carbon composites
Колич.характеристики :6 с
Место публикации : Diam. Relat. Mat.: ELSEVIER SCIENCE SA, 2000. - Vol. 9: 10th European Conference on Diamond, Diamond-Like Materials, Nitrides and Silicon Carbide (Diamond 1999) (SEP 12-17, 1999, PRAGUE, CZECH REPUBLIC), Is. 03.06.2013. - P1104-1109. - ISSN 0925-9635, DOI 10.1016/S0925-9635(99)00256-3
Примечания : Cited References: 9
Предметные рубрики: CVD DIAMOND
CONDUCTIVITY
FILMS
RAMAN
Ключевые слова (''Своб.индексиров.''): diamond composites--laser flash technique--tem--thermal conductivity
Аннотация: The thermal conductivity, k, of diamond/carbon composites with different ratios of sp(2)/sp(3)-bonded carbon is measured by the laser flash technique. The thermal conductivity of nanocomposites containing 6 nm diamond particles falls within the range of k = 0.003-0.017 W/cmK; at room temperature. The thermal conductivity increases while nanopores are gradually filled with pyrolytic carbon (pyrocarbon/diamond mass ratio variation of 0.0-0.5). Transmission electron microscopy data reveal a fairly uniform mixture of two carbon phases, the diamond and matrix having similar grain sizes. Estimates show that the phonon free path is limited by dimensions of carbon matrix layer. Thermal data for coarse-grain (1-2 mu m) composites are also given for comparison. (C) 2000 Elsevier Science S.A. All rights reserved.
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3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Gladyshev M.I., Levin L.A., Sushchik N.N.
Заглавие : The influence of a monolayer of an aliphatic acid on temperature oscillation in the surface layer of water
Место публикации : Izvestiya - Atmospheric and Ocean Physics. - 1996. - Vol. 32, Is. 3. - С. 378-380. - ISSN 00014338 (ISSN)
Ключевые слова (''Своб.индексиров.''): aliphatic acid--surface films--temperature--thermal spots
Аннотация: The influence of a monolayer of a palmitic acid on amplitude-frequency characteristics of temperature oscillations caused by thermal spots of a surface film was experimentally determined in a Langmuir tank. An analysis of the power spectra showed that the temperature oscillations were multimodal. In addition, no consistant differences between the spectrum for a pure surface and the spectrum for a surface covered by an acid monolayer were found. A roughened gain-frequency factor was found that is equal to the ratio of the average period between the thermal spots to the dispersion of the time series of temperature oscillations. The factor significantly differed over a wide range of temperatures for a pure surface and for a surface covered with the monolayer. The experimental results do not confirm the existence of a leading frequency in the temperature oscillations of a cold surface film due to an appearance of thermal spots.
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4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shishatskaya, Ekaterina I., Menzyanova, Natalia G., Shumilova, Anna A.
Заглавие : The effect of the chemical composition and structure of polymer films made from resorbable polyhydroxyalkanoates on blood cell response
Колич.характеристики :11 с
Коллективы : Russian Science FoundationRussian Science Foundation (RSF) [17-15-01352]
Место публикации : Int. J. Biol. Macromol.: ELSEVIER, 2019. - Vol. 141. - С. 765-+. - ISSN 0141-8130, DOI 10.1016/j.ijbiomac.2019.09.015. - ISSN 1879-0003(eISSN)
Примечания : Cited References:57. - The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The study is supporting by the Russian Science Foundation, Project No 17-15-01352.
Предметные рубрики: 3-HYDROXYBUTYRATE
BIOCOMPATIBILITY
BIOSYNTHESIS
ADHESION
STENTS
Аннотация: Four PHA types were synthesized in the culture of Cupriavidus eutrophus B-10646 under special conditions, poly(3 hydroxybutyrate) [P(3HB)] and of copolymers, which contained 3HB monomers and 4 hydroxybutyrate (4HB), 3 hydroxyvalerate (3HV), or 3 hydroxyhexanoate (3HHx). All copolymers had the M-w of about 550-670 kDa, and the homopolymer P(3HB) had a significantly higher M-w - 920 kDa. P(3HB co 4HB) and P(3HB co 3HHx) had the lowest C-x (42 and 49%) while P(3HB co 3HV) and P(3HB) exhibited higher C-x values (76%). Polymer films were prepared from different PHAs. Electron microscopy showed differences in the surface microstructure of the films. Films prepared from the P(3HB) were more hydrophobic and the arithmetic mean surface roughness of 71-75 nm, than the copolymer films, which were hydrophilic (57-60 degrees) and had considerably higher roughness (158-177 nm). Blood parameters (hemoglobin and hemolysis) and response of the cells (erythrocytes, platelets, and monocytes) were studied in experiments with blood directly contacting the surface of the films of PHAs with different compositions. Cultivation of blood cells on polymer films did not cause any adverse effects on adhesion and morphology of all cell types. Results of studying blood cell response suggested that the films made from low-crystallinity copolymers containing 4 hydroxybutyrate and 3 hydroxyhexanoate were the best for contact with blood. (C) 2019 Elsevier B.V. All rights reserved.
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5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shishatskaya E. I., Menzyanova N. G., Shumilova A. A.
Заглавие : The effect of the chemical composition and structure of polymer films made from resorbable polyhydroxyalkanoates on blood cell response
Место публикации : Int. J. Biol. Macromol.: Elsevier B.V., 2019. - Vol. 141. - С. 765-774. - ISSN 01418130 (ISSN) , DOI 10.1016/j.ijbiomac.2019.09.015
Аннотация: Four PHA types were synthesized in the culture of Cupriavidus eutrophus B-10646 under special conditions, poly(3?hydroxybutyrate) [P(3HB)] and of copolymers, which contained 3HB monomers and 4?hydroxybutyrate (4HB), 3?hydroxyvalerate (3HV), or 3?hydroxyhexanoate (3HHx). All copolymers had the Mw of about 550–670 kDa, and the homopolymer P(3HB) had a significantly higher Mw – 920 kDa. P(3HB?co?4HB) and P(3HB?co?3HHx) had the lowest Cx (42 and 49%) while P(3HB?co?3HV) and P(3HB) exhibited higher Cx values (76%). Polymer films were prepared from different PHAs. Electron microscopy showed differences in the surface microstructure of the films. Films prepared from the P(3HB) were more hydrophobic and the arithmetic mean surface roughness of 71–75 nm, than the copolymer films, which were hydrophilic (57–60°) and had considerably higher roughness (158–177 nm). Blood parameters (hemoglobin and hemolysis) and response of the cells (erythrocytes, platelets, and monocytes) were studied in experiments with blood directly contacting the surface of the films of PHAs with different compositions. Cultivation of blood cells on polymer films did not cause any adverse effects on adhesion and morphology of all cell types. Results of studying blood cell response suggested that the films made from low-crystallinity copolymers containing 4?hydroxybutyrate and 3?hydroxyhexanoate were the best for contact with blood. © 2019 Elsevier B.V.
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6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Syromotina D. S., Surmenev R. A., Surmeneva M. A., Boyandin A. N., Nikolaeva E. D., Prymak O., Epple M., Ulbricht M., Oehr C., Volova T. G.
Заглавие : Surface wettability and energy effects on the biological performance of poly-3-hydroxybutyrate films treated with RF plasma
Место публикации : Mater. Sci. Eng. C. - 2016. - Vol. 62. - С. 450-457. - ISSN 09284931 (ISSN) , DOI 10.1016/j.msec.2016.01.075
Ключевые слова (''Своб.индексиров.''): plasma--polar component--poly-3-hydroxybutyrate membranes--surface energy--surface treatment--ammonia--biodegradable polymers--cell adhesion--contact angle--free energy--interfacial energy--plasma applications--plasmas--surface chemistry--surface properties--surface roughness--surface topography--wetting--biological performance--crystalline structure--polar components--poly-3-hydroxybutyrate--surface free energy--surface roughness changes--surface wettability--water contact angle--surface treatment
Аннотация: The surface properties of poly-3-hydroxybutyrate (P3HB) membranes were modified using oxygen and an ammonia radio-frequency (RF, 13.56 MHz) plasma. The plasma treatment procedures used in the study only affected the surface properties, including surface topography, without inducing any significant changes in the crystalline structure of the polymer, with the exception being a power level of 250 W. The wettability of the modified P3HB surfaces was significantly increased after the plasma treatment, irrespective of the treatment procedure used. It was revealed that both surface chemistry and surface roughness changes caused by the plasma treatment affected surface wettability. A treatment-induced surface aging effect was observed and resulted in an increase in the water contact angle and a decrease in the surface free energy. However, the difference in the water contact angle between the polymers that had been treated for 4 weeks and the untreated polymer surfaces was still significant. A dependence between cell adhesion and proliferation and the polar component of the surface energy was revealed. The increase in the polar component after the ammonia plasma modification significantly increased cell adhesion and proliferation on biodegradable polymer surfaces compared to the untreated P3HB and the P3HB modified using an oxygen plasma. © 2016 Elsevier B.V.
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7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Maillard-Schaller E., Kuettel O.M., Diederich L., Schlapbach L., Zhirnov V.V., Belobrov P.I.
Заглавие : Surface properties of nanodiamond films deposited by electrophoresis on Si(100)
Место публикации : Diamond and Related Materials. - 1999. - Vol. 8, Is. 2-5. - С. 805-808. - ISSN 09259635 (ISSN)
Ключевые слова (''Своб.индексиров.''): energy band diagram--nanodiamond--raman spectroscopy--surface characterization--band structure--electrodeposition--electrophoresis--hydrogen--nanostructured materials--nitrogen--oxidation--oxygen--phonons--plasma applications--silicon wafers--surface properties--dielectrophoresis--negative electron affinity (nea)--phonon confinement effect--diamond films
Аннотация: The surface properties of diamond nanoparticles (40-50 A in diameter) have been investigated by X-ray photoelectron spectroscopy (XPS), UV photoelectron spectroscopy (UPS) and Raman spectroscopy. The diamond nanoparticles have been deposited on flat Si(100) substrates by electrophoresis/dielectrophoresis. The as-deposited films are strongly oxidized and present a 1-2% nitrogen content. After treatment at 850 В°C in H2 plasma for 60 min, the oxygen is removed, and the position of the C 1s core-level peak indicates a n-type electronic comportment of the diamond nanoparticles. Raman spectroscopy of the as-deposited film shows a sp3 contribution at 1321 cm-1 and a sp2 contribution around 1620 cm-1. The 12 cm-1 shift of the sp3 contribution with respect to the bulk diamond peak at 1333 cm-1 is attributed to a phonon confinement effect due to the size of the diamond particles. The H2 plasma treatment induces a size decrease of the nanocrystallites confirmed by Raman and scanning electron microscopy (SEM) measurements. UPS spectroscopy shows a negative electron affinity of -0.2 eV of the hydrogenated nanodiamond film.
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8.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Slabko V.V., Volova T.G., Krasnov P.O., Kuzubov A.A., Shishatskaya E.I.
Заглавие : Surface modification of bioresorbable polymer scaffolds by laser treatment
Место публикации : Biophysics. - 2010. - Vol. 55, Is. 2. - С. 234-238. - ISSN 00063509 (ISSN) , DOI 10.1134/S0006350910020120
Ключевые слова (''Своб.индексиров.''): hydrophilicity--laser irradiation--microbial biocompatible and biodegradable polymers--polyhydroxybuturate--surface properties
Аннотация: The effect of laser irradiation on the properties of the surface of films prepared from a bioresorbable polymer poly(hydroxybuturate) has been studied. To determine the spectral region of the polymer optimal for the effective action of radiation on electron molecular bonds, theoretical investigations have been performed, which have shown that, for modifying the surface of PHB scaffolds, it is expedient to use a vacuum laser at a wavelength of 160 nm. Using laser irradiation at a power from 3 to 30 W, a series of films with modified surface, from roughnesses to perforations, have been obtained. The microstructure and properties of the film surface depending on the mode of irradiation have been examined, and conditions have been found under which the contact marginal angles of film wetting with water can be decreased to 50В° (compared with 76-80В° in starting products). Thus, conditions of laser treatment of PHB scaffolds have been theoretically substantiated and experimentally realized that provide a beneficial effect on the properties of the surface without destroying the structure of the material. В© 2010 Pleiades Publishing, Ltd.
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9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Belyaeva O.G., Plotnikov V.F., Puzyr' A.P.
Заглавие : Studies of Biodegradation of Microbial Polyhydroxyalkanoates
Место публикации : Prikladnaya Biokhimiya i Mikrobiologiya. - 1998. - Vol. 34, Is. 5. - С. 543. - ISSN 05551099 (ISSN)
Аннотация: Biodegradation of polyhydroxyalkanoates (PHA) - polymers of hydroxylated fatty acids - differing in chemical composition, crystallinity, melting temperature, and molecular weight was studied in soil and water environments under conditions of varying ambient temperature and pH. Under similar conditions, homogeneous films of polyhydroxybutyrate (PHB) with different initial properties were degraded at virtually equal rates. Hydroxybutyrate-hydroxyvalerate copolymers with a lower crystallinity and different microstructure in comparison to PHB were degraded at a 20 to 30% higher rate on average. The ambient temperature significantly influenced the rate of PHA biodegradation.
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10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Belyaeva O.G., Plotnikov V.F., Puzyr' A.P.
Заглавие : Studies of biodegradation of microbial polyhydroxyalkanoates
Место публикации : Applied Biochemistry and Microbiology. - 1998. - Vol. 34, Is. 5. - С. 488-492. - ISSN 00036838 (ISSN)
Аннотация: Biodegradation of polyhydroxyalkanoates (PHA) - polymers of hydroxylated fatty acids - differing in chemical composition, crystallinity, melting temperature, and molecular weight was studied in soil and water environments under conditions of varying ambient temperature and pH. Under similar conditions, homogeneous films of polyhydroxybutyrate (PHB) with different initial properties were degraded at virtually equal rates. Hydroxybutyrate-hydroxyvalerate copolymers with a lower crystallinity and different microstructure in comparison to PHB were degraded at a 20 to 30% higher rate on average. The ambient temperature significantly influenced the rate of PHA biodegradation.
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11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Ismagilov, Rinat, Malykhin, Sergei, Puzyr, Aleksey, Loginov, Artem, Kleshch, Victor, Obraztsov, Alexander
Заглавие : Single-Crystal Diamond Needle Fabrication Using Hot-Filament Chemical Vapor Deposition
Колич.характеристики :9 с
Коллективы : Russian Science FoundationRussian Science Foundation (RSF) [19-79-00203]; Russian Foundation for Basic ResearchRussian Foundation for Basic Research (RFBR) [18-29-19071]
Место публикации : Materials: MDPI, 2021. - Vol. 14, Is. 9. - Ст.2320. - ISSN 1996-1944(eISSN), DOI 10.3390/ma14092320
Примечания : Cited References:32. - This work was supported by the Russian Science Foundation (project no. 19-79-00203) and by the Russian Foundation for Basic Research (grant no. 18-29-19071, in part for PL and Raman inspection).
Аннотация: Single-crystal diamonds in the form of micrometer-scale pyramids were produced using a combination of hot-filament (HF) chemical vapor deposition (CVD) and thermal oxidation processes. The diamond pyramids were compared here with similar ones that were manufactured using plasma-enhanced (PE) CVD. The similarities revealed in the morphology, Raman, and photoluminescent characteristics of the needles obtained using the hot-filament and plasma-enhanced CVD are discussed in connection with the diamond film growth mechanism. This work demonstrated that the HF CVD method has convincing potential for the fabrication of single-crystal diamond needles in the form of regularly shaped pyramids on a large surface area, even on non-conducting substrates. The experimental results demonstrated the ability for the mass production of the single-crystal needle-like diamonds, which is important for their practical application.
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12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zhila, Natalia, Shishatskaya, Ekaterina
Заглавие : Properties of PHA bi-, ter-, and quarter-polymers containing 4-hydroxybutyrate monomer units
Колич.характеристики :8 с
Коллективы : Russian Science Foundation [17-15-01352]
Место публикации : Int. J. Biol. Macromol.: ELSEVIER SCIENCE BV, 2018. - Vol. 111. - С. 1019-1026. - ISSN 0141-8130, DOI 10.1016/j.ijbiomac.2018.01.130. - ISSN 1879-0003(eISSN)
Примечания : Cited References:39. - The research was supported by the Russian Science Foundation (grant No. 17-15-01352).
Предметные рубрики: ALCALIGENES-FAECALIS T1
COMAMONAS-ACIDOVORANS
ENZYMATIC DEGRADATION
Ключевые слова (''Своб.индексиров.''): polyhydroxyalkanoates--4-hydroxybutyrate monomer units--physicochemical--and mechanical properties
Аннотация: The present study investigates physicochemical, mechanical, and biological properties of polyhydroxyalkanoate (PHA) copolymers containing 4-hydroxybutyrate (4HB) synthesized in Cupriavidus eutrophus B10646 culture. In poly(3-hydroxybutyrate/4-hydroxybutyrate) [P(3HB/4HB)]bipolymers, 4HB varied between 10.4 and 75.0 mol%; in poly(3-hydroxybutyrate/3-hydroxyvalerate/4-hydroxybutyrate) terpolymers, 4HB constituted 28.7-55.6 mol%; and in poly(3-hydroxybutyrate/3-hydroxyvalerate/4-hydroxybutyrate/3-hydroxyhexanoate) quaterpolymers, 4HB varied between 9.3 and 13.3 mol%. The degree of crystallinity of P(3HB/4HB) copolymers decreased consistently with an increase in 4HB content, reaching 38%. The incorporation of 3-hydroxyvalerate and 3-hydroxyhexanoate into copolymers enhanced that effect. The effect of 4HB monomer units on temperature properties of copolymers was exhibited as lowering of the melting temperature and crystallization temperature, which improved the processing-related properties of the copolymers. All copolymers containing 4HB showed enhanced elongation at break compared to poly(3-hydroxybutyrate). Polymer films prepared from PHA5 with different chemical composition had similar microstructure and porosity and had no toxic effect on mouse fibroblast NIH 3 T3 cells, proving their high biocompatibility. (C) 2018 Elsevier B.V. All rights reserved.
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13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T., Kiselev E., Nemtsev I., Lukyanenko A., Sukovatyi A., Kuzmin A., Ryltseva G., Shishatskaya E.
Заглавие : Properties of degradable polyhydroxyalkanoates with different monomer compositions
Колич.характеристики :17 с
Коллективы : RFBRRussian Foundation for Basic Research (RFBR) [19-43-240012]; Ministry of Education and Science of the Russian FederationMinistry of Education and Science, Russian Federation [FSRZ-2020-0006]
Место публикации : Int. J. Biol. Macromol.: ELSEVIER, 2021. - Vol. 182. - С. 98-114. - ISSN 0141-8130, DOI 10.1016/j.ijbiomac.2021.04.008. - ISSN 1879-0003(eISSN)
Примечания : Cited References:106. - The part of the reported study on polymer synthesis and examinationwas funded by RFBR and KKRF [Grant No. 19-43-240012 "Biological and physical principles of production of new generation biomaterials"]. The work on production and investigation of polymer films was carried out as part of the State Assignment of the Ministry of Education and Science of the Russian Federation [Grant No. FSRZ-2020-0006].
Предметные рубрики: PALM KERNEL OIL
RALSTONIA-EUTROPHA
BIODEGRADABLE POLYMERS
Аннотация: Purpose: To synthesize and investigate polyhydroxyalkanoates (PHAs) with different monomer composition and percentages and polymer films prepared from them. Results: Various PHAs: homopolymer poly-3-hydroxybutyrate P(3HB) and 2-, 3-, and 4-component copolymers comprising various combinations of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 4-hydroxybutyrate (4HB), and 3-hydroxyhexanoate (3HHx) monomers were synthesized under specialized conditions. Relationships were found between the monomer composition of PHAs and their molecular-weight and thermal properties and degree of crystallinity. All copolymers had decreased weight average molecular weights, Mw (to 390-600 kDa), and increased values of polydispersity (3.2-4.6) compared to the P(3HB). PHA copolymers showed different thermal behavior: an insignificant decrease in Tmelt and the presence of the second peak in the melting region and changes in parameters of crystallization and glass transition. At the same time, they retained thermostability, and the difference between Tmelt and Tdegr was at least 100-120 degrees C. Incorporation of 4HB, 3HV, and 3HHx monomer units into the 3-hydroxybutyrate chain caused changes in the amorphous to crystalline ratio and decreased the degree of crystallinity (Cx) to 20-40%. According to the degree to which the monomers reduced crystallinity, they were ranked as follows: 4HB - 3HHx - 3HV. A unique set of films was produced; their surface properties and physical/mechanical properties were studied as dependent on PHA composition; monomers other than 3hydroxybutyrate were found to enhance hydrophilicity, surface development, and elasticity of polymer films. Conclusion: An innovative set of PHA copolymers was synthesized and solution-cast films were prepared from them; the copolymers and films were investigated as dependent on polymer chemical composition. Results obtained in the present study contribute to the solution of a critical issue of producing degradable polymer materials. (C) 2021 Elsevier B.V. All rights reserved.
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14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T., Kiselev E., Nemtsev I., Lukyanenko А., Sukovatyi A., Kuzmin A., Ryltseva G., Shishatskaya E.
Заглавие : Properties of degradable polyhydroxyalkanoates with different monomer compositions
Место публикации : Int. J. Biol. Macromol.: Elsevier B.V., 2021. - Vol. 182. - С. 98-114. - ISSN 01418130 (ISSN), DOI 10.1016/j.ijbiomac.2021.04.008
Аннотация: Purpose: To synthesize and investigate polyhydroxyalkanoates (PHAs) with different monomer composition and percentages and polymer films prepared from them. Results: Various PHAs: homopolymer poly-3-hydroxybutyrate P(3HB) and 2-, 3-, and 4-component copolymers comprising various combinations of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 4-hydroxybutyrate (4HB), and 3-hydroxyhexanoate (3HHx) monomers were synthesized under specialized conditions. Relationships were found between the monomer composition of PHAs and their molecular-weight and thermal properties and degree of crystallinity. All copolymers had decreased weight average molecular weights, Mw (to 390–600 kDa), and increased values of polydispersity (3.2–4.6) compared to the P(3HB). PHA copolymers showed different thermal behavior: an insignificant decrease in Tmelt and the presence of the second peak in the melting region and changes in parameters of crystallization and glass transition. At the same time, they retained thermostability, and the difference between Tmelt and Tdegr was at least 100–120 °C. Incorporation of 4HB, 3HV, and 3HHx monomer units into the 3-hydroxybutyrate chain caused changes in the amorphous to crystalline ratio and decreased the degree of crystallinity (Cx) to 20–40%. According to the degree to which the monomers reduced crystallinity, they were ranked as follows: 4HB – 3HHx – 3HV. A unique set of films was produced; their surface properties and physical/mechanical properties were studied as dependent on PHA composition; monomers other than 3-hydroxybutyrate were found to enhance hydrophilicity, surface development, and elasticity of polymer films. Conclusion: An innovative set of PHA copolymers was synthesized and solution-cast films were prepared from them; the copolymers and films were investigated as dependent on polymer chemical composition. Results obtained in the present study contribute to the solution of a critical issue of producing degradable polymer materials. © 2021 Elsevier B.V.
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15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zhila, Natalia O., Sapozhnikova, Kristina Yu, Kiselev, Evgeniy G., Vasiliev, Alexander D., Nemtsev, Ivan, V, Shishatskaya, Ekaterina, I, Volova, Tatiana G.
Заглавие : Properties of Degradable Polyhydroxyalkanoates (PHAs) Synthesized by a New Strain, Cupriavidus necator IBP/SFU-1, from Various Carbon Sources
Колич.характеристики :19 с
Коллективы : Russian FederationRussian Federation [075-15-2021-626, 220]; State Assignment of the Ministry of Science and Higher Education of the Russian Federation [FSRZ-2020-0006]
Место публикации : Polymers: MDPI, 2021. - Vol. 13, Is. 18. - Ст.3142. - ISSN 2073-4360(eISSN), DOI 10.3390/polym13183142
Примечания : Cited References:78. - This work was financially supported by Project "Agropreparations of the new generation: a strategy of construction and realization" (Agreement No 075-15-2021-626) in accordance with Resolution No 220 of the Government of the Russian Federation of 9 April 2010, "On measures designed to attract leading scientists to the Russian institutions of higher learning" (strain isolation, polymer synthesis and investigation), and by the State Assignment of the Ministry of Science and Higher Education of the Russian Federation No. FSRZ-2020-0006 (study of film properties).
Предметные рубрики: RALSTONIA-EUTROPHA
POLY(3-HYDROXYBUTYRATE) PRODUCTION
PLANT OIL
ACID
Аннотация: The bacterial strain isolated from soil was identified as Cupriavidus necator IBP/SFU-1 and investigated as a PHA producer. The strain was found to be able to grow and synthesize PHAs under autotrophic conditions and showed a broad organotrophic potential towards different carbon sources: sugars, glycerol, fatty acids, and plant oils. The highest cell concentrations (7-8 g/L) and PHA contents were produced from oleic acid (78%), fructose, glucose, and palm oil (over 80%). The type of the carbon source influenced the PHA chemical composition and properties: when grown on oleic acid, the strain synthesized the P(3HB-co-3HV) copolymer; on plant oils, the P(3HB-co-3HV-co-3HHx) terpolymer, and on the other substrates, the P(3HB) homopolymer. The type of the carbon source influenced molecular-weight properties of PHAs: P(3HB) synthesized under autotrophic growth conditions, from CO2, had the highest number-average (290 +/- 15 kDa) and weight-average (850 +/- 25 kDa) molecular weights and the lowest polydispersity (2.9 +/- 0.2); polymers synthesized from organic carbon sources showed increased polydispersity and reduced molecular weight. The carbon source was not found to affect the degree of crystallinity and thermal properties of the PHAs. The type of the carbon source determined not only PHA composition and molecular weight but also surface microstructure and porosity of the polymer films. The new strain can be recommended as a promising P(3HB) producer from palm oil, oleic acid, and sugars (fructose and glucose) and as a producer of P(3HB-co-3HV) from oleic acid and P(3HB-co-3HV-co-3HHx) from palm oil.
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16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zhila N. O., Sapozhnikova K. Yu., Kiselev E. G., Vasiliev A. D., Nemtsev I. V., Shishatskaya E. I., Volova T. G.
Заглавие : Properties of degradable polyhydroxyalkanoates (Phas) synthesized by a new strain, cupriavidus necator ibp/sfu-1, from various carbon sources
Место публикации : Polym.: MDPI, 2021. - Vol. 13, Is. 18. - Ст.3142. - ISSN 20734360 (ISSN), DOI 10.3390/polym13183142
Аннотация: The bacterial strain isolated from soil was identified as Cupriavidus necator IBP/SFU-1 and investigated as a PHA producer. The strain was found to be able to grow and synthesize PHAs under autotrophic conditions and showed a broad organotrophic potential towards different carbon sources: sugars, glycerol, fatty acids, and plant oils. The highest cell concentrations (7–8 g/L) and PHA contents were produced from oleic acid (78%), fructose, glucose, and palm oil (over 80%). The type of the carbon source influenced the PHA chemical composition and properties: when grown on oleic acid, the strain synthesized the P(3HB-co-3HV) copolymer; on plant oils, the P(3HB-co-3HV-co-3HHx) terpolymer, and on the other substrates, the P(3HB) homopolymer. The type of the carbon source influenced molecular-weight properties of PHAs: P(3HB) synthesized under autotrophic growth conditions, from CO2, had the highest number-average (290 ± 15 kDa) and weight-average (850 ± 25 kDa) molecular weights and the lowest polydispersity (2.9 ± 0.2); polymers synthesized from organic carbon sources showed increased polydispersity and reduced molecular weight. The carbon source was not found to affect the degree of crystallinity and thermal properties of the PHAs. The type of the carbon source determined not only PHA composition and molecular weight but also surface microstructure and porosity of the polymer films. The new strain can be recommended as a promising P(3HB) producer from palm oil, oleic acid, and sugars (fructose and glucose) and as a producer of P(3HB-co-3HV) from oleic acid and P(3HB-co-3HV-co-3HHx) from palm oil. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T. G., Vinogradova O. N., Zhila N. O., Peterson I. V., Kiselev E. G., Vasiliev A. D., Sukovatiy A. G., Shishatskaya E. I.
Заглавие : Properties of a novel quaterpolymer P(3HB/4HB/3HV/3HHx)
Место публикации : Polymer: Elsevier Ltd, 2016. - Vol. 101. - С. 67-74. - ISSN 00323861 (ISSN) , DOI 10.1016/j.polymer.2016.08.048
Ключевые слова (''Своб.индексиров.''): physicochemical and mechanical properties--polyhydroxyalkanoates--quaterpolymers--biocompatibility--cell culture--chain length--chains--decomposition--3-hydroxyhexanoate--degrees of crystallinity--elongation at break--physico-chemical and mechanical properties--polyhydroxyalkanoates--quaterpolymers--short chain lengths--thermal decomposition temperature--film preparation
Аннотация: Cupriavidus eutrophus В10646 was used to synthesize a series of polyhydroxyalkanoate (PHA) quaterpolymers composed of the short-chain-length 3-hydroxybutyrate (3HB), 4-hydroxybutyrate (4HB), and 3-hydroxyvalerate (3HV) and the medium-chain-length 3-hydroxyhexanoate (3HHx). The molar fraction of 3HB in the quaterpolymers varied between 63.5 and 93.1 mol.%, 3HV – between 1.1 and 24.6 mol.%, 4HB – between 2.4 and 15.6 mol.%, and 3HHx – between 0.4 and 4.8 mol.%. The properties of PHA quaterpolymers were significantly different from those of the P(3HB) homopolymer: they had much lower degrees of crystallinity (up to 30–45%), and lower melting points and thermal decomposition temperatures, with the interval between these temperatures remaining practically unchanged. Films prepared from PHA quaterpolymers were rougher and more porous than P(3HB) films; they showed higher values of elongation at break (up to 6–113%), i.e. were more elastic. Films prepared from PHA quaterpolymers were biocompatible and had no toxic effect on mouse fibroblast NIH 3T3 cells. © 2016 Elsevier Ltd
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18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Sevastianov V.I., Perova N.V., Shishatskaya E.I., Kalacheva G.S., Volova T.G.
Заглавие : Production of purified polyhydroxyalkanoates (PHAs) for applications in contact with blood
Колич.характеристики :14 с
Место публикации : J. Biomater. Sci.-Polym. Ed.: VSP BV, 2003. - Vol. 14, Is. 10. - P1029-1042. - ISSN 0920-5063, DOI 10.1163/156856203769231547
Примечания : Cited References: 34
Предметные рубрики: BIODEGRADABLE POLYESTERS
POLYMERS
Ключевые слова (''Своб.индексиров.''): polyhydroxyalkanoates (phas)--polyhydroxybutyrate (phb)--poly(hydroxybutyrate-co-hydroxyvalerate) (phbv)--endotoxins--beta-hydroxy acids--hemocompatibility
Аннотация: Samples of olyhydroxyalkanoates (PHAs), polyhydroxybutyrate (PHB) and copolymers poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with 4 and 18 mol% hydroxyvalerate, synthesized by the bacteria Ralstonia eutropha B5786, were investigated. PHA films in contact with blood did not activate the hemostasis system at the level of cell response, but they did activate the coagulation system and the complement reaction. To detect biologically-active components in the PHAs, a detailed analysis of the composition of the polymers was conducted. Gas chromatography-mass spectrometry revealed long-chain fatty acids (FAs) in the tested PHAs. Their total concentration in the polymer ranged from tenths of mol% to 2-3 mol%, depending on the purification method. C-16:0 constituted the largest proportion, up to 70%. Of the long-chain hydroxy acids, only beta-OH-C-14:0 was detected and it did not exceed 0.06 mol%. The analysis of the hemocompatibility properties of the PHAs purified by a specialized procedure, including the quantitative and morphological estimation of platelets adherent to the surface of polymer films, the plasma recalcification time and complement activation studies, indicated that PHB and PHBV can be used in contact with blood. It has been found out that the lipopolysaccharides of bacteria producing PHAs, which contain mostly long-chain hydroxy acids, can be the factor activating the hemostasis systems. Thus, the technology of PHA purification must satisfy rather stringent specific requirements.
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19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Sevastianov V.I., Perova N.V., Shishatskaya E.I., Kalacheva G.S., Volova T.G.
Заглавие : Production of purified polyhydroxyalkanoates (PHAs) for applications in contact with blood
Место публикации : Journal of Biomaterials Science, Polymer Edition. - 2003. - Vol. 14, Is. 10. - С. 1029-1042. - ISSN 09205063 (ISSN) , DOI 10.1163/156856203769231547
Ключевые слова (''Своб.индексиров.''): ?-hydroxy acids--endotoxins--hemocompatibility--poly(hydroxybutyrate-co-hydroxyvalerate) (phbv)--polyhydroxyalkanoates (phas)--polyhydroxybutyrate (phb)--bacterium lipopolysaccharide--carbon--complement--copolymer--hydroxyacid--long chain fatty acid--poly(3 hydroxybutyric acid)--polyhydroxyalkanoic acid--valeric acid derivative--adult--article--biofilm--biotechnology--blood analysis--blood clotting--blood compatibility--cell function--chemical analysis--chemical composition--complement activation--concentration (parameters)--controlled study--gas chromatography--hemostasis--human--human cell--mass spectrometry--micromorphology--nonhuman--priority journal--purification--quantitative analysis--sampling--synthesis--thrombocyte adhesion--wautersia eutropha--biocompatible materials--blood--blood coagulation tests--chromatography, gas--complement activation--cupriavidus necator--fatty acids--humans--platelet adhesiveness--polyesters--surface properties
Аннотация: Samples of olyhydroxyalkanoates (PHAs), polyhydroxybutyrate (PHB) and copolymers poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with 4 and 18 mol% hydroxyvalerate, synthesized by the bacteria Ralstonia eutropha B5786, were investigated. PHA films in contact with blood did not activate the hemostasis system at the level of cell response, but they did activate the coagulation system and the complement reaction. To detect biologically-active components in the PHAs, a detailed analysis of the composition of the polymers was conducted. Gas chromatography-mass spectrometry revealed long-chain fatty acids (FAs) in the tested PHAs. Their total concentration in the polymer ranged from tenths of mol% to 2-3 mol%, depending on the purification method. C16:0 constituted the largest proportion, up to 70%. Of the long-chain hydroxy acids, only ?-OH-C14:0 was detected and it did not exceed 0.06 mol%. The analysis of the hemocompatibility properties of the PHAs purified by a specialized procedure, including the quantitative and morphological estimation of platelets adherent to the surface of polymer films, the plasma recalcification time and complement activation studies, indicated that PHB and PHBV can be used in contact with blood. It has been found out that the lipopolysaccharides of bacteria producing PHAs, which contain mostly long-chain hydroxy acids, can be the factor activating the hemostasis systems. Thus, the technology of PHA purification must satisfy rather stringent specific requirements.
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20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Boyandin, Anatoly Nikolayevich, Dvoinina, Ljublyana Mikhailovna, Sukovatyi, Aleksey Grigorievich, Sukhanova, Anna Alekseevna
Заглавие : Production of Porous Films Based on Biodegradable Polyesters by the Casting Solution Technique Using a Co-Soluble Porogen (Camphor)
Колич.характеристики :12 с
Коллективы : Ministry of Science and Higher Education of the Russian Federation [FEFE-2020-0015]
Место публикации : Polymers: MDPI, 2020. - Vol. 12, Is. 9. - Ст.1950. - ISSN 2073-4360(eISSN), DOI 10.3390/polym12091950
Примечания : Cited References:42. - This work was carried out by the team of the scientific laboratory "Smart Materials and Structures" within the state assignment of the Ministry of Science and Higher Education of the Russian Federation for the implementation of the project "Development of multifunctional smart materials and structures based on modified polymer composite materials capable to function in extreme conditions" (Project No. FEFE-2020-0015).
Предметные рубрики: TISSUE ENGINEERING APPLICATIONS
SCAFFOLDS
FABRICATION
POLYMERS
Аннотация: Porous films have been prepared from degradable polymers-poly-3-hydroxybutyrate (PHB), poly-epsilon-caprolactone (PCL) and a blend of these polymers (1:3)-by adding porogen (camphor) to the polymer solution at 10%, 30% or 50% of the total mass of the polymer and porogen, and leaching it out afterwards. After the rinse, camphor content in films decreased to about 0.025%. The structure, physical/mechanical and biological properties of the films were investigated as dependent on their composition and porosity, which varied depending on the amount of camphor added. The surface of PHB films was porous, the PCL films were relatively smooth, and the PHB/PCL films had an intermediate structure. The addition of camphor increased the thickness (from 35 to 45 mu m, from 40 to 80 mu m and from 20 to 65 mu m for PHB, PCL and PHB/PCL, respectively) and porosity (from 4.2(+/- 3.6)% to 50.0(+/- 12.8)%, from 6.4(+/- 5.5)% to 54.5(+/- 6.0)% and from 4.9(+/- 4.8)% to 51.5(+/- 5.8)%, respectively) of the films. The introduction (and removal) of 10% camphor into the PHB and PHB/PCL films led to an approximately twofold increase in the polar component of the free surface energy (from 5.4 +/- 0.38 to 11.8 +/- 1.33 and from 2.7 +/- 0.13 to 5.2 +/- 0.09 mN/m, respectively) but in other cases, on the contrary, a decrease in this indicator was registered. The increase of camphor addition from 0% to 50% gradually impaired mechanical properties of the films: so, Young's modulus decreased from 3.6 to 1.8 GPa, from 0.30 to 0.12 GPa and from 0.50 to 0.20 GPa for PHB, PCL and PHB/PCL, respectively. At the same time, the water vapor transmission rate considerably increased from 197.37 +/- 23.62 to 934.03 +/- 114.34 g/m(2)/d for PHB films; from 1027.99 +/- 154.10 to 7014.62 +/- 280.81 g/m(2)/d for PCL films; and from 715.47 +/- 50.08 to 4239.09 +/- 275.54 g/m(2)/d for PHB/PCL films. Results of biocompatibility testing in the culture of NIH 3T3 mouse fibroblast cells showed that for the most of experimental samples cell adhesion and proliferation were comparable or superior to the corresponding parameters on the initial nonporous films. The best results were obtained for PHB films where at Day 3 of the experiment the registered cell density for experimental samples arrived at 2.66(+/- 0.26) x 10(5) cells/cm(2) versus 1.29(+/- 0.33) x 10(5) cells/cm(2) in the control. So, the proposed method can be used to construct highly porous cell scaffolds for cellular engineering.
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