Библиотека института биофизики СО РАН

Главная

Базы данных

Труды сотрудников ИБФ СО РАН - результаты поиска

Вид поиска

Каталог книг и продолжающихся изданий библиотеки Института биофизики СО РАН

Иностранные журналы библиотеки Института биофизики СО РАН

Отечественные журналы библиотеки Института биофизики СО РАН

Каталог диссертаций ИБФ СО РАН

Труды сотрудников ИБФ СО РАН

Область поиска

в найденном

Формат представления найденных документов:
полный	информационный	краткий

Отсортировать найденные документы по:
автору	заглавию	году издания	типу документа

Поисковый запрос: (<.>K=Copolymers<.>)

Общее количество найденных документов : 36
Показаны документы с 1 по 20

1-20 21-36

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.
Scopus
Найти похожие

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.
Scopus
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T., Shishatskaya E., Sevastianov V., Efremov S., Mogilnaya O.
Заглавие : Results of biomedical investigations of PHB and PHB/PHV fibers
Место публикации : Biochemical Engineering Journal. - 2003. - Vol. 16, Is. 2. - С. 125-133. - ISSN 1369703X (ISSN) , DOI 10.1016/S1369-703X(03)00038-X
Ключевые слова (''Своб.индексиров.''): biocompatibility--fibers--implants--poly-3-hydroxybutyrate (phb)--poly-3-hydroxybutyrate-co-poly-3-hydroxyvalerate (phb/phv)--polyhydroxyalkanoates (phas)--tissue reaction--bacteriology--calcification (biochemistry)--copolymers--flammability--tissue--tissue response--biomedical engineering--acid phosphatase--poly(3 hydroxybutyric acid)--poly(3 hydroxybutyric acid) co poly(3 hydroxyvaleric acid)--polyhydroxyalkanoic acid--suture material--unclassified drug--animal experiment--article--bacterial metabolism--biochemistry--biocompatibility--biomedicine--calcification--catgut--correlation analysis--dose time effect relation--enzyme activity--fascia--fiber--foreign body--functional assessment--giant cell--implantation--in vivo study--inflammation--intermethod comparison--macrophage--materials testing--multinuclear cell--muscle injury--necrosis--nonhuman--parameter--phagocytosis--physiology--postoperative period--priority journal--process monitoring--ralstonia eutropha b 5786--scar formation--silk--strength--suture--synthesis--tissue reaction--wautersia eutropha--wound healing--animalia--ralstonia--wautersia eutropha
Аннотация: The paper presents the results of biomedical investigations of sutures made of polyhydroxyalkanoates (PHAs) of two types (poly-3-hydroxybutyrate (PHB) and poly-3-hydroxybutyrate-co-poly-3-hydroxyvalerate (PHB/PHV)), synthesized by the bacteria Ralstonia eutropha B 5786 in the experiment on test animals in vivo, in comparison with silk and catgut sutures. PHB and PHB/PHV (PHBV) implants produced no adverse effect on physiological, biochemical and functional parameters of the animals during the post-surgery period. The tested PHA sutures featured the necessary strength throughout the healing period of the muscle-fascial cuts. The reaction of tissues to the implantation of PHB and PHB/PHV fibers fitted into the usual scheme characteristic of the wound process and of the reaction to a foreign-body invasion. This reaction and the reaction of tissues to silk had the similar nature and period of inflammation, but it was much less pronounced than the reaction to catgut. The tissue response to the implantation of PHAs consisted in a short-duration (up to 2 weeks) post-traumatic inflammation and the formation of a fibrous capsule less than 200 ?m thick during weeks 4-8, which in 4-6 months was reduced to 40-60 ?m in the course of reverse development. There were no adverse changes, such as suppurative inflammation, necrosis, calcification, and malignization of the cicatrice, at the site of implantation of PHA filaments, unlike in the cases with silk and catgut. In the case of PHA implantation there was a typical prolonged (throughout the post-surgery monitoring period) pronounced macrophagal stage with a large number of macrophages present. The macrophages were of the phagocytic type and multinucleate giant foreign cells, with a high activity of acid phosphomonoesterase that correlated with the activity of the enzyme in blood. Throughout the period of monitoring no differences in the tissue response to the implantation of the polymer filaments of two PHA types were recorded. В© 2003 Elsevier Science B.V. All rights reserved.
Scopus
Найти похожие

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.
Scopus
Найти похожие

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.
WOS
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Plotnikov V.F., Shishatskaya E.I., Mironov P.V., Vasil'ev A.D.
Заглавие : Physicochemical properties of two-component polyhydroxyalkanoates, 3-hydroxybutyrate-3-hydroxyvalerate copolymers
Место публикации : Biophysics. - 2004. - Vol. 49, Is. 6. - С. 934-942. - ISSN 00063509 (ISSN)
Ключевые слова (''Своб.индексиров.''): hydroxybutyrate-hydroxyvalerate copolymers--physicochemical properties--polyhydroxyalkanoates--structure--bacteria (microorganisms)--cupriavidus necator
Аннотация: A series of two-component polyhydroxyalkanoates composed of hydroxybutyrate-hydroxyvalerate copolymers with different monomer ratio was obtained with the use of bacteria Ralstonia eutropha B5786. The properties of the polyhydroxyalkanoates in comparison with the homopolymer of hydroxybutyric acid were studied by X-ray diffraction analysis, IR spectroscopy, differential thermal analysis, and viscometry. The ratio of crystalline to amorphous phase in the copolymers tends to unity with increasing hydroxyvalerate content. This is accompanied by a decrease in the degree of crystallinity of the copolymers from 70-80 to 45-50%, the dependence is virtually linear within the range, of hydroxyvalerate mole fraction from several to 25-30 mol%. Thermal characteristics, melting temperature (Tm) and decomposition temperature (Td), of the polyhydroxyalkanoate copolymers are lower than those for polyhydroxybutyrate, whose Tm and Td are 168-170 and 260-265В°C, respectively. Both parameters decrease to 150-160 and 200-220В°C, respectively, when the hydroxyvalerate mole fraction is raised. No distinct correlation between polymer composition and molecular weight has been revealed. Copyright В© 2004 by MAIK "Nauka/Interperiodica".
Scopus
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shishatskaya E.I., Volova T.G., Puzyr A.P., Mogilnaya O.A., Efremov S.N.
Заглавие : Tissue response to the implantation of biodegradable polyhydroxyalkanoate sutures
Место публикации : Journal of Materials Science: Materials in Medicine. - 2004. - Vol. 15, Is. 6. - С. 719-728. - ISSN 09574530 (ISSN) , DOI 10.1023/B:JMSM.0000030215.49991.0d
Ключевые слова (''Своб.индексиров.''): necrosis--polymeric implants--suppurative inflammation--tissue reaction--biodegradation--calcification (biochemistry)--cells--copolymers--implants (surgical)--silk--tissue--tumors--materials science--acid phosphatase--copolymer--poly(3 hydroxybutyric acid)--polyhydroxyalkanoic acid--polyhydroxyvaleric acid--unclassified drug--animal experiment--animal model--article--biodegradable implant--blood vessel reactivity--catgut--controlled study--enzyme activity--female--giant cell--histochemistry--inflammation--macrophage--nonhuman--priority journal--rat--silk--suture--tensile strength--tissue reaction--tissue structure--wound healing--young modulus--absorbable implants--animals--female--fibrosis--foreign-body reaction--hydroxybutyrates--muscle, skeletal--polyesters--polymers--rats--rats, wistar--sutures--treatment outcome--wounds, penetrating--animalia
Аннотация: Polyhydroxyalkanoate (PHA) sutures were implanted to test animals intramuscularly, and tissue reaction was investigated and compared with the reaction to silk and catgut. Tested monofilament sutures made of PHAs of two types polyhydroxybutyrate (PHB) and a copolymer of hydroxybutyrate and hydroxyvalerate (PHV) featured the strength necessary for the healing of muscle-fascial wounds. The reaction of tissues to polymeric implants was similar to their reaction to silk and was less pronounced than the reaction to catgut; it was expressed in a transient post-traumatic inflammation (up to four weeks) and the formation of a fibrous capsule less than 200 ?m thick, which became as thin as 4060 ?m after 16 weeks, in the course of reverse development. Macrophages and foreign-body giant cells with a high activity of acid phosphatase were actively involved in this process. PHB and PHB/PHV sutures implanted intramuscularly for an extended period (up to one year) did not cause any acute vascular reaction at the site of implantation or any adverse events, such as suppurative inflammation, necrosis, calcification of the fibrous capsule or malignant tumor formation. No statistically significant differences were revealed in the tissue response to polymer sutures of the two types. Capsules around silk and catgut sutures did not become significantly thinner.
Scopus
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Plotnikov V.F., Shishatskaya E.I., Mironov P.V., Vasil'ev A.D.
Заглавие : Physicochemical properties of two-component polyhydroxyalkanoates [Poly(3HB/3HV)]
Колич.характеристики :9 с
Место публикации : Biofizika: MEZHDUNARODNAYA KNIGA, 2004. - Vol. 49, Is. 6. - P1038-1046. - ISSN 0006-3029
Примечания : Cited References: 21
Предметные рубрики: BACTERIAL POLYHYDROXYALKANOATES
POLYESTERS
Ключевые слова (''Своб.индексиров.''): polyhydroxyalkanoates--copolymers of hydroxybutyrate and hydroxyvalerate--structure--physicochemical properties
Аннотация: A series of two-component polyhydroxyalkanoates consisting of hydroxybutyrate and hydroxyvalerate monomer at different ratios were synthesized using the bacterium Ralstonia eutropha B5786. The properties of polyhydroxyalkanoates were compared with those of the homopolymer of hydroxybutyric acid by X-ray structure analysis, IR spectroscopy, differential scanning calorimetry, and viscosimetry. With an increase in the molar fraction of hydroxyvalerate, an equalization of the ratio of the crystalline and amorphous phases in the copolymer was observed. The degree of crystallinity of the polymer decreased from 70-80 to 45-50%; in the range of an increase in the hydroxyvalerate molar fraction from several to 25-30 mol %, the dependence was linear. The temperature characteristics, the melting temperature (T-m), and the degradation temperature (T-d) were lower in polyhydroxyalkanoates than in polyhydroxybutyrate, for which T-m and T-d were 168-170 and 260-265degreesC, respectively. In the copolymer, as the molar fraction of hydroxyvalerate grew, both parameters decreased. In the range of variation of monomer ratio studied, they decreased to 150-160 and 200-220degreesC, respectively. No distinct correlation between the composition of the polymer and its molecular mass was found.
WOS
Найти похожие

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Kalacheva G.S.
Заглавие : The synthesis of hydroxybutyrate and hydroxyvalerate copolymers by the bacterium Ralstonia eutropha
Место публикации : Mikrobiologiya. - 2005. - Vol. 74, Is. 1. - С. 63-69. - ISSN 00263656 (ISSN)
Ключевые слова (''Своб.индексиров.''): ?-ketothiolase--controlled synthesis--poly(hydroxybutyrate-co-hydroxyvalerate)--ralstonia eutropha--bacteria (microorganisms)--cupriavidus necator--acetoacetyl coenzyme a--acetyl coenzyme a acyltransferase--acyl coenzyme a--acyltransferase--butyric acid derivative--carbon dioxide--fructose--hydrogen--poly(3 hydroxybutyrate) co (3 hydroxyvalerate)--poly(3-hydroxyalkanoic acid) synthase--poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate)--polyester--polyhydroxyalkanoate synthase--valeric acid derivative--article--chemistry--crystallization--culture medium--metabolism--wautersia eutropha--acetyl-coa c-acyltransferase--acyl coenzyme a--acyltransferases--butyrates--carbon dioxide--crystallization--culture media--cupriavidus necator--fructose--hydrogen--polyesters--valerates
Аннотация: The paper deals with the study of the synthesis of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) copolymers by the bacterium Ralstonia eutropha B-5786 grown under different carbon nutrition conditions (growth on carbon dioxide, fructose, and CO2-valerate and fructose-valerate mixtures). The parameters to be analyzed included the yield of biomass, the yield, synthesis rate, and composition of copolymers, the activity of the key enzymes of polyhydroxyalkanoate (PHA) synthesis (?-ketothiolase, acetoacetyl-CoA reductase, and PHA synthase), the maximum tolerable concentration of valerate to the bacterium, and the conditions that govern the incorporation of hydroxyvalerate to copolymers. This allowed the relationship between cultivation conditions and the proportion of monomers in the copolymers to be deduced. We were able to synthesize a range of 3HB/3HV copolymers and found that the thermal characteristics and the degree of crystallinity of these copolymers depend on the molar fraction of 3HV.
Scopus
Найти похожие

10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shishatskaya E.I., Volova T.G., Gordeev S.A., Puzyr A.P.
Заглавие : Degradation of P(3HB) and P(3HB-co-3HV) in biological media
Место публикации : Journal of Biomaterials Science, Polymer Edition. - 2005. - Vol. 16, Is. 5. - С. 643-657. - ISSN 09205063 (ISSN) , DOI 10.1163/1568562053783678
Ключевые слова (''Своб.индексиров.''): degradation rate--fiber properties--morphology--poly(hydroxybutyrate-co-hydroxyvalerate) (p(3hb-co-3hv))--polyhydroxyalkanoates(phas)--polyhydroxybutyrate (p(3hb))--copolymers--degradation--differential scanning calorimetry--enzymes--morphology--scanning electron microscopy--tensile strength--tissue--transmission electron microscopy--degradation rate--fiber properties--polyhydroxyalkanoates (phas)--polyhydroxybutyrate (p(3hb))--biopolymers--buffer--copolymer--poly(3 hydroxybutyric acid)--polyhydroxybutyrate hydroxyvalerate copolymer--unclassified drug--animal experiment--animal model--animal tissue--article--biodegradation--controlled study--crystal structure--fiber--giant cell--in vitro study--in vivo study--macrophage--morphology--nonhuman--ph--priority journal--rat--structure analysis--tensile strength--tissue water--weight reduction--animals--biodegradation, environmental--buffers--humans--hydrogen-ion concentration--hydroxybutyrates--macrophages--microscopy, electron, scanning--microscopy, electron, transmission--muscle, skeletal--polyesters--rats--rats, wistar
Аннотация: The biodegradability of oriented fibers made of polyhydroxybutyrate (P(3HB)) and its co-polymer with ?-hydroxyvalerate (P(3HB-co-3HV)) was investigated in buffer solutions and in biological media in vitro and in vivo. The fibers of both polymer types demonstrated resistance to hydrolytic degradation in buffer solutions at 38В°C and pH from 4.5 to 7.0 (for up to 180 days). It has been found that the biodegradation of the fibers in vitro in blood and serum and in vivo is accompanied by weight losses and minor changes in the microstructure with no significant losses in the tensile strength over a long time (up to 180 days). The biodegradation rate of the less crystalline co-polymer P(3HB-co-3HV) fibers was 1.4-2.0-times higher than that of the homopolymer P(3HB). It has also been shown that the degradation of the fibers in vivo is influenced both by tissue fluid enzymes and cells (macrophages and foreign-body giant cells). The fibers were eroded on the surface only with no gross defects and no dramatic effects on their mechanical performance. В© VSP 2005.
Scopus
Найти похожие

11.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Kalacheva G.S.
Заглавие : The synthesis of hydroxybutyrate and hydroxyvalerate copolymers by the bacterium Ralstonia eutropha
Место публикации : Microbiology. - 2005. - Vol. 74, Is. 1. - С. 54-59. - ISSN 00262617 (ISSN) , DOI 10.1007/s11021-005-0028-5
Ключевые слова (''Своб.индексиров.''): ?-ketothiolase--controlled synthesis--poly(hydroxybutyrate-co-hydroxyvalerate)--ralstonia eutropha--bacteria (microorganisms)--ralstonia--wautersia eutropha
Аннотация: The paper deals with the study of the synthesis of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) copolymers by the bacterium Ralstonia eutropha B-5786 grown under different carbon nutrition conditions (growth on carbon dioxide, fructose, and CO2-valerate and fructose-valerate mixtures). The parameters to be analyzed included the yield of biomass; the yield, synthesis rate, and composition of copolymers; the activity of the key enzymes of polyhydroxyalkanoate (PHA) synthesis ?-ketothiolase, acetoacetyl-CoA reductase, and PHA synthase); the maximum tolerable concentration of valerate to the bacterium; and the conditions that govern the incorporation of hydroxyvalerate into copolymers. This allowed the relationship between cultivation conditions and the proportion of monomers in the copolymers to be deduced. We were able to synthesize a range of 3HB/3HV copolymers and found that the thermal characteristics and the degree of crystallinity of such copolymers depend on the molar fraction of 3HV. В© 2005 Pleiades Publishing, Inc.
Scopus
Найти похожие

12.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Nikolaeva E.D., Shishatskaya E.I., Mochalov K.E., Volova T.G., Sinsky A.J.
Заглавие : Comparative investigation of polyhydroxyalkanoate scaffolds with various chemical compositions
Место публикации : Cellular Transplantation and Tissue Engineering. - 2011. - Vol. 6, Is. 4. - С. 54-63. - ISSN 1815445X (ISSN)
Ключевые слова (''Своб.индексиров.''): biopolymers--scaffolds--tissue engineering
Аннотация: The authors have constructed and characterized a series of membranes based on resorbable polyhydroxyalkanoates of different compositions. Five PHA types have been studied: a homopolymer of 3-hydroxybutyric acid, copolymers of 3-hydroxybutyric and 4-hydroxybutyric acids, 3-hydroxybutyric and 3-hydroxyvaleric acids, 3-hydroxybutyric and 3-hydroxyhexanoic acids. Scanning electron microscopy and atomicforce microscopy were used to examine the microstructure of membrane surfaces, showing that membranes based on the copolymer of 3-hydroxybutyrate and 3-hydroxyhexanoate had the roughest surface, while membranes based on the copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate had the smoothest surface. The contact angle for water in air was smaller and hydrophilic properties better in the copolymer membranes than in the membranes based on the high-crystallinity homopolymer of 3-hydroxybutyric acid. The culture of mouse fibroblast cell line NIH 3,3 was used to test PHAbased membranes; results of fluorescent probes of DNA DAPI and the MTT assay show that membranes based on studied PHAs are not cytotoxic on direct contact with cells and are highly biocompatible; their adhesive properties and ability to maintain fibroblast proliferation are similar to those of polystyrene and better than those of polylactic acid membranes.
Scopus
Найти похожие

13.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Zhila N.O., Kalacheva G.S., Sokolenko V.A., Sinski E.J.
Заглавие : Synthesis of 3-hydroxybutyrate-CO-4-hydroxybutyrate copolymers by hydrogen-oxidizing bacteria
Место публикации : Applied Biochemistry and Microbiology. - 2011. - Vol. 47, Is. 5. - С. 494-499. - ISSN 00036838 (ISSN) , DOI 10.1134/S0003683811050152
Ключевые слова (''Своб.индексиров.''): bacteria (microorganisms)--cupriavidus--cupriavidus necator
Аннотация: Synthesis of 3- and 4-hydroxybutyrate copolymer (3HB-co-4HB), the most promising member of the biodegradable polyhydroxyalkanoate (PHA) family, has been studied. Cultivation conditions of naturally occurring strains of hydrogen-oxidizing bacteria Ralstonia eutropha B5786 and Cupriavidus eutrophus B10646 have been optimized to ensure efficient synthesis of the 3HB-co-4HB copolymer. A set of highly pure samples of the 3HB-co-4HB copolymer with 4HB content varying from 8.7 to 24.3 mol% has been obtained. Incorporation of 4HB into the copolymer was shown to cause a more pronounced decrease in polymer crystallinity than the incorporation of 3-hydroxyvalerate or 3-hydroxyhexanoate; samples with a degree of crystallinity below 30% have been obtained. The weight average molecular mass of the 3HB-co-4HB copolymers was shown to be independent on the monomer ratio and to vary broadly (from 540 to 1110 kDa). В© 2010 Pleiades Publishing, Ltd.
Scopus
Найти похожие

14.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Goreva A.V., Shishatskaya E.I., Volova T.G., Sinskey A.J.
Заглавие : Characterization of polymeric microparticles based on resorbable polyesters of oxyalkanoic acids as a platform for deposition and delivery of drugs
Место публикации : Polym. Sci. Ser. A: MAIK NAUKA/INTERPERIODICA/SPRINGER, 2012. - Vol. 54, Is. 2. - С. 94-105. - 12. - ISSN 0965-545X, DOI 10.1134/S0965545X12020022
Примечания : Cited References: 33. - This work was supported by the program for Support of Leading Scientific Schools of the Russian Federation (project no. 11.G34.31.0013.2010, Biotechnology of New Biomaterials) and the program of integrated studies of the Presidium of the Siberian Branch, Russian Academy of Sciences (project no. 93).
Предметные рубрики: IN-VITRO RELEASE
POLYHYDROXYBUTYRATE MICROSPHERES
BLENDS
RIFAMPICIN
BIOCOMPATIBILITY
DEGRADATION
FORMULATION
COMPOSITE
CARRIERS
MODEL
Аннотация: The effect of the preparation technique (chemical composition of a polymer, type and method of emulsion mixing, and molecular mass of a drug) on the yield, structure, and size of microparticles obtained from resorbable polyesters of microbiological origin, polyhydroxyalkanoates, is studied. It is found that the concentration of the polymer solution and the method of emulsion mixing are the most significant factors affecting the diameter of microparticles based on polyhydroxyalkanoates; the surface structure of particles depends to a higher extent on the chemical composition of the polymer. The family of microparticles from 100-200 nm to 50-70 mu m in diameter is synthesized. It is shown that the rate of drug release from microparticles in vitro into the medium is higher in the case of 3-hydroxybutyrate copolymers with 3-hydroxyvalerate than in the case of the homopolymer of 3-hydroxybutyrate. This parameter increases with the content of 3-hydroxyvalerate units in the copolymer and the porosity and mass fraction of the drug in particles with a decrease in their sizes. For in vitro systems containing a phosphate buffer, variation in the preparation parameters makes it possible to obtain microparticles with various characteristics suitable for deposition of drugs. For microparticles obtained from polyhydroxyalkanoates and having different diameters, the mathematical description of the kinetics of drug release from the polymer matrix is provided.
Найти похожие

15.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shishatskaya E.I., Nikolaeva E.D., Goreva A.V., Brigham C.J., Volova T.G., Sinskey A.J.
Заглавие : An in vivo study of pha matrices of different chemical composition: Tissue reaction and biodegradation
Место публикации : Cellular Transplantation and Tissue Engineering. - 2012. - Vol. 7, Is. 1. - С. 73-80. - ISSN 1815445X (ISSN)
Ключевые слова (''Своб.индексиров.''): degradable polymer matrices--degradation--phas--polyhydroxyalkanoates--subcutaneous implantation--tissue reaction
Аннотация: The study addresses consequences of subcutaneous implantation of film matrices prepared from different PHAs to laboratory animals. No negative effects of subcutaneous implantation of PHA matrices on physiological and biochemical characteristics of the animals were determined. Independently of the matrices composition and duration of the contact with the internal environment of the organism we did not observe any deviations in the behavior of animals, their growth and development, as well as blood functions. Response of the tissues to PHA matrices was comparable with the response to polylactide, but substantially less expressed at the earlier time periods after implantation. Tissues response to implantation of PHA of all types is characterized by short-term (up to 2 weeks) post-traumatic inflammation with formation of fibrous capsules by 30th-60th days with the thickness less than 100 microns, which get thinner down to 40-60 microns by 180th day as the result of involution. No differences in response of tissues and the whole organism were observed for the matrices produced from the homopolymer of 3-hydroxybutyric acid (P3HB), copolymers of 3-hydroxybutyric and 4-hydroxybutyric acids (P3HB/4HB), 3-hydroxybutyric acid and 3-hydroxyvalerianic acids (P3HB/3HV), 3-hydroxybutyric and 3-hydroxyhexanoate acids (P3HB/3HH). Macrophages and foreign-body giant cells actively participate in the response of the tissues to PHAs. In the studied conditions matrices from the copolymers containing 3-hydroxyhexanoate and 4 hydroxybutyrate were determined as more actively degraded PHA. The next less degraded matrices were matrices from the copolymer of P3HB/3HV and the most resistant were P3HB matrices. The slower degradation of PHA matrices was accompanied by delayed development of giantcells response. The studied PHA matrices can be placed in the following range by their degradation: P3HB/3HH - P3HB/4HB - P3HB/HV - P3HB.
Scopus
Найти похожие

16.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Murueva A.V., Shishatskaya E.I., Kuzmina A.M., Volova T.G., Sinskey A.J.
Заглавие : Microparticles prepared from biodegradable polyhydroxyalkanoates as matrix for encapsulation of cytostatic drug
Место публикации : Journal of Materials Science: Materials in Medicine. - 2013. - Vol. 24, Is. 8. - С. 1905-1915. - ISSN 09574530 (ISSN) , DOI 10.1007/s10856-013-4941-2
Ключевые слова (''Своб.индексиров.''): 3-hydroxybutyric acid--average diameter--cell attachments--chemical compositions--mass concentration--mouse-fibroblasts--polyhydroxyalkanoates--solvent evaporation techniques--biocompatibility--cell culture--cells--loading--3 hydroxybutyric acid--3 hydroxyhexanoic acid--4 hydroxybutyric acid--4',6 diamidino 2 phenylindole--dna--doxorubicin--nanoparticle--polyhydroxyalkanoic acid--polymer--polystyrene--solvent--unclassified drug--animal cell--article--biocompatibility--biodegradability--cell adhesion--cell proliferation--cell strain 3t3--cell viability--chemical composition--chemical structure--controlled study--cytotoxicity--drug efficacy--drug release--electrophoretic mobility--encapsulation--evaporation--fibroblast--in vitro study--nonhuman--particle size--priority journal--stain--study--surface charge--zeta potential
Аннотация: Microparticles made from degradable polyhydroxyalkanoates of different chemical compositions a homopolymer of 3-hydroxybutyric acid, copolymers of 3-hydroxybutyric and 4-hydroxybutyric acids (P3HB/4HB), 3-hydroxybutyric and 3-hydroxyvaleric acids (P3HB/3HV), 3-hydroxybutyric and 3-hydroxyhexanoic acids (P3HB/3HHx) were prepared using the solvent evaporation technique, from double emulsions. The study addresses the influence of the chemical compositions on the size and ?-potential of microparticles. P3HB microparticles loaded with doxorubicin have been prepared and investigated. Their average diameter and ?-potential have been found to be dependent upon the level of loading (1, 5, and 10 % of the polymer mass). Investigation of the in vitro drug release behavior showed that the total drug released from the microparticle into the medium increased with mass concentration of the drug. In this study mouse fibroblast NIH 3T3 cells were cultivated on PHA microparticles, and results of using fluorescent DAPI DNA stain, and MTT assay showed that microparticles prepared from PHAs of different chemical compositions did not exhibit cytotoxicity to cells cultured on them and proved to be highly biocompatible. Cell attachment and proliferation on PHA microparticles were similar to those on polystyrene. The cytostatic drug encapsulated in P3HB/3HV microparticles has been proven to be effective against HeLa tumor cells. В© 2013 Springer Science+Business Media New York.
Scopus
Найти похожие

17.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Zhila N.O., Shishatskaya E.I., Mironov P.V., Vasil'Ev A.D., Sukovatyi A.G., Sinskey A.J.
Заглавие : The physicochemical properties of polyhydroxyalkanoates with different chemical structures
Место публикации : Polymer Science - Series A. - 2013. - Vol. 55, Is. 7. - С. 427-437. - ISSN 0965545X (ISSN) , DOI 10.1134/S0965545X13070080
Ключевые слова (''Своб.индексиров.''): amorphous and crystalline phasis--degrees of crystallinity--physicochemical property--poly(3-hydroxybutirate)--polyhydroxyalkanoate copolymer--temperature characteristic--thermal degradation temperatures--thermoplastic materials--copolymers--monomers--thermoplastic elastomers--structure (composition)
Аннотация: A set of polyhydroxyalkanoates are synthesized, and a comparative study of their physicochemical properties is performed. The molecular masses and polydispersities of polyhydroxyalkanoates are found to be independent of their chemical structures. It is shown that the temperature characteristics and degrees of crystallinity of polyhydroxyalkanoates are affected by the chemical compositions of the monomers and their quantitative contents in the polymers. The incorporation of 4-hydroxybutyrate, 3-hydroxyvalerate, and 3-hydroxyhexanoate units into the chain of poly(3-hydroxybutyrate) decreases its melting point and thermal degradation temperature relative to these parameters of a homogeneous poly(3-hydroxybutyrate) sample (175 В± 5 C and 275 В± 5 C, respectively). The higher the content of the second monomer units in the poly(3-hydroxybutirate) chain, the greater the changes. The degrees of crystallinity of polyhydroxyalkanoate copolymers are generally lower than that of poly(3-hydroxybutyrate) (75 В± 5%). The effect on the ratio of the amorphous and crystalline phases of the copolymer samples becomes more pronounced in the series 3-hydroxy-valerate-3-hydroxyhexanoate-4- hydroxybutyrate. The prepared samples exhibit different properties ranging from rigid thermoplastic materials to engineering elastomers. В© 2013 Pleiades Publishing, Ltd.
Scopus
Найти похожие

18.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T..., Goncharov D..., Sukovatyi A..., Shabanov A..., Nikolaeva E..., Shishatskaya E...
Заглавие : Electrospinning of polyhydroxyalkanoate fibrous scaffolds: effects on electrospinning parameters on structure and properties
Колич.характеристики :24 с
Коллективы : Project 'Biotechnologies of novel biomaterials: innovative biopolymers and devices for biomedicine' [1, 11.G34.31.0013]; Government of the Russian Federation [220]; RF President for supporting young Doctors of Sciences [MD-3112.2012.4]
Место публикации : J. Biomater. Sci.-Polym. Ed.: TAYLOR & FRANCIS LTD, 2014. - Vol. 25, Is. 4. - С. 370-393. - ISSN 0920-5063, DOI 10.1080/09205063.2013.862400
Примечания : Cited References: 52. - This study was financially supported by Project 'Biotechnologies of novel biomaterials: innovative biopolymers and devices for biomedicine' (Agreement No. 1 of 15.02.2013 to Agreement No. 11.G34.31.0013) in accordance with Resolution No. 220 of the Government of the Russian Federation of April 9, 2010, 'On measures designed to attract leading scientists to the Russian institutions of higher learning' and Grant of the RF President for supporting young Doctors of Sciences No. MD-3112.2012.4.
Предметные рубрики: TISSUE ENGINEERING APPLICATIONS
FIBER MATS
POLY 3-HYDROXYBUTYRATE
POLY(3-HYDROXYBUTYRATE-CO-3-HYDROXYVALERATE)
BIOCOMPATIBILITY
PROLIFERATION
FABRICATION
NANOFIBERS
COPOLYMERS
MEMBRANES
Ключевые слова (''Своб.индексиров.''): electrospinning--polyhydroxyalkanoates--ultrafine fibers--physical-mechanical properties--fibroblast cells
Аннотация: In this study, electrospinning was used to prepare ultrafine fibers from PHAs with different chemical compositions: P(3HB) and copolymers: P(3HB-co-4HB), P(3HB-co-3HV), and P(3HB-co-3HHx). The main process parameters that influence ultrafine fiber diameter and properties (polymer concentration, solution feeding rate, working distance, and applied voltage) have been investigated and their effects evaluated. The study revealed electrospinning parameters for the production of high-quality ultrafine fibers and determined which parameters should be varied to tailor the properties of the products. This study is the first to compare biological and physical-mechanical parameters of PHAs with different chemical compositions as dependent upon the fractions of monomers constituting the polymers and ultrafine fiber orientation. Mechanical strength of aligned ultrafine fibers prepared from different PHAs is higher than that of randomly oriented ones; no significant effect of ultrafine fiber orientation on surface properties has been found. None of the fibrous scaffolds produced by electrospinning from PHAs had any adverse effects on attachment, growth, and viability of NIH 3T3 mouse fibroblast cells, and all of them were found to be suitable for tissue engineering applications.
WOS,
Scopus
Найти похожие

19.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Shishatskaya E.I., Nikolaeva E.D., Sinskey A.J.
Заглавие : In vivo study of 2D PHA matrices of different chemical compositions: Tissue reactions and biodegradations
Место публикации : Mater. Sci. Technol. - 2014. - Vol. 30, Is. 5. - С. 549-557. - ISSN 17432847 (ISSN) , DOI 10.1179/1743284713Y.0000000470
Ключевые слова (''Своб.индексиров.''): biocompatibility--biodegradation--implantation--pha--polyhydroxyalkanoates--tissue response--biocompatibility--biodegradable polymers--copolymers--degradation--ion implantation--microbiology--tissue--chemical compositions--foreign body giant cells--hydroxybutyric acids--maximum thickness--pha--polyhydroxyalkanoates--polymer matrices--tissue response--biodegradation
Аннотация: Matrices based on resorbable polyhydroxyalkanoates (PHAs) of five types {a homopolymer of 3- hydroxybutyric acid, copolymers of 3-hydroxybutyric and 4-hydroxybutyric acids [P(3HB/4HB)], 3-hydroxybutyric and 3-hydroxyvaleric acids [P(3HB/3HV)], 3-hydroxybutyric and 3-hydroxyhexanoic acids [P(3HB/3HHx)]} have been constructed and characterised. No significant differences have been found in tissue response to implantation of these PHAs. Non-coarse fibrous capsules that formed around PHA matrices reached their maximum thickness (60-90 ?m) 90 days after implantation; by day 180, the average thickness of the capsules had decreased by 1·5-2·3 times. The number of foreign body giant cells, resorbing PHAs, remained high. In vivo biodegradation behaviour of polymer matrices is related to the chemical composition of the PHA. Matrices prepared from copolymers P(3HB/4HB) and P(3HB/3HHx) exhibited the fastest degradation rates. P3HB/3HV matrices were degraded more slowly, and P3HB matrices were the most durable. In the PHA matrices that were degraded more slowly, giant cell reaction developed later. © 2014 Institute of Materials, Minerals and Mining.
Scopus
Найти похожие

20.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Volova T.G., Shishatskaya E.I., Nikolaeva E.D., Sinskey A.J.
Заглавие : In vivo study of 2D PHA matrices of different chemical compositions: tissue reactions and biodegradations
Колич.характеристики :9 с
Коллективы : Government of the Russian Federation
Место публикации : Mater. Sci. Technol.: MANEY PUBLISHING, 2014. - Vol. 30, Is. 5. - С. 549-557. - ISSN 0267-0836, DOI 10.1179/1743284713Y.0000000470. - ISSN 1743-2847
Примечания : Cited References: 31. - The study was supported by the project initiated by the Government of the Russian Federation (decree no. 220 of 09.04.2010) for governmental support of scientific research conducted under the guidance of leading scientists at Russian institutions of higher learning (agreement no. 11.G34.31.0013) and the Program of Integrated Research of the Presidium of SB RAS (project no. 96).
Предметные рубрики: BIOMEDICAL INVESTIGATIONS
POLYHYDROXYALKANOATES
VITRO
BIOCOMPATIBILITY
DEGRADATION
SCAFFOLDS
CONDUITS
POLYMERS
Ключевые слова (''Своб.индексиров.''): pha--polyhydroxyalkanoates--biocompatibility--implantation--tissue response--biodegradation
Аннотация: Matrices based on resorbable polyhydroxyalkanoates (PHAs) of five types {a homopolymer of 3-hydroxybutyric acid, copolymers of 3-hydroxybutyric and 4-hydroxybutyric acids [P(3HB/4HB)], 3-hydroxybutyric and 3-hydroxyvaleric acids [P(3HB/3HV)], 3-hydroxybutyric and 3-hydroxyhexanoic acids [P(3HB/3HHx)]} have been constructed and characterised. No significant differences have been found in tissue response to implantation of these PHAs. Non-coarse fibrous capsules that formed around PHA matrices reached their maximum thickness (60-90 mm) 90 days after implantation; by day 180, the average thickness of the capsules had decreased by 1.5- 2.3 times. The number of foreign body giant cells, resorbing PHAs, remained high. In vivo biodegradation behaviour of polymer matrices is related to the chemical composition of the PHA. Matrices prepared from copolymers P(3HB/4HB) and P(3HB/3HHx) exhibited the fastest degradation rates. P3HB/3HV matrices were degraded more slowly, and P3HB matrices were the most durable. In the PHA matrices that were degraded more slowly, giant cell reaction developed later.
WOS
Найти похожие