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Sundstrom T.,University of Bergen | Daphu I.,University of Bergen | Wendelbo I.,University of Bergen | Hodneland E.,University of Bergen | And 11 more authors.
Cancer Research | Year: 2013

Biologic and therapeutic advances in melanoma brain metastasis are hampered by the paucity of reproducible and predictive animal models. In this work, we developed a robust model of brain metastasis that empowers quantitative tracking of cellular dissemination and tumor progression. Human melanoma cells labeled with superparamagnetic iron oxide nanoparticles (SPION) were injected into the left cardiac ventricle of mice and visualized by MRI. We showed that SPION exposure did not affect viability, growth, or migration in multiple cell lines across several in vitro assays. Moreover, labeling did not impose changes in cell-cycle distribution or apoptosis. In vivo, several SPION-positive cell lines displayed similar cerebral imaging and histologic features. MRI-based automated quantification of labeled cells in the brain showed a sigmoid association between metastasis frequency and doses of inoculated cells. Validation of this fully automated quantification showed a strong correlation with manual signal registration (r2=0.921, P < 0.001) and incidence of brain metastases (r2= 0.708, P < 0.001). Metastasis formation resembled the pattern seen in humans and was unaffected by SPION labeling (histology; tumor count, P=0.686; survival, P=0.547). In summary, we present here a highly reproducible animal model that can improve the predictive value of mechanistic and therapeutic studies of melanoma brain metastasis. Cancer Res; 73(8); 2445-56. © 2013 American Association for Cancer Research.


Weszka J.,Silesian University of Technology | Weszka J.,Polish Academy of Sciences | Szindler M.M.,Silesian University of Technology | Chwastek-Ogierman M.,Polish Academy of Sciences | And 2 more authors.
Archives of Materials Science and Engineering | Year: 2012

Purpose: The purpose of this paper was to analyse the surface morphology and optical properties of polyoxadiazoles thin films. Design/methodology/approach: A few different conducting polymers were dissolved in N-methyl- 2-pyrrolid(in)one. Then the solutions were deposited on a glass substrate by spin coating method with a different spin rate. Changes in surface topography and optical properties were observed. A confocal laser scanning microscope CLSM Zeiss LSM 5 Exciter has been used. Photos have been taken from area of 120 x 120 microns. Findings: The analysis of images and spectra has confirmed that the quality of thin films depends upon the used polymers. It was also observed that the parameters of the spin coating method have significant effect on the morphology and the optical properties. The spin rate has got a strong impact on them. Research limitations/implications: The morphology and optical properties of polyoxadiazoles thin films has been described. This paper include description how the spin rate influence on the polymer thin films. In order to use a polymer thin film in photovoltaics or optoelectronics it must have a high internal transmission density. Further research of polymer thin films are recommended. Practical implications: The spin coating method allows to deposit a uniform thin films. It is important to know how the spin rate influence on the thin films properties. It is also important to find a new use for this group of material engineering in photovoltaic or optoelectronics devices. Originality/value: The good properties of thin films make them suitable for various applications. The value of this paper is defining the optimal parameters of spin-coating technology for polyoxadiazoles thin films. The results allow the choosing optimal parameters of the deposition process. Spin coating is a very good method to obtain thin films which are obligated to have the same thickness over the whole surface. © Copyright by International OCSCO World Press. All rights reserved. 2012.


Hamciuc E.,Institute of Macromolecular Chemical | Hamciuc C.,Institute of Macromolecular Chemical | Ronova I.A.,RAS Nesmeyanov Institute of Organoelement Compounds
Revue Roumaine de Chimie | Year: 2012

Aromatic polyimides with pendant carboxylic groups were prepared starting from 3,5-diaminobenzoic acid, DABA, or equimolar amount of DABA and 4,4'-(4,4'-isopropylidenediphenyl-1,1'-diyldioxy)dianiline, and different aromatic dianhydrides. The polymers exhibited high thermal stability with initial decomposition temperature above 430°C and glass transition temperature in the range of 251-302°C. They showed good solubility in polar amidic solvents and some of them in less polar liquids, like chloroform. The polymer solutions could be cast into flexible films. A study of the relation between conformational parameters and properties of these polymers has been carried out by using the Monte Carlo method, and the results were compared with the experimental data and discussed in relation with the rigidity of the chains.


Starostenko O.,Institute of Macromolecular Chemical | Bershtein V.,RAS Ioffe Physical - Technical Institute | Fainleib A.,Institute of Macromolecular Chemical | Egorova L.,RAS Ioffe Physical - Technical Institute | And 3 more authors.
Macromolecular Symposia | Year: 2012

A series of hybrid polycyanurate - epoxy cyclohexyl-functionalized polyhedral oligomeric silsesquioxane (PCN/ECH-POSS) nanocomposite networks with ECH-POSS content varying from 0.025 to 10 wt. % were synthesized and characterized using FTIR, DSC, DMA and CRS techniques. It was revealed that already as low as 0.025 wt. % POSS cardinally changed PCN glass transition characteristics including the strong shift of the transition onset to higher temperatures and manifesting a second, higher-temperature glass transition characterizing interfacial dynamics; additionally, enhancing creep resistance and thermal stability at the earlier stage of degradation were observed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Sergeyeva T.A.,NASU Institute of Molecular Biology and Genetics | Gorbach L.A.,Institute of Macromolecular Chemical | Slinchenko O.A.,Institute of Macromolecular Chemical | Goncharova L.A.,Institute of Macromolecular Chemical | And 4 more authors.
Materials Science and Engineering C | Year: 2010

Colorimetric test-system for the express-control of phenols content in water was developed. The system consisted of free-standing molecularly imprinted polymer (MIP) membranes which contained synthetic binding sites capable of phenol binding. The MIP membranes were obtained by co-polymerisation of a functional monomer (e.g. itaconic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, acrylamide or methacrylic acid) with triethyleneglycoldimethacrylate and oligourethaneacrylate. Rational choice of the functional monomers was based on the results of computational modelling. The phenol-selective MIP membranes were used as a basis for the colorimetric test-system for measuring phenol in aqueous samples. Phenol molecules were selectively adsorbed by the MIP membranes and quantified using color reaction with 4-aminoantipyrine. The intensity of the membranes' staining was proportional to the phenol concentration in the analysed sample. The optimised colorimetric test-system based on MIP membranes demonstrated a low detection limit (50 nM), a wide working range - 50 nM-0.5 mM and an excellent storage stability at room temperature (12 months). As compared to the traditional methods of phenols detection the developed test-system is superior because of simplicity of operation, small size and low cost. © 2009 Elsevier B.V.


Hamciuc C.,Institute of Macromolecular Chemical | Hamciuc E.,Institute of Macromolecular Chemical | Bacosca I.,Institute of Macromolecular Chemical | Okrasa L.,Technical University of Lodz
Revue Roumaine de Chimie | Year: 2010

Two aromatic polyimides have been prepared by solution polycondensation reaction of a fluorinated bis(o-aminophenol), namely 2,2-bis(3-amino-4- hydroxyphenyl)hexafluoropropane, with aromatic dianhydrides such as 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride and 2,2-bis-[4-(3,4-dicarboxyphenoxy)phenyl]isopropane dianhydride. A poly(amide imide) containing hydroxylic groups has been synthesized by using the same fluorinated bis(o-aminophenol) and 2,2-bis[N-(4-chloroformylphenyl)phthalimidyl] hexafluoropropane. All polymers were soluble in polar organic solvents, such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, as well as in less polar organic solvents, such as tetrahydrofuran. They were amorphous, afforded transparent and flexible films by solution casting, and exhibited good thermal stability. Electrical insulating properties of polymer films were evaluated on the basis of dielectric constant and dielectric loss and their variation with frequency and temperature. The values of the dielectric constant at 10 kHz and 20°C were in the range of 3.41-3.71 for polyimides and 3.93 for poly(amide imide). Two subglass transitions, γ and β, were evidenced by dielectric spectroscopy.


Burel F.,INSA Rouen | Oulyadi H.,CNRS Organic Chemistry, Bioorganic Chemistry: Reactivity and Analysis | Bunel C.,INSA Rouen | Grishchenko V.,Institute of Macromolecular Chemical | And 3 more authors.
Journal of Polymer Research | Year: 2011

Azo-bis(isobutyroamidoxime) was synthesized and used as functionalized initiator to prepare a liquid isoprene bearing amidoxime end groups via radical polymerization. The polymer was characterized by FT-IR, Gel Permeation Chromatography and NMR. In particular, the structure of the polymer was investigated using 1D and 2D NMR techniques. The distribution of the different isoprene units (1,4-trans, 1,4-cis, 1,2 and 3,4), as well as the structure of the amidoxime end-groups was determined. It was found that the structure of the end groups was governed by the steric hindrance of the initiator. Only 1,4 and 4,1 functionalized end units were evidenced, with a majority of 4,1 end units. © 2011 Springer Science+Business Media B.V.


Bershtein V.,RAS Ioffe Physical - Technical Institute | Fainleib A.,Institute of Macromolecular Chemical | Yakushev P.,RAS Ioffe Physical - Technical Institute | Egorova L.,RAS Ioffe Physical - Technical Institute | And 3 more authors.
Polymers for Advanced Technologies | Year: 2015

Thermostable densely crosslinked cyanate ester resins (CER) with different chemical structures, derived from monomer dicyanate esters of bisphenol E (DCBE), bisphenol A (DCBA), hexafluorobisphenol A (6F-DCBA) or from cyanated phenol-formaldehyde oligomer PT-30, and the nanocomposites based thereon, with 0.01 to 10wt% epoxycyclohexyl-functionalized polyhedral oligomeric silsesquioxane (ECH-POSS), were synthesized and characterized by means of dynamic mechanical analysis, differential scanning calorimetry, far-infrared, and creep rate spectroscopy techniques. As shown, thermal and mechanical properties increased in a row of matrices prepared from DCBEg=248, 275, 300, and ~400°C (DMA, 1Hz), respectively, had dynamic modulus E' values of 1.8, 2.7-3.0, and 3.6GPa at 20°C; high rigidity (dynamic modulus of about 1-2GPa) retained at temperatures up to 200°C for DCBE matrix, 250°C for DCBA and 6F-DCBA matrices, but up to 380°C for PT-30-based matrix. The maximal effects from introducing ECH-POSS nanoparticles, covalently embedded into CER network, were attained mainly at their ultra-low contents (<<1wt%); however, the ECH-POSS impact decreases in a row of matrices prepared from DCBE>DCBA>6F-DCBA>PT-30. © 2015 John Wiley & Sons, Ltd.


Karabanova L.V.,Institute of Macromolecular Chemical | Whitby R.L.D.,University of Brighton | Bershtein V.A.,RAS Ioffe Physical - Technical Institute | Korobeinyk A.V.,University of Brighton | And 4 more authors.
Colloid and Polymer Science | Year: 2013

Acid-oxidized multiwalled carbon nanotubes (MWCNTs) were introduced into a polyurethane (PU) matrix at low filler levels (0.01-0.25 wt%) through either van der Waals or covalent interactions, and their glass transition dynamics using dynamic mechanical analysis and laser-interferometric creep rate spectroscopy was investigated. The nanocomposites reveal substantial impact on the PU glass transition dynamics, which depends on the nanotube content and type of interfacial interactions. The pronounced dynamic heterogeneity within the glass transition covering 200 C range and the displacement of main PU relaxation maxima from around 0 to 80-140 C were registered. The results are treated in the framework of chemical inhomogeneity, constrained dynamics effects, and different motional cooperativities. The peculiariaties of the glass transition dynamics in the composites are reflected in their dynamic and static mechanical properties, in particular a two- to threefold increase in modulus and tensile strength for the covalent interfacial interaction of MWCNTs with PU. © 2012 Springer-Verlag.


Sergeyeva T.A.,NASU Institute of Molecular Biology and Genetics | Gorbach L.A.,Institute of Macromolecular Chemical | Piletska E.V.,Cranfield University | Piletsky S.A.,Cranfield University | And 6 more authors.
Analytica Chimica Acta | Year: 2013

An easy-to-use colorimetric test-system for the efficient detection of creatinine in aqueous samples was developed. The test-system is based on composite molecularly imprinted polymer (MIP) membranes with artificial receptor sites capable of creatinine recognition. A thin MIP layer was created on the surface of microfiltration polyvinylidene fluoride (PVDF) membranes using method of photo-initiated grafting polymerization. The MIP layer was obtained by co-polymerization of a functional monomer (e.g. 2-acrylamido-2-methyl-1-propanesulfonic acid, itaconic acid or methacrylic acid) with N, N'-methylenebisacrylamide as a cross-linker. The choice of the functional monomer was based on the results of computational modeling. The creatinine-selective composite MIP membranes were used for measuring creatinine in aqueous samples. Creatinine molecules were selectively adsorbed by the MIP membranes and quantified using color reaction with picrates. The intensity of MIP membranes staining was proportional to creatinine concentration in an analyzed sample. The colorimetric test-system based on the composite MIP membranes was characterized with 0.25. mM detection limit and 0.25-2.5. mM linear dynamic range. Storage stability of the MIP membranes was estimated as at least 1 year at room temperature. As compared to the traditional methods of creatinine detection the developed test-system is characterized by simplicity of operation, small size and low cost. © 2013 Elsevier B.V.

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