bluuebunny/crossref_metadata_2025 huggingface dataset:
A single low dose of dendritic cells modified with lentivirus containing a truncated neu gene can effectively suppress neu‐overexpressing tumors
Authors: Li Gong‐Bo , Lu Guang‐Xiu
Published: June 2010

Background

Several types of viral‐transduced HER2/neu‐modified dendritic cells (DCHER2/neu) have been used for preventing and/or treating HER2/neu‐overexpressing tumors. However, to date, lentivirus has not been used to generate HER2/neu‐modified DCs.

Methods

In the present study, we used recombinant lentivirus containing a truncated neu gene (rLVneu) to transduce murine bone marrow‐derived dendritic cells and investigated their preventive and therapeutic effects on HER2/neu‐overexpressing tumors.

Results

The data obtained show that a single low dose of lentiviral‐transduced DCHER2/neu could significantly elevate serum anti‐neu antibody level, stimulate the proliferation of CD4 and CD8 T lymphocytes and interferon‐γ secretion, induce a long lasting preventive effect against HER2/neu‐overexpressing tumors and significantly suppress the growth of established HER2/neu‐overexpressing tumors.

Conclusions

The present study demonstrates that a single low dose of DCs modified with rLV containing a truncated neu oncogene can achieve a strong and long lasting effect on neu‐overexpressing tumors, suggesting the possible clinical application of this strategy. Copyright © 2010 John Wiley & Sons, Ltd.
Surface optical Raman modes in GaN nanoribbons
Authors: Bhattacharya Santanu , Datta Anindya , Dhara Sandip , Chakravorty Dipankar
Published: June 2010

Raman scattering studies were performed in GaN nanoribbons grown along [1 0 0]. These samples were prepared inside Na‐4 mica nanochannels by the ion‐exchange technique and subsequent annealing in NH3 ambient. Detailed morphological and structural studies including the crystalline orientation were performed by analyzing the vibrational properties in these GaN nanoribbons. Pressure in the embedded structure was calculated from the blue shift of the E2(high) phonon mode of GaN. Possible red shift of optical phonon modes due to the quantum confinement is also discussed. In addition to the optical phonons allowed by symmetry, two additional Raman peaks were also observed at ∼633 and 678 cm−1 for these nanoribbons. Calculations for the wavenumbers of the surface optical (SO) phonon modes in GaN in Na‐4 mica yielded values close to those of the new Raman modes. The SO phonon modes were calculated in the slab (applicable to belt‐like nanoribbon) mode, as the wavenumber and intensity of these modes depend on the size and the shape of the nanostructures. The effect of surface‐modulation‐assisted electron–SO phonon scattering is suggested to be responsible for the pronounced appearance of SO phonon modes. A scaling factor is also estimated for the interacting surface potential influencing the observed SO Raman scattering intensities. Copyright © 2010 John Wiley & Sons, Ltd.
Interaction of an Endosomolytic Polyamidoamine ISA23 with Vesicles Mimicking Intracellular Membranes: A SANS/EPR Study
Authors: Griffiths Peter C. , Nilmini Renuka , Carter Emma , Dodds Patrick , Murphy Damien M. , Khayat Zeena , Lattanzio Ettore , Ferruti Paolo , Heenan Richard K. , King Stephen M. , Duncan Ruth
Published: June 2010

The mechanism of ISA23 · HCl interaction with model membrane vesicles (80–100 nm in diameter) was investigated using EPR in conjunction with SANS. For EPR, 16‐DSE was dissolved in the vesicle membrane to measure its dynamics and polarity, whereas a spin‐labeled (Tempo)‐ISA 23 analogue was used to give a measure of the polymer flexibility. When ISA23 was added to the external vesicle surface, no interaction was found. This observation conflicts with the reported ability to lyse RBC, but is in agreement with recent studies that showed no effect on membrane permeability when a PAA was added to an incubation medium containing isolated lysosomal vesicles. The vesicle‐mimetic models used here provide a new and useful tool for studying endosomolytic polymer/membrane interactions.

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Analysis of PKR Activation Using Analytical Ultracentrifugation
Authors: Cole James L.
Published: June 2010

Protein kinase R (PKR) is a central component of the interferon antiviral defense pathway. Upon binding to dsRNA, PKR undergoes autophosphorylation reactions that activate the kinase, resulting in the inhibition of protein synthesis in virally‐infected cells. We have used analytical ultracentrifugation and related biophysical methods to quantitatively characterize the stoichiometries, affinities, and free energy couplings that govern the assembly of the macromolecular complexes in the PKR activation pathway. These studies demonstrate that PKR dimerization play a key role in enzymatic activation and support a model where the role of dsRNA is to bring two or more PKR monomers in close proximity to enhance dimerization.

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FTIR Imaging of Poly(3‐hydroxybutyrate) and Isotactic Poly(propylene oxide) Spherulites
Authors: Merten Christian , Kowalik Thomas , Aßhoff Sarah J. , Hartwig Andreas
Published: June 2010

FTIR spectroscopic imaging is combined with linear dichroism measurements to investigate the structures of spherulites of poly(3‐hydroxybutyrate) and isotactic poly(propylene oxide). It is shown that this technique can be used to easily gain qualitative information about relative orientations of chemical bonds within a solid polymeric sample. Furthermore the imaging technique is shown to have the considerable advantage that the obtained images are easy to understand and easy to interpret even without deep knowledge of FTIR linear dichroism measurements.

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Dendronized Polymers with Aromatic Sulfonimide Dendrons
Authors: Abdel‐Rahman Mona Ahmed , Schweizer Bernd W. , Lukin Oleg , Zhang Afang , Schlüter A. Dieter
Published: June 2010

The synthesis of high‐molar‐mass first‐ and second‐generation, aromatic sulfonamide‐based dendronized polymers PG1(CH3) and PG1(NO2) as well as PG2(CH3) and PG2(NO2) has been achieved. For PG3(CH3) at least oligomeric material could be obtained. The polymers exhibit glass transition temperatures in the range of 135–162 °C and are valuable components for a presently ongoing in depth analysis of the persistence length of dendronized polymers by SANS. The corresponding monomers MG2(CH3) and MG2(NO2) were crystallized and their structures in the crystal determined by XRD. These single crystals are the first ever obtained of dendritic macromonomers. The polymerizable units were found not to be in a proper spatial relation to allow for a solid‐state polymerization.

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Thermal Sensitivity of tert‐Butyloxycarbonylmethyl‐Modified Polyquats in Condensed Phase and Solubility Properties of Copolymers with N‐Isopropylacrylamide
Authors: Gonsior Nina , Schmitz Sarah , Ritter Helmut
Published: June 2010

The synthesis of the easily decomposable ionic monomer 2‐tert‐butoxy‐N‐[2‐(methacryloyl‐oxy)ethyl]‐N,N‐dimethyl‐2‐oxoethanammonium chloride (3) via thermally induced syn‐elimination of a tert‐butyl ester group was realized simply by mixing N,N‐dimethylaminoethyl methacrylate (1) and tert‐butyl chloroacetate (2) at ambient temperature without solvent. The obtained salt was polymerized via free radical polymerization. The decomposition and foaming via iso‐butene formation takes place by heating up to about 160 °C. IR, DSC, TGA, and GC/MS measurements were performed to follow this pyrolysis reaction. Furthermore, the copolymerization of 3 with N‐isopropylacrylamid (NiPAAm, 5) was carried out with different monomer ratios. Molar mass distributions were measured using an asymmetrical flow field‐flow fractionation (aFFFF) system. The obtained copolymers 6–10 exhibit lower critical solution temperature (LCST) behaviour in water with cloud points at different temperatures depending on the monomer ratio.

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New Thermoresponsive Luminescent Electrospun Nanofibers Prepared from Poly[2,7‐(9,9‐dihexylfluorene)]‐block‐poly(N‐isopropylacrylamide)/PMMA Blends
Authors: Tzeng Ping , Kuo Chi‐Ching , Lin Sung‐Tso , Chiu Yu‐Chen , Chen Wen‐Chang
Published: June 2010

Novel luminescent electrospun (ES) polymer nanofibers were successfully prepared via a two‐fluid spinneret for thermo‐tunable colorimetric sensor applications. Binary blends of conjugated rod–coil poly[2,7‐(9,9‐dihexylfluorene)]‐block‐poly(N‐isopropylacrylamide) (PF‐b‐PNIPAAm)/poly(methyl methacrylate) (PMMA) were used as the material system for preparing the ES nanofibers. In order to produce uniform ES nanofibers, the shell layer was injected with THF to retard the rapid solidification of core polymer blend solutions that occurred at the nozzle tip. The prepared ES nanofibers, with an average diameter of 500 nm, exhibited a reversible photoluminescence (PL) spectra‐shifting, as the temperature cycle varied between 20 and 40 °C. Such reversible PL switching resulted from the extended/compact structural transformation on the PNIPAAm segment, which led to different PF aggregation sizes. The thermo‐responsive sensing characteristics of the prepared ES nanofibers were significantly enhanced as the PNIPAAm coil length was increased. In particular, PF7‐b‐PNIPAAm516/PMMA ES nanofibers exhibited a blue luminescence color at 20 °C but this changed to a greenish‐blue luminescence color at 40 °C. On the other hand, the corresponding spin‐coated thin film from the blend remained in the blue luminescence. Furthermore, the temperature‐responsive wettability of the surface could be switched between hydrophobicity and hydrophilicity via temperature variations. This study demonstrated that novel ES nanofibers exhibit both reversible thermo‐responsive luminescence characteristics and wettability, suggesting their potential for application as a new kind of sensory material.

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Processing of Poly(propylene)/Carbon Nanotube Composites using scCO2‐Assisted Mixing
Authors: Ma Jia , Deng Hua , Peijs Ton
Published: June 2010

scCO2 was used to assist in the preparation of PP/CNT composites. Two types of CNTs were used: MWNTs with and without HDPE coating (cMWNTs). The morphology of the nanocomposites and their mechanical and thermal properties were investigated and compared with samples made by traditional melt compounding. The use of cMWNT leads to better dispersion and properties in melt‐compounded nanocomposites. For systems prepared using scCO2‐assisted mixing, however, better properties were obtained using pristine MWNTs, avoiding the additional costs of nanotube modification. It was also shown that observed improvements in the mechanical properties for these materials were due to a combination of matrix modification and nanotube reinforcement, rather than a reinforcement effect caused solely by MWNTs.

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Conducting Polymer Enzyme Alloys: Electromaterials Exhibiting Direct Electron Transfer
Authors: Thompson Brianna C. , Winther‐Jensen Orawan , Vongsvivut Jitraporn , Winther‐Jensen Bjørn , MacFarlane Douglas R.
Published: June 2010

Glucose oxidase (GOx) is an important enzyme with great potential application for enzymatic sensing of glucose, in implantable biofuel cells for powering of medical devices in vivo and for large‐scale biofuel cells for distributed energy generation. For these applications, immobilisation of GOx and direct transfer of electrons from the enzyme to an electrode material is required. This paper describes synthesis of conducting polymer (CP) structures in which GOx has been entrained such that direct electron transfer is possible between GOx and the CP. CP/enzyme composites prepared by other means show no evidence of such “wiring”. These materials therefore show promise for mediator‐less electronic connection of GOx into easily produced electrodes for biosensing or biofuel cell applications.

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Synthesis, Characterization and Preliminary Biological Evaluation of P(HPMA)‐b‐P(LLA) Copolymers: A New Type of Functional Biocompatible Block Copolymer
Authors: Barz Matthias , Wolf Florian K. , Canal Fabiana , Koynov Kaloian , Vicent Maria J. , Frey Holger , Zentel Rudolf
Published: June 2010

We describe a synthetic pathway to functional P(HPMA)‐b‐P(LLA) block copolymers. The synthesis relies on a combination of ring‐opening polymerization of L‐lactide, conversion into a chain transfer agent (CTA) for the RAFT polymerization of pentafluorophenyl methacrylate. A series of block copolymers was prepared that exhibited molecular weights $\overline M _{\rm n}$ ranging from 7 600 to 34 300 g · mol−1, with moderate PDI between 1.3 and 1.45. These reactive precursor polymers have been transformed into biocompatible P(HPMA)‐b‐P(LLA) copolymers and their fluorescently labeled derivatives by facile replacement of the pentafluorophenyl groups. The fluorescence label attached to this new type of a partially degradable amphiphilic block copolymer was used to study cellular uptake in human cervix adenocarcinoma (HeLa) cells as well as aggregation behavior by fluorescence correlation spectroscopy (FCS).

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Conformational Behavior of Bottle‐Brush Polyelectrolytes with Charged and Neutral Side Chains
Authors: Cao Qianqian , Zuo Chuncheng , Li Lujuan , Zhang Nan
Published: June 2010

The conformational transition of a single bottle‐brush polyelectrolyte with charged and neutral side chains is studied through MD simulations. Counterions are included explicitly and no additional salt is added. The structure of the polyelectrolyte and the counterion condensation are found to depend greatly on the Bjerrum length. As the Bjerrum length increases, the neutral side chains in a poor solvent can condense into clusters with variable size. Moreover, the polyelectrolyte forms globular structures at large or very small Bjerrum lengths. This transition is quite different from that in the case of a good solvent, in which there are not observable clusters and a globular structure is only formed at large Bjerrum lengths.

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Thermally curable polyurethanes containing naphthoxazine groups in the main chain
Authors: Yeganeh Hamid , Jangi Abolfazl
Published: June 2010

A new methodology has been developed for the modification of polyurethanes with reactive naphthoxazine moieties in order to expand their industrial applicability as electrical insulators. Thermoplastic and organosoluble poly(urethane‐co‐naphthoxazine)s were prepared by the reaction of NCO‐terminated urethane prepolymers made from various soft segments with a naphthoxazine‐containing diol chain extender. The prepared polymers were easily processed into thin films using either solution casting or compression moulding techniques. Heat treatment of these films under optimized conditions (200 °C for 30 min) led to the thermally activated ring‐opening polymerization of naphthoxazine moieties, and consequently crosslinked networks were obtained. All of the starting materials and the final polymeric compounds were fully characterized using spectroscopic methods and their physical and chemical properties evaluated and then correlated with their chemical structures. Due to their good elongation property (up to 70% elongation at break) in comparison to polynaphthoxazines, significant enhancement in decomposition temperature as well as high value of dielectric breakdown strength (up to 30 kV mm−1) in comparison to polyurethanes, these materials are potentially applicable as electrical insulators with service temperatures higher than those for related unmodified polyurethanes. Copyright © 2010 Society of Chemical Industry
pH responsive surfaces with nanoscale topography
Authors: Bousquet Antoine , Ibarboure Emmanuel , Teran Francisco J. , Ruiz Leire , Garay María Teresa , Laza José Manuel , Vilas José Luis , Papon Eric , Rodríguez‐Hernández Juan
Published: June 2010

We report the preparation of nanostructured adaptive polymer surfaces by diffusion of an amphihilic block copolymer toward the interface. The surface segregation of a diblock copolymer, polystyrene‐block‐poly(acrylic acid) (PS‐b‐PAA), occurred when blended with high molecular weight polystyrene employed as a matrix. On annealing, the polymer surfaces changed both the chemical composition and the hydrophilicity depending on the environment and pH, respectively. By exposure to either water vapor or air, the surface wettability varied between hydrophilic and hydrophobic. In addition, surface enrichment on diblock copolymer by water vapor annealing led to self‐assembly occurring at the interface. Hence, nanostructured domains can be observed by AFM in liquid media. Moreover, the PAA segments placed at the interface respond to pH and can switch from an extended hydrophilic state at basic pH values to a collapsed hydrophobic state in acidic media. Accordingly, the surface morphology changed from swelled micelles to nanometer size holes. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2982–2990, 2010
Investigation of nitroxide radical coupling reaction in wide temperature range and different catalyst system
Authors: Lin Wencheng , Huang Bing , Fu Qiang , Wang Guowei , Huang Junlian
Published: June 2010

The effect of temperature, catalyst system, and the structure of bromine connected groups on the nitroxide radical coupling (NRC) reaction is investigated in details. A series of polymers with different bromine connected groups as poly (tert‐butyl acrylate) (PtBA‐Br), polystyrene (PS‐Br), and poly (methyl methacrylate) (PMMA‐Br) are prepared by atom transfer radical polymerization first, then the bromine‐containing polymers were coupled with 2,2,6,6‐tetramethylpiperidinyl‐1‐oxy‐containing poly(ε‐caprolactone) (PCL‐TEMPO) in different catalyst systems as CuBr/PMDETA, Cu0/PMDETA and CuBr/Cu0/PMDETA in the temperature range from 90 °C to 25 °C. The result shows that the catalyst system of CuBr/Cu0/PMDETA is the best one for NRC reaction, in which the NRC reaction could be conducted in high efficiency in the wide temperature range from room temperature to high temperature. The efficiency of NRC reaction between PtBA‐Br and PCL‐TEMPO is more than 85% in the temperature range from 25 to 75 °C, the efficiency between PS‐Br and PCL‐TEMPO is more than 90% from 25 to 90 °C, and the efficiency between PMMA‐Br and PCL‐TEMPO is more than 90% only at the room temperature. The effect of bromine connected groups on the NRC reaction is discussed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2991–2999, 2010
Synthesis and characterization of a hyperbranched hydrogen bond acidic carbosilane sorbent polymer
Authors: Higgins Bernadette A. , Simonson Duane L. , Houser Eric J. , Kohl James G. , Mcgill R. Andrew
Published: June 2010

Sorbent polymers can be designed to target molecular interactions with a variety of hazardous chemicals including explosives, chemical agents, narcotics, and toxic industrial chemicals. Applications of functionalized sorbent polymers include preconcentrator devices, SPME fibers, membrane introduction systems, chromatographic stationary phases and coatings for chemical sensors. One common feature of a wide range of hazardous chemicals is their hydrogen bond (h‐b) basicity. In this work, we report on the synthesis and characterization of a h‐b acidic hyperbranched carbosilane fluoroalcohol based sorbent polymer (poly(methyldi(1,1,1‐trifluoro‐2‐trifluoromethyl‐2‐hydroxypent‐4‐enyl)silane; HCSFA2), which is suitable for sorbing these hazardous h‐b basic analytes. Multiple batches of HCSFA2 were characterized with routine composition, spectroscopic, thermal analysis, and inverse gas chromatography (iGC) to evaluate polymer physicochemical properties. In comparison with previously developed h‐b acidic polymers (e.g., FPOL and SXFA), HCSFA2 exhibits a sorption improvement of 10–15 fold for h‐b basic analytes. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3000–3009, 2010
One‐step synthesis of hyperbranched polyethylene macroinitiator and its block copolymers with methyl methacrylate or styrene via ATRP
Authors: Wang Wen‐Jun , Liu Pingwei , Li Bo‐Geng , Zhu Shiping
Published: June 2010

Block copolymers of hyperbranched polyethylene (PE) and linear polystyrene (PS) or poly(methyl methacrylate) (PMMA) were synthesized via atom transfer radical polymerization (ATRP) with hyperbranched PE macroinitiators. The PE macroinitiators were synthesized through a “living” polymerization of ethylene catalyzed with a Pd‐diimine catalyst and end‐capped with 4‐chloromethyl styrene as a chain quenching agent in one step. The macroinitiator and block copolymer samples were characterized by gel permeation chromatography, 1H and 13C NMR, and differential scanning calorimetry. The hyperbranched PE chains had narrow molecular weight distribution and contained a single terminal benzyl chloride per chain. Both hyperbranched PE and linear PS or PMMA blocks had well‐controlled molecular weights. Slow initiation was observed in ATRP because of steric effect of hyperbranched structures, resulting in slightly broad polydispersity index in the block copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3024–3032, 2010
Bis(β‐enaminoketonato) vanadium (III or IV) complexes as catalysts for olefin polymerization
Authors: Wu Ji‐Qian , Li Bai‐Xiang , Zhang Sen‐Wang , Li Yue‐Sheng
Published: June 2010

Bis(β‐enaminoketonato) vanadium(III) complexes (2a–c) [O(R1)CC(H)xC(R2)NC6H5]2VCl(THF) and the corresponding vanadium(IV) complexes (3a–c) [O(R1)CC(H)xC(R2) NC6H5]2VO (R1 = (CH2)4, R2 = H, x = 0, a; R1 = C6H5, R2 = H, x = 1, b; R1 = C6H5, R2 = C6H5, x = 1, c) have been synthesized from VCl3(THF)3 and VOCl2(THF)2, respectively, by treating with 2.0 equivalent β‐enaminoketonato ligands in tetrahydrofuran. Structures of 2b and 3a–c were further confirmed by X‐ray crystallographic analysis. The complexes were investigated as the catalysts for ethylene polymerization in the presence of Et2AlCl. Complexes 2a–c and 3a–c exhibited high catalytic activities (up to 23.76 kg of PE/mmolV h bar), and afforded polymers with unimodal molecular weight distributions at 70 °C indicating the good thermal stability. The catalytic behaviors were influenced not only by the oxidation state of the catalyst precursors but also by the ligand structures. Complexes 2a–c and 3a–c were also effective catalyst precursors for ethylene/1‐hexene copolymerization. The influence of polymerization parameters such as reaction temperature, Al/V molar ratio and hexene feed concentration on the ethylene/hexene copolymerization behaviors have bee also investigated in detail. In addition, the agents such as AlMe3, AliBu3, MeMgBr, MgCl2, and ZnEt2 were applied to control the molecular weight and molecular weight distribution modal. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3062–3072, 2010
Synthesis and properties of cationic polyelectrolyte with regioregular polyalkylthiophene backbone and ionic‐liquid like side groups
Authors: Bondarev Dmitrij , Zedník Jiří , Šloufová Ivana , Sharf Ahmed , Procházka Marek , Pfleger Jiří , Vohlídal Jiří
Published: June 2010

High‐regioregular poly{3‐[6‐(1‐methylimidazolium‐3‐yl)hexyl]thiophene‐2,5‐diyl bromide}, PMHT‐Br, has been prepared by reaction of high‐regioregular (above 92%) poly[3‐(6‐bromohexyl)thiophene‐2,5‐diyl] with 1‐methylimidazole. PMHT‐Br is soluble in water and water miscible solvents such as methanol, DMSO and shows solvatochromism; λmax (nm): 423 (H2O); 435 (MeOH); 452 (DMSO). Increased absorption band broadening observed for aqueous solution as well as NMR spectra in D2O suggests a micelle‐like structure of PMHT‐Br molecules in these solutions: poly(3‐hexylthiophene) core and 1‐methylimidazolium bromide shell. Despite the disturbing effect of ionic groups, the solid‐state PMHT‐Br shows absorption maximum at 520 nm, the band edge at 660 nm (ca. 1.9 eV), and fluorescence emission with maximum at 635 nm, in a good agreement with the polymer regioregularity. Fluorescence emission maxima: λem (nm): 598 (H2O); 562 (MeOH); 574 (DMSO), occur in a vicinity of corresponding adsorption band edges. Plot of electrical conductivity of PMHT‐Br (measured under the dynamic vacuum conditions, 5 × 10−5 Pa) versus 1/T shows a break at about 70 °C same as the temperature dependence of λmax of the solid PMHT‐Br. These breaks indicate an increase in the mobility of polymer segments and ions within PMHT‐Br; however, a thermal analysis did not provide solid evidence for it. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3073–3081, 2010
Multiple micellar morphologies from tri‐ and tetrablock copoly(2‐oxazoline)s in binary water–ethanol mixtures
Authors: Fustin Charles‐André , Thijs‐Lambermont Hanneke M. L. , Hoeppener Stephanie , Hoogenboom Richard , Schubert Ulrich S. , Gohy Jean‐François
Published: June 2010

We report on the micellization behavior of tri‐ and tetrablock copoly(2‐oxazoline)s in water–ethanol mixtures. The copolymers are based on different combinations of 2‐methyl‐, 2‐ethyl‐, 2‐phenyl‐, and 2‐nonyl‐2‐oxazoline. The solvophilic/solvophobic balance of these copolymers can be tuned thanks to the solubility dependence of the poly(2‐phenyl‐2‐oxazoline) block on the solvent composition. Characterization of the obtained micelles by dynamic light scattering and transmission electron microscopy revealed that their size and morphology depend on the solvophobic content of the copolymers and on the block order. Spherical micelles are always obtained when poly(2‐nonyl‐2‐oxazoline) is the only solvophobic block. When the solvophobic fraction consists of both the poly(2‐phenyl‐2‐oxazoline) and poly(2‐nonyl‐2‐oxazoline) blocks, spherical and cylindrical micelles as well as vesicles have been observed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3095–3102, 2010
Synthesis and morphology of model PS‐b‐PDMS copolymers
Authors: Ninago Mario D. , Satti Angel J. , Ciolino Andrés E. , Vallés Enrique M. , Villar Marcelo A. , Vega Daniel A. , Sanz Alejandro , Nogales Aurora , Rueda Daniel R.
Published: June 2010

True model linear poly(styrene‐b‐dimethylsiloxane) PS‐b‐PDMS copolymers were synthesized by using sequential addition of monomers and anionic polymerization (high‐vacuum techniques), employing the most recent experimental procedures that allow the controlled polymerization of each monomer to obtain blocks with controlled molar masses. The model diblock copolymers obtained were analyzed by using different techniques, such as size‐exclusion chromatography, 1H NMR, Fourier transform infrared spectroscopy, small angle X‐rays scattering (SAXS), and wide angle X‐rays scattering (WAXS). The PS‐b‐PDMS copolymers obtained showed narrow molar mass distribution and variable PDMS content, ranging from 2 up to 55 wt %. Compacted powder samples were investigated by SAXS to reveal their structure and morphology changes on thermal treatment in the interval from 30 to 200 °C. The sample with the highest PDMS content exhibits a lamellar morphology, whereas two other samples show hexagonally packed cylinders of PDMS in a PS matrix. For the lowest PDMS content samples, the SAXS pattern corresponds to a disordered morphology and did not show any changes on thermal treatment. Detailed information about the morphology of scattering domains was obtained by fitting the SAXS scattering curves. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3119–3127, 2010
On the evolution of the rate of polymerization, number and size distribution of particles in styrene emulsion polymerization above CMC
Authors: Carro Shirley , Herrera‐Ordonez Jorge , Castillo‐Tejas Jorge
Published: June 2010

This work is an extension of a communication reported by two of the authors [Carro and Herrera‐Ordoñez, Macromol Rapid Commun 2006, 27, 274], where bimodal particle size distributions (PSD), obtained by asymmetric flow‐field flow fractionation (AFFF, AF4), were taken as evidence of certain degree of stability of primary particles. Now, emulsion polymerizations of styrene were performed under conditions employed before by other researchers, intending to examine if the behavior observed is general. The number of particles (N) and PSD were studied by means of dynamic light scattering and AF4. By the later, bimodal PSDs were detected in all cases, where the population corresponding to primary particles (diameter <20 nm) depends on reaction conditions. Regarding N, AF4 results show that it is constant during interval II, in contrast to DLS results. Primary particle coagulation was evidenced as minimums in N evolution and the rate of polymerization curves, monitored by calorimetry and gravimetry, which are enhanced when higher particle number is generated and/or the ionic strength is increased. These results suggest that particle coagulation is not as extensive as it would be expected according to the coagulative theory. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3152–3160, 2010
Synthesis and characterization of indenofluorene‐based copolymers containing 2,5‐bis(2‐thienyl)‐N‐arylpyrrole for bulk heterojunction solar cells and polymer light‐emitting diodes
Authors: Tamilavan Vellaiappillai , Sakthivel Pachagounder , Li Yinan , Song Myungkwan , Kim Chul‐Hyun , Jin Sung‐Ho , Hyun Myung Ho
Published: June 2010

Two novel alternating π‐conjugated copolymers, poly[2,8‐(6,6′,12,12′‐tetraoctyl‐6,12‐dihydroindeno‐[1,2b]fluorene‐ alt‐5(1‐(2,6‐diisopropylphenyl)‐2,5‐di(2‐thienyl)pyrrole) (P1) and poly[2,8‐(6,6′,12,12′‐tetraoctyl‐6,12‐dihydroindeno‐[1,2b]fluorene‐ alt‐5(1‐(p‐octylphenyl)‐2,5‐di(2‐thienyl)pyrrole) (P2), were synthesized via the Suzuki coupling method and their optoelectronic properties were investigated. The resulting polymers P1 and P2 were completely soluble in various common organic solvents and their weight‐average molecular weights (Mw) were 5.66 × 104 (polydispersity: 1.97) and 2.13× 104 (polydispersity: 1.54), respectively. Bulk heterojunction (BHJ) solar cells were fabricated in ITO/PEDOT:PSS/polymer:PC70BM(1:5)/TiOx/Al configurations. The BHJ solar cell with P1:PC70BM (1:5) has a power conversion efficiency (PCE) of 1.12% (Jsc= 3.39 mA/cm2, Voc= 0.67 V, FF = 49.31%), measured using AM 1.5 G solar simulator at 100 mW/cm2 light illumination. We fabricated polymer light‐emitting diodes (PLEDs) in ITO/PEDOT:PSS/emitting polymer:polyethylene glycol (PEG)/Ba/Al configurations. The electroluminescence (EL) maxima of the fabricated PLEDs varied from 526 nm to 556 nm depending on the ratio of the polymer to PEG. The turn‐on voltages of the PLEDs were in the range of 3–8 V depending on the ratio of the polymer to PEG, and the maximum brightness and luminance efficiency were 2103 cd/m2 and 0.37 cd/A at 12 V, respectively. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3169–3177, 2010
On the origin of ionic liquid‐induced variations in hydroxypropyl methacrylate propagation rate coefficients
Authors: Jeličić Aleksandra , Köhler Franziska , Winter Alette , Beuermann Sabine
Published: June 2010

Pulsed laser polymerizations were used to study the propagation kinetics of hydroxypropyl methacrylate (HPMA) in ionic liquids (ILs) and common organic solvents. The functional monomer was chosen to investigate the complex interplay of all interactions between monomer molecules and between monomer and solvent molecules and to obtain a deeper understanding of the impact of these interactions. The solvent effect on the HPMA propagation rate coefficient (kp) was examined using a linear solvation energy relationship (LSER) based on Kamlet‐Taft solvatochromic parameters π*, α, and β. The results suggest that dipolarity/polarizability, associated with π*, and hydrogen bond–donating ability of the solvents, accounted for by α, majorly contribute to variations in kp. Hydrogen bond–accepting (electron pair donating) ability of the solvents (β parameter) is of much lesser importance. In addition, LSER enables the prediction of HPMA kp based on solvatochromic parameters of the solvents. The results suggest that interactions between the hydroxyl group of the monomer and the anion are dominant compared with classical hydrogen bonding between carbonyl and hydroxyl groups of the monomer units. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3188–3199, 2010
Microphase separation in thin films of supramolecular assemblies composed of a triblock copolymer and low‐molecular‐weight additive
Authors: Nandan Bhanu
Published: June 2010

The phase behavior of supramolecular assemblies (SMAs) formed by poly(4‐vinylpyridine)‐block‐polystyrene‐block‐poly(4‐vinylpyridine) (P4VP‐b‐PS‐b‐P4VP) triblock copolymer with 2‐(4′‐hydroxybenzeneazo)benzoic acid (HABA) was investigated with respect to the molar ratio (X) between HABA and 4VP monomer unit in bulk as well as in thin films. The results were compared with SMAs formed by a PS‐b‐P4VP diblock copolymer of similar composition as the triblock but half the molecular weight to ascertain the effect of molecular architecture on microphase separation. In bulk, both the di‐ and triblock SMAs showed composition‐dependent morphological transitions, which could be tuned by HABA/4VP molar ratio. The domain spacing of the SMA was not significantly affected by the molecular architecture of the constituting block copolymers. In thin films also, both the di‐ and triblock SMAs showed more or less similar morphological transitions depending on X. Interestingly, the domain orientation of the cylindrical or lamellar microdomains in the SMAs was influenced by the molecular architecture of the block copolymer. After chloroform annealing, although the diblock SMAs showed in‐plane orientation of the domains, triblock SMAs showed perpendicular domain orientation. The perpendicular orientation of the microdomains in triblock was favored because it allowed the mid‐PS blocks to acquire normal distribution of loop and bridged conformations. Furthermore, the orientation of the lamellar and cylindrical microdomains of the diblock SMAs was found to switch to perpendicular orientation after annealing in 1,4‐dioxane vapors. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1594–1605, 2010
Effects of castration on insulin levels and glucose tolerance in the mouse differ from those in man
Authors: Inoue Takamitsu , Zakikhani Mahvash , David Stéphanie , Algire Carolyn , Blouin Marie‐José , Pollak Michael
Published: June 2010

BACKGROUND

Plasma insulin concentration is increased in prostate cancer patients during androgen deprivation therapy (ADT) and hyperinsulinemia has been associated with aggressive prostate cancer behavior. To investigate the possible role of castration‐induced hyperinsulinemia as a mechanism that may attenuate the beneficial effects of ADT in patients with prostate cancer, a murine model would be useful. We therefore investigated long‐term metabolic effects of castration in several mouse models.

METHODS

We studied the long‐term influence of castration on energy intake, body weight, glucose tolerance, plasma‐insulin, plasma insulin‐like growth factor‐1 (IGF‐1), plasma adiponectin, and plasma leptin in C57BL/6, Swiss nu/nu, and CB17 scid mice receiving various diets. In each case, mice were randomized to have either bilateral orchiectomy or a sham operation.

RESULTS

Energy intake, body weight, blood glucose levels in glucose tolerance test, plasma insulin, plasma IGF‐1, and plasma leptin level in all had a trend to be decreased in castrated as compared to sham operated mice. Plasma adiponectin level was increased in the castrated mice.

CONCLUSIONS

The effects of castration on glucose, insulin, and related markers in several mouse models studied does not coincide with clinical observations; further studies in this area will require clinical research and/or the use of alternate models such as the dog. Prostate 70: 1628–1635, 2010. © 2010 Wiley‐Liss, Inc.
Development of metastatic and non‐metastatic tumor lines from a patient's prostate cancer specimen—identification of a small subpopulation with metastatic potential in the primary tumor
Authors: Lin Dong , Bayani Jane , Wang Yuwei , Sadar Marianne D. , Yoshimoto Maisa , Gout Peter W. , Squire Jeremy A. , Wang Yuzhuo
Published: June 2010

BACKGROUND

Metastasis is the major cause of prostate cancer deaths. Tumor heterogeneity in both primary and metastatic prostate cancers is a major hurdle in elucidating the mechanisms of metastasis in this disease. To circumvent this obstacle and improve our understanding of prostate cancer metastasis, we developed multiple tumor tissue lines from one patient's primary prostate cancer specimen to examine differences in metastatic ability.

METHODS

Pieces of tissue from different foci of a patient's primary prostate tumor were grafted into subrenal capsules of NOD‐SCID mice and transplantable tumor sublines were established by serial passage. The metastatic ability of each subline was tested via orthotopic grafting into mice. Chromosomal alterations exclusively presented in a metastatic subline were examined by SKY and investigated for their presence in parental tissues by fluorescence in situ hybridization.

RESULTS

Three transplantable sublines were developed, resembling the primary tumor histologically, exhibiting poor differentiation, and different growth rates. Importantly, the LTL‐220N and LTL‐221N sublines were non‐metastatic, whereas the LTL‐220M subline was spontaneously metastatic in vivo. SKY analysis showed limited but unique chromosomal alterations in each subline. Some chromosomal alterations, exclusively present in the metastatic LTL‐220M subline, were also observed in a small portion of the parental cancer tissues.

CONCLUSION

The results indicate that in primary prostate tumors metastatic potential can be confined to a minority of cancer cells. Subrenal capsule xenograft methodology can be used to dissect heterogeneous cancer cells in a patient's primary tumor and sublines derived from such cells provide valuable tools for investigating mechanisms underlying prostate cancer metastasis. Prostate 70: 1636–1644, 2010. © 2010 Wiley‐Liss, Inc.
The relationship between adiposity and gleason score in men with localized prostate cancer
Authors: Hack Erica E. , Siemens D. Robert , Groome Patti A.
Published: June 2010

BACKGROUND

We investigated the relationship between body mass index (BMI) at the time of cancer diagnosis and malignant phenotype as measured by Gleason score.

METHODS

This was a population‐based cross‐sectional study conducted on 1,096 prostate cancer patients treated for cure in Ontario, Canada between 1990 and 1998. An electronic‐linked data set was enhanced by retrospective chart review. BMI was categorized as: normal (BMI <25.0), overweight (BMI 25.0–29.9), and obese (BMI ≥30). We also investigated the role of diabetic status. Gleason scores were categorized as: 2–4, 5–6, 7, and 8–10. We assessed the effect modification by patient age.

RESULTS

BMI was not associated with Gleason score; 9.7% of those with normal BMI had a Gleason score ≥8, and 9.4% fell into this Gleason category in both the overweight and obese groups (P = 0.73). 11.7% of diabetics had a Gleason score ≥8 compared to 9.3% in the non‐diabetic group (P = 0.79). Both of these results persisted in a multivariate analysis controlling for age and diagnosis year. When stratified by age, only the Gleason score distribution in the youngest cohort (50‐ to 59‐year olds) indicated higher Gleason scores in the obese group, with marginally significant results (P = 0.16).

CONCLUSIONS

With a possible exception in younger men, elevated BMI at the time of diagnosis does not appear to be associated with aspects of aggressive behavior associated with Gleason grade. The effect of adiposity on prostate cancer outcome is complex, requiring further study that includes attention to factors such as length of exposure, concomitant co‐morbidities, and ethnicity. Prostate 70: 1683–1691, 2010. © 2010 Wiley‐Liss, Inc.
The relationship between proangiogenic gene expression levels in prostate cancer and their prognostic value for clinical outcomes
Authors: Mori Ryutaro , Dorff Tanya B. , Xiong Shigang , Tarabolous Chad J. , Ye Wei , Groshen Susan , Danenberg Kathleen D. , Danenberg Peter V. , Pinski Jacek K.
Published: June 2010

BACKGROUND

Androgens stimulate the expression of vascular endothelial growth factor (VEGF) through activation of hypoxia inducible factor (HIF). These genes play a major role in cancer angiogenesis. This study assesses the relationship among expression levels for the androgen receptor (AR), HIF1a, VEGF‐A, and VEGF‐C genes in human prostate cancer tissue and their impact on prostate cancer outcomes. It also examines the impact of pre‐operative androgen deprivation therapy (ADT) on the expression of these genes.

METHODS

Radical prostatectomy specimens were obtained from 138 patients with D1 prostate cancer from the University of Southern California prostatectomy database; 30% received pre‐operative and 23% received post‐operative ADT. Gene expression levels were determined by quantitative real‐time PCR. Specimens were stratified into three groups for each gene based on expression levels, and groups were compared for clinical outcomes (PSA and clinical recurrence, overall survival).

RESULTS

There was a significant correlation in expression levels amongst all genes. Patients treated with pre‐operative ADT had significantly lower HIF1a expression, mean 2.64 (CI 2.34–2.94) than patients not treated, mean 3.25 (CI 2.97–3.53, P = 0.006), adjusting for age, PSA, Gleason score, and stage. Higher VEGF‐A expression was significantly associated with better overall survival (HR 0.49, P = 0.015). The risk of developing clinical recurrence was significantly lower with higher VEGF‐C expression (HR 0.4, P = 0.014).

CONCLUSIONS

Significant correlation was noted among AR, HIF1a, VEGF‐A, and VEGF‐C. This study shows that ADT is associated with lower HIF1a gene expression in human prostate cancer tissue and documents prognostic value for VEGF‐A and VEGF‐C expression levels. Prostate 70: 1692–1700, 2010. © 2010 Wiley‐Liss, Inc.
Adipose tissue‐derived stem cells promote prostate tumor growth
Authors: Prantl Lukas , Muehlberg Fabian , Navone Nora M. , Song Yao‐Hua , Vykoukal Jody , Logothetis Christopher J. , Alt Eckhard U.
Published: June 2010

BACKGROUND

Recent evidence indicates that cancer stem cells play an important role in tumor initiation and maintenance. Additionally, the effect of tissue‐resident stem cells located in the surrounding healthy tissue on tumor progression has been demonstrated. While most knowledge has been derived from studies of breast cancer cells, little is known regarding the influence of tissue resident stem cells on the tumor biology of prostate cancer.

METHODS

Twenty male athymic Swiss nu/nu mice (age: 6–8 weeks) were randomized into two treatment groups: (1) subcutaneous injection of 106 MDA PCa 118b human prostate cancer cells into the upper back or (2) subcutaneous injection of 106 MDA PCa 118b cells mixed directly with 105 GFP‐labeled human adipose tissue‐derived stem cells (hASCs). Tumor growth and volumes over the ensuing 3 weeks were assessed using calipers and micro‐computed tomography. Immunohistochemistry was performed to identify engrafted hASCs in tumor sections.

RESULTS

At 3 weeks after injection, the mean tumor volume in the MDA PCa 118b/hASC co‐injection group (1019.95 ± 73.49 mm3) was significantly higher than that in the MDA PCa 118b‐only group (308.70 ± 21.06 mm3). Engrafted hASCs exhibited the nuclear marker of proliferation Ki67 and expressed markers for endothelial differentiation, indicating their engraftment in tumor vessels.

CONCLUSION

Our study revealed for the first time that ASCs subcutaneously co‐injected with prostate cancer cells engraft and promote tumor progression. Further evaluation of the cross‐talk between tumor and local tissue‐resident stem cells may lead to new strategies for prostate cancer therapy. Prostate 70: 1709–1715, 2010. © 2010 Wiley‐Liss, Inc.
Contribution of HPC1 (RNASEL) and HPCX variants to prostate cancer in a founder population
Authors: Agalliu Ilir , Leanza Suzanne M. , Smith Lorie , Trent Jeffrey M. , Carpten John D. , Bailey‐Wilson Joan E. , Burk Robert D.
Published: June 2010

BACKGROUND

Prostate cancer is a genetically complex disease with locus and disease heterogeneity. The RNASEL gene and HPCX locus have been implicated in hereditary prostate cancer; however, their contributions to sporadic forms of this malignancy remain uncertain.

METHODS

Associations of prostate cancer with two variants in the RNASEL gene (a founder mutation, 471delAAAG, and a non‐synonymous SNP, rs486907), and with five microsatellite markers in the HPCX locus, were examined in 979 cases and 1,251 controls of Ashkenazi Jewish descent. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression models.

RESULTS

There was an inverse association between RNASEL rs486907 and prostate cancer in younger men (<65 years) and those with a first‐degree relative with prostate cancer; men with AA genotype had ORs of 0.64 and 0.47 (both P < 0.05), respectively, in comparison to men with GG genotype. Within the HPCX region, there were positive associations for allele 135 of bG82i1.1 marker (OR = 1.77, P = 0.01) and allele 188 of DXS1205 (OR = 1.65, P = 0.02). In addition, allele 248 of marker D33 was inversely associated (OR = 0.65, P = 0.05) with Gleason score ≥7 tumors.

CONCLUSIONS

Results suggest that variants in RNASEL contribute to susceptibility to early onset and familial forms of prostate cancer, whereas HPCX variants are associated with prostate cancer risk and tumor aggressiveness. The observation that a mutation predicted to completely inactivate RNASEL protein was not associated with prostate cancer, but that a missense variant was associated, suggests that the effect is due to either partial inactivation of the protein, and/or acquisition of a new protein activity. Prostate 70: 1716–1727, 2010. © 2010 Wiley‐Liss, Inc.
Prostate cancer risk‐associated variants reported from genome‐wide association studies: Meta‐analysis and their contribution to genetic Variation
Authors: Kim Seong‐Tae , Cheng Yu , Hsu Fang‐Chi , Jin Tao , Kader A. Karim , Zheng S. Lilly , Isaacs William B. , Xu Jianfeng , Sun Jielin
Published: June 2010

BACKGROUND

Genome‐wide association studies (GWAS) have led to the discovery of multiple single nucleotide polymorphisms (SNPs) that are associated with prostate cancer (PCa) risk. These SNPs may potentially be used for risk prediction. To date, there is not a stable estimate of their effect on PCa risk and their contribution to the genetic variation both of which are important for future risk prediction.

METHODS

A literature review was conducted to identify SNPs associated with PCa risk with the following criteria: (1) GWAS in the Caucasian population; (2) SNPs with P‐value <1.0 × 10−6; and (3) one SNP from each independent LD block. A meta‐analysis was performed to estimate combined odds ratio (OR) and its 95% confidence interval (CI) for the identified SNPs. The proportion of total genetic variance that is attributable by each of these SNPs was also estimated.

RESULTS

Thirty PCa risk‐associated SNPs were identified. These SNPs had OR estimates between 1.12 and 1.47 except for marker rs16901979 (OR = 1.80). Significant heterogeneity in OR estimates was found among different studies for 13 SNPs. The proportion of total genetic variance attributed by each SNP ranged between 0.2% and 0.9%. These 30 SNPs explained ∼13.5% of the total genetic variance of PCa risk in the Caucasian population.

CONCLUSION

This study provides more stable OR estimates for PCa risk‐associated SNPs, which is an important baseline for the effect of these SNPs in risk prediction. These SNPs explain a considerable proportion of genetic variance, however, the majority of genetic variance has yet to be explained. Prostate 70: 1729–1738, 2010. © 2010 Wiley‐Liss, Inc.