bluuebunny/crossref_metadata_2025 huggingface dataset:
Funding corporate rescue: the Impact of the financial crisis
Authors: Vriesendorp Reinout D. , Gramatikov Martin A.
Published: November 2010

Insolvency reform across many jurisdictions over the last twenty years has focused on the development of legislation to facilitate business reorganizations. However, any regime which involves rescue requires a degree of support from the commercial environment. The rescue regimes may therefore be severely tested in situations where there is a general economic downturn such as the world has experienced in the last two years. This article evaluates empirically the perceived impact of the Global Financial Crisis on the opportunities for rescue on the basis of a survey we set out among insolvency professionals worldwide. Most of the 562 respondents to the survey from 56 jurisdictions agree that the credit crisis of 2007 stifled the access of distressed business to financial facilities so needed for successful restructuring. It retrenched the access to financial facilities and thus impacted negatively the prospects for preventing or even ending the bankruptcy procedure with reorganization instead of winding up of the estate assets. Several reasons that have been pointed out by the insolvency professionals in our survey are discussed in this article. We conclude that somewhat paradoxically just when rescue is needed the most, the practical reality may be that businesses will not be saved if there is insufficient support available either by way of additional credit or because other (funding) creditors are so financially stressed themselves that they are unable or unwilling to support any potential rescue. Copyright © 2010 John Wiley & Sons, Ltd.
Ginsenoside Rh2 induces Bcl‐2 family proteins‐mediated apoptosis in vitro and in xenografts in vivo models
Authors: Choi Sunga , Oh Jun‐Young , Kim Soo‐Jin
Published: November 2010

The cancer chemoprevention effects of ginseng saponins have been demonstrated against a variety of experimental tumors; however, their molecular mechanisms in vitro and in in vivo models are not well studied. This study was undertaken to gain insights into the molecular mechanisms of ginsenoside Rh2 (Rh2)‐induced cell death in human breast cancer cell lines as well as in in vivo xenografts. Rh2 treatment significantly inhibited viability of both MCF‐7 and MDA‐MB‐231 human breast cells in a concentration‐dependent manner, which correlated with mitochondria‐mediated apoptosis. Rh2‐induced apoptosis was accompanied by the down‐regulation of antiapoptotic proteins Bcl‐2, Bcl‐xL, and Mcl‐1. It also caused induction of the proapoptotic members Bak, Bax, and Bim leading to mitochondrial translocation of Bax and activation of caspases. Moreover, Rh2‐induced apoptosis was partially, yet significantly protected by transient transfection of MCF‐7 cells with Bax‐ and Bak‐targeted siRNAs. Oral gavage of 5 mg Rh2/kg of mouse (three times a week) significantly caused apoptosis of MDA‐MB‐231 xenografts. An increase in Bax and Bak and a decrease in Bcl‐2 and Bcl‐xL transcript levels, in accordance with their protein expression, were observed in tumor tissue. Tumors from Rh2‐treated mice exhibited a markedly higher count of apoptotic bodies and reduced proliferation index compared with control tumors. Our data suggest that Rh2 used in traditional oriental medicine for the treatment of various ailments, may be an attractive agent for the treatment and/or prevention of human breast cancers. J. Cell. Biochem. 112: 330–340, 2011. © 2010 Wiley‐Liss, Inc.
Suppression of the proinflammatory response of metastatic melanoma cells increases TRAIL‐induced apoptosis
Authors: Ivanov Vladimir N. , Partridge Michael A. , Huang Sarah X.L. , Hei Tom K.
Published: November 2010

Melanoma is the most lethal form of human skin cancer. However, only limited chemotherapy is currently available for the metastatic stage of the disease. Since chemotherapy, radiation and sodium arsenite treatment operate mainly through induction of the intrinsic mitochondrial pathway, a strongly decreased mitochondrial function in metastatic melanoma cells, could be responsible for low efficacy of the conventional therapy of melanoma. Another feature of metastatic melanoma cells is their proinflammatory phenotype, linked to endogenous expression of the inflammatory cytokines, such as TNFα IL6 and IL8, their receptors, and constitutive NF‐κB‐ and STAT3‐dependent gene expression, including cyclooxygenase‐2 (PTGS2/COX2). In the present study, we treated melanoma cells with immunological (monoclonal antibody against TNFα or IL6), pharmacological (small molecular inhibitors of IKKβ–NF‐κB and JAK2–STAT3) or genetic (specific RNAi for COX‐2) agents that suppressed the inflammatory response in combination with induction of apoptosis via TRAIL. As a result of these combined treatments, exogenous TRAIL via interactions with TRAIL‐R2/R1 strongly increased levels of apoptosis in resistant melanoma cells. The present study provides new understanding of the regulation of TRAIL‐mediated apoptosis in melanoma and will serve as the foundation for the potential development of a novel approach for a therapy of resistant melanomas. J. Cell. Biochem. 112: 463–475, 2011. © 2010 Wiley‐Liss, Inc.
Phytoestrogens directly inhibit TNF‐α‐induced bone resorption in RAW264.7 cells by suppressing c‐fos‐induced NFATc1 expression
Authors: Karieb Sahar , Fox Simon W.
Published: November 2010

TNF‐α‐induced osteoclastogenesis is central to post‐menopausal and inflammatory bone loss, however, the effect of phytoestrogens on TNF‐α‐induced bone resorption has not been studied. The phytoestrogens genistein, daidzein, and coumestrol directly suppressed TNF‐α‐induced osteoclastogenesis and bone resorption. TRAP positive osteoclast formation and resorption area were significantly reduced by genistein (10−7 M), daidzein (10−5 M), and coumestrol (10−7 M), which was prevented by the estrogen antagonist ICI 182,780. TRAP expression in mature TNF‐α‐induced osteoclasts was also significantly reduced by these phytoestrogen concentrations. In addition, in the presence of ICI 182,780 genistein and coumestrol (10−5–10−6 M) augmented TNF‐α‐induced osteoclast formation and resorption. However, this effect was not observed in the absence of estrogen antagonist indicating that genistein's and coumestrol's ER‐dependent anti‐osteoclastic action normally negates this pro‐osteoclastic effect. To determine the mechanism mediating the anti‐osteoclastic action we examined the effect of genistein, coumestrol, and daidzein on caspase 3/7 activity, cell viability and expression of key genes regulating osteoclast differentiation and fusion. While anti‐osteoclastic phytoestrogen concentrations had no effect on caspase 3/7 activity or cell viability they did significantly reduce TNF‐α‐induced c‐fos and NFATc1 expression in an ER dependent manner and also inhibited NFATc1 nuclear translocation. Significant decreases in NFκB and DC‐STAMP levels were also noted. Interestingly, constitutive c‐fos expression prevented the anti‐osteoclastic action of phytoestrogens on differentiation, resorption and NFATc1. This suggests that phytoestrogens suppress TNF‐α‐induced osteoclastogenesis via inhibition of c‐fos‐dependent NFATc1 expression. Our data provides further evidence that phytoestrogens have a potential role in the treatment of post‐menopausal and inflammatory bone loss directly inhibiting TNF‐α‐induced resorption. J. Cell. Biochem. 112: 476–487, 2011. © 2010 Wiley‐Liss, Inc.
JAK2/STAT3 pathway is involved in the early stage of adipogenesis through regulating C/EBPβ transcription
Authors: Zhang Kunming , Guo Wei , Yang Ying , Wu Jiarui
Published: November 2010

Signal transducer and activator of transcription 3 (STAT3) was reported to be involved in adipogenesis. However, the regulating mechanism of STAT3 remains unclear. The present results showed that STAT3 was activated within 2‐h adipogenic induction, in which the phosphorylated STAT3 translocated from cytoplasm to the nucleus. In addition, we detected Janus kinase2 (JAK2) acted upstream of the STAT3 activation at the early stage of adipogenesis. Accordingly, the JAK2 inhibitor AG490 and siRNAs led to the partial inhibition of the STAT3 activation, and the inhibition of 3T3‐L1 adipocyte differentiation. Furthermore, the results based on luciferase, chromatin immunoprecipitation, and gel shift approaches indicated that STAT3 could regulate the transcription of C/EBPβ by binding the distal region of C/EBPβ promoter at the early stage of adipogenesis. Collectively, our findings reveal that JAK2/STAT3 pathway is involved in the early stage of 3T3‐L1 adipocyte differentiation though regulating the C/EBPβ transcription. J. Cell. Biochem. 112: 488–497, 2011. © 2010 Wiley‐Liss, Inc.
Protein stability of mitochondrial superoxide dismutase SOD2 is regulated by USP36
Authors: Kim Myung‐Sun , Ramakrishna Suresh , Lim Key‐Hwan , Kim Jun‐Hyun , Baek Kwang‐Hyun
Published: November 2010

SOD2 is a key mitochondrial antioxidant enzyme and its perturbation leads to oxidative cell death, which results in various disorders. In this study, we identified a deubiquitinating enzyme USP36 that regulates the protein stability of SOD2. The regulatory effect of USP36 on SOD2 was initially identified by 2‐DE and MALDI‐TOF/MS analyses. In addition, endogenous USP36 and SOD2 were shown to interact in an immunoprecipitation assay, which was verified using the yeast two‐hybrid system. Furthermore, we demonstrated that SOD2 binds with ubiquitin molecules to form polyubiquitination chains and undergoes degradation through the ubiquitin‐proteasomal pathway. Finally, USP36 was shown to be a specific deubiquitinating enzyme that reduces the ubiquitination level of SOD2 and was involved in SOD2 protein stability by extending its half‐life. J. Cell. Biochem. 112: 498–508, 2011. © 2010 Wiley‐Liss, Inc.
Gambogic acid‐induced degradation of mutant p53 is mediated by proteasome and related to CHIP
Authors: Wang Jia , Zhao Qing , Qi Qi , Gu Hong‐yan , Rong Jing‐jing , Mu Rong , Zou Mei‐juan , Tao Lei , You Qi‐dong , Guo Qing‐long
Published: November 2010

As an oncoprotein, mutant p53 is a potential tumor‐specific target for cancer therapy. Most mutated forms of the protein are largely accumulated in cancer cells due to their increased stability. In the present study, we demonstrate that mutant p53 protein stability is regulated by gambogic acid (GA). Following GA exposure, protein levels of mutant p53 decreased while the mRNA levels were not affected in MDA‐MB‐435 cells, which indicate that GA down‐regulates mutant p53 at post‐transcription level. Co‐treatment with GA and cycloheximide, a protein synthesis inhibitor, induced a decrease of half‐life of mutant p53 protein. These findings indicated that the reduction of mutant p53 by GA was due to the destabilization and degradation of the protein. Furthermore, inhibition of proteasome activity by MG132 blocked GA‐induced down‐regulation of mutant p53, causing mutant p53 accumulation in detergent‐insoluble cellular fractions. Further studies revealed that mutant p53 was ubiquitinated and it was chaperones related ubiquitin ligase carboxy terminus of Hsp70‐interacting protein (CHIP) rather than MDM2 involved in the degradation of mutant p53. In addition, GA prevented Hsp90/mutant p53 complex formation and enhanced interaction of mutant p53 with Hsp70. Depletion of CHIP stabilized mutant p53 in GA treated cells. In conclusion, mutant p53 may be down‐regulated by GA through chaperones‐assisted ubiquitin/proteasome degradation pathway in cancer cells. J. Cell. Biochem. 112: 509–519, 2011. © 2010 Wiley‐Liss, Inc.
Stercurensin inhibits nuclear factor‐κB‐dependent inflammatory signals through attenuation of TAK1–TAB1 complex formation
Authors: Kim Young‐Joo , Kim Han‐Cheon , Ko Hyeonseok , Amor Evangeline C. , Lee Jong Wha , Yang Hyun Ok
Published: November 2010

We identified a chalcone, 2′,4′‐dihydroxy‐6′‐methoxy‐3′‐methylchalcone (stercurensin), as an active compound isolated from the leaves ofSyzygium samarangense. In the present study, the anti‐inflammatory effects and underlying mechanisms of stercurensin were examined using lipopolysaccharide (LPS)‐stimulated RAW264.7 cells and mice. To determine the effects of stercurensin in vitro, inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2) expression were analyzed by RT‐PCR and immunoblotting. Nuclear factor‐κB (NF‐κB) activation and its upstream signaling cascades were also investigated using a dual‐luciferase reporter assay, electrophoretic mobility shift assay, immunoblotting, immunofluorescence, and immunoprecipitation. To verify the effects of stercurensin in vivo, the mRNA expression levels of iNOS and COX‐2 were evaluated in isolated mouse peritoneal macrophages by quantitative real‐time PCR, and the production of tumor necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6), and IL‐1β were assessed in serum samples from mice using a Luminex system. Pretreatment with stercurensin reduced LPS‐induced iNOS and COX‐2 expression, thereby inhibiting nitric oxide (NO) and prostaglandin E2production, respectively. In addition, an inhibitory effect of stercurensin on NF‐κB activation was shown by the recovery of LPS‐induced inhibitor of κB (I‐κB) degradation after blocking the transforming growth factor‐β‐activated kinase 1 (TAK1)/I‐κB kinase signaling pathway. In mouse models, stercurensin negatively regulated NF‐κB‐dependent pro‐inflammatory mediators and cytokines. These results demonstrate that stercurensin modulates NF‐κB‐dependent inflammatory pathways through the attenuation of TAK1–TAB1 complex formation. Our findings demonstrating the anti‐inflammatory effects of stercurensin in vitro and in vivo will aid in understanding the pharmacology and mode of action of stercurensin. J. Cell. Biochem. 112: 548–558, 2011. © 2010 Wiley‐Liss, Inc.
ADAMTS‐5 and Intervertebral Disc Degeneration: The Results of Tissue Immunohistochemistry and In Vitro Cell Culture
Authors: Zhao Chang‐Qing , Zhang Yue‐Hui , Jiang Sheng‐Dan , Li Hai , Jiang Lei‐Sheng , Dai Li‐Yang
Published: November 2010

Matrix metalloproteinases (MMPs) are known to be involved in IVD degeneration by hydrolyzing the extracellular matrix (ECM), especially the collagens. The degradation of proteoglycans, which is another main ECM component in the IVD, however, has not been extensively investigated. This study aimed to determine the expression of ADAMTS‐5 in human herniated intervertebral disc (IVD) tissues and to investigate whether interleukin‐1β (IL‐1β)‐induced expression of ADAMTS‐5 is mediated by nitric oxide (NO). Forty‐five herniated IVDs were harvested and immunostained to determine the distribution and type of ADAMTS‐5 expressing cells. Rat NP cells maintained in alginate beads were treated with IL‐1β, accumulation of NO was detected by Griess reaction, the expression of ADAMTS‐5 and inducible nitric oxide synthase (iNOS) was analyzed by reverse transcriptase‐polymerase chain reaction (RT‐PCR), the content of proteoglycans in alginate beads was visualized by alcian blue staining, and the effect of aminoguanidine on the changes in alginate beads induced by IL‐1β treatment were also examined. Immunohistochemical results from 45 herniated discs showed that ADAMTS‐5‐positive cells are commonly seen in cell clusters, that the percentage of ADAMTS‐5‐positive cells was higher in uncontained herniated discs than in contained ones, and that the percentage of ADAMTS‐5‐positive cells correlated with the age of the patients. IL‐1β treatment resulted in increased accumulation of NO, increased expression of ADAMTS‐5 and iNOS, whereas the accumulation of proteoglycan in alginate beads decreased. Aminoguanidine significantly reversed the changes in alginate beads induced by IL‐1β treatment. We thus suggested that ADAMTS‐5 is probably involved in the process of IVD degeneration, and that IL‐1β‐induced expression of ADAMTS‐5 is mediated by NO. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:718–725, 2011
Kinetics of phosphorus release from calcareous soils under different land use in Iran
Authors: Jalali Mohsen , Ahmadi Mohammad Zinli Najmeh
Published: November 2010

The rate of phosporus (P) release from soils can significantly influence P fertility of soils. The objectives of this study were to investigate the effects of land‐use types on the kinetics of P release under different management practices and the relationship between kinetic parameters and soil physical and chemical properties from calcareous soils. The kinetics of P release in 0.01 M CaCl2 was studied in surface samples of 30 calcareous soils planted to garlic, garden, pasture, potato, vegetables, and wheat. Trend in P‐release kinetics was similar between land‐use types. Significantly different quantities of P were released under different land use. The maximum amount (average of five soils) (46.4 mg kg–1) of P was released in soil under potato and the minimum amount (10.4 mg kg–1) under pasture. The kinetics of P release from soils can be described as an initial rapid rate followed by a slower rate. Different models were used to describe P release. In general, parabolic diffusion and power equation were found to be appropriate for modeling P release. The P‐release rate for the soils was estimated by parabolic equation for the studied land‐use types. The constant b was lower for pasture and wheat than for garlic and potato. The relationship between the rate of P release with Olsen‐P was linear, while it was curved with respect to the CaCl2‐P, indicating that release of P was diffusion‐controlled. When the kinetic parameters of models were regressed on soil properties, CaCl2‐P and CaCO3 appeared to be the most important soil properties influencing P‐release rates in these soils.
Interaction of arbuscular mycorrhizal fungi and rhizobia: Effects on flax yield in spoil‐bank clay
Authors: Rydlová Jana , Püschel David , Sudová Radka , Gryndler Milan , Mikanová Olga , Vosátka Miroslav
Published: November 2010

This study focused on the application of native strains of arbuscular mycorrhizal fungi (AMF) and Sinorhizobium in effective crop production during reclamation of coal‐mine spoil banks. Two greenhouse experiments were conducted in spoil‐bank clay with a low dose of organic amendment to determine whether the microbial inoculation improves growth and utility qualities of two cultivars of Linum usitatissimum L. (oil and fiber flax). Inoculation with two native AMF isolates (Glomus mosseae, G. intraradices, and their mixture) significantly increased growth and shoot phosphorus (P) concentration of both flax cultivars. Inoculated fiber flax plants produced fivefold more fibers than the uninoculated ones. In oil flax, mycorrhizal inoculation significantly but quantitatively to a minor degree decreased the concentration of nonsaturated fatty acids in the seed oil. A mixture of five native Sinorhizobium sp. strains supported growth and P uptake of oil flax only in the absence of AMF. However, these beneficial effects of the bacteria were significantly lower as compared to AMF. No synergic action of Sinorhizobium strains and AMF was observed, and their interactions were often even antagonistic. Inoculation with AMF significantly decreased population density of Sinorhizobium in the soil. These results suggest that a careful selection of suitable bacterial strains is necessary to provide effective AMF combinations and maximize flax‐growth support.
The onsite cost of gully erosion and cost‐benefit of gully rehabilitation: A case study in Ethiopia
Authors: Yitbarek T.W. , Belliethathan S. , Stringer L.C.
Published: November 2010

Gully erosion often indicates extreme land degradation. In the highlands of Ethiopia, wide and deep gullies are common features, significantly affecting land used for agriculture. However, little action is being taken to address the problem. Where rehabilitation actions in Ethiopia are taking place, they are rarely studied by financially quantifying their costs and benefits. Therefore, this study developed methods of quantifying gully erosion costs and rehabilitation costs and benefits by considering the soil components of four model rehabilitated gullies in Ethiopia. Data were obtained from a physical survey supported by secondary information from relevant agricultural offices. Quantification was achieved by monetizing gully erosion cost through yield loss and gully rehabilitation calculations according to expenditure, while rehabilitation benefits were obtained by monetizing estimated deposited soil nutrients using fertilizer prices. Cost‐benefit values show that investment in gully rehabilitation can be an economically viable proposition in some instances. Stakeholders involved in gully rehabilitation should continue to invest in appropriate techniques of gully rehabilitation and management to ensure continued benefits from rehabilitated gullies and use of surrounding farmlands. Copyright © 2010 John Wiley & Sons, Ltd.
Soil conservation policies: Conditions for their effectiveness in the Czech Republic
Authors: Prazan J. , Dumbrovsky M.
Published: November 2010

Conservation of agricultural soil is an important issue in the Czech Republic. This paper is focused on the assessment of the institutions and policies targeted at soil conservation in order to explain the degree to which they are effective and why. The study was carried out at both national and regional level (Svratka River basin) to document the performance of policies. The most important types of soil degradation in the case study area are soil erosion, soil compaction and loss of organic matter. Farming adds to soil degradation because soil protection practices are not applied. Farmers lack motivation to protect soil when they do not trust policies. Evidence from the case study area suggests that agri‐environmental schemes are the most effective policy. Land consolidation could be more successful if the process is better managed. The Law on Soil Protection is not a powerful tool to prevent land degradation because it is not enforced sufficiently. Farmers currently do not have partners in the case study area who could facilitate policy implementation. A lack of political support and the unfavourable division of responsibilities concerning soil conservation has not allowed the design of an integrated policy framework. Areas to be addressed in order to increase the effectiveness of policies are: (i) design e.g. the vague wording of legislation, (ii) implementation e.g. conflicts of interests and lack of advice, (iii) policy evaluation and (iv) policy integration. We suggest integrating the existing measures in an overarching soil conservation strategy. Copyright © 2010 John Wiley & Sons, Ltd.
Multi‐Featured Macroporous Agarose–Alginate Cryogel: Synthesis and Characterization for Bioengineering Applications
Authors: Tripathi Anuj , Kumar Ashok
Published: November 2010

In this study agarose–alginate scaffolds are synthesized using cryogelation technology in different formats like monolith, sheet, discs, and beads, and show amiable mechanical strength like soft tissue properties and high interconnected macroporous degradable architecture. In cell–material interactions, fibroblast (NIH‐3T3) cells showed good adherence and proliferation on these scaffolds presenting its potential application in soft tissue engineering. The application of cryogel beads and monoliths was also examined by the efficient immobilization of bacterial cells (BL21) on these matrices revealing their use for recovery of product from continuous fermentation systems without cell leakage. These scaffolds also showed potential as a filter for repeated recovery of heavy metal binding, such as copper and nickel from the waste water. The cryogels prepared herein do have a number of unique features that make them an important class of soft materials for developing multi‐featured scaffolds as a novel carrier for bioengineering applications.

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An Optimized RGD‐Decorated Micellar Drug Delivery System for Albendazole for the Treatment of Ovarian Cancer: From RAFT Polymer Synthesis to Cellular Uptake
Authors: Kim Yoseop , Pourgholami Mohammad H. , Morris David L. , Stenzel Martina H.
Published: November 2010

Block copolymers were prepared via RAFT polymerization with P(PEGMEMA) as the hydrophilic block to form micelles for the controlled delivery of ABZ. The group contribution method was used to estimate the partial solubility parameters for ABZ and various polymers as potential core‐forming block to achieve optimum compatibility. Different ratios between MMA and LMA, a non‐compatible monomer, were prepared. Cytotoxicity tests revealed a high toxicity of the ABZ‐loaded micelle resulting in 80% cell deaths at a micelle concentration of 10 µg · mL−1. Cellular uptake of micelles has been studied using fluorescently labeled micelles, showing that a large fraction of micelles is readily taken up by OVCAR‐3 cells. RGD‐conjugated micelles were prepared and showed an increased cellular uptake.

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Polyurethane/Dermatan Sulfate Copolymers as Hemocompatible, Non‐Biofouling Materials
Authors: Xu Fangmin , Flanagan Claire E. , Ruiz Amaliris , Crone Wendy C. , Masters Kristyn S.
Published: November 2010

The range of application of polyurethanes has been limited by their poor hemocompatibility and inability to resist non‐specific binding of biomolecules and cells. In this work, a non‐adhesive PU‐based material was synthesized via the copolymerization of PU with dermatan sulfate. Incorporation of DS into the PU backbone dramatically increased material hydrophilicity and decreased protein adsorption. The in vitro adhesion of several cell types, including platelets, also significantly decreased with increasing DS content. Both the physical and biological properties of the DS contributed to the anti‐adhesive properties of the PU/DS copolymer, and this anti‐adhesive nature of PU/DS renders this new biomaterial attractive for blood‐contacting or non‐fouling applications.

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Effect of a Scaffold Fabricated Thermally from Acetylated PLGA on the Formation of Engineered Cartilage
Authors: Kang Sun‐Woong , Lee Suk‐Jun , Kim Jin‐Su , Choi Eun‐Hee , Cha Byung‐Hyun , Shim Jin‐Hyung , Cho Dong‐Woo , Lee Soo‐Hong
Published: November 2010

A MHDS has been employed to fabricate 3D scaffolds from PLGA with acetyl endgroups to achieve in vivo regeneration of cartilage tissue. The fabricated acetylated‐PLGA scaffold showed open pores and interconnected structures. Rabbit chondrocytes were seeded on the PLGA scaffolds and transplanted immediately into subcutaneous sites of athymic mice. Chondrocytes transplantation with untreated PLGA scaffolds served as a control. Histological analysis of the implants at 4 weeks with H&E staining and alcian blue staining revealed higher extracellular matrix and GAG expression at the neocartilage in the PLGA‐6Ac scaffolds than that of the PLGA‐6OH scaffold group. This endgroup‐modified scaffold may be useful for successful cartilage tissue engineering in orthopedic applications.

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Dipeptide and Tripeptide Conjugates as Low‐Molecular‐Weight Hydrogelators
Authors: Adams Dave J.
Published: November 2010

Dipeptide and tripeptide conjugates are receiving significant current interest as LMWG, driven by the accessibility of these materials, their relatively low cost and also the large number of examples that successfully form hydrogels. Their behaviour can easily modified by changes in the amino acids or the aromatic end groups chosen. The assembly process has been relatively well described for a small subset of these gelators, giving a good idea of the behaviour of these molecules and allowing an understanding of the conditions under which assembly will occur. Here, we critically review the literature in this area and consider the importance of gelator choice and method of assembly on the outcome of the gelation. We also discuss the applications of these hydrogels.

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Coating of Titanium Implant Materials with Thin Polymeric Films for Binding the Signaling Protein BMP2
Authors: Lorenz Corinna , Hoffmann Andrea , Gross Gerhard , Windhagen Henning , Dellinger Philip , Möhwald Kai , Dempwolf Wibke , Menzel Henning
Published: November 2010

A fast and simple approach for immobilization using copolymers as interlayers is reported. The synthesized copolymers form stable self‐assembled layers on implant materials like, e.g., titanium in a simple coating/drying/washing sequence and have functional groups which can bind proteins from an aqueous solution. The copolymer films have been characterized via ellipsometry and contact angle measurements and were tested for biocompatibility. An immunoassay was used to determine the amount of BMP2 and demonstrated an approximately 10‐fold increase as compared to previously used self‐assembled monolayers.1 A BMP2‐responsive cell line with luciferase detection was used to determine the biological activity of the bound signaling protein.

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Di‐ and Triblock siRNA‐PEG Copolymers: PEG Density Effect of Polyelectrolyte Complexes on Cellular Uptake and Gene Silencing Efficiency
Authors: Lee Soo Hyeon , Mok Hyejung , Park Tae Gwan
Published: November 2010

Di‐ and triblock siRNA/PEG copolymers were synthesized and complexed with cationic SLN for assessing their gene silencing efficiency as a function of PEG density. A sssiRNA and a sassiRNA were separately conjugated with PEG via a disulfide linkage. AB‐type diblock and ABA‐type triblock copolymers were successfully prepared by stoichiometric hybridization of sssiRNA‐PEG conjugate with sassiRNA and sassiRNA‐PEG conjugate, respectively. The resultant di‐ and triblock copolymers were characterized by means of GPC and gel electrophoresis. The serum stability of siRNA in the copolymers was enhanced as compared to that of naked siRNA. Using cationic SLN as a model carrier, the PEGylation density effect of the siRNA‐PEG/SLN complexes on gene silencing and cellular uptake was analyzed.

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Electrospun Nanofibrous Polycaprolactone Scaffolds for Tissue Engineering of Annulus Fibrosus
Authors: Koepsell Laura , Zhang Lifeng , Neufeld Daniel , Fong Hao , Deng Ying
Published: November 2010

The annulus fibrosus comprises concentric lamellae that can be damaged due to intervertebral disc degeneration; to provide permanent repair of these acquired structural defects, one solution is to fabricate scaffolds that are designed to support the growth of annulus fibrosus cells. In this study, electrospun nanofibrous scaffolds of polycaprolactone are fabricated in random, aligned, and round‐end configurations. Primary porcine annulus fibrosus cells are grown on the scaffolds and evaluated for attachment, proliferation, and production of extracellular matrix. The scaffold consisting of round‐end nanofibers substantially outperforms the random and aligned scaffolds on cell adhesion; additionally, the scaffold with aligned nanofibers strongly affects the orientation of cells.

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A Liquid‐Crystalline Co‐Polysiloxane with Asymmetric Bent Side Chains
Authors: Bubnov Alexej , Novotná Vladimíra , Pociecha Damian , Kašpar Miroslav , Hamplová Vĕra , Galli Giancarlo , Glogarová Milada
Published: November 2010

A co‐polysiloxane has been prepared with an asymmetric bent side group based on a liquid‐crystalline monomer showing a B2 (SmCP) phase. In order to dilute the side chain mesogens along the polymer backbone, octyl side chains were also incorporated. X‐ray studies confirmed that the resulting co‐polysiloxane exhibits a liquid‐crystalline layered phase, the siloxane polymer chains being microphase segregated from the incompatible side chain mesogens. The mesophase of polymer exhibits a homeotropic structure that can be successfully aligned by unidirectional shear. This phase does not exhibit polar switching under an applied electric field unlike the bent‐core monomer used as the side chains of this polymer. This can be caused by the homeotropic alignment of the polymer samples.

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Polyterthiophenes Incorporating 3,4‐Difluorothiophene Units: Application in Organic Field‐Effect Transistors
Authors: Crouch David J. , Sparrowe David , Heeney Martin , McCulloch Iain , Skabara Peter J.
Published: November 2010

Two terthiophenes bearing core fluorinated thienyl units have been synthesised as potential semiconductor materials for organic field‐effect transistors. Polymerisation of these compounds has been achieved using conventional iron(III) chloride oxidative coupling methods and by electrochemical oxidation. Characterisation of the fluorinated materials has been achieved by absorption spectroscopy and cyclic voltammetry. A soluble hexyl‐functionalised polymer (poly8b) was used in an OFET device; hole mobilities were measured up to 3 × 10−3 cm2 · V−1 · s−1, and the device had an on/off ratio of 105 and a turn‐on voltage of +4 V.

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Polyethylene/Clay Nanocomposites Made with Metallocenes Supported on Different Organoclays
Authors: Maneshi Abolfazl , Soares João B.P. , Simon Leonardo C.
Published: November 2010

The success of in situ polymerizations, measured by means of high polymerization activity, uniform exfoliation and clay dispersion in the polymer matrix, and good powder morphology, depends on how well the catalyst is supported onto the clay surface. A novel catalyst supporting method that does not require the addition of methylaluminoxane was applied to different organically modified clays and sodium montmorillonite. The supported catalysts were used to polymerize ethylene. We found out that only the clay modified with tertiary ammonium salts was an effective support for ethylene polymerization, generating a supported catalyst that has high polymerization activity, and produces nanocomposites with good powder morphology and excellent clay exfoliation.

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Disulfide‐Containing Hyperbranched Polyethylenimine Derivatives via Click Chemistry for Nonviral Gene Delivery
Authors: Jiang Xulin , Liu Jia , Xu Li , Zhuo Renxi
Published: November 2010

Reducible disulfide‐containing hyperbranched PEI‐SS‐HP was synthesized via click chemistry and evaluated as nonviral gene carrier. The structure of the polymers was confirmed by 1H NMR and FTIR. It was shown that the PEI‐SS‐HP was able to bind plasmid DNA to positively charged nanoparticles. The reduction sensitivity of the PEI‐SS‐HP was confirmed by gel retardation assay in the presence of DTT mimicking an intracellular reductive environment. In vitro experiments revealed that the reducible PEI‐SS‐HP not only had much lower cytotoxicity, but also posed superior transfection activity as compared to non‐degradable 25‐kDa PEI. The results indicate that a reducibly degradable PEI‐SS‐HP can be a promising gene vector.

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Luminescent Sensory Polymer Coating Composed of Platinumporphyrin and Poly(trimethylsilylpropyne) for Real‐Time Oxygen Visualization in Operating PEFCs
Authors: Hyakutake Tsuyoshi , Ishigami Yuta , Kato Junji , Inukai Junji , Miyatake Kenji , Nishide Hiroyuki , Watanabe Masahiro
Published: November 2010

A luminescent PtTFP/PMSP polymer coating was prepared for the oxygen partial pressure visualization inside a PEFC. PMSP formed a smooth and tough coating as a highly oxygen‐permeable matrix with a thickness of ca. 2 µm in which the PtTFP was homogeneously dispersed. The coating displayed a strong red luminescence with significantly decreasing intensity upon increasing oxygen partial pressure. The sensitivity for the oxygen partial pressure was high and the analytical curve of the sensor polymer coating was undisturbed by external factors. The PtTFP/PMSP sensor was coated on the surface of a cathode gas diffusion layer on the air flow channel inside PEFC. The oxygen‐pressure distribution in the air flow channel was successfully visualized while operating the PEFC.

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Structure and Behavior of Polydiacetylene‐Based Micelles
Authors: Perino Aurélia , Klymchenko Andrey , Morere Alexandre , Contal Emmanuel , Rameau Alain , Guenet Jean‐Michel , Mély Yves , Wagner Alain
Published: November 2010

The effect of photopolymerization on the structure, stability and encapsulation properties of polydiacetylene micelles containing nitrilotriacetic acid head groups are investigated. Micellar nanostructures of 7–10 nm diameter are identified that are invariant after polymerization. In the micelles, the polymerized ene‐yne chains are much shorter than in planar lipid membranes. SANS confirmed the presence of a monodisperse population of small particles before and after polymerization. It is shown that the CMC decreases manifold after micelle photopolymerization, indicating that it stabilizes the micellar structure. After photopolymerization, these micelles preserved their strong ability to solubilize a hydrophobic pigment, which makes them potentially interesting as drug delivery vehicles.

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Design of Patterned Surfaces with Selective Wetting Using Nanoimprint Lithography
Authors: Bessonov Aleksander , Kim Jeong‐Gil , Seo Jung‐Woo , Lee Jong‐Woo , Lee Sukwon
Published: November 2010

The fabrication of flexible surfaces with a combination of ultrahydrophobic and hydrophilic properties at alternating locations by UV NIL is reported. A new method for master fabrication based on nanoimprinting combined with photolithography is described. The master is used for a double replica technique to imprint nanopillars atop microstripes on a plastic substrate. Selective wetting is achieved due to ultrahydrophobic nanopatterned regions with 126° WCA and hydrophilic flat regions with 70° WCA on a single surface. By covering surface with hydrophobic SAM, a static contact angle of nanopillars is increased up to 163° indicating superhydrophobicity. We also show that the Cassie‐Wenzel theory successfully predicts the experimental apparent contact angles.

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Enzymatic Synthesis and Chemical Recycling of Polythiocaprolactone
Authors: Shimokawa Keisuke , Kato Makoto , Matsumura Shuichi
Published: November 2010

High‐molecular‐weight polythiocaprolactone (PTCL) was prepared in a green process via lipase‐catalyzed ROP of a cyclic 6‐mercaptohexanoic acid (6MH) oligomer. PTCL was readily depolymerized by lipase to cyclic 6MH in dilute toluene solution, which was then readily repolymerized by the same lipase to produce PTCL with the same $\overline {M} _{{\rm w}} $ as the initial PTCL in a chemical recycling process. The Tm of PTCL was higher than that of the corresponding PCL. A P(TCL‐co‐CL) copolymer with 60 mol‐% TCL (6MH) units showed a higher Tm as the PCL homopolymer. Similar apparent Km values were obtained for the cyclic 6MH oligomers and caprolactone oligomers, however, the Vmax of cyclic 6MH oligomers was significantly lower than that of the corresponding caprolactone oligomers.

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Synthesis and Photovoltaic Properties of Donor–Acceptor Copolymer Based on Dithienopyrrole and Thienopyrroledione
Authors: Zhou Erjun , Cong Junzi , Tajima Keisuke , Yang Chunhe , Hashimoto Kazuhito
Published: November 2010

A novel donor–acceptor (D–A) type alternating copolymer based on dithieno[3,2‐b:2′,3′‐d]pyrrole (DTP) and thieno[3,4‐c]pyrrole‐4,6‐dione (TPD) was synthesized. The polymer has a broad absorption spectrum in the range of 350–810 nm. The energy levels of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the copolymer were −5.11 and −3.63 eV, respectively, as determined by cyclic voltammetry. Bulk heterojunction type polymer solar cells based on PDTP‐TPD and PC70BM, showed power conversion efficiency (PCE) up to 1.6% with an open‐circuit voltage of VOC = 0.66 V, a short‐circuit current of ISC = 4.98 mA · cm−2, and a fill factor of FF = 0.50. The VOC of 0.66 V is the highest value among DTP‐based photovoltaic polymers.

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Solid‐State Polymerization of Poly(ethylene terephthalate): The Effect of Water Vapor in the Carrier Gas
Authors: Filgueiras Viviane , Vouyiouka Stamatina N. , Papaspyrides Constantine D. , Lima Enrique L. , Pinto Jose Carlos
Published: November 2010

SSP of PET has been thoroughly investigated under the regimes of chemical reaction and particle diffusion control. However, the majority of industrial PET plants operate under conditions of surface by‐product diffusion control, mainly due to recycling cycles of the carrier gas. The presence of residual volatile by‐products in the carrier gas (especially water) may affect adversely the polymerization reaction and the resulting polymer quality. For this reason, the effects caused by varying water vapor content of the carrier gas on the course of the PET SSP are analyzed, with emphasis on the intrinsic viscosity. The presence of small amounts of water in the carrier gas is found to exert a pronounced effect on the course of polymerization, leading to significant reduction of the molar masses of the final product.

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Amine‐Reactive PEGylated Nanoparticles for Potential Bioconjugation
Authors: Delaittre Guillaume , Justribó‐Hernández Gemma , Nolte Roeland J. M. , Cornelissen Jeroen J. L. M.
Published: November 2010

Water‐dispersible PEGylated nanoparticles (NPs) presenting amine‐reactive conjugation sites at their surfaces were synthesized and their ability to react with amines was demonstrated. An amphiphilic block copolymer bearing an N‐succinimidyl ester at its water‐soluble end was synthesized by the consecutive controlled radical polymerization of poly(ethylene glycol) methacrylate and styrene from a functional halide initiator. After purification of the copolymer, NPs of approximately 40 nm were obtained by a self‐assembly process in water. The reactivity of the NPs was evidenced by reacting them with primary amines, including a fluorescent dye. The activated ester remained stable throughout all synthetic steps and a nearly quantitative coupling efficiency was obtained.

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Kinetic Control of Monomer Sequence Distribution in Living Anionic Copolymerisation
Authors: Natalello Adrian , Hall John N. , Eccles E. Alex L. , Kimani Solomon M. , Hutchings Lian R.
Published: November 2010

Sequence control in synthetic polymers is a subject that is sparsely reported with little research in the field of sequence control in chain growth polymerisation. We report herein preliminary investigations into anionic copolymerisation of diphenylethylene (DPE) and its derivatives with styrene. DPE is a monomer that will only copolymerise and can form alternating copolymers. However, by introducing electron donating or withdrawing substituents onto the phenyl rings of DPE it is possible to prepare new range of (alternating) copolymers and with careful choice of monomer combination and conditions, the kinetically controlled (simultaneous) copolymerisation of three or more monomers results in copolymers with a greater degree of monomer sequence control.

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De Novo Design of Supercharged, Unfolded Protein Polymers, and Their Assembly into Supramolecular Aggregates
Authors: Kolbe Anke , del Mercato Loretta L. , Abbasi Azhar Z. , Rivera Gil Pilar , Gorzini Sekineh J. , Huibers Wim H. C. , Poolman Bert , Parak Wolfgang J. , Herrmann Andreas
Published: November 2010

Here we report for the first time the design and expression of highly charged, unfolded protein polymers based on elastin‐like peptides (ELPs). Positively and negatively charged variants were achieved by introducing lysine and glutamic acid residues, respectively, within the repetitive pentapeptide units. Subsequently it was demonstrated that the monodisperse protein polyelectrolytes with precisely defined amino acid compositions, sequences, and stereochemistries can be transferred into superstructures exploiting their electrostatic interactions. Hollow capsules were assembled from oppositely charged protein chains by using the layer‐by‐layer technique. The structures of the capsules were analyzed by various microscopy techniques revealing the fabrication of multilayer containers. Due to their low toxicity in comparison to other polyelectrolytes, supercharged ELPs are appealing candidates for the construction of electrostatically induced scaffolds in biomedicine.

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Designer Template Initiator for Sequence Regulated Polymerization: Systems Design for Substrate‐Selective Metal‐Catalyzed Radical Addition and Living Radical Polymerization
Authors: Ida Shohei , Ouchi Makoto , Sawamoto Mitsuo
Published: November 2010

“Template initiator”' platforms (1) have been designed for expressing the sequence information in a template in radical polymerization. Thus, we demonstrated the structural adequacy of 1 consisting of two initiating sites placed ortho to each other in benzene: one for living cationic polymerization to introduce a template carrying substrate‐recognition tags, and the other for metal‐catalyzed living radical polymerization to achieve sequence regulation. For example, for two positional isomers with an amine template for an acid monomer, only the ortho initiator induced selective radical addition of MAA (recognizable) over MMA (non‐recognizable). Another version was an oligo(vinyl ether) with a multiple amine template, which demonstrated template effects for MAA recognition over BzMA in copolymerization.

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Toroidal Nanostructures from Self‐Assembly of Block Copolypeptides Based on Poly(L‐Arginine) and β‐Sheet Peptide
Authors: Lim Yong‐beom , Lee Eunji , Lee Myongsoo
Published: November 2010

We demonstrate here that rationally designed block copolypeptides based on poly(L‐arginine) and β‐sheet peptides can form toroidal nanostructures. In aqueous solution, we found that 1D nanoribbons roll up and connect in an end‐to‐end fashion under charge‐balanced conditions, resulting in the formation of barrel‐like toroidal nanostructures. Toroidal diameter was highly uniform (10 nm), indicating that there is a preferred geometrical packing requirement for toroid formation. Our results demonstrate that, when suitably designed, β‐sheet nanostructures can be manipulated to form more complex 2D nanostructures. This finding offers new opportunities not only for the fabrication of more sophisticated peptide‐based nanobiomaterials, but also for understanding and inhibiting protein misfolding diseases.

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Mathematical Modeling of the Microstructure of Poly(propylene) Made with Ziegler‐Natta Catalysts in the Presence of Electron Donors
Authors: Alshaiban Ahmad , Soares João B. P.
Published: November 2010

Two different modeling techniques, the method of moments and Monte Carlo simulation, were compared for propylene polymerization with coordination catalysts including a new mechanistic step, site transformation by electron donors. We used the models to show how the molecular weight and tacticity distributions of several poly(propylene) chain populations were affected by changing the concentration of hydrogen, electron donor, and propylene in the reactor, under steady‐state or dynamic operating conditions. The Monte Carlo simulation describes the molecular weight and tacticity distributions for the whole polymer and chain populations with distinct microstructural characteristics. We have also applied the Monte Carlo model to simulate the pentad sequence distributions and its equivalent 13C NMR spectra.

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Proceedings of the eighth annual conference of the British Association for biological anthropology and osteoarchaeology bar is 1743 Megan Brickley & Shannon Dixon Smith (eds). British Archaeological Reports (BAR), John and Erica Hedges Ltd., Oxford, UK, 2008. 120 pp, ISBN 978‐1407‐3018‐53, (paperback).
Authors: Cunha Eugénia
Published: November 2010

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