39 research outputs found

    Self-aligned and bundled electrospun fibers prepared from blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) with a hairt-rod polyphenylene copolymer

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    Cataloged from PDF version of article.Bundled and self-aligned fibers were obtained by electrospinning blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) with a hairy-rod polyphenylene-g-polystyrene/poly(a-caprolactone) (PP-g-PS/PCL) copolymer. The self-alignment and bundling characteristics of these electrospun fibers were ascribed to the unique molecular architecture of the conjugated polymer, PP-g-PS/PCL, and its interactions with the solvent and the polymer matrixes used for the electrospinning. The self-alignment and bundling was found to be much more pronounced for PP-g-PS/PCL-PS blend when compared to PP-g-PS/PCL-PMMA blend. Furthermore we found that the degree of self-alignment of the fiber bundles was enhanced by increasing the amount of PP-g-PS/PCL in the blends but the alignment completely disappeared when the solvent dimethylformamide was changed to chloroform. © 2009 Elsevier B.V. All rights reserved

    Neonatal Fc Receptor: From Immunity to Therapeutics

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    The neonatal Fc receptor (FcRn), also known as the Brambell receptor and encoded by Fcgrt, is a MHC class I like molecule that functions to protect IgG and albumin from catabolism, mediates transport of IgG across epithelial cells, and is involved in antigen presentation by professional antigen presenting cells. Its function is evident in early life in the transport of IgG from mother to fetus and neonate for passive immunity and later in the development of adaptive immunity and other functions throughout life. The unique ability of this receptor to prolong the half-life of IgG and albumin has guided engineering of novel therapeutics. Here, we aim to summarize the basic understanding of FcRn biology, its functions in various organs, and the therapeutic design of antibody- and albumin-based therapeutics in light of their interactions with FcRn

    Perspectives on Immunoglobulins in Colostrum and Milk

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    Immunoglobulins form an important component of the immunological activity found in milk and colostrum. They are central to the immunological link that occurs when the mother transfers passive immunity to the offspring. The mechanism of transfer varies among mammalian species. Cattle provide a readily available immune rich colostrum and milk in large quantities, making those secretions important potential sources of immune products that may benefit humans. Immune milk is a term used to describe a range of products of the bovine mammary gland that have been tested against several human diseases. The use of colostrum or milk as a source of immunoglobulins, whether intended for the neonate of the species producing the secretion or for a different species, can be viewed in the context of the types of immunoglobulins in the secretion, the mechanisms by which the immunoglobulins are secreted, and the mechanisms by which the neonate or adult consuming the milk then gains immunological benefit. The stability of immunoglobulins as they undergo processing in the milk, or undergo digestion in the intestine, is an additional consideration for evaluating the value of milk immunoglobulins. This review summarizes the fundamental knowledge of immunoglobulins found in colostrum, milk, and immune milk

    Synthesis and characterization of alternating copolymers of thiophene-containing N-phenyl maleimide and styrene by photoinduced radical polymerization and their use in electropolymerization

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    A novel N-(4-(3-thienyl methylene)-oxycarbonylphenyl) maleimide (MBThi) monomer was synthesized by the esterification reaction of maleimidobenzoic acid (MBA) with 3-thiophene methanol. Photoinduced radical polymerization was employed to prepare the alternating copolymers of MBThi with styrene (St) at room temperature using omega,omega-dimethoxy-omega-phenylacetophenone (DMPA) as photoinitiator. Different copolymerization conditions were examined to estimate the influence of the used solvents and comonomers' total molar concentration on the conversion, the number-average molecular weight (M-n), and polydispersity index (M-w/M-n) of the resulting polymers. Thermal behavior of the alternating copolymers (PSt-alt-MBThi) was also investigated by thermogravimetrical analysis (TGA) and differential scanning calorimetry. Moreover, the obtained alternating copolymers were employed in electropolymerization experiments and random conjugated graft copolymers with thiophene or pyrrole were synthesized through their pendant thienyl groups. These polymers were characterized by cyclic voltammetry (CV), FTIR and scanning electron microscopy (SEM). Conductivity measurements were carried out by the four-probe technique

    Conducting copolymers of thiophene-functionalized polystyrene

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    The syntheses of conducting copolymers of thiophene-functionalized polystyrene and pyrrole (PS/PPy) were achieved using p-toluene sulfonic acid (PTSA) as the supporting electrolyte via constant potential electrolysis technique. Characterization of the samples was performed by a combination of techniques: cyclic voliammetry (CV), thermogravimetric analysis (TGA), differential scanning colorimetry (DSC), scanning electron microscopy (SEM), NMR, and FT-IR analyses. The conductivities were measured by the four-probe technique

    Immobilization of invertase and glucose oxidase in conducting copolymers of thiophene functionalized poly(vinyl alcohol) with pyrrole

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    WOS: 000236451300007In this study, immobilizations of invertase and glucose oxidase were achieved in conducting thiophene functionalized copolymers of vinyl alcohol with thiophene side groups and pyrrole (PVATh/PPy) via electrochemical polymerization. The kinetic parameters, V-max (maximum reaction rate) and K-m (substrate affinity), of both free and immobilized enzymes were determined. The effect of supporting electrolytes, p-toluene sulfonic acid and sodium dodecyl sulfate, on the enzyme activity and film morphologies was examined. The optimum temperature, operational and storage stabilities of immobilized enzymes were determined. PVATh/PPy copolymer was found to exhibit significantly enhanced properties compared to pristine polypyrrole. (c) 2005 Elsevier B.V. All rights reserved

    Immobilization of invertase and glucose oxidase in conducting copolymers of thiophene functionalized poly(vinyl alcohol) with pyrrole

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    In this study, immobilizations of invertase and glucose oxidase were achieved in conducting thiophene functionalized copolymers of vinyl alcohol with thiophene side groups and pyrrole (PVATh/PPy) via electrochemical polymerization. The kinetic parameters, V-max (maximum reaction rate) and K-m (substrate affinity), of both free and immobilized enzymes were determined. The effect of supporting electrolytes, p-toluene sulfonic acid and sodium dodecyl sulfate, on the enzyme activity and film morphologies was examined. The optimum temperature, operational and storage stabilities of immobilized enzymes were determined. PVATh/PPy copolymer was found to exhibit significantly enhanced properties compared to pristine polypyrrole. (c) 2005 Elsevier B.V. All rights reserved
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