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  • Polymer and Materials Science  (78)
  • Organic Chemistry  (10)
  • Wiley-Blackwell  (88)
  • American Chemical Society
  • New York : Wiley-Interscience
  • Periodicals Archive Online (PAO)
  • 1
    Electronic Resource
    Electronic Resource
    Explorations in cell biology and pharmacology using synthetic polymersPaper presented at the meeting of the GDCh-Fachgruppe “Makromolekulare Chemie” on “Polymers and Biological Functions” in Bad Nauheim (West-Germany) on April 18/19, 1988. (1989)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 166 (1989), S. 191-200 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: We have used synthetic polymers as tools to probe endocytosis and lysosome function. Their particular value lies in their well-defined chemical constitution and in the possibility to custom-synthesize molecules with desired characteristics. Polyvinylpyrrolidone, Percoll and polystyrene beads have been 125I-labelled and used to explore the borderland of pinocytosis and phagocytosis. Derivatized poly(aspartamide), poly(hydroxypropylmethacrylamide) and a polylysine-poly(ethylene oxide) block copolymer have been used to investigate the effects of hydrophobic moieties and sugar residues on substrate-selection in pinocytosis. The effect of cationic moieties has been studied using vinylpyrrolidone-vinylamine copolymers.Poly(hydroxypropylmethacrylamide) with certain oligopeptide side---chains have been shown to be susceptible to lysosomal peptidases. Ethylene glycol oligomers are being used to study the basal permeability of the lysosome membrane.Soluble macromolecules have considerable potential in targeted drug-delivery. Drugs attached to appropriate polymers by covalent links that are susceptible to lysosomal enzymes can deliver drug to target cells and avoid unwanted sideeffects. Synthetic macromolecules have several advantages over their natural counterparts: they are chemically more robust, less immunogenic, and easier and cheaper to prepare in bulk.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1989.051660114
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  • 2
    Electronic Resource
    Electronic Resource
    Enantioselective Allylic Substitution Catalyzed by Chiral [Bis(dihydrooxazole)]palladium Complexes: Catalyst structure and possible mechanism of enantioselection (1995)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 78 (1995), S. 265-284 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Allylpalladium complexes with chiral bis(dihydrooxazole) ligands were studied as catalysts for the enantioselective allylic substitution reaction of rac-1,3-diphenylprop-2-enyl acetate (rac-5) with the anion of dimethyl malonate (Scheme 1). Using enantiomerically pure (S,E)-1-(4-tolyl)-3-phenylprop-2-enyl acatete ((S)-25) as substrate, the reaction was shown to proceed by a clean ‘syn’ displacement of acetate by dimethyl malonate (Scheme 6). The [Pd11(η3-allyl)] complex 18 and the analogous [Pd(η3-1,3-diphenylallyl)] complex 20, both containing the same bis(dihydrooxazole) ligand, were characterized by X-ray structure analysis and by NMR spectroscopy in solution. The structural data reveal that steric interactions of the allyl system with the chiral ligand result in selective electronic activation of one of the allylic termini. The higher reactivity of one allylic terminus toward nucleophilic attack is reflected in a significantly longer Pd—C bond and a shift of the corresponding 13C-NMR resonance to higher frequency.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19950780202
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  • 3
    Electronic Resource
    Electronic Resource
    Methods of targeting N-(2-hydroxypropyl) methacrylamide copolymers to particular cell types (1985)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 9 (1985), S. 3-12 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Soluble synthetic polymers will only be useful as drug carriers, if methods can be devised for targeting them to specific cell types. Two approaches are currently being investigated. Firstly, the incorporation of specific residues such as galactosamine into N-(2-hydroxypropyl) methacrylamide copolymers has been shown to enhance greatly pinocytic capture by liver cells. Secondly, antibodies have been evaluated as a more universal address system. Binding rat IgG to N-(2-hydroxypropyl) methacrylamide copolymers increased their rate of uptake by rat visceral yolk sacs cultured in vitro and simultaneously enhanced their rate of exocytosis.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1985.020091985102
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  • 4
    Electronic Resource
    Electronic Resource
    Micelle-forming block copolymers: Pinocytosis by macrophages and interaction with model membranes (1985)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 186 (1985), S. 725-733 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A block copolymer (6) with both hydrophilic and hydrophobic regions was synthesized, in order to examine its interaction with model membranes and its uptake by living cells. The copolymer comprised poly(ethylene oxide) and poly(L-lysine) with 50 mol-% substitution of the ε-amino groups with palmitoyl groups. To permit 125I-labelling, p-methoxyphenyl residues (1-4 mol-%) were incorporated into the block copolymer and into a poly(ethylene oxide) used for comparison. Sudan Red 7 B solubilization studies indicated that the block copolymer, but not the homopolymer, forms micelles. Differential scanning calorimetry of dipalmitoyl-phosphatidylcholine liposomes indicated that the block copolymer interacts with and probably penetrates lipid membranes. Both poly(ethylene oxide) and the block copolymer were captured by rat peritoneal macrophages in vitro, and inhibitor studies indicated that uptake of both polymers was by pinocytosis. Rates of uptake were indicative of adsorptive pinocytosis, and it is concluded that both poly(ethylene oxide) and the block copolymer present a largely hydrophilic aspect which interacts positively with the cell surface.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1985.021860406
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  • 5
    Electronic Resource
    Electronic Resource
    Polymers containing enzymatically degradable bonds, 7Part 6, cf. Biomaterials 3, 150 (1982). Design of oligopeptide side-chains in poly[N-(2-hydroxypropyl)methacrylamide] copolymers to promote efficient degradation by lysosomal enzymesDedicated to Professor Otto Wichterle on the occasion of his 70th birthday (1983)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 184 (1983), S. 1997-2008 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: N-(2-Hydroxypropyl)methacrylamide copolymers are considered to be a potential drug delivery system. To fulfil this role the drug-polymer linkage must be susceptible to intralysosomal hydrolysis. Taking p-nitroanilide as a drug analogue, copolymers were synthesized bearing oligopeptidyl-p-nitroanilide side-chains designed to match known specificities of the lysosomal enzymes cathepsin L or cathepsin D. Degradation of side-chains by rat liver lysosomal enzymes (measured by monitoring terminal p-nitroaniline release) occurred only in the presence of reduced glutathione (5 mmol/l) and was effectively inhibited by leupeptin, indicating the involvement of thiol-proteinases in every case. Depending on side-chain composition, between 20 and more than 50% of the terminal p-nitroaniline residues were liberated during a 5 h incubation. It has also been shown that 1) a polymer molecule may contain side-chains of a single type that are nevertheless differentially susceptible to lysosomal hydrolysis; 2) two of the side-chains studied liberate only a p-nitroaniline residue, whereas the others also release amino-acyl-p-nitroanilides; 3) the cleavage of all side-chains displays a broad pH optimum pH 5 to pH 7; 4) the Michaelis-Menten constant Km for side-chain cleavage varied between 26,1 and 143,2 mg/ml, depending on the amino acid sequence of the side-chain.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1983.021841005
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  • 6
    Electronic Resource
    Electronic Resource
    The desorption of ethane-butane mixtures from polyethyleneProd. No. 1611 (1967)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 11 (1967), S. 2007-2019 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The desorption of mixtures of ethane and butane at atmospheric pressure from low-density polyethylene was investigated over the temperature range from 20 to 60°C. Desorbed penetrants were continuously trapped in glass tubes immersed in liquid nitrogen, and composition was determined as a function of time by means of gas chromatography. The ratio of the quantity of desorbed gas at any time t, qt, to the quantity at complete desorption, q∞, was used to determine diffusion coefficients and solubility constants. The diffusion coefficients for both ethane and butane increase with increasing butane concentration in the temperature interval investigated. The solubility of both penetrants can be correlated by Henry's law at 40, 50, and 60°C. However, at 20 and 30°C. the solubility constant for both penetrants increases with increasing butane concentration. This trend is consistent with experimental observations for single-component diffusion and solubility of several hydrocarbons in polyethylene, where increasing concentration of penetrant plasticizes the polymer, resulting in increasing diffusion coefficients and solubility constants.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1967.070111017
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  • 7
    Electronic Resource
    Electronic Resource
    Permeation of ethane-butane mixtures through polyethylene (1968)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 12 (1968), S. 2083-2095 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Permeation of ethane-butane mixtures a t atmospheric pressure through polyethylene was investigated in the temperature interval of 30-60°C. The integral permeation constant P̄ and the integral diffusion coefficient D̄ of both ethane and butane were satisfactorily correlated by using an exponential and also a linear function of butane concentration. This was attributed to the plasticizing of the film by butane, whose solubility constant is approximately ten times that of ethane in the temperature interval investigated. The separation factor Gi, j defined as the ratio of the permeation constant of butane to the permeation constant of ethane over the range of mixture compositions and temperatures investigated, remained nearly constant at values in the range of 2.8-3.2. The insignificant change in Gi, j is due to the proximity of the activation energies of permeation of ethane and butane (10.95 and 10.75 kcal/mol, respectively) and the similar magnitude of change in the permeation constants with increasing butane concentration. Experiments were run in which the film was initially in equilibrium with the same partial pressure of butane as in the mixture to be studied. It can be shown that the diffusion coefficient of ethane in this case is related to the following function of film position: D = D(o)(β0 + β1x)δ. The time lag of diffusion of ethane in these experiments decreased with inrreasing butane concentration.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1968.070120911
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  • 8
    Electronic Resource
    Electronic Resource
    The synthesis of acetals of poly(vinyl alcohol) which show lower consolute temperature behavior in water (1976)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 20 (1976), S. 1721-1722 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1976.070200632
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  • 9
    Electronic Resource
    Electronic Resource
    Carbon-13 NMR of hydroxyethylcellulose: An accurate method for structural determination (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 21 (1977), S. 621-627 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The high-resolution carbon-13 NMR spectrum of hydroxyethylcellulose (HEC) with about 2.5 moles of ethylene oxide (MS 2.5) average substitution per anhydroglucose ring (AHG) is presented. From models, the CMR chemical shifts for all of the different carbon atoms are assigned. Direct measurement of the relative intensities of the CMR signals for certain carbon atoms in HEC permits rapid and accurate computation of (1) the average chain length of poly(ethylene oxide); (2) the degree of substitution of ethylene oxide, and (3) the average relative degree of substitution of the alcohol groups on the AHG ring.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1977.070210304
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  • 10
    Electronic Resource
    Electronic Resource
    Ionically crosslinked poly(acrylic acid) membranes. III. Reverse osmosis results for dry cast membranes (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 24 (1979), S. 1341-1351 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The reverse osmosis properties of ionically crosslinked polyacrylic acid membranes were investigated in terms of the salt separation of a 0.1% NaCl solution and water flux. The membranes were synthesized and crosslinked with the metal ion Al3+ via the dry casting technique described in a previous paper. The effect of such variables as the polymer concentration in the casting solution, the ratios of solvents used (DMF/H2O), the ratio of monomer to the crosslinking agent (AA/Al), the evaporation time and temperature, and the nonsolvent nature and treatment times were studied in some detail. The most important variable was found to be the length and nature of the treatment in the nonsolvents acetone and methanol. In the best series of the membranes that were synthesized, fluxes of more than 3.0 gfd, with salt separations at the 80%-85% level, were obtained.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070240518
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