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  • 1
    Electronic Resource
    Electronic Resource
    Tailoring of macromolecule conjugates using reversed micelles as matrix microreactors (1990)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 2801-2814 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Being solubilized in systems of reversed micelles of a surfactant, the macromolecules incorporate into the inner cavities of the micelles, whose size can be changed by varying the degree of hydration, w0 = [H2O]/[surfactant]. The conjugates of proteins (α-chymotrypsin, bovine serum albumin (BSA), monoclonal antibodies to insulin) with linear polyelectrolytes (poly(methacrylic acid), quaternized poly(4-vinylpyridine)) are synthesized in reversed micelles of Aerosol OT (sodium bis(2-ethylhexyl)sulfosuccinate) in the octane with 100% yield. The yield critically depends on the degree of hydration: the reaction does not proceed at low w0, but if w0 exceeds a threshold value (which differs for various macromolecules) the yield increases sharply and reaches 100%. Using the ultracentrifugation it was demonstrated that at low w0 the polyelectrolyte represents a compact globule compressed by the micellar matrix in the inner cavity of a micelle. Under these conditions, there is no space for the protein in a micelle which contains polyelectrolyte, and therefore reaction does not proceed. If w0 exceeds a threshold value the micelles become large enough to entrap the conjugated macromolecules simultaneously. The possibility of regulation of the conjugate composition by variation of w0 (via the size of the micellar matrix) was demonstrated by a conjugate of BSA with quaternized poly(4-vinylpyridine).
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1990.021911129
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  • 2
    Electronic Resource
    Electronic Resource
    DNA interpolyelectrolyte complexes as a tool for efficient cell transformation (1991)
    New York : Wiley-Blackwell
    Biopolymers 31 (1991), S. 1437-1443 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A tool was developed for enhancement of plasmid penetration into an intact cell, based on increasing DNA hydrophobicity via inclusion into a soluble interpolyelectrolyte complex (IPC) with polycations. The characteristics of formation of DNA IPC with synthetic polycations [poly(N-ethyl-4-vinylpyridinium)bromide (PVP) and PVP modified with 3% of N-cetyl-4-vinylpyridinium units (PVP-C)] were studied using ultracentrifugation and polyacrylamide gel electrophoresis methods. The conditions were established under which the mixing of DNA and polycation aqueous solutions results in the selfassembly of soluble IPC species. Incorporation of DNA into IPC results in the enhancement of DNA binding with isolated Bacillus subtilis membranes. A considerable increase in the efficiency of transformation of B. subtilis cells with pBC16 plasmid resulted from incorporation of the plasmid into the IPC with PVP and CVP.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360311210
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  • 3
    Electronic Resource
    Electronic Resource
    Effects of Pluronic P85 Unimers and Micelles on Drug Permeability in Polarized BBMEC and Caco-2 Cells (1998)
    Springer
    Pharmaceutical research 15 (1998), S. 1525-1532 
    Details
    ISSN: 1573-904X
    Keywords: pluronic block copolymer ; intestinal delivery ; drug ; micelles ; blood brain barrier
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Purpose. Using polarized bovine brain microvessel endothelial cells (BBMEC) monolayers as in vitro model of the blood brain barrier and Caco-2 monolayers as a model of the intestinal epithelium, the present work investigates the effects of Pluronic P85 block copolymer (P85) on the transport of the P-gycoprotein (P-gp)- dependent probe, rhodamine 123 (R123). Methods. The permeability and cell efflux studies are performed with the confluent cell monolayers using Side-Bi-Side diffusion cells. Results. At concentrations below the critical micelle concentration, P85 inhibits P-gp efflux systems of the BBMEC and Caco-2 cell monolayers resulting in an increase in the apical to basolateral permeability of R123. In contrast, at high concentrations of P85 the drug incorporates into the micelles, enters the cells and is then recycled back out to the apical side resulting in decrease in Rl 23 transport across the cell monolayers. Apical to basolateral permeability of micelle-incorporated R123 in BBMEC monolayers was increased by prior conjugation of P85 with insulin, suggesting that modified micelles undergo receptor-mediated transcytosis. Conclusions. Pluronic block copolymers can increase membrane transport and transcellular permeability in brain microvessel endothelial cells and intestinal epithelium cells. This suggests that these block copolymers may be useful in designing formulations to increase brain and oral absorption of select drugs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011942814300
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  • 4
    Electronic Resource
    Electronic Resource
    Competitive reactions in solutions of DNA and water-soluble interpolyelectrolyte complexes (1995)
    New York : Wiley-Blackwell
    Biopolymers 35 (1995), S. 523-531 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of competitive binding of two polyanions - DNA and synthetic fluorescence-tagged poly(methacrylate) (PMA*) - with the polycation-quencher poly(N-ethyl-4-vinyl-pyridinium) (PEVP) was studied by fluorescence quenching technique. It was found that ability of DNA to displace PMA *from the water-soluble nonstoichiometric interpolyelectrolyte complex (NPEC) formed by PMA* and PEVP - NPEC(PMA*-PEVP) - and to form water-soluble NPEC(DNA-PEVP) \documentclass{article}\pagestyle{empty}\begin{document}$$ NPEC(PMA^{*}\hbox{-}PEVP) + DNA \Leftrightarrow NPEC(DNA\hbox{-}PEVP) + PMA^{*}$$\end{document} can be determined by the parameter Ψ = PPMA*/PPEVP where PPMA* and PPEVP are the degrees of polymerization of PMA* and PEVP, respectively. In the case of Ψ 〈 1 the decrease of Ψ leads to the shift of the reaction equilibrium to the right, which can be explained by the gain of entropy due to the increase of the total number of polymeric particles in the solution. Introduction of alkali metal cations into the reaction mixture results in the shift of the reaction equilibrium, and according to their ability to shift the equilibrium to the right the cations can be arranged in the series Na+ 〉 K+ 〉 Li+. The substitution of native DNA by denatured DNA practically does not affect the reaction equilibrium in solutions of NaCl and KCl but considerably shifts it to the right in solutions of LiCl. The data obtained are in accordance with the differences in the selectivity of alkali cations binding with competitive polyanions. © 1995 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360350511
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  • 5
    Electronic Resource
    Electronic Resource
    Some new aspects of polymerization reaction (1979)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 3 (1979), S. 41-68 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: This paper deals with general and also specific aspects of matrix polyreactions on macromolecular templates, namely, mutual assistance of active centres of propagating chains and template units in elementry steps of propagatior. Such assistance has been found in polymerization of 4-vinylpyridine on polyacids and propargyl compounds on poly-4-vinylpyridine. These examples have shown that these kinds of assistance are the crucial points in kinetic template effects.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1979.020031979103
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  • 6
    Electronic Resource
    Electronic Resource
    Catalytic behaviour of metalcomplexes immobilized in functional polymeric carriers (1981)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 5 (1981), S. 121-154 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The general principles of construction of gel-immobilized catalyst systems (GICS) are reported as well as some peculiarities of the polymerization of ethylene and of the dimerization of ethylene and propylene in the presence of these systems.GICS consist of a transition metal complex and a specially designed polymeric support. Advantages offered by gel-immobilized catalyst systems are discussed with respect to homogeneous and microheterogeneous metal complex catalysts.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1981.020051981109
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  • 7
    Electronic Resource
    Electronic Resource
    Cooperative interpolyelectrolyte reactions (1985)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 13 (1985), S. 137-155 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Water-soluble nonstoichiometric polyelectrolyte complexes (NPEC) are formed as a result of interaction of opposite charged polyelectrolytes used in nonequivalent ratios. One of the most important properties of NPEC is their ability to participate in intermacromolecular exchange and substitution reactions in aqueous solutions. The kinetics of exchange and substitution reactions has been studied by the method of luminescence quenching. It has been found that such reactions proceed by the contact mechanism and that addition of low molecular electrolytes to the reaction mixtures results in a dramatic increase in the rates of the reactions. The kinetics of the reactions is well described by the equation q = 1-exp(- kt∝) (here q is the degree of conversion and ∝ 〈 1), deduced under the assumption that exchange and substitution occur by the nucleation mechanism and the development of nuclei is inhibited in time. The studied reactions represent a new class of interpolymer reactions and they can be very important, in particular, for understanding the mechanism of functioning of biologically important macromolecules and for the interpretation of the physiological activity of polyelectrolytes.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1985.020131985111
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  • 8
    Electronic Resource
    Electronic Resource
    Properties of polyelectrolyte complexes containing poly(N-tert-butylaziridine) (1986)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 187 (1986), S. 1151-1158 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Interpolymer reactions between poly(acrylic acid) (PAA) or poly(methacrylic acid) (PMAA) and poly(N-tert-butylaziridine) (PTBA) were studied and compared with the corresponding reactions of these polyacids with linear polyethyleneimine (LPEI). In aqueous alkaline and salt media the presence of the bulky non-polar N-substituent in the main chain of PTBA results in a decrease of stability of polyacid-PTBA polyelectrolyte complexes. LPEI, which forms stronger salt bonds with PAA, substitutes PTBA in the PAA-PTBA polyelectrolyte complexes. Addition of simple salts to aqueous solutions of non-stoichiometric polyelectrolyte complexes (N-PEC) PAA-PTBA and PMAA-PTBA at room temperature causes a phase separation due to macromolecular exchange and disproportionation reactions. At elevated temperatures (T = 40 - 60 °C), however, the macromolecular exchange between different N-PEC particles does not occur and phase separation in aqueous salt solution of the N-PEC's PAA-PTBA, PMAA-PTBA is not observed. This is attributed to hydrophobic interactions in polyacid-PTBA complexes due to the presence of the tert-butyl groups in the latter.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1986.021870512
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  • 9
    Electronic Resource
    Electronic Resource
    Active transport of linear polyions in oppositely charged swollen polyelectrolyte networks (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 2211-2216 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The interaction between oppositely charged linear and crosslinked polyelectrolytes and the molecular mechanism of the transport of linear polyelectrolytes into oppositely charged gels were studied. The mechanism represents a “relay-race” transfer of polyion segments from one fragment of the polyelectrolyte network to the other via interpolyelectrolyte exchange reaction. Thus, the whole layer of the formed interpolyelectrolyte complex serves as an active zone. The driving force for the transport is produced by interpolyelectrolyte addition reaction on the solution/gel interface.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021900921
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  • 10
    Electronic Resource
    Electronic Resource
    A new class of complex water-soluble polyelectrolytes (1984)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 6 (1984), S. 259-276 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Water-soluble nonstoichiometric polyelectrolyte complexes (N-PEC) constitute a new class of polyelectrolytes. N-PEC are formed as a result of interaction between oppositely charged polyelectrolytes taken in non-equivalent rations and thus they are macromolecular compounds. An N-PEC particle can be represented as a macromolecule of a segmented block copolymer. The behaviour of the N-PEC in aqueous-salt media shows their polyelectrolyte nature, but in contrast to ordinary polyelectrolytes, they undergo considerable conformational changes. These transitions precede phase separations, which are unique and are accompanied by the phenomena of disproportionation. Using N-PEC as enzyme carriers it is possible to produce self-regulating systems with a feedback and also thermostable systems, which are the simplest models of a spore. The N-PEC formed by synthetic polyelectrolytes and some proteins, show a pronounced physiological activity and belong to the class of highly immunogenic antigens.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1984.020061984120
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