Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1990-1994  (3)
  • 1
    Electronic Resource
    Electronic Resource
    New polyurethane compositions able to bond high amounts of both albumin and heparin (1994)
    Springer
    Journal of materials science 5 (1994), S. 779-783 
    Details
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Abstract In order to prepare polymers provided with better haemocompatibility with respect both to the coagulative cascade and to platelet aggregation and activation, we have synthesized new polyurethanes containing in the chain extender [di-(2-hydroxyethyl) hexa-decylamine (DHHA)] both a long chain alkyl group (able to bond albumin) and a tertiary ammonium group able, after suitable quaternization reaction, to bind ionically significant amounts of heparin. The amounts of heparin and albumin bonded to the polymer films were determined spectrophotometrically. A biological in vitro evaluation of the heparinized and albuminized films was also carried out, with respect to the blood coagulation factors (by APTT measurements) and to platelet adhesion. For the sake of comparison, polyurethanes containing as chain extenders two different monomers (containing, respectively, the long alkyl and the quaternary ammonium group), and polymer blends consisting of these copolymers, were also prepared and evaluated as above. It was seen that the type of the adsorption sequence for albumin and heparin, respectively, onto films of the various homopolymers, copolymers and blends, plays an important role in their biological properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213134
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Synthesis and characterization of new hydrophobic polyurethanes for biomedical applications (1994)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 195 (1994), S. 875-888 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The synthesis of new segmented polyurethanes containing as chain extender N-hexadecyl-2,2-bis(hydroxymethyl)propionamide (alone or with 1,4-butanediol at different mole ratios) is described. The degree of hydrophobicity and the glass transition temperatures Tg were found to be proportional to the alkyl chain content of the polymer. Also the amount of bonded albumin is proportional to the alkyl group content of the polymer, and platelet adhesion is remarkably lower for the 100% alkylated polymer (PEUHDA) than for the standard non-alkylated polyurethane (PEU). This behaviour was confirmed by SEM evaluation, showing a much lower degree of activation of platelets on albuminized PEUHDA films. It was not possible to ascertain with sufficient reliability a different behaviour, with respect to platelet adhesion, of the polymers containing alkyl chains in the range 9 ÷ 50 mol-%, due to the relatively high error of the evaluation systems.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1994.021950306
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    New polyurethanes able to bind high amounts of heparin, suitable as biomedical compositions (1993)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 4 (1993), S. 319-328 
    Details
    ISSN: 1042-7147
    Keywords: Segemented polyurethanes ; Heparin ; Ionic bond ; 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
    Notes: The synthesis of new segmented polyurethanes containing different amounts of N,N-diethylaminoethyl-N′-2,2 hydroxymethylpropionamide, and able to bind, after suitable quaternization, high amounts of heparin, is described. The quaternization is carried out on organic solutions of the polymers. Polymers have been characterized by spectroscopic techniques (transmission and reflectance IR and 1H and 13C NMR), molecular weight measurements and differential scanning calorimetry. The heparin content of the polymer films was determined by a colorimetric system, and its biological activity was evaluated in vitro by activated partial thromboplastin time (APTT) measurements. The distribution of heparin on the surface and in bulk of the heparinized films was evaluated by scanning electron microscopy (SEM) combined with X-ray energy dispersive spectroscopy.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pat.1993.220040501
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...