Oxidative mechanisms of poly(carbonate urethane) and poly(ether urethane) biodegradation: In vivo and in vitro correlations

Authors

  • Elizabeth M. Christenson,

    1. Center for Applied Polymer Research, Case Western Reserve University, Cleveland, Ohio 44106
    2. Department of Macromolecular Science, Case Western Reserve University, Cleveland, Ohio 44106
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  • James M. Anderson,

    1. Department of Macromolecular Science, Case Western Reserve University, Cleveland, Ohio 44106
    2. Department of Biomedical Engineering and Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106
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  • Anne Hiltner

    Corresponding author
    1. Center for Applied Polymer Research, Case Western Reserve University, Cleveland, Ohio 44106
    2. Department of Macromolecular Science, Case Western Reserve University, Cleveland, Ohio 44106
    • Center for Applied Polymer Research, Case Western Reserve University, Cleveland, Ohio 44106
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Abstract

This study used an in vitro environment that simulated the microenvironment at the adherent cell-material interface to reproduce and accelerate the biodegradation of poly(ether urethane) (PEU) and poly(carbonate urethane) (PCU). Polyurethane films were treated in vitro for 24 days in 20% hydrogen peroxide/0.1 M cobalt chloride solution at 37°C. Characterization with ATR-FTIR and SEM showed soft segment and hard segment degradation consistent with the chemical changes observed after long-term in vivo treatment. Overall, the PCU underwent less degradation and the degraded surface layer was much thinner than PEU. Nevertheless, the results supported a common oxidation mechanism for biodegradation of these polymers. The observed in vitro degradation was inhibited by adding an antioxidant to the polyurethane film. Our findings further support the use of the in vitro H2O2/CoCl2 system in evaluating the biostability of polyurethanes under accelerated conditions. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 245–255, 2004

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