title: Oxidative mechanisms of poly(carbonate urethane) and poly(ether urethane) biodegradation: in vivo and in vitro correlations.
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 degrees 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 H(2)O(2)/CoCl(2) system in evaluating the biostability of polyurethanes under accelerated conditions.
authors.affiliation: Center for Applied Polymer Research and Department of Macromolecular Science, Case Western Reserve University, Cleveland, Ohio 44106, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Christenson
authors.forename: James M
authors.initials: JM
authors.lastname: Anderson
authors.forename: Anne
authors.initials: A
authors.lastname: Hiltner
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001672:Biocompatible Materials / Q000737:chemistry / Q000493:pharmacokinetics*; D001673:Biodegradation, Environmental; D002084:Butylated Hydroxytoluene / Q000031:analogs & derivatives* / Q000494:pharmacology; D003035:Cobalt; D004355:Drug Stability; D006861:Hydrogen Peroxide; D066298:In Vitro Techniques; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D011108:Polymers / Q000737:chemistry / Q000493:pharmacokinetics*; D011140:Polyurethanes / Q000737:chemistry / Q000493:pharmacokinetics*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D000975:Antioxidants; D001672:Biocompatible Materials; D011108:Polymers; D011140:Polyurethanes; C110029:poly(carbonate urea) urethane; C115016:polyetherurethane; D002084:Butylated Hydroxytoluene; D003035:Cobalt; C030594:Santowhite powder; D006861:Hydrogen Peroxide; C018021:cobaltous chloride