title: Polyurethane elastomer biostability.
abstract: Polyurethanes have unique mechanical and biologic properties that make them ideal for many implantable devices. They are subject to some in vivo degradation mechanisms, however. Polyester polyurethanes are subject to hydrolytic degradation and are no longer used in long-term implanted devices. Polyether polyurethanes, while hydrolytically stable, are subject to oxidative degradation in several forms, including environmental stress cracking and metal ion oxidation. Mineralization is also known to occur. A new polycarbonate polyurethane has superior biostability in early in vivo qualification tests compared to the polyether polyurethanes, including no evidence of hydrolysis, ESC or MIO.
authors.affiliation: Medtronic, Inc., Minneapolis, MN 55432-3576, USA.
authors.forename: K
authors.initials: K
authors.lastname: Stokes
authors.forename: R
authors.initials: R
authors.lastname: McVenes
authors.forename: J M
authors.initials: JM
authors.lastname: Anderson
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001826:Body Fluids / Q000737:chemistry; D002114:Calcinosis / Q000503:physiopathology; D004781:Environmental Exposure; D005549:Foreign-Body Reaction / Q000276:immunology; D008422:Materials Testing; D008670:Metals / Q000737:chemistry; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D055585:Physical Phenomena; D010825:Physics; D011140:Polyurethanes / Q000737:chemistry*; D019736:Prostheses and Implants; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D008670:Metals; D011140:Polyurethanes