A Bioactive Polymer Designed for Cardiac Assist Devices

DESCRIPTION (provided by applicant): The ultimate objective of this proposal is the development of a novel, bioactive polymer for use in ventricular assist devices (VAD), and other long-term blood contacting implantable devices. Although VADs are becoming an important therapeutic option for patients in heart failure, serious problems persist secondary to thromboembolic complications and continue to be a challenge at times to clinicians, despite aggressive anti-coagulation regimens. Anti-coagulant (i.e., heparin) coatings are currently being used for short-term use. These coatings either dissolve rapidly, or are eventually covered by proteins resulting in reduced bioactivity. The polymer developed here will provide a slow, in situ release or anti-coagulants at the blood: surface interface, thereby changing the local coagulation properties. The bioactive polymer will be optimized, and characterized in Phase I. Preliminary studies have demonstrated that anti-coagulants can be incorporated in to a biomedical polyurethane currently used in several different cardiac assist devices. An optimal polymer formulation, based on key properties for use in a VAD design will be developed. The release rates of the anti-coagulant from the polymer will also be measured. Key components manufactured from the bioactive polymer will be tested for long-term use to determine any impact on the overall device reliability. Finally, several prototype VADs will be built to demonstrate that current manufacturing procedures are transferable to the bioactive polymer. The Phase I study will demonstrate the compatibility of the bioactive polymer with a VAD design. Phase II will primarily involve testing of a VAD constructed with the polymer. Readiness testing will be completed to verify the long-term device reliability. This will include detailed pre-clinical animal studies to determine the benefits of the use of a bioactive polymer for long-term VAD implantation.