Due to the gruesome toll of cardiovascular disease (CVD) through-out the world, improvements in treatment for CVD are of profound medical, societal and economic importance. The proposed research will be conducted in collaboration with renowned artificial heart pioneer, Dr. Robert Jarvik, and is designed to improve the operating lifetime of Ventricular Assist Devices (VADs) used to treat CVD, from 2 years to 10 years. The two most important remaining hurdles to accomplish this life-saving objective are improvements in the wear resistance of certain high stress parts and improvements in anti-thrombogenicity of the interior blood-contacting surfaces of the VAD. Ultrananocrystalline diamond (UNCD), an extremely smooth, low cost diamond coating was successfully developed by the applicant for many diverse applications requiring low wear, low friction and chemical inertness. The substrate materials utilized in the Jarvik 2000 VAD, silicon carbide and titanium, provide an excellent substrate match for UNCD coating. Initial UNCD deposition work by ADT and verified by Jarvik Heart, has demonstrated that if the seeding and deposition steps are well controlled UNCD, can be grown even on the inside surfaces of 3-D parts. Beginning from this starting point, this proposed project addresses the development of VAD-quality UNCD films to significantly improve the knowledge base regarding the defect mechanisms of UNCD films, and to reduce or eliminate known wear-inducing imperfections in the film and to then thoroughly characterize and test the films and assembled UNCD-coated VADs. Additional research is proposed on functionalized UNCD films that were observed during the initial research to demonstrate even less interaction with the blood-clotting fibrinogen than non-functionalized UNCD. After the defect reduction and seeding experiments to improve film adhesion and coating quality, the best candidate deposition method will be down-selected for coating and assembly of VAD parts from Jarvik Heart. These will be thoroughly tested with mechanical and blood-simulating fluid hydrodynamic testing at Jarvik Heart for full verification of the new coating technology. This research builds upon a foundation of demonstrated UNCD application success at ADT and the encouraging initial UNCD development work for Jarvik Heart. The low cost of UNCD is another factor in the potential for UNCD in implantable devices. In production, a set of Jarvik VAD parts could be coated with UNCD for <1% of the device cost. The potential for medical and economic success with this effort is sufficiently promising that Jarvik Heart is funding all of the parts costs, assembly and testing from its own resources. If successful, the potential US market for a 10-year lifetime VAD is at least 40,000 units per year and the total available US market for VADs is >$5 billion annually. With world-wide sales of approximately four times this, and other implantable devices that could benefit from the application of UNCD, the total available world-wide implantable device market for UNCD coatings is >$120 million annually.
Cardiovascular disease is the #1 killer in the US today;however, it is being treated successfully for short periods of time with lifesaving Ventricular Assist Devices (VADs). If successful, the proposed research will demonstrate that ultrananocrystalline diamond (UNCD) thin films can be used as highly wear resistant and inexpensive anti-thrombotic coatings for these lifesaving devices to extend their effective operating lifetime from 1-2 years up to 10 years and greatly reduce patient morbidity and mortality from cardiovascular disease. A reduction or elimination of the need for powerful immunosuppressant drugs after VAD implantation is also expected because of the anti-thrombogenic properties of UNCD.
