SBIR-STTR Award

Thrombogenicity of foreign substances is one of the leading issues limiting long term use of circulatory support devices and other devices having direct contact with blood. Numerous studies indicate that thrombogenic properties of a foreign surface can be significantly reduced by surface modifications. One very promising new technology is a biomimetic surfactant polymer coating developed by Marchant et. al. This coating has demonstrated excellent non-thrombogenic properties on graphite substrates, but under low shear stress environments. In Phase I, we will evaluate the feasibility of this novel coating for use in an extracorporeal blood pump, which is currently under design at BIOMEC. We will apply the surfactant polymer coating to critical surfaces of the pump, which have been coated with diamondlike carbon film. To evaluate the stability of our coating under the high shear stress conditions of the blood pump, we will subject test samples to high shear stress in a rotating disk apparatus. If successful, this will demonstrate the feasibility of surfactant polymer coatings for blood pumps and other circulatory devices, such as heart valves, cannulas for membrane oxygenators, and ventricular assist devices, and will improve the outcome of transplantations and other cardiac procedures. PROPOSED COMMERCIAL APPLICATIONS: The biomimetic coatings to be developed in this proposal are applicable to devices with blood contacting surfaces, including blood pumps, ventricular assist devices, artificial heart valves, and cannulas for extracorporeal membrane oxygenators.

The activation of blood coagulation and the activation of inflammatory response by foreign surfaces are leading issues limiting long-term use of circulatory support devices and other devices having direct contact with blood, such as heart valves, cannulae for membrane oxygenators, and ventricular assist devices. Numerous studies indicate that thrombogenic properties of a foreign surface can be significantly reduced by surface modifications. One very promising new technology is a biomimetic surfactant polymer coating, proposed by Marchant et. al. This coating had demonstrated excellent non-thrombogenic properties on graphite substrates but had been only investigated under low shear stress environments. In Phase I, we demonstrated the feasibility of this novel coating for use in an extracorporeal blood pump, which presents a high-shear environment for coatings. We applied the surfactant polymer coating to sample substrates of materials used in blood pumps, some coated with diamond-like carbon film. To evaluate the stability of our coating under the operating conditions of blood pumps, we subjected test samples to high shear stress in a rotating disk apparatus. The coating was found to maintain its surface properties even after four hours of exposure to a shear stress of 530 dynes/cm2, thus demonstrating the feasibility of surfactant polymer coatings for blood pumps and other circulatory devices. The aim of the Phase II research is to coat existing commercial blood pumps and to validate the biocompatiblity of the coatings through in-vitro studies using human blood and through in-vivo studies in animals. After Phase II, we will be prepared to start human clinical trials and to finish the commercialization process.

Thesaurus Terms:
biomaterial development /preparation, biomimetics, circulatory assist, surface coating, surfactant biomaterial compatibility, biomaterial evaluation, biomedical equipment development, cardiovascular prosthesis, mechanical stress, polymer clinical research, human subject, swine