Bald Zürcher Kunstherzen aus Silikon? Rendez-vous

We aim at developing a biomimetic ventricular assist device providing 100% hemocompatibility, to avoid hemolysis and coagulation. Akin to a diaphragm pump, pulsatile displacement of deformable membranes will generate propulsion and all surfaces in contact with blood will be covered by an endothelium. The key challenge of the proposed research is the realization of a bio-composite membrane, with an endothelial cell layer firmly attached to a synthetic substrate, resisting hundreds of millions of stretch cycles and shear stress from blood flow, without loss of its main biomechanical and biological functionalities.

We call this material system a hyperelastic hybrid membrane. This membrane integrates a living biological layer into a mechanical system, thus posing novel scientific challenges, but also opens new avenues for the realization of blood vessel constructs and ultimately a unique biomimetic blood propulsion device.

The larger part of the research focus on engineering the material system (WP1, WP2, WP3), i.e. the synthetic and biological components, so as to optimize the interaction between substrate and cell layer, with the goal of guaranteeing long term adhesion and integrity of the endothelium. A new bioreactor for simultaneous application of biaxial deformation and fluid flow shear stresses is used as a benchmark model system for evaluation of the different hybrid membrane configurations. Biochemical and molecular biology assays will be applied for biofunctional characterization.

Blood pump design activities (WP4) focus on the realization of a blood pump configuration which minimizes mechanical loading of the hybrid membrane. State of the art engineering science methodologies are applied to this end, including fluid-structure interaction simulations, design optimization, 3D printing for prototype realization, whole system modeling, control and performance testing in steady state and transient conditions. The final objective is to realize and implement a hybrid hyperelastic membrane into the blood pump system, and verify its performance on a hybrid mock circulation. The project will address all related science and engineering challenges and will end with the preparation for the next phase, which includes long term in vivo experiments.

10 PhD students and senior scientists from 3 research institutions (ETH Zurich, University of Zurich and Empa St. Gallen) and from different backgrounds (biology, material science, mechanical engineering, biomedical engineering, and electrical engineering) contribute to this research. Our regular PhD students meetings and work-package (WP) meetings are genuine examples of the unique opportunities and challenges of modern transdisciplinary research cooperations.