Hydrodynamic-derived centrifugal blood pump design for stable-low-flow-rate rate performance: from surface to structure

Long-lasting stability of the anticoagulant coating on centrifugal blood pumps (CBPs) is of vital importance to ensure the hemocompatibility of the blood circulation system therein. Heparin coatings are often prepared using static wet chemical technique, but these face risks of delamination or deactivation induced by blood flow. Inspired by the flow-shear-stress mediated conformation changes of von Willebrand factor, a novel fluid-driven deposition technique was employed to apply polydopamine-heparin coatings within CBPs. Moreover, most FDA-approved CBPs are designed for high-flow-rate CBPs of major organs like the heart and lungs (1000∼8000 ml/min). Few are tailored for low-flow-rate perfusion of other organs such as the liver, kidney and brain (<50-300 mL/min). Our approach addresses this gap by developing low-flow-rate CBPs through anti-thrombogenic coatings and anti-hemolytic structural optimizations. In this study, we introduced an axial magnetic direct drive motor with our optimized low-flow-rate CBPs, achieving a stable-low-flow-rate rate ranging from 16.3 mL/min (300 rpm) to 121.0 mL/min (2000 rpm). The resulting CBPs system exhibited enhanced flow stability and hemocompatibility in rabbit model experiments, demonstrating significantly lower hemolysis rates and lower thrombus formation risks. These results indicate that the polydopamine-assisted heparin coating provides short-term stability under dynamic flow, offering a promising strategy for low-flow-rate CBPs, though its long-term durability and clinical translation potential require further validation.