A NOVEL STRATEGY FOR CONCURRENT REDUCTION OF FLUID DRAG AND PROTEIN ADSORPTION FOR CARDIOVASCULAR MEDICAL DEVICES

Abstract

Hemolysis is often known to be induced in extracorporeal blood pumps due to high rotation rates of the impeller, resulting in high shear forces that distort and ultimately destroy the blood cells. A recent proposal to address this problem is to use superhydrophobic (SHP) surface to achieve partial slip-flow and reduce fluid stresses, so as to reduce stress-induced hemolysis. However, such surfaces are typically made of hydrophobic material, and experience non-specific protein adsorption, which can disable the slip-flow characteristics, limiting their functional durability. Here, we report a novel strategy to achieve both drag reduction and lower non-specific proteins adsorption comparing to the pristine unstructured PDMS surface by grafting polyethylene glycol (PEG) on micrometer-sized pillar-shaped PDMS surfaces. Compared to a pristine PDMS surface, we observed that PEG-modified PDMS surfaces were more resistant to protein adsorption, and could maintain higher contact angles even after protein fouling. Further, the PEG-modified PDMS surfaces also maintained some drag force reduction characteristics, which was more apparent at higher surface flow rates. This strategy could potentially be applied to cardiovascular medical devices such as extracorporeal blood pumps.