Shear stress related decreases in cell proliferation and platelet and monocyte adherence to bovine aortic endothelial cells seeded on solid or porous polyester substrates

Endothelial cell seeding of vascular grafts has long been considered an approach to preventing thrombosis and/or growth of connective tissue cells often associated with loss of graft patency. In these studies, the influence of elevated shear stress preconditioning of bovine aortic endothelial cells (BAEC) seeded on either a porous or solid polyester substrate is examined with respect to three important aspects of endothelial function; namely, cell proliferation monocyte adherence, and platelet adherence. Cultured BAEC were seeded on either collagen coated 5 μm pore polyester mesh or solid polyester film and allowed to attain either near or full confluence. Endothelialized polyester to shear were placed in parallel plate flow chambers and exposure to shear stress levels ranging from < 1 to 90 dynes/cm² dynes/cm² and greater for 24-48 h resulted in a decrease in BAEC proliferation rates inversely proportional to the level of imposed shear stress. Addition of pulsatility (1 Hz) at the equivalent mean shear stress levels resulted in a further inhibition of cell proliferation rates. Monocyte and platelet adhesion studies were performed on endothelialized material preconditioned to either high (30 dynes/cm²) or low (<1 dyne/cm² shear stress. These stress exhibit significantly less Cr-monocyte (66%) nd Cr-Platelet (75%) adherence relative to cells exposed to low shear stress.