(535f) Effect of Ligand Spacing On Cell Adhesion and Rolling Under Flow

Cell adhesion and rolling on the vascular wall is critical to both inflammation and thrombosis. Whether a cell adheres and rolls is a delicate balance between the fluid forces that promote cell detachment and the receptor-ligand interactions that mediate adhesion. Recent studies have suggested that the spacing and/or clustering of ligands can have profound impacts on a cell's response (i.e. adhesion, migration, activation). Ligand spacing in vivo is often heterogeneous, with proteins often being clustered in patches. Thus to better mimic the in vivo situation, we have developed a protein patterning methods which allows us to fabricated lines and dots of protein with dimensions of 2 ? 20 μm. With these patterns we demonstrate the role of contact area and ligand spacing on the adhesion of neutrophils and platelets under flow.