(78c) Micropatterned Surfaces for Controlling Cell Adhesion and Rolling

The current practice to study the adhesive interactions of leukocytes or platelets under flow is to coat substrates with adhesion proteins by simple adsorption or incorporation into a phospholipids bilayer and then perfuse isolated cells over the coated substrate in a flow perfusion assay. Although these methods have led to a wealth of knowledge on the molecular interactions that mediate leukocyte and platelet adhesion and rolling under flow, potential drawbacks include (a) protein molecules are randomly distributed on the surface; (b) only a single protein concentration can be studied at a time; and (c) only a single protein can be studied. Many studies could benefit from the use of substrates in which adhesion proteins are patterned into well-defined microenvironments, and multiple proteins or protein concentrations are patterned simultaneously. In this paper we describe a method to fabricate protein pattern surfaces for use in cell rolling studies. Using microfluidic channels we were able to fabricated parallel lines of adhesion proteins (P-selectin and E-selectin) to control the location and speed at which leukocytes roll. We also demonstrate that this technique can also be applied to platelet rolling on von Willebrand factor (vWf).