Blood platelet adhesion to printed von Willebrand factor

Von Willebrand factor (vWF), a glycoprotein in blood, mediates the adhesion of blood platelets and thus plays a crucial role in hemostasis and thrombosis. Functional coating of surfaces with vWF allows the investigation of in vitro adhesion of blood platelet. We used soft lithography to create a functional patterned substrate. vWF was printed on plasma-treated glass and mica surfaces, producing elongated network-like fibril structures. A minimum layer thickness of 3 nm was observed, corresponding to the height of a monolayer of vWF. The stability of the patterns was verified in a laminar fluid flow, and the bioactivity of the structures was tested with platelet adhesion experiments. Platelets adhered to and spread on printed vWF. These results indicate that printed vWF substrates are stable and functional in typical perfusion experiments, and thus provide a useful tool for studying thrombus formation in vitro.