Platelet Function Assessment in a Microfabricated Device

Although platelets are small and simple in shape, they are complicated in their physiologhy. Their alpha granules and dense bodies secrete a large number of agents that are involved in haemostasis, and the glycoproteins on their surfaces form the linkages with proteins like fibrinogen, fibronectin, collagen and von Willebrand factor that are necessary for adhesion and aggregation (Frojmovic, 1998). Diseases such as heart attack (Meade, 1992), stroke (Harker, 1998) and eclampsia (Schindler et al., 1990), can be the result of pathologies in platelets. Although devices have been recently developed to diagnose platelet function (Nicholson et al., 1998), there is still a need for devices that can examine the multiple factors of platelet physiology that affect thrombus formation. Because fluid shear is a key factor in platelet adhesion and aggregation (Colantuoni et al., 1977), it is necessary to test platelet function under conditions of flow. Also, because of the large number of adhesion receptors and secreted agents that make up a platelet’s physiology, a complete diagnosis of platelet function should be performed on a variety of substrates.