Biosensor for platelet function testing

PhD project Loes van Zijp

Master student: Joris Goudsmits

Under normal conditions platelets circulate in the vascular system having little interaction with each other or with other cells. The platelets become activated when the system is disturbed, for instance by a blood vessel damage that exposes collagen to the platelets. Activation causes specific receptors/molecules to be exposed on the cell membrane, which support adhesion, spreading and aggregation of the platelets onto the damaged vessel. A schematic of the activation process of a blood platelet is shown below.

The platelet function is altered in some cardiovascular diseases. For example, when platelets respond too slowly to activation triggers, a patient suffers from a bleeding disease. When platelets are too easily activated, a patient suffers from a thrombotic disease.

The platelet function, in particular the platelet activation sensitivity, can be analyzed in research laboratories with the aid of flow cytometry. We are investigating biosensor technologies for integrated platelet testing, in order to simplify and miniaturize platelet function testing in the future. We are particularly interested in the use of superparamagnetic particles, because such particles are suited as detection labels and for the manipulation of platelets in an integrated device.

The figure below shows an example of an assay concept with magnetic particles as a detection label. The particles and the sensor surface are functionalized with specific antibodies, against general markers as well as activation markers on the platelet membrane.

This PhD project is performed in collaboration with the University Medical Center Utrecht, Future Diagnostics and Philips Research, within the Circulating Cells project of the Center for Translational Molecular Medicine (CTMM, www.ctmm.nl).