Probing the interaction of a glycoprotein IIb/IIIa receptor antagonist with bound platelets using electrochemical impedance

- Patterned protein surfaces can provide an improved assay for monitoring antiplatelet therapy.
- Patterning significantly influences the spreading of platelets compared to conventional, homogeneously coated surfaces.
- Electrochemical impedance can be used to rapidly measure the surface coverage of platelets without the need for labelling.

A label-free assay is described to monitor the interaction of abciximab, a glycoprotein IIb/IIIa receptor antagonist (ReoPro), with platelets bound to a fibrinogen-functionalised electrode surface. Firstly, fibrinogen is deposited in a defined pattern onto a gold electrode using microcontact printing, and then platelets from whole blood are captured on the patterned surface. Patterning influences the spreading of platelets, which is strikingly different to that observed on homogeneously coated surfaces. The drug-platelet interaction has been investigated using AC impedance on uniform and patterned fibrinogen-modified surfaces. The results demonstrate that patterned fibrinogen surfaces can provide deep insights into the interaction of abciximab with different platelet sub-populations. The key advantages of this approach are that it is rapid, label free and does not require pre-processing of patient blood samples.

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