Abstract

Development of Innovative Microfluidic Assay of Platelet Functions

Sehyun Shin, Professor & Director, Korea University

Since platelets are a crucial blood cell on hemostasis and thrombosis, there have been significant developments of innovative methods and devices to assay platelet functions and drug-response in recent 10 years. The major achievements were focused on their function corresponding to mechanical shear stress as well as agonists such as ADP and collagen. However, the developed methods yield low correlation among them and technical drawbacks such as hematocrit-dependence and other cellular factors. We have developed a microfluidic assay system of shear-induced platelet function as well as drug-response of platelet. Platelet activation was clearly observed with applying shear stress with rotational stirrer and adding agonists. When prepared blood is driven by pressure through the microchannel, activated platelets adhere to a collagen-coated surface, causing blood flow to significantly slow and eventually stop. Depending on the degree of platelet activation, the migration distance and velocity through microchannel were apparently different. Thus, migration distance and touchdown time were recorded and compared with control which was not shear-activated. The present methods were further examined and found that it is independent of hematocrits as well as sample viscosity. Therefore, the present system could be easy and useful to examine platelet functions and diagnose cerebro-cardio-vascular diseases such as strokes and heart attacks with simple test.