A simple microfluidic technology for assaying platelet adhesion and aggregation under physiological flow / 军事医学

ABSTRACT

Objective To develop a simple microfluidic chip technology for analyzing platelet adhesion and aggregation under the condition of physiological flow .Methods The basic structure of the proposed microfluidic chip was a straight microchannel , where a sample pool and an outlet were located on each side respectively .The fluid dynamic behavior ,of the fluid in the microchannel was analyzed by theoretical calculation and finite element numerical analysis software ANSYS . The microchannel was first coated with type Ⅰ collagen protein.Then,blood flowed through the microchannel at 200 s-1 venous physiological shear rate and 1000 s-1 arterial physiological shear rate respectively .The behavior of the fluorescence labeled platelet adhesion and aggregation was recorded by fluorescence microscopy .Results Theoretical calculation and finite element numerical analysis showed that the microchannel with a width of 700 μm and a height of 70 μm ( aspect ration 101 ) had a uniform fluidic shear rate distribution .Compared with those at the 200 s-1 shear rate, the initial adhesion time, aggregation rate and the maximum surface cover rate of the platelet were significantly reduced at the 1000 s-1 shear rate ( P<0.05 ) .At the 1000 s-1 shear rate, tirofiban, an anticoagulant drug , significantly reduced the platelet aggregation in a concentration-dependent manner and the IC 50 was 23.8 nmol/L.Conclusion The technology developed in this paper can dynamically assay platelet adhesion and aggregation under the condition of physiological flow . The proposed microfluidic methods have the advantage of simple implementation and low sample cousumpation , and can be used for point-of-care detection of human platelet function , assay of the efficacy of anticoagulant drugs and for inspection of the thrombin behaviors of small animal models .