Evaluation of Platelet Behavior in Response to Varied Conditions in a Microfluidic Flow Cells.

Abstract 5075

Platelet function under shear flow can be tested using a variety of instruments ranging from cone and plate viscometers to microfluidic flow cells. While these methods offer relevant data, they generally suffer from high blood volume requirements, low throughput and complex operating protocols. We have developed a flow-based well plate microfluidic device that operates at very wide shear ranges (from 0-200dyn/cm²) and use minimal blood volumes ('1ml per experiment). Here we present data using the microfluidic device to examine platelet response over time on coated surfaces. Flow channels were coated with fibronectin, von Willebrand factor (vWF), and collagen I. Whole blood was introduced at increasing shear stress ranging from 0-200dyn/cm². Devices were used to study dose responses to abciximab (ReoPro) on vWF and collagen I at 200 and 10dyn/cm² respectively by examining percent platelet coverage following application of flow. Within the concentration range tested, 1.25-20 μg/ml (26.5nM-470nM), for both collagen and vWF, the IC₅₀ fell slightly below 26.5nM. We compared the data generated in the microfluidic channels to data generated in traditional parallel plate flow chambers. While response to coated surfaces and ReoPro were predictably comparable, the time to set up the microfluidic device and the volume of blood used were significantly decreased, 6X and 10X respectively, leading to higher throughput in one experimental session and more data generated from one donor. Therefore, the use of such microfluidic devices can greatly streamline studies with multiple variables enabling many data points to be generated from single donors within a single device.