Multiparameter microfluidics assay of thrombus formation reveals increased sensitivity to contraction and antiplatelet agents at physiological temperature

Introduction: Current developments to assess qualitative and quantitative platelet traits in flowed whole-blood are based on microfluidic devices that mostly operate at room temperature. However, operation at physiological temperature (37 degrees;C) may increase the assay's sensitivity, and facilitates the comparison to other platelet function tests of the diagnostic laboratory. Materials and methods: We adapted the conventional microspot-based microfluidic device with a simple thermocoupled pre-heating module. Automated analysis of microscopic images assisted in obtaining five timedependent parameters of thrombus formation over collagen microspots (shear rate 1000 s- 1). These modifications allowed rapid testing of control and patient blood samples at physiological temperature. Results and conclusion: The higher temperature enhanced platelet adhesion and aggregation as well as late thrombus characteristics such as size and contraction, when compared to room temperature. Moreover, assessment at 37 degrees C indicated a time-dependent impairment of the thrombus parameters in blood from patients taking common antiplatelet medication, i.e. aspirin and/or clopidogrel. This pointed to increased contribution of the autocrine platelet agonists thromboxane A2 and ADP in the buildup of contracted thrombi under flow. Overall, this study underlined the advantage of multiparameter assessment of microfluidic thrombus formation in detecting an acquired platelet dysfunction, when operating at physiological temperature. This work may bring microfluidics tests closer to the diagnostic laboratory. Introduction: Current developments to assess qualitative and quantitative platelet traits in flowed whole-blood are based on microfluidic devices that mostly operate at room temperature. However, operation at physiological temperature (37 degrees C) may increase the assay's sensitivity, and facilitates the comparison to other platelet function tests of the diagnostic laboratory. Materials and methods: We adapted the conventional microspot-based microfluidic device with a simple thermocoupled pre-heating module. Automated analysis of microscopic images assisted in obtaining five timedependent parameters of thrombus formation over collagen microspots (shear rate 1000 s- 1). These modifications allowed rapid testing of control and patient blood samples at physiological temperature. Results and conclusion: The higher temperature enhanced platelet adhesion and aggregation as well as late thrombus characteristics such as size and contraction, when compared to room temperature. Moreover, assessment at 37 degrees C indicated a time-dependent impairment of the thrombus parameters in blood from patients taking common antiplatelet medication, i.e. aspirin and/or clopidogrel. This pointed to increased contribution of the autocrine platelet agonists thromboxane A2 and ADP in the buildup of contracted thrombi under flow. Overall, this study underlined the advantage of multiparameter assessment of microfluidic thrombus formation in detecting an acquired platelet dysfunction, when operating at physiological temperature. This work may bring microfluidics tests closer to the diagnostic laboratory.

Automated summary

This study demonstrated the advantage of multiparameter assessment of platelet traits at physiological temperature in detecting acquired platelet dysfunction. Results showed that higher temperature enhanced platelet adhesion and aggregation, particularly in the formation of contracted thrombi.