(394d) Sub-Cellular Modeling of Platelet Transport and Adhesion in Microcirculation

 

Platelet transport and its adhesive function are the major contributing factors to the formation of thrombi in the circulation. We perform high-fidelity mesoscopic simulations of blood flow in microchannels with or without constriction, where the wall shear rates within the constrictions reach levels as high as 8, 000 sâ??1 , similar to those encountered in moderate atherosclerotic plaques. Both red blood cells and platelets are resolved at sub- cellular resolution using the Dissipative Particle Dynamics (DPD) method, and stochastic bond formation/dissociation are included to account for platelet adhesive dynamics at the site of injury. We find that higher levels of constriction and wall shear rates lead to significantly enhanced margination of platelets, which may explain the experimental observations of enhanced post-stenosis platelet aggregation. Platelet adhesion inside the constrictions is mostly mediated through GPIba receptors on plateletâ??s surface and von Willebrand Factor multimers. We study the mechanics of adhesion under different shear rate and flow conditions as well.