Computational mechanical simulation of the aggregation and dissociation of platelets mediated by von Willebrand factor

摘要

Platelets play an important role in blood coagulation, particularly in the formation of primary thrombi. The aggregation of platelets, which initiates primary thrombi formation, is thought to be mediated by the von Willebrand factor (vWF). The vWF is a long-chain macromolecule that exists in a soluble form in the blood flow and an insoluble form in the vessel wall. Figure 1 schematically shows normal (a) and pathological (b) thrombus formation processees. In both cases, platelets adhere to the injured vessel wall and then form a thrombus in cooperation with the fibrin network, red cells, and other blood constituents. The vWF plays a more important role in pathological thrombosis formation than in the normal hemostatic process, due to its ability to sense and react to hemodynamic stress. In this study, we analyzed the mechanical interactions between platelets, the vessel wall, and the vWF, simultaneously using both a Stokesian dynamics method (SDM) and a discrete element method (DEM) that can treat solid elements in a flow without assuming continuity.