Mathematical modeling of shear-induced platelet activation in high shear flow

Platelets feel shear stress in flowing blood via special sensors known as von Willebrand factor (VWF). These multimers undergo globule-stretch transition under high shear stress. When shear stress is larger than specific threshold VWF multimers unwind, exposing more domains capable of binding platelet receptors. Multivalent binding of VWF molecules with platelet receptors may lead to platelet activation and increasing of arterial thrombus formation risk. The presentation will be dedicated to describing of mathematical approach for analyzing shear-induced platelet activation in large human vessels. It will be shown how the conditions of VWF unwinding under unsteady shear flows were established via combination of nonlinear dynamics and computational fluid dynamics methods. The application of the approach to analyzing of platelet activation in specific clinical settings will be given. In particular, it will be shown that “no activation” condition in large arteries obeys the power law relating the size of VWF multimers with blood volume flow rate through vessel.