Flow-induced stress distribution on von Willebrand factor protein molecules in turbulent flow

Under the effects of non-physiological hemodynamic stresses, von Willebrand factor (vWF) protein molecules that circulate witin the blood are known to unravel causing loss of efficacy.^1,2 In this study, the distributions of shear and extensional stress along the trajectories of passive particles that serve as surrogates of vWF molecules were calculated. Poiseuille and Poiseuille-Couette flows in conditions that correspond to blood pumps and transitional flow in ventricular assist devices, respectively, were simulated with the use of Lagrangian methods and direct numerical simulations. It was found that the distribution of hydrodynamic stress was a function of the location where the vWF particles were released into the channel and of the exposure time. Apart from the distribution of stresses, the history of the stresses was also computed allowing the evaluation of how many particles experience stresses above the critcal value for protein damage. This type of work can contribute to the design of medical devices.

References

1. Springer, T.A., Blood. 124, 1412 (2014).

2. Pham et al., Scientific Reports 12, 171 (2022)