Experimental and numerical study of platelets rolling on a von Willebrand factor-coated surface

Blood platelets circulate in the blood and adhere to wounded vessels to initiate coagulation and healing. The first step of this process is the capture of flowing platelets by adhesive molecules located at the wounded vessel wall. In this article, we study the transport of fixed blood platelets in a microfluidic channel coated with von Willebrand factor (vWF), a large multimeric protein expressed by endothelial cells in the vicinity of wounds. We measure the number of platelets adsorbed at the channel surface as a function of both time and space. Experimental results are compared with a new transport model. We show that transverse diffusion is an important feature of our model, while the rolling behaviour of the bounded platelets can be neglected.