Adhesion of a blood platelet to injured tissue

A numerical study of platelet adhesion to injured endothelial wall during blood flow is conducted using the boundary-element method for Stokes flow. An idealised model is presented where the platelet is treated as an elliptical particle carried over a plane wall in simple shear flow. When the platelet is sufficiently close to the wall, adhesive bonds are established tethering the platelet via receptors distributed around its perimeter to ligands sited at specified locations on an injured section of the wall. A generalised boundary-integral equation of the second kind is formulated to determine the translational and angular velocities of the platelet and the force acting on the platelet due to adhesive bonds. Numerical simulations are performed for a small number of bonds behaving as simple springs, and the force required to capture and immobilise an elliptical particle is estimated. Further simulations conducted using an adhesive bond dynamics model show that bond formation operating at realistic biophysical parameter values can lead to platelet capture and arrest.