Figure 4

Theoretical analysis of platelet capture by intravascularly adherent neutrophils. Platelet motion in a flow channel exhibiting a bump structure was modeled along a longitudinal cross-section with a fluid dynamics simulation of an ellipsoid as detailed in Methods. Panel (A) shows the blood flow velocity profile (pseudocolors) and the motion kinetics of a platelet moving over the bump structure (white; assuming the absence of bimolecular interactions) in a flow channel. Platelet velocity (B) and its relative angle (C) during its movement over the bump structure are shown. Panel (D) shows that the acceleration of the platelet decreases the distance of the platelet’s center of mass to the bump surface (‘COM’). Additionally, a flipping motion brings one end of the platelet into close proximity to the bump surface, further reducing the nearest distance (‘ND’) and thus allowing biochemical binding (arrow).