Development of virtual platelets implementing the functions of three platelet membrane proteins with different adhesive characteristics.

Aim: Computer simulation is a new method for understanding biological phenomena. In this report, we developed a simple platelet simulator representing platelet adhesion under blood flow conditions. Methods: We generated virtual platelets based on the functions of three key adhesive proteins: glycoprotein (GP) Iba, GPIIb/IIIa and collagen receptors. The adhesive force between GPIba and von Willebrand factor (VWF) was set to increase in association with increments in the fluid shear stress. GPIIb/IIIa acquires an adhesive force to bind with ligands only when platelets are activated following multiple GPIba stimulation by VWF or collagen receptors. Results: Upon perfusion over the area of virtual endothelial injury, the virtual platelets adhered and became activated to form platelet thrombi. A total of 286/mm(2) of activated platelets was found to have accumulated downstream of the flow obstacle within 30 seconds, with 59/mm(2) platelets adhering upstream. The results obtained with the virtual model were consistent with those for real platelets in human blood in the presence of similarly shaped flow obstacles. Conclusions: Our computer platelet simulator, which employs the functions of three key platelet membrane proteins, shows similar findings for adhesion in the presence and absence of blood flow obstacles.