To elucidate a mechanism of prothrombotic effects of carbon nanotubes (CNTs), we report here that multiwalled CNTs activate blood platelets by inducing extracellular Ca2+ influx that could be inhibited by calcium channel blockers; SKF 96365 and 2-APB. We also demonstrate platelet aggregating activity of different single-walled and multiwalled CNTs.
In addition, we show that CNT-induced platelet activation is associated with a marked release of platelet membrane microparticles positive for the granular secretion markers CD62P and CD63.