**2.2 Preparation of human plasma**

Human plasma, collected in sodium citrate tubes, was prepared from three healthy volunteers. After cooling, the blood was centrifuged in 800g for 10 min and plasma, free from red blood cells, was drawn from the top of the tube. SiO2, ZnO/6% Al doped, Al2O3 and CNO were then exposed to three plasma samples respectively. In all nanoparticle exposures fresh plasma was used.
