Titanium dioxide food additive (E171) and zinc oxide nanoparticles alter coagulation markers in endothelial cells and activate platelets.

E171 additive food and zinc oxide nanoparticles (ZnO NPs) are used in the manufacture of many products for human use. They are translocated into the circulatory system, reaching the blood, platelets, and endothelial cells. The effects of these particles were analyzed in HBEC-5i cells and on platelet function. Results showed that HBEC-5i cells and platelets internalized E171. Both particles decreased proliferation, and ZnO NPs induced apoptosis. ZnO NPs altered tissue factor (TF) expression and increased nitric oxide (NO) production and total antioxidant capacity (TAC) in HBEC-5i cells. Conditioned medium from endothelial cells incubated with E171 induced platelet aggregation in the absence of an agonist. In human platelet-rich plasma (PRP), E171 increased platelet aggregation induced by thrombin. Although neither particle affected coagulation times, both induced platelet activation. In conclusion, E171 and ZnO NPs activate endothelial cells and platelets, which may contribute to alterations in systemic homeostasis and the development of thrombotic events.