Interaction of Amorphous Silica Nanoparticles with Erythrocytes in Vitro: Role of Oxidative Stress

Abstract

Background/Aims: The use of engineered nanomaterials in the form of nanoparticles (NP) for various biomedical applications, as well as in consumer products, has raised concerns about their safety for human health. These NP are intended to be administered directly into the circulation following intravenous injection, or they may reach the circulation following other routes of administration such as oral or inhalation, and interact with circulating cells such as erythrocytes. However, little is known about the interaction of amorphous SiNP with erythrocytes. Methods: We studied the interaction of amorphous silica nanoparticles (SiNP) at various concentrations (1, 5, 25 and 125µg/ml) with mouse erythrocytes in vitro. Results: Incubation of erythrocytes with SiNP caused a dose-dependent hemolytic effect. Likewise, the activity of lactate dehydrogenase was dose-dependently increased by SiNP. Transmission electron microscopy analysis revealed that SiNP are taken up by erythrocytes. Lipid erythrocyte susceptibility to in vitro peroxidation measured by malondialdehyde showed a significant and dose-dependent increase in erythrocytes. SiNP also enhanced the antioxidant activities of superoxide dismutase (SOD), catalase and reduced glutathione (GSH). Moreover, SiNP increased caspase 3, triggered annexin V-binding and caused a dose-dependent increase of cytosolic calcium concentration. Conclusion: It can be concluded that SiNP cause a dose-dependent hemolytic activity and are taken up by the erythrocytes. We also found that SiNP induce the occurrence of oxidative activity, apoptosis and increase cytosolic Ca²⁺, which may explain their haemolytic activity. Our in vitro data suggest that SiNP may, plausibly, lead to anemia and circulatory disorders in vivo.