The in Vitro Effect of Polyvinylpyrrolidone and Citrate Coated Silver Nanoparticles on Erythrocytic Oxidative Damage and Eryptosis

Background/Aims: Silver nanoparticles (AgNPs) are increasingly used as antimicrobial agents and drug carriers in various biomedical fields. AgNPs can encounter erythrocytes either directly following intravenous injection, or indirectly via translocation from the site of administration. However, information regarding the pathophysiological effects and possible mechanism of action of AgNPs on the erythrocytes are still inadequately studied. Thus, the aim of our study was to investigate the mechanism underlying the effect of coating and concentration of AgNPs on mouse erythrocytes in vitro. Methods: We studied the interaction of polyvinylpyrrolidone (PVP) and citrate (CT) coated AgNPs (10 nm) at various concentrations (2.5, 10, 40 μg/ml) with mouse erythrocytes in vitro using various techniques including transmission electron microscopy (TEM), hemolysis, and colorimetric measurement of markers of oxidative stress comprising malondialdehyde (MDA), reduced glutathione (GSH), and catalase (CAT). Intracellular calcium (Ca ²⁺ ) was determined using Fura 2AM fluorescence. Annexin V was quantified using ELISA and the caspase 3 was determined both flurometrically and by western blot technique. Results: Following incubation of the erythrocytes with AgNPs, both PVP-and CT-AgNPs induced significant and dose-dependent increase in hemolysis. TEM revealed that both PVP-and CT-AgNPs were taken up by erythrocytes. The erythrocyte susceptibility to lipid peroxidation measured by MDA was significantly increased in both PVP-and CT-AgNPs. The concentration of GSH and CAT activity were significantly decreased by both types of AgNPs. Additionally, PVP-and CT-AgNPs significantly increased intracellular Ca ²⁺ in a dose-dependent manner. Likewise, the concentration of the cellular protein annexin V was significantly and dose-dependently enhanced by both types of AgNPs. Furthermore, PVP-and CT-AgNPs induced significant increase in calpain activity in incubated erythrocytes. Conclusion: We conclude that both PVP-and CT-AgNPs causes hemolysis, and are taken up by erythrocytes. Moreover, we demonstrated that AgNPs induces oxidative stress and eryptosis. These findings provide evidence for the potential pathophysiological effect of PVP-and CT-AgNPs on erythrocyte physiology.