Effect of engineered TiO2and ZnO nanoparticles on erythrocytes, platelet-rich plasma and giant unilamelar phospholipid vesicles

Metka Šimundić,Veronika Kralj-Iglič,Jernej Zupanc,Deniz Erdogmus,Vid Šuštar,Roman Štukelj,Henry Hägerstrand,Damjana Drobne,Darko Makovec,Barbara Drašler

doi:10.1186/1746-6148-9-7

Abstract

BackgroundMassive industrial production of engineered nanoparticles poses questions about health risks to living beings. In order to understand the underlying mechanisms, we studied the effects of TiO2 and ZnO agglomerated engineered nanoparticles (EPs) on erythrocytes, platelet-rich plasma and on suspensions of giant unilamelar phospholipid vesicles.ResultsWashed erythrocytes, platelet-rich plasma and suspensions of giant unilamelar phospholipid vesicles were incubated with samples of EPs. These samples were observed by different microscopic techniques. We found that TiO2 and ZnO EPs adhered to the membrane of washed human and canine erythrocytes. TiO2 and ZnO EPs induced coalescence of human erythrocytes. Addition of TiO2 and ZnO EPs to platelet-rich plasma caused activation of human platelets after 24 hours and 3 hours, respectively, while in canine erythrocytes, activation of platelets due to ZnO EPs occurred already after 1 hour. To assess the effect of EPs on a representative sample of giant unilamelar phospholipid vesicles, analysis of the recorded populations was improved by applying the principles of statistical physics. TiO2 EPs did not induce any notable effect on giant unilamelar phospholipid vesicles within 50 minutes of incubation, while ZnO EPs induced a decrease in the number of giant unilamelar phospholipid vesicles that was statistically significant (p < 0,001) already after 20 minutes of incubation.ConclusionsThese results indicate that TiO2 and ZnO EPs cause erythrocyte aggregation and could be potentially prothrombogenic, while ZnO could also cause membrane rupture.

Highlights

Massive industrial production of engineered nanoparticles poses questions about health risks to living beings
The populations of Titanium dioxide (TiO2) and zinc oxide nanopowder (ZnO) engineered nanoparticles (EPs) in glucose solution as measured with dynamic light scattering (DLS) method were heterogeneous in size (Table 1), with large aggregates present in both suspensions tested
When dissolved in PBS or glucose, TiO2 EPs and ZnO EPs were found to be mildly negatively charged as they displayed negative zeta potentials (Table 1)

Summary

Introduction

Massive industrial production of engineered nanoparticles poses questions about health risks to living beings. Giant unilamelar phospholipid vesicles larger than 1 μm (GUVs) [25,26,27,28] are a convenient model system as they can be observed in motion under a light microscope and enable studies of biological membrane structure [22], phase behaviour [29,30], permeability [31,32] and elasticity [33,34], as well as of their interaction with macromolecules [35] Another suitable model is represented by mammalian erythrocytes. Some types of nanoparticles cause formation of reactive oxygen species [38], induce platelet activation, aggregation and adhesion [39,40], and increase the risk of thromboembolic disorders [41,42]

Results

Discussion

Conclusion