In vitro assessment of engineered nanomaterials using a hepatocyte cell line: cytotoxicity, pro-inflammatory cytokines and functional markers

Abstract

Effects on the liver C3A cell line treated with a panel of engineered nanomaterials (NMs) consisting of two zinc oxide particles (ZnO; coated 100 nm and uncoated 130 nm), two multi-walled carbon nanotubes (MWCNTs), one silver (Ag < 20 nm), one 7 nm anatase, two rutile TiO₂ nanoparticles (10 and 94 nm) and two derivatives with positive and negative covalent functionalisation of the 10 nm rutile were evaluated. The silver particles elicited the greatest level of cytotoxicity (24 h LC50 – 2 µg/cm²). The silver was followed by the uncoated ZnO (24 h LC50 – 7.5 µg/cm²) and coated ZnO (24 h LC50 – 15 µg/cm²) particles with respect to cytotoxicity. The ZnO NMs were found to be about 50–60% soluble which could account for their toxicity. By contrast, the Ag was <1% soluble. The LC50 was not attained in the presence of any of the other engineered NMs (up to 80 µg/cm²). All NMs significantly increased IL-8 production. Meanwhile, no significant change in TNF-α, IL-6 or CRP was detected. Urea and albumin production were measured as indicators of hepatic function. These markers were only altered by the coated and uncoated ZnO, which significantly decreased albumin production.

Keywords::

• Liver
• inflammation
• IL-8
• albumin
• urea

Acknowledgements

This work has been financially supported by the European seventh framework programme co-operation (Grant code – NMP4-SL-2009-228789). The authors are grateful to colleagues at Heriot-Watt University and Edinburgh Napier University. The authors would also like to thank Andrea Brunelli and Davide Cristofori (University Ca' Foscari Venice) for their technical support during characterisation of the nanomaterials.