Comparative cytotoxicity induced by bulk and nanoparticulated ZnO in the fish and human hepatoma cell lines PLHC-1 and Hep G2

Abstract

Navas (2013) Comparative cytotoxicity induced by bulk and nanoparticulated ZnO in the fish and human hepatoma cell lines PLHC-1 and Hep G2, Nanotoxicology, 7:5, 935-952, DOI: 10.3109/17435390.2012 AbstractThe increasing presence of ZnO nanoparticles (NPs) in consumer products may be having a dramatic impact in aquatic environments. The evaluation of ZnO NP toxicity represents a great challenge. This study aimed at evaluating the cytotoxic effect of micro-and nanosized ZnO in a fish and a mammalian hepatoma cell line. A detailed characterisation of the particles in exposure media showed that ZnO NPs formed large aggregates. ZnO cytotoxicity was evaluated with a battery of in vitro assays including LUCS, a new approach based on DNA alteration measurements. In fish cells, ZnO NP aggregates contributed substantially to the cytotoxic effects whereas toxicity in the human cells appeared to be mainly produced by the dissolved fraction. ROS production did not contribute to the observed cytotoxicity. This work also showed that measuring concentrations of NPs is essential to understand the mechanisms underlying their toxicity.

The potentiation effect makes the difference: Non-toxic concentrations of ZnO nanoparticles enhance Cu nanoparticle toxicity in vitro

“…A volume of 100 μL of NP suspension in serum-free medium was added to each well. Final concentrations of CuNPs ranging from 0.39 to 25.0 μg/mL were applied alone or together with 6.25 μg/mL ZnONPs (a non-toxic concentration for HepG2 cells, as determined by Fernandez-Cruz et al, 2013). For NP co-exposure, CuNPs and ZnONPs suspensions were first mixed (v/v = 1:1) and then added to the culture wells.…”

“…The cellular concentration (we were unable to distinguish between the inside and the surface of the cell) of zinc and copper was determined by inductively coupled plasma mass spectrometry (ICP-MS), as described in Fernandez-Cruz et al (2013) and in Song et al (2014). Details of the method have been included in the Supplementary Material.…”

“…Cells (5 × 10 5 cells/mL) were cultured in Eagle's minimum essential medium (EMEM) supplemented with 10% fetal bovine serum (FBS), 1% penicillin/streptomycin (P/S), 1% ultraglutamine and 1% non-essential amino acids 100× (NEAA) and exposed to NPs in 96-well plates (Greiner Bio-one GmbH) following the method previously described (Fernandez-Cruz et al, 2013). Stock CuNPs and ZnONPs suspensions of 200 μg/mL were freshly prepared and dispersed in serum-free medium using sonication for 10 min in an S 40H Elmasonic water bath sonicator (Elma, Germany).…”

“…Stock CuNPs and ZnONPs suspensions of 200 μg/mL were freshly prepared and dispersed in serum-free medium using sonication for 10 min in an S 40H Elmasonic water bath sonicator (Elma, Germany). Afterwards, vortexing for 1 min was used before applying suspensions to the cells, as described in Song et al (2014) and Fernandez-Cruz et al (2013) respectively. A volume of 100 μL of NP suspension in serum-free medium was added to each well.…”

“…In order to shed light on this field, we recently performed in-depth studies in a variety of hepatic cell lines of mammalian and piscine origin in an attempt to determine the contribution of ionic and NP fractions to the cytotoxicity of ZnONPs and CuNPs (Fernandez-Cruz et al, 2013;Song et al, 2014). We revealed the complexity of the toxic effects of these nanomaterials and showed that although the toxicity is influenced by the metal (Zn or Cu) ions released during the dissolution of NPs in the culture medium, the NP itself greatly contributes to the toxicity observed.…”