Effects of various physicochemical characteristics on the toxicities of ZnO and TiO2 nanoparticles toward human lung epithelial cells

Hsiao, I‐Lun; Huang, Yumeng

doi:10.1016/j.scitotenv.2010.12.033

Cited by 307 publications

(196 citation statements)

References 43 publications

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“…Suspensions were prepared using phosphate ions as a dispersing agent. The phosphate salts used are based on physiological PBS, which consists of two salts with total 12 mM PO 4 . Pure water with 10 mM Na 2 HPO 4 Á12H 2 O (Fluka Analytical, Sigma-Aldrich Chemie GmbH, Steinheim, Germany) and 2 mM KH 2 PO 4 (Carl Roth GmbH & Co. KG, Karlsruhe, Germany) were taken without the addition of NaCl and KCl, both also found in physiological PBS.…”

Section: Suspension Preparationmentioning

confidence: 99%

“…One related question is whether nanoparticles are more toxic than their larger counterparts [2,3]. Hsiao and Huang [4], for example, were able to demonstrate that the cytotoxicity of ZnO is size-dependent. In contrast, Lin et al [5] examined the differences between nanoscale and submicron zinc oxides (70 and 420 nm) in human lung epithelial cells (A549) and found nearly identical EC 50 values of 13.6 and 14.2 lg/ml.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, the presence or absence of serum in in vitro experiments with ZnO nanomaterials influences proliferation and genotoxicity [9]. The extent of dissolution of ZnO in serum-free media also seems to be lower [4]. Thus, interactions of ZnO as well as zinc ions with serum have to be investigated.…”

Section: Introductionmentioning

confidence: 99%

“…It has been discussed that nanoparticles that are positively charged at physiological pH usually penetrate cells more readily than negatively charged particles do [4,11]. To prove or disprove such a statement is difficult because zeta potential measurements in toxicological studies are often measured only in water [4,12,13], or it is not clear as to where the potential was measured [11]. So far, only one study on characterization of the zeta potential of ZnO in various media has been published [14].…”

Section: Introductionmentioning

confidence: 99%

“…Especially under physiological conditions, the ZnO behavior, mainly its dissolution, is influenced by constituents of the cell culture media [15,16]. With respect to surface charge and zeta potential and their influence on the toxicity, several hypotheses have been proposed [4,11,14]. It is known that albumin adsorbs onto the ZnO surface, with consequences for the conformation of the bound albumin [17].…”

Section: Introductionmentioning

confidence: 99%

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Implications of the stability behavior of zinc oxide nanoparticles for toxicological studies

2014

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The increasing use of zinc oxide (ZnO) nanoparticles in sunscreens and other cosmetic products demands a risk assessment that has to be done in toxicological studies. Such investigations require profound knowledge of the behavior of ZnO in cell culture media. The current study was performed to get well-dispersed suspensions of a hydrophilic (ZnO-hydro) and a lipophilic coated (ZnO-lipo) ZnO nanomaterial for use in in vitro tests. Therefore, systematic tests were carried out with common dispersants (phosphate, lecithin, proteins) to elucidate chemical and physical changes of ZnO nanoparticles in water and physiological solutions (PBS, DMEM). Nonphysiological stock suspensions were prepared using ultrasonication. Time-dependent changes of pH, conductivity, zeta potential, particle size and dissolution were recorded. Secondly, the stock suspensions were added to physiological media with or without albumin (BSA) or serum (FBS), to examine characteristics such as agglomeration and dissolution. Stable stock suspensions were obtained using phosphate as natural and physiological electrostatic stabilizing agent. Lecithin proved to be an effective wetting agent for ZnO-lipo. Although the particle size remained constant, the suspension changed over time. The pH increased as a result of ZnO dissolution and formation of zinc phosphate complexes. The behavior of ZnO in physiological media was found to depend strongly on the additives used. Applying only phosphate as additive, ZnOhydro agglomerated within minutes. In the presence of lecithin or BSA/serum, agglomeration was inhibited. ZnO dissolution was higher under physiological conditions than in the stock suspension. Serum especially promoted this process. Using body-related dispersants (phosphate, lecithin) non-agglomerating stock suspensions of hydrophilic and lipophilic ZnO were prepared as a prerequisite to perform meaningful toxicological investigation. Both nanomaterials showed a non-negligible dissolution behavior that strongly depended on the surrounding conditions. Agglomeration of ZnO particles in physiological media is a complex function of particle coating, used dispersants and serum proteins if supplemented. The present study gives a clear guideline how to prepare and handle suspensions with ZnO for in vitro testing and allows the correlation between the chemical-physical particles behavior with findings from toxicological tests.

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Section: Suspension Preparationmentioning

confidence: 99%