toxics Article Cellular Uptake and Toxicological Effects of Differently Sized Zinc Oxide Nanoparticles in Intestinal Cells † Anna Mittag 1,* , Christian Hoera 2, Alexander Kämpfe 2 , Martin Westermann 3, Jochen Kuckelkorn 4, Thomas Schneider 1 and Michael Glei 1 1 Department of Nutritional Toxicology, Institute of Nutritional Sciences, Friedrich Schiller University Jena, Dornburger Straße 24, 07743 Jena, Germany;
[email protected] (T.S.);
[email protected] (M.G.) 2 German Environment Agency, Swimming Pool Water, Chemical Analytics, Heinrich-Heine-Straße 12, 08645 Bad Elster, Germany;
[email protected] (C.H.);
[email protected] (A.K.) 3 Electron Microscopy Centre, Friedrich Schiller University Jena, Ziegelmühlenweg 1, 07743 Jena, Germany;
[email protected] 4 German Environment Agency, Toxicology of Drinking Water and Swimming Pool Water, Heinrich-Heine-Straße 12, 08645 Bad Elster, Germany;
[email protected] * Correspondence:
[email protected] † In respectful memory of Dr. Tamara Grummt. Abstract: Due to their beneficial properties, the use of zinc oxide nanoparticles (ZnO NP) is constantly increasing, especially in consumer-related areas, such as food packaging and food additives, which is leading to an increased oral uptake of ZnO NP. Consequently, the aim of our study was to investigate the cellular uptake of two differently sized ZnO NP (<50 nm and <100 nm; 12–1229 µmol/L) using two human intestinal cell lines (Caco-2 and LT97) and to examine the possible resulting toxic effects. ZnO NP (<50 nm and <100 nm) were internalized by both cell lines and led to intracellular changes. Citation: Mittag, A.; Hoera, C.; Kämpfe, A.; Westermann, M.; Both ZnO NP caused time- and dose-dependent cytotoxic effects, especially at concentrations of Kuckelkorn, J.; Schneider, T.; Glei, M.