Research Article Age Modulates Fe 3 O 4 Nanoparticles Liver Toxicity: Dose-Dependent Decrease in Mitochondrial Respiratory Chain Complexes Activities and Coupling in Middle-Aged as Compared to Young Rats Yosra Baratli, 1,2 Anne-Laure Charles, 1 Valérie Wolff, 1 Lotfi Ben Tahar, 3 Leila Smiri, 3 Jamal Bouitbir, 1 Joffrey Zoll, 1,4 Mohsen Sakly, 2 Cyril Auger, 5 Thomas Vogel, 1 Hafedh Abdelmelek, 2 Olfa Tebourbi, 2 and Bernard Geny 1,4 1 EA 3072, Mitochondries, Stress Oxydant et Protection Musculaire, F´ ed´ eration de M´ edecine Translationnelle de Strasbourg, Universit´ e de Strasbourg, 67000 Strasbourg, France 2 Laboratoire de Physiologie Int´ egr´ ee, Facult´ e des Sciences de Bizerte, Universit´ e de Carthage, 7021 Jarzouna, Tunisia 3 Laboratoire de Synth` ese et Structures de Nanomat´ eriaux, UR11ES30, Facult´ e des Sciences de Bizerte, Universit´ e de Carthage, 7021 Jarzouna, Tunisia 4 Service de Physiologie et d’Explorations Fonctionnelles, Pˆ ole de Pathologie oracique, NHC, 67000 Strasbourg, France 5 UMR CNRS 7213-Laboratoire de Biophotonique et Pharmacologie, Facult´ e de Pharmacie, Universit´ e de Strasbourg, 74 route du Rhin, 67401 Illkirch, France Correspondence should be addressed to Bernard Geny; bernard.geny@chru-strasbourg.fr Received 10 February 2014; Revised 3 April 2014; Accepted 4 April 2014; Published 6 May 2014 Academic Editor: N. Chandrasekaran Copyright © 2014 Yosra Baratli et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. We examined the efects of iron oxide nanoparticles (IONPs) on mitochondrial respiratory chain complexes activities and mitochondrial coupling in young (3 months) and middle-aged (18 months) rat liver, organ largely involved in body iron detoxiication. Isolated liver mitochondria were extracted using diferential centrifugations. Maximal oxidative capacities ( max , complexes I, III, and IV activities), succ (complexes II, III, and IV activities), and tmpd , (complex IV activity), together with mitochondrial coupling ( max / 0 ) were determined in controls conditions and ater exposure to 250, 300, and 350 g/ml Fe 3 O 4 in young and middle-aged rats. In young liver mitochondria, exposure to IONPs did not alter mitochondrial function. In contrast, IONPs dose-dependently impaired all complexes of the mitochondrial respiratory chain in middle-aged rat liver: max (from 30 ± 1.6 to 17.9 ± 1.5;  < 0.001), succ (from 33.9 ± 1.7 to 24.3 ± 1.0;  < 0.01), tmpd (from 43.0 ± 1.6 to 26.3 ± 2.2 mol O 2 /min/g protein;  < 0.001) using Fe 3 O 4 350 g/ml. Mitochondrial coupling also decreased. Interestingly, 350 g/ml Fe 3 O 4 in the form of Fe 3+ solution did not impair liver mitochondrial function in middle-aged rats. hus, IONPs showed a speciic toxicity in middle-aged rats suggesting caution when using it in old age. 1. Introduction Because of their unique properties, some nanoparticles have been approved for clinical use like iron oxide nanoparticles (IONPs). IONPs hold immense potential in a vast variety of biomedical applications such as magnetic resonance imaging (MRI), targeted delivery of drugs or genes, tissue engineering, targeted destruction of tumor tissue through hyperthermia, magnetic transfections, iron detection, chelation therapy, and tissue engineering [14]. Reports demonstrate that IONPs have the ability to assess focal hepatic lesions [5] and to label human hepatocytes [6]. However, nanoparticles pose a high health risk because of their ability to reach every part of the organs and tissues and their interaction with cellular functions. Concerning NP clearance, it is known that they are primarily phagocytozed by macrophages in the liver (Kupfer cells) [7]. hus, the largest detoxiication organ of human Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 474081, 10 pages http://dx.doi.org/10.1155/2014/474081