title: Visualization, quantification and coordination of Ag+ions released from silver nanoparticles in hepatocytes.
abstract: Silver nanoparticles (AgNPs) can enter eukaryotic cells and exert toxic effects, most probably as a consequence of the release of Ag+ions. Due to the elusive nature of Ag+ionic species, quantitative information concerning AgNP intracellular dissolution is missing. By using a synchrotron nanoprobe, silver is visualized and quantified in hepatocytes (HepG2) exposed to AgNPs; the synergistic use of electron microscopy allows for the discrimination between nanoparticular and ionic forms of silver within a single cell. AgNPs are located in endocytosis vesicles, while the visualized Ag+ions diffuse in the cell. The averaged NP dissolution rates, measured by X-ray absorption spectroscopy, highlight the faster dissolution of citrate-coated AgNPs with respect to the less toxic PVP-coated AgNPs; these results are confirmed at the single-cell level. The released Ag+ions recombine with thiol-bearing biomolecules: the Ag-S distances measured in cellulo, and the quantitative evaluation of gene expression, provide independent evidence of the involvement of glutathione and metallothioneins in Ag+binding. The combined use of cutting-edge imaging techniques, atomic spectroscopy and molecular biology brings insight into the fate of AgNPs in hepatocytes, and more generally into the physicochemical transformations of metallic nanoparticles in biological environments and the resulting disruption of metal homeostasis.
authors.affiliation: CNRS, Laboratoire de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UGA, F-38054 Grenoble, France and CEA, LCBM, F-38054 Grenoble, France and Université Grenoble Alpes, LCBM, F-38054 Grenoble, France. giulia.veronesi@esrf.fr aurelien.deniaud@cea.fr isabelle.michaud-soret@cea.fr and ESRF, The European Synchrotron, 71, Avenue des Martyrs, 38043 Grenoble, France.
authors.forename: G
authors.identifier: http://orcid.org/0000-0001-9228-6082
authors.initials: G
authors.lastname: Veronesi
authors.affiliation: CNRS, Laboratoire de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UGA, F-38054 Grenoble, France and CEA, LCBM, F-38054 Grenoble, France and Université Grenoble Alpes, LCBM, F-38054 Grenoble, France. giulia.veronesi@esrf.fr aurelien.deniaud@cea.fr isabelle.michaud-soret@cea.fr.
authors.forename: A
authors.initials: A
authors.lastname: Deniaud
authors.affiliation: CNRS, Laboratoire de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UGA, F-38054 Grenoble, France and CEA, LCBM, F-38054 Grenoble, France and Université Grenoble Alpes, LCBM, F-38054 Grenoble, France. giulia.veronesi@esrf.fr aurelien.deniaud@cea.fr isabelle.michaud-soret@cea.fr.
authors.forename: T
authors.initials: T
authors.lastname: Gallon
authors.affiliation: INAC-MEM, Université Grenoble Alpes, Grenoble, France and CEA, INAC-MEM, Grenoble, France.
authors.forename: P-H
authors.initials: PH
authors.lastname: Jouneau
authors.affiliation: ESRF, The European Synchrotron, 71, Avenue des Martyrs, 38043 Grenoble, France.
authors.forename: J
authors.initials: J
authors.lastname: Villanova
authors.affiliation: Université Grenoble Alpes, INAC-SCIB, F-38054 Grenoble, France and CEA, INAC-SyMMES, F-38054 Grenoble, France.
authors.forename: P
authors.initials: P
authors.lastname: Delangle
authors.affiliation: Université Grenoble Alpes, INAC-SCIB, F-38054 Grenoble, France and CEA, INAC-SyMMES, F-38054 Grenoble, France.
authors.forename: M
authors.initials: M
authors.lastname: Carrière
authors.affiliation: BM30B/FAME beamline, ESRF, F-38043 Grenoble cedex 9, France and Observatoire des Sciences de l'Univers de Grenoble, UMS 832 CNRS Université Joseph Fourier, F-38041 Grenoble, France.
authors.forename: I
authors.initials: I
authors.lastname: Kieffer
authors.affiliation: CNRS, Laboratoire de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UGA, F-38054 Grenoble, France and CEA, LCBM, F-38054 Grenoble, France and Université Grenoble Alpes, LCBM, F-38054 Grenoble, France. giulia.veronesi@esrf.fr aurelien.deniaud@cea.fr isabelle.michaud-soret@cea.fr.
authors.forename: P
authors.initials: P
authors.lastname: Charbonnier
authors.affiliation: CNRS, Laboratoire de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UGA, F-38054 Grenoble, France and CEA, LCBM, F-38054 Grenoble, France and Université Grenoble Alpes, LCBM, F-38054 Grenoble, France. giulia.veronesi@esrf.fr aurelien.deniaud@cea.fr isabelle.michaud-soret@cea.fr.
authors.forename: E
authors.initials: E
authors.lastname: Mintz
authors.affiliation: CNRS, Laboratoire de Chimie et Biologie des Métaux (LCBM) UMR 5249 CNRS-CEA-UGA, F-38054 Grenoble, France and CEA, LCBM, F-38054 Grenoble, France and Université Grenoble Alpes, LCBM, F-38054 Grenoble, France. giulia.veronesi@esrf.fr aurelien.deniaud@cea.fr isabelle.michaud-soret@cea.fr.
authors.forename: I
authors.initials: I
authors.lastname: Michaud-Soret
mesh_terms: D002951:Citrates; D056945:Hep G2 Cells; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D007477:Ions; D053768:Metal Nanoparticles; D012834:Silver / Q000032:analysis*
chemical_list: D002951:Citrates; D007477:Ions; D012834:Silver