title: Is there a Trojan-horse effect during magnetic nanoparticles and metalloid cocontamination of human dermal fibroblasts?
abstract: This study investigates the issue of nanoparticles/pollutants cocontamination. By combining viability assays, physicochemical and structural analysis (to probe the As speciation and valence), we assessed how γFe(2)O(3) nanoparticles can affect the cytotoxicity, the intra- and extracellular speciation of As(III). Human dermal fibroblasts were contaminated with γFe(2)O(3) nanoparticles and As(III) considering two scenarios: (i) a simultaneous coinjection of the nanoparticles and As, and (ii) an injection of the nanoparticles after 24 h of As adsorption in water. In both scenarios, we did not notice significant changes on the nanoparticles surface charge (zeta potential ∼ -10 mV) nor hydrodynamic diameters (∼950 nm) after 24 h. We demonstrated that the coinjection of γFe(2)O(3) nanoparticles and As in the cellular media strongly affects the complexation of the intracellular As with thiol groups. This significantly increases at low doses the cytotoxicity of the As nonadsorbed at the surface of the nanoparticles. However, once As is adsorbed at the surface the desorption is very weak in the culture medium. This fraction of As strongly adsorbed at the surface is significantly less cytotoxic than As itself. On the basis of our data and the thermodynamics, we demonstrated that any disturbance of the biotransformation mechanisms by the nanoparticles (i.e., surface complexation of thiol groups with the iron atoms) is likely to be responsible for the increase of the As adverse effects at low doses.
authors.affiliation: Aix-Marseille Université, CNRS, IRD, CEREGE UM34, UMR 7330, 13545 Aix en Provence, France. auffan@cerege.fr
authors.forename: Melanie
authors.initials: M
authors.lastname: Auffan
authors.forename: Jerome
authors.initials: J
authors.lastname: Rose
authors.forename: Olivier
authors.initials: O
authors.lastname: Proux
authors.forename: Armand
authors.initials: A
authors.lastname: Masion
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Laila
authors.initials: L
authors.lastname: Benameur
authors.forename: Fabio
authors.initials: F
authors.lastname: Ziarelli
authors.forename: Alain
authors.initials: A
authors.lastname: Botta
authors.forename: Corinne
authors.initials: C
authors.lastname: Chaneac
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Bottero
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000493:pharmacokinetics / Q000633:toxicity*; D002478:Cells, Cultured; D003470:Culture Media; D005347:Fibroblasts / Q000187:drug effects*; D006801:Humans; D058185:Magnetite Nanoparticles / Q000737:chemistry / Q000633:toxicity; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000633:toxicity*; D058955:Metalloids; D012867:Skin / Q000166:cytology; D013816:Thermodynamics
chemical_list: D003470:Culture Media; D058185:Magnetite Nanoparticles; D058955:Metalloids; D001151:Arsenic