title: Bioavailability of cobalt and iron from citric-acid-adsorbed CoFe2O4 nanoparticles in the terrestrial isopod Porcellio scaber.
abstract: The aim of this study was to determine whether citric acid adsorbed onto cobalt ferrite (CoFe2O4) nanoparticles (NPs) influences the bioavailability of their constituents Co and Fe. Dissolution of Co and Fe was assessed by two measures: (i) in aqueous suspension using chemical analysis, prior to application onto the food of test organisms; and (ii) in vivo, measuring the bioavailability in the model terrestrial invertebrate (Porcellio scaber, Isopoda, Crustacea). The isopods were exposed to citric-acid-adsorbed CoFe2O4 NPs for 2 weeks, and tissue accumulation of Co and Fe was assessed. This was compared to pristine CoFe2O4 NPs, and CoCl2 and Fe(III) salts as positive controls. The combined data shows that citric acid enhances free metal ion concentration from CoFe2O4 NPs in aqueous suspension, although in vivo, very similar amounts of assimilated Co were found in isopods exposed to both types of NPs. Therefore, evaluation of the dissolution in suspension by chemical means is not a good predictor of metal assimilation of this model organism; body assimilation of Co and Fe is rather governed by the physiological capacity of P. scaber for the uptake of these metals. Moreover, we propose that citric acid, due to its chelating properties, may hinder the uptake of Co that dissolves from citric-acid-adsorbed CoFe2O4 NPs, if citric acid is present in sufficient quantity.
authors.affiliation: Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia. Electronic address: tea.romih@student.uni-lj.si.
authors.forename: Tea
authors.initials: T
authors.lastname: Romih
authors.affiliation: Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Barbara
authors.initials: B
authors.lastname: Drašler
authors.affiliation: Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Anita
authors.initials: A
authors.lastname: Jemec
authors.affiliation: Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Damjana
authors.initials: D
authors.lastname: Drobne
authors.affiliation: Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Sara
authors.initials: S
authors.lastname: Novak
authors.affiliation: Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Miha
authors.initials: M
authors.lastname: Golobič
authors.affiliation: Jožef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
authors.forename: Darko
authors.initials: D
authors.lastname: Makovec
authors.affiliation: Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva cesta 5, 1000 Ljubljana, Slovenia.
authors.forename: Robert
authors.initials: R
authors.lastname: Susič
authors.affiliation: Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva cesta 5, 1000 Ljubljana, Slovenia.
authors.forename: Ksenija
authors.initials: K
authors.lastname: Kogej
mesh_terms: D000818:Animals; D003035:Cobalt / Q000032:analysis* / Q000378:metabolism; D005290:Ferric Compounds / Q000737:chemistry*; D007501:Iron / Q000032:analysis* / Q000378:metabolism; D033321:Isopoda / Q000378:metabolism*; D053768:Metal Nanoparticles / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism
chemical_list: D005290:Ferric Compounds; D012989:Soil Pollutants; C001215:ferrite; D003035:Cobalt; D007501:Iron
keywords: Bioavailability; Citric acid; Cobalt ferrite; Dissolution; Nanoparticles; Voltammetry