title: Thirty-femtogram detection of iron in mammalian cells.
abstract: Inorganic nanomaterials and particles with enhanced optical, mechanical, or magnetic attributes are currently being developed for a wide range of applications. Safety issues have developed however concerning their potential cyto- and genotoxicity. For in vivo and in vitro experimentations, recent developments have heightened the need for simple and facile methods to measure the amount of nanoparticles taken up by cells or tissues. In this work, a rapid and highly sensitive method for quantifying the uptake of iron oxide nanoparticles in mammalian cells is reported. The approach exploits the digestion of incubated cells with concentrated hydrochloric acid reactant and a colorimetric-based UV-visible absorption technique. The technique allows the detection of iron in cells over 4 decades in masses from 0.03 to 300 picograms per cell. Applied on particles of different surface chemistry and sizes, the protocol demonstrates that the coating is the key parameter in the nanoparticle/cell interactions. The data are corroborated by scanning and transmission electron microscopy, and the results stress the importance of resiliently adsorbed nanoparticles at the plasma membrane.
authors.affiliation: Matière et Systèmes Complexes, UMR 7057 CNRS Université Denis Diderot Paris-VII, Bâtiment Condorcet, 10 rue Alice Domon et Léonie Duquet, Paris, France.
authors.forename: Aymeric
authors.initials: A
authors.lastname: Galimard
authors.forename: Malak
authors.initials: M
authors.lastname: Safi
authors.forename: Nawel
authors.initials: N
authors.lastname: Ould-Moussa
authors.forename: David
authors.initials: D
authors.lastname: Montero
authors.forename: Hélène
authors.initials: H
authors.lastname: Conjeaud
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Berret
mesh_terms: D000818:Animals; D007501:Iron / Q000378:metabolism*; D051379:Mice; D041681:NIH 3T3 Cells; D053758:Nanoparticles / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D007501:Iron