title: Interactions between magnetic nanowires and living cells: uptake, toxicity, and degradation.
abstract: We report on the uptake, toxicity, and degradation of magnetic nanowires by NIH/3T3 mouse fibroblasts. Magnetic nanowires of diameters 200 nm and lengths between 1 and 40 μm are fabricated by controlled assembly of iron oxide (γ-Fe(2)O(3)) nanoparticles. Using optical and electron microscopy, we show that after 24 h incubation the wires are internalized by the cells and located either in membrane-bound compartments or dispersed in the cytosol. Using fluorescence microscopy, the membrane-bound compartments were identified as late endosomal/lysosomal endosomes labeled with lysosomal associated membrane protein (Lamp1). Toxicity assays evaluating the mitochondrial activity, cell proliferation, and production of reactive oxygen species show that the wires do not display acute short-term (<100 h) toxicity toward the cells. Interestingly, the cells are able to degrade the wires and to transform them into smaller aggregates, even in short time periods (days). This degradation is likely to occur as a consequence of the internal structure of the wires, which is that of a noncovalently bound aggregate. We anticipate that this degradation should prevent long-term asbestos-like toxicity effects related to high aspect ratio morphologies and that these wires represent a promising class of nanomaterials for cell manipulation and microrheology.
authors.affiliation: Matière et Systèmes Complexes, UMR 7057 CNRS Université Denis Diderot Paris-VII, Bâtiment Condorcet 10 rue Alice Domon et Léonie Duquet, 75205 Paris, France.
authors.forename: Malak
authors.initials: M
authors.lastname: Safi
authors.forename: Minhao
authors.initials: M
authors.lastname: Yan
authors.forename: Marie-Alice
authors.initials: MA
authors.lastname: Guedeau-Boudeville
authors.forename: Hélène
authors.initials: H
authors.lastname: Conjeaud
authors.forename: Virginie
authors.initials: V
authors.lastname: Garnier-Thibaud
authors.forename: Nicole
authors.initials: N
authors.lastname: Boggetto
authors.forename: Armelle
authors.initials: A
authors.lastname: Baeza-Squiban
authors.forename: Florence
authors.initials: F
authors.lastname: Niedergang
authors.forename: Dietrich
authors.initials: D
authors.lastname: Averbeck
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Berret
mesh_terms: D016475:3T3 Cells; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004705:Endocytosis; D005290:Ferric Compounds / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity*; D008280:Magnetics; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D053770:Nanowires / Q000737:chemistry / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors
chemical_list: D005290:Ferric Compounds; D017382:Reactive Oxygen Species; C000499:ferric oxide