title: Influence of the length of imogolite-like nanotubes on their cytotoxicity and genotoxicity toward human dermal cells.
abstract: Physical-chemical parameters such as purity, structure, chemistry, length, and aspect ratio of nanoparticles (NPs) are linked to their toxicity. Here, synthetic imogolite-like nanotubes with a set chemical composition but various sizes and shapes were used as models to investigate the influence of these physical parameters on the cyto- and genotoxicity and cellular uptake of NPs. The NPs were characterized using X-ray diffraction (XRD), small angle X-ray scattering (SAXS), and atomic force microscopy (AFM). Imogolite precursors (PR, ca. 5 nm curved platelets), as well as short tubes (ST, ca. 6 nm) and long tubes (LT, ca. 50 nm), remained stable in the cell culture medium. Internalization into human fibroblasts was observed only for the small particles PR and ST. None of the tested particles induced a significant cytotoxicity up to a concentration of 10(-1) mg·mL(-1). However, small sized NPs (PR and ST) were found to be genotoxic at very low concentration 10(-6) mg·mL(-1), while LT particles exhibited a weak genotoxicity. Our results indicate that small size NPs (PR, ST) were able to induce primary lesions of DNA at very low concentrations and that this DNA damage was exclusively induced by oxidative stress. The higher aspect ratio LT particles exhibited a weaker genotoxicity, where oxidative stress is a minor factor, and the likely involvement of other mechanisms. Moreover, a relationship among cell uptake, particle aspect ratio, and DNA damage of NPs was observed.
authors.affiliation: CEREGE, UMR 7330, CNRS-Aix Marseille University, BP 80, 13545 Aix en Provence, France.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Perrine
authors.initials: P
authors.lastname: Chaurand
authors.forename: Carole
authors.initials: C
authors.lastname: Di Giorgio
authors.forename: Michel
authors.initials: M
authors.lastname: De Méo
authors.forename: Antoine
authors.initials: A
authors.lastname: Thill
authors.forename: Mélanie
authors.initials: M
authors.lastname: Auffan
authors.forename: Armand
authors.initials: A
authors.lastname: Masion
authors.forename: Daniel
authors.initials: D
authors.lastname: Borschneck
authors.forename: Florence
authors.initials: F
authors.lastname: Chaspoul
authors.forename: Philippe
authors.initials: P
authors.lastname: Gallice
authors.forename: Alain
authors.initials: A
authors.lastname: Botta
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Bottero
authors.forename: Jérôme
authors.initials: J
authors.lastname: Rose
mesh_terms: D000535:Aluminum / Q000737:chemistry / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects*; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects*; D005857:Germanium / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D043942:Nanotubes / Q000737:chemistry*; D010316:Particle Size; D013329:Structure-Activity Relationship
chemical_list: D005857:Germanium; D000535:Aluminum