title: Method for toxicity test of titanium dioxide nanoparticles in ciliate protozoan Tetrahymena.
abstract: Titanium dioxide (TiO2) nanoparticles have a high surface-to-mass ratio and rapidly aggregate in water causing great difficulties for toxicity test exposed to aquatic organisms or other cell lines. This study uses a cell viability kit for routine toxicity test of TiO2 as well as other nanoparticles which accumulate in the aquatic environment. Tetrahymena immediately endocytoses TiO2 nanoparticles and stores them in food vacuoles until the particles undergo exocytosis as larger aggregates. However, during the process of endocytosis and exocytosis, TiO2 particles interfere with cell growth and consequently induce acute toxicity. It exerted high cell growth inhibition at 20 h incubation and induces significant cytotoxic effects. Surprisingly, the effect of TiO2 decreases at 40 h incubation, due to the recovery of cell growth and reduction of the cytotoxicity of the particles.
authors.affiliation: Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Molecular EXposomics (MEX), Neuherberg, Germany. asad.uddaula@googlemail.com
authors.forename: Asad
authors.initials: A
authors.lastname: Ud-Daula
authors.forename: Gerd
authors.initials: G
authors.lastname: Pfister
authors.forename: Karl-Werner
authors.initials: KW
authors.lastname: Schramm
mesh_terms: D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D013768:Tetrahymena / Q000254:growth & development*; D014025:Titanium / Q000633:toxicity*; D018675:Toxicity Tests / Q000379:methods*
chemical_list: C009495:titanium dioxide; D014025:Titanium