title: Effects of SiO₂, ZrO₂, and BaSO₄ nanomaterials with or without surface functionalization upon 28-day oral exposure to rats.
abstract: The effects of seven nanomaterials (four amorphous silicon dioxides with or without surface functionalization, two surface-functionalized zirconium dioxides, and barium sulfate) upon 28-day oral exposure to male or female rats were investigated. The studies were performed as limit tests in accordance with OECD Test Guideline 407 applying 1,000 mg test substance/kg body weight/day. Additionally, the acute phase proteins haptoglobin and α2-macroglobulin as well as cardiac troponin I were determined, and metabolome analysis was performed in plasma samples. There were no test substance-related adverse effects for any of the seven nanomaterials. Moreover, metabolomics changes were below the threshold of effects. Since test substance organ burden was not analyzed, it was not possible to establish whether the lack of findings related to the absence of systemic exposure of the tested nanomaterials or if the substances are devoid of any potential for toxicity. The few published subacute oral or short-term inhalation studies investigating comparable nanomaterials (SiO₂, ZrO₂, and BaSO₄) also do not report the occurrence of pronounced treatment-related findings. Overall, the results of the present survey provide a first indication that the tested nanomaterials neither cause local nor systemic effects upon subacute oral administration under the selected experimental conditions. Further investigations should aim at elucidating the extent of gastrointestinal absorption of surface-functionalized nanomaterials.
authors.affiliation: Experimental Toxicology and Ecology, BASF SE, 67056, Ludwigshafen am Rhein, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Buesen
authors.forename: Robert
authors.initials: R
authors.lastname: Landsiedel
authors.forename: Ursula G
authors.initials: UG
authors.lastname: Sauer
authors.forename: Wendel
authors.initials: W
authors.lastname: Wohlleben
authors.forename: Sibylle
authors.initials: S
authors.lastname: Groeters
authors.forename: Volker
authors.initials: V
authors.lastname: Strauss
authors.forename: Hennicke
authors.initials: H
authors.lastname: Kamp
authors.forename: Bennard
authors.initials: B
authors.lastname: van Ravenzwaay
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001466:Barium Sulfate / Q000737:chemistry / Q000633:toxicity*; D005260:Female; D008297:Male; D049329:Nanostructures; D017208:Rats, Wistar; D012822:Silicon Dioxide / Q000737:chemistry / Q000633:toxicity*; D013499:Surface Properties; D059550:Toxicity Tests, Subchronic; D015040:Zirconium / Q000737:chemistry / Q000633:toxicity*
chemical_list: D001466:Barium Sulfate; D012822:Silicon Dioxide; D015040:Zirconium; C028541:zirconium oxide