title: Inhaled silica-coated TiO2 nanoparticles induced airway irritation, airflow limitation and inflammation in mice.
abstract: The wide use of nanotechnology is here to stay. However, the knowledge on the health effects of different engineered nanomaterials (ENMs) is lacking. In this study, irritation and inflammation potential of commercially available silica-coated TiO2 ENMs (10 × 40 nm, rutile) were studied. Single exposure (30 min) at mass concentrations 5, 10, 20 and 30 mg/m(3), and repeated exposure (altogether 16 h, 1 h/day, 4 days/week for 4 weeks) at mass concentration of 30 mg/m(3) to silica-coated TiO2 induced first phase of pulmonary irritation (P1), which was seen as rapid, shallow breathing. During repeated exposures, P1 effect was partly evolved into more intense pulmonary irritation. Also sensory irritation was observed at the beginning of both single and repeated exposure periods, and the effect intensified during repeated exposures. Airflow limitation started to develop during repeated exposures. Repeated exposure to silica-coated TiO2 ENMs induced also pulmonary inflammation: inflammatory cells infiltrated in peribronchial and perivascular areas of the lungs, neutrophils were found in BAL fluids, and the number of CD3 and CD4 positive T cells increased significantly. In line with these results, pulmonary mRNA expression of chemokines CXCL1, CXCL5 and CXCL9 was enhanced. Also expression of mRNA levels of proinflammatory cytokines TNF-α and IL-6 was elevated after repeated exposures. Taken together, these results indicated that silica-coated TiO2 ENMs induce pulmonary and sensory irritation after single and repeated exposure, and airflow limitation and pulmonary inflammation after repeated exposure.
authors.affiliation: Department of Environmental Science, University of Eastern Finland , Kuopio , Finland .
authors.forename: Maija
authors.initials: M
authors.lastname: Leppänen
authors.forename: Anne
authors.initials: A
authors.lastname: Korpi
authors.forename: Santtu
authors.initials: S
authors.lastname: Mikkonen
authors.forename: Pasi
authors.initials: P
authors.lastname: Yli-Pirilä
authors.forename: Maili
authors.initials: M
authors.lastname: Lehto
authors.forename: Lea
authors.initials: L
authors.lastname: Pylkkänen
authors.forename: Henrik
authors.initials: H
authors.lastname: Wolff
authors.forename: Veli-Matti
authors.initials: VM
authors.lastname: Kosma
authors.forename: Harri
authors.initials: H
authors.lastname: Alenius
authors.forename: Jorma
authors.initials: J
authors.lastname: Joutsensaari
authors.forename: Pertti
authors.initials: P
authors.lastname: Pasanen
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000009:adverse effects*; D008168:Lung / Q000187:drug effects / Q000276:immunology; D008173:Lung Diseases, Obstructive / Q000139:chemically induced* / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011014:Pneumonia / Q000139:chemically induced* / Q000276:immunology*; D012822:Silicon Dioxide / Q000737:chemistry / Q000633:toxicity*; D014025:Titanium / Q000737:chemistry / Q000633:toxicity*; D018675:Toxicity Tests
chemical_list: D020099:Coated Materials, Biocompatible; C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium
keywords: Engineered nanomaterials; inflammation; inhalation; pulmonary irritation; titanium dioxide