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Open Access Research

Inhalation exposure to nanosized and fine TiO2 particles inhibits features of allergic asthma in a murine model

Elina M Rossi1, Lea Pylkkänen1, Antti J Koivisto2, Heli Nykäsenoja1, Henrik Wolff3, Kai Savolainen2 and Harri Alenius1*

Author Affiliations

1 Unit of Excellence for Immunotoxicology, Finnish Institute of Occupational Health, Helsinki, Finland

2 New Technologies and Risks, Finnish Institute of Occupational Health, Helsinki, Finland

3 Biological Mechanisms and Prevention of Work-Related Diseases/Immunopathology, Finnish Institute of Occupational Health, Helsinki, Finland

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Particle and Fibre Toxicology 2010, 7:35 doi:10.1186/1743-8977-7-35

Published: 25 November 2010

Abstract

Background

Nanotechnology and engineered nanomaterials (ENM) are here to stay. Recent evidence suggests that exposure to environmental particulate matter exacerbates symptoms of asthma. In the present study we investigated the modulatory effects of titanium dioxide particle exposure in an experimental allergic asthma.

Methods

Nonallergic (healthy) and ovalbumin-sensitized (asthmatic) mice were exposed via inhalation to two different sizes of titanium dioxide particles, nanosized (nTiO2) and fine (fTiO2), for 2 hours a day, three days a week, for four weeks at a concentration of 10 mg/m3. Different endpoints were analysed to evaluate the immunological status of the mice.

Results

Healthy mice elicited pulmonary neutrophilia accompanied by significantly increased chemokine CXCL5 expression when exposed to nTiO2. Surprisingly, allergic pulmonary inflammation was dramatically suppressed in asthmatic mice which were exposed to nTiO2 or fTiO2 particles - i.e. the levels of leucocytes, cytokines, chemokines and antibodies characteristic to allergic asthma were substantially decreased.

Conclusions

Our results suggest that repeated airway exposure to TiO2 particles modulates the airway inflammation depending on the immunological status of the exposed mice.