Effects of titanium dioxide nanoparticles on airway inflammation in experimental asthma model

Background Recently, nanoparticles (NPs) have been developed to carry drugs and vaccines which contribute in diagnosis and handling of diseases but also they can act as a potential source of pulmonary toxicity and induce harmful effects. Titanium dioxide (TiO2) have been widely used in a number of applications like semiconductors, photocatalyst belts, solar cells, medicine as well as in consumer products including sunscreens, paints and food supplements.

Objective The objective was to analyze the local effect of the TiO2 Nanoparticles on the allergic airway inflammation and to investigate their uptake in an OVA-mouse model for allergic airway inflammation.

Methods BALB/c female wild-type (9 weeks old)-OVA mouse model was used to induce allergic airway inflammation. Treated groups received TiO2 nanoparticles (50 mg/ml) intranasally on days 17 and 20. Staining and histological study, lung function measurement and investigation of NPs phagocytosis were performed. In addition, Th2-cytokinins were evaluated in the lung homogenate with ELISA.

Results Both OVA and OVA-titanium dioxide NPs groups demonstrated a large eosinophilic infiltration and mucus overproduction in lung tissues compared to other groups. However, there was a modest exacerbation in the reactivity of the lungs following TiO2 exposure. Moreover, we observed a significant elevation in Th2 immune response after nanoparticles exposure; IL-4, IL-5 and IL-13 were found to be significantly increased after TiO2 NPs exposure. Titanium dioxide nanoparticles were uptaked by alveolar macrophages at all time points and this intracellular uptake was almost saturated within the 0,0125 – 0,025 mg concentration range of NPs.

Conclusion In light of our findings exposure to nano-sized TiO2 particles would have an adjuvant effect by promoting the asthmatic reaction and exacerbating the airway inflammation.