TY - JOUR T1 - Inhalation of nano-scaled titianium dioxide particles aggravates airway inflammation in allergen-challenged mice JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p3314 AU - Sofia Jonasson AU - Åsa Gustafsson AU - Bo Koch AU - Emelie Näslund-Salomonsson AU - Anders Bucht Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p3314.abstract N2 - Titanium dioxide (TiO2) nanoparticles are manufactured worldwide and although TiO2 is chemically inert, it may have adverse health effects especially in sensitive populations. The use of nanomaterials has increased over the past years and the detrimental effects on various airway diseases are poorly characterized. Thus we investigated if a single exposure of TiO2 before or during ovalbumin (OVA)-challenge could promote airway inflammation in mice with allergic airway disease.BALB/c mice were sensitized to OVA (10 μg i.p.) on day 0 and 14, then challenged with nebulized 1% OVA for 30 min on day 29,32 and 34. Lung exposure of aerosolized TiO2 was performed before (day 28) and during OVA challenge (day 33). The approximated deposited dose of TiO2 in the mouse lung was estimated to be 0.53 ml/m3 (2h, nose-only exposure). The experiment ended on day 35 with assessment of bronchial reactivity to methacholine and inflammatory cell counts in bronchoalveolar lavage (BAL).Total inflammatory cell counts in BAL was increased both when TiO2 was exposed on day 28 and day 33 (both p<0.05) compared to exposure to only OVA. When mice were exposed for TiO2 before OVA challenge there was a larger decline in respiratory compliance (p=0.03) and a greater impact on peripheral airways (tissue resistance and tissue elastance (both p<0.05)) compared to TiO2 administrated during the OVA-challenge and to animals exposed to only OVA. In conclusion, we aimed to study effects of combined exposure of nanoparticles and pro-allergic proteins in a mouse model of asthma, indicating that TiO2 administration before and during allergen-challenge have proinflammatory effects in peripheral airways. ER -