Katrin Löschner

Effects of prenatal exposure to surface-coated nanosized titanium dioxide (UV-Titan). A study in mice

BackgroundEngineered nanoparticles are smaller than 100 nm and designed to improve or achieve new physico-chemical properties. Consequently, also toxicological properties may change compared to the parent compound. We examined developmental and neurobehavioral effects following maternal exposure to a nanoparticulate UV-filter (UV-titan L181).MethodsTime-mated mice (C57BL/6BomTac) were exposed by inhalation 1h/day to 42 mg/m3 aerosolized powder (1.7·106 n/cm3; peak-size: 97 nm) on gestation days 8-18. Endpoints included: maternal lung inflammation; gestational and litter parameters; offspring neurofunction and fertility. Physicochemical particle properties were determined to provide information on specific exposure and deposition.ResultsParticles consisted of mainly elongated rutile titanium dioxide (TiO2) with an average crystallite size of 21 nm, modified with Al, Si and Zr, and coated with polyalcohols. In exposed adult mice, 38 mg Ti/kg was detected in the lungs on day 5 and differential cell counts of bronchoalveolar lavage fluid revealed lung inflammation 5 and 26-27 days following exposure termination, relative to control mice. As young adults, prenatally exposed offspring tended to avoid the central zone of the open field and exposed female offspring displayed enhanced prepulse inhibition. Cognitive function was unaffected (Morris water maze test).ConclusionInhalation exposure to nano-sized UV Titan dusts induced long term lung inflammation in time-mated adult female mice. Gestationally exposed offspring displayed moderate neurobehavioral alterations. The results are discussed in the light of the observed particle size distribution in the exposure atmosphere and the potential pathways by which nanoparticles may impart changes in fetal development.

Correction: Effects of prenatal exposure to surface-coated nanosized titanium dioxide (UV-Titan). A study in mice.

Correction Some statements in our paper [1] are incorrect, below find corrections. Table one, Zirkonium The content of Zirkonium in the UV Titan was miscalculated by a factor 10. The correct number is therefore 0.86% (and not 8.65%). P. 12, 1 column (In discussion) For calculation of the retained amount of titanium, some inconsistencies appear in the text regarding titanium vs. the studied particle UV Titan, leading to overestimation of the retained dose. The correct text and numbers are given below: Assuming each animal inhaled 1.8 L/hr with a particle concentration of 42.4 mg/m through 11 exposure sessions, each animal inhaled a total of 840 μg. Applying the deposition estimated above and ignoring clearance and potential translocation, we expected a deposition of 72.5 μg in the pulmonary and 48 μg in the tracheobronchial region. The majority of the mass was expected to deposit in the gastrointestinal tract (356 μg) and skull (267 μg). Hence, with an average lung weight of 274 mg, the estimated deposited pulmonary dose amounts to 263-440 mg UV Titan/kg lung depending on whether pulmonary or bronchopulmonary regions are considered. Adjusting for Ti in the sample, this corresponds to 112-159 mg Ti/kg lung (Table one). The lungs of females contained 38 and 33 mg Ti/kg at 5 and 26-27 days post-exposure, respectively. Thus, approximately 21-24% of predicted pulmonary UV-Titan deposition could be accounted for.” Page 5, 2 column (last lines of “Behavioral testing”) Final paragraph should read “The average of the 10 middle startle trials %PPI = 100-((AVG at prepulse+startle trial)/(AVG at startle trial))*100%”.