Researches on the target organ and its hazard of engineering nanoparticles by intratracheal instillation

将金红石型纳米二氧化钛分散于蒸馏水中，采用超离心分离法分离出平均粒径为55 nm的纳米二氧化钛。大鼠肺经气管灌注TiO2 0.2 mg、0.5mg。随后用电感耦合等离子体发射光谱（ICP-AES）测定肺、血、肝、肾、脾中TiO2的含量。TiO2从肺中清除，生物半衰期分别为3.4个月（0.2mg）和3.9个月（0.5mg）。其他器官和血液中的TiO2含量未测定或极低。BALF中总细胞和中性粒细胞没有剂量依赖性的增加。组织病理学检查显示炎症细胞轻微浸润，未见纤维化和增生性改变。

Titanium dioxide nanoparticle, rutile crystalline structure, was dispersed in distilled water and average 55 nm size particles were fractionated by ultracentrifugation. 0.2 mg and 0.5mg TiO2 were intratracheally instilled into rat's lung. The amounts of TiO2 in lungs, bloods, livers, kidneys, spleens were determined by ICP-AES subsequently. TiO2 were cleared from lungs and the biological half time of were 3.4 months(0.2mg) and 3.9 months(0.5mg). TiO2 amounts in the other organ and blood were not determined or extremely low. There were no dose-dependent increases of total cells and neutrophils in BALF. The histopathological examination reveals the slight infiltration of inflammatory cells and no fibrosis and hyperplasic changes.