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

将金红石晶体结构的二氧化钛纳米颗粒分散在蒸馏水中，并通过超离心法将平均55 nm尺寸的颗粒分级。0.2肺内分别注入0.5mg和0.5mg TiO_2。采用电感耦合等离子体原子发射光谱法（ICP-AES）测定肺、血、肝、肾、脾中二氧化钛的含量。TiO 2从肺中清除，生物半衰期为3.4个月（0.2mg）和3.9个月（0.5mg）。其他器官和血液中的TiO 2含量未测定或极低。BALF中总细胞和中性粒细胞无剂量依赖性增加。组织病理学检查显示轻度炎性细胞浸润，无纤维化和增生改变。

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.