研究人员发现，通过静脉注射的二氧化硅和二氧化钛纳米颗粒能导致怀孕小鼠发生孕期综合征，新成果发表在4月在线出版的《自然—纳米技术》期刊上，说明纳米颗粒对怀孕小鼠有影响。

科学家们已经知道，纳米颗粒能穿越小鼠胎盘屏障，将有毒物质引入小鼠后代，但他们并不十分清楚这种效应对怀孕动物的具体影响。Yasuo Yoshioka和同事合作，将二氧化钛纳米颗粒和各种大小的二氧化硅纳米颗粒注射到怀孕小鼠体内。他们发现，与只接受盐溶液注射的对照组小鼠相比较，接受二氧化钛和最小体积二氧化硅的小鼠的子宫重量更轻、胚胎更小。而其他普通的纳米颗粒如富勒烯等，并不会引发孕期综合征。他们还指出，当硅纳米颗粒表面被羧基和氨基修饰时，异常现象就会消失。此外，注射含有硅纳米颗粒的肝磷脂则能预防子宫和胎儿的畸形，表明这种综合征可能发生在凝血通道。

尽管这项研究显示了纳米颗粒对小鼠的影响，但作者强调：小鼠和人类胎盘在解剖学和结构上的差别意味着不能将这项工作外推至人类。然而，纳米颗粒对繁殖健康的影响是一个值得认真考虑的问题。 

原文出处：

Nature Nanotechnology  doi:10.1038/nnano.2011.41

Silica and titanium dioxide nanoparticles cause pregnancy complications in mice

Kohei Yamashita,1, 2, 11 Yasuo Yoshioka,1, 2, 3, 11 Kazuma Higashisaka,1, 2 Kazuya Mimura,4 Yuki Morishita,1, 2 Masatoshi Nozaki,4 Tokuyuki Yoshida,1, 2 Toshinobu Ogura,1, 2 Hiromi Nabeshi,1, 2 Kazuya Nagano,2 Yasuhiro Abe,2 Haruhiko Kamada,2, 3 Youko Monobe,5 Takayoshi Imazawa,5 Hisae Aoshima,6 Kiyoshi Shishido,7 Yuichi Kawai,8 Tadanori Mayumi,8 Shin-ichi Tsunoda,2, 3, 9 Norio Itoh,1 Tomoaki Yoshikawa,1, 2 Itaru Yanagihara,4 Shigeru Saito10 & Yasuo Tsutsumi1, 2, 3

The increasing use of nanomaterials has raised concerns about their potential risks to human health. Recent studies have shown that nanoparticles can cross the placenta barrier in pregnant mice and cause neurotoxicity in their offspring, but a more detailed understanding of the effects of nanoparticles on pregnant animals remains elusive. Here, we show that silica and titanium dioxide nanoparticles with diameters of 70 nm and 35 nm, respectively, can cause pregnancy complications when injected intravenously into pregnant mice. The silica and titanium dioxide nanoparticles were found in the placenta, fetal liver and fetal brain. Mice treated with these nanoparticles had smaller uteri and smaller fetuses than untreated controls. Fullerene molecules and larger (300 and 1,000 nm) silica particles did not induce these complications. These detrimental effects are linked to structural and functional abnormalities in the placenta on the maternal side, and are abolished when the surfaces of the silica nanoparticles are modified with carboxyl and amine groups.