Nagano Kazuya
Laboratory of Biopharmaceutical Research, National Institute of Biomedical Innovation, Osaka.
Yakugaku Zasshi. 2011 Feb;131(2):225-8. doi: 10.1248/yakushi.131.225.
Nanomaterials acquire revolutionary functions such as anti-inflammatory and anti-viral effects by increasing surface area per unit weight, due to the reduction to nanosize. Such nanomaterials are rapidly put to practical use without safety evaluation. This is because it is widely assumed that nanomaterials are merely of the same molecular composition as existing materials of more than submicron size, and that nanomaterials cannot be absorbed from the digestive tract or skin as is the case with existing materials of more than submicron size. On the other hand, as was the case with thalidomide, evidence shows that fetuses and infants are affected more than adults by a variety of environmental toxins, because of physiological immaturity. Thus, placental or breast milk-mediated exposure to nanomaterials may possibly induce unexpected biological effects. To our knowledge, however, no studies have examined effects of pregnant animal exposure to nanomaterials on transitivity to placenta or infants, or on maintenance of pregnancy. Therefore, using nanosilica particles (nSPs) employed as additives in cosmetics and foods, we will report on the efficiency of transitivity of nSPs of various diameters to the circulation through the placental barrier after nanomaterial exposure and the risks of nSP exposure to pregnant mice. In this review, I will discuss the development of safety in nanomaterials and the maintenance of good health.
纳米材料由于尺寸减小至纳米级，单位重量的表面积增加，从而获得了抗炎和抗病毒等革命性功能。这类纳米材料未经安全评估便迅速投入实际应用。这是因为人们普遍认为纳米材料仅仅与现有的亚微米以上尺寸的材料具有相同的分子组成，并且纳米材料不会像现有的亚微米以上尺寸的材料那样从消化道或皮肤吸收。另一方面，正如沙利度胺的例子所示，有证据表明，由于生理上的不成熟，胎儿和婴儿比成年人更容易受到各种环境毒素的影响。因此，通过胎盘或母乳接触纳米材料可能会引发意想不到的生物学效应。然而，据我们所知，尚无研究考察怀孕动物接触纳米材料对胎盘或婴儿的传递性以及对维持妊娠的影响。因此，我们将使用在化妆品和食品中用作添加剂的纳米二氧化硅颗粒（nSPs），报告纳米材料暴露后不同直径的nSPs通过胎盘屏障进入循环的传递效率以及nSPs暴露对怀孕小鼠的风险。在这篇综述中，我将讨论纳米材料安全性的发展以及健康的维持。
