Institute of Nanoproduct Safety Research, Hoseo University, 165 Sechul-ri, Baebang-myun, Asan 336-795 South Korea.
Part Fibre Toxicol. 2013 Aug 1;10:36. doi: 10.1186/1743-8977-10-36.
Silver nanoparticles are known to be distributed in many tissues after oral or inhalation exposure. Thus, understanding the tissue clearance of such distributed nanoparticles is very important to understand the behavior of silver nanoparticles in vivo. For risk assessment purposes, easy clearance indicates a lower overall cumulative toxicity. Accordingly, to investigate the clearance of tissue silver concentrations following oral silver nanoparticle exposure, Sprague-Dawley rats were assigned to 3 groups: control, low dose (100 mg/kg body weight), and high dose (500 mg/kg body weight), and exposed to two different sizes of silver nanoparticles (average diameter 10 and 25 nm) over 28 days. Thereafter, the rats were allowed to recover for 4 months. Regardless of the silver nanoparticle size, the silver content in most tissues gradually decreased during the 4-month recovery period, indicating tissue clearance of the accumulated silver. The exceptions were the silver concentrations in the brain and testes, which did not clear well, even after the 4-month recovery period, indicating an obstruction in transporting the accumulated silver out of these tissues. Therefore, the results showed that the size of the silver nanoparticles did not affect their tissue distribution. Furthermore, biological barriers, such as the blood-brain barrier and blood-testis barrier, seemed to play an important role in the silver clearance from these tissues.
纳米银颗粒经口服或吸入暴露后会分布在许多组织中。因此，了解这些分布的纳米颗粒的组织清除情况对于理解纳米银在体内的行为非常重要。出于风险评估的目的，易于清除表明总体累积毒性较低。因此，为了研究口服纳米银颗粒暴露后组织中银浓度的清除情况，将 Sprague-Dawley 大鼠分为 3 组：对照组、低剂量组（100mg/kg 体重）和高剂量组（500mg/kg 体重），并在 28 天内暴露于两种不同尺寸的纳米银颗粒（平均直径为 10nm 和 25nm）。之后，大鼠被允许恢复 4 个月。无论纳米银颗粒的大小如何，大多数组织中的银含量在 4 个月的恢复期内逐渐下降，表明积累的银被清除。例外的是大脑和睾丸中的银浓度，即使在 4 个月的恢复期后，也没有很好地清除，表明积累的银从这些组织中排出受阻。因此，结果表明纳米银颗粒的大小并不影响它们的组织分布。此外，生物屏障，如血脑屏障和血睾屏障，似乎在这些组织中清除银方面发挥了重要作用。
