Effects of silver nanoparticles on pregnant dams and embryo-fetal development in rats

Although the potential risk of silver nanoparticles (AgNPs) to humans has recently increased due to widespread application, the potential effects of AgNPs on embryo-fetal development have not yet been determined. This study investigated the potential effects of AgNPs on pregnant dams and embryo-fetal development after maternal exposure on gestational days (GD) 6-19 in rats. AgNPs were administered to pregnant rats by gavage at concentrations of 0, 100, 300, and 1000 mg/kg/day. All dams were subjected to Cesarean section on GD 20 and the fetuses were examined for signs of embryotoxic and teratogenic effects. Examinations of hepatic oxidant/antioxidant balance and serum biochemistry were also added to the routine developmental toxicity study. Treatment with AgNPs caused a decrease in catalase and glutathione reductase activities at >= 100 mg/kg/day and a reduction in glutathione content at 1000 mg/kg/day in maternal liver tissues. However, no treatment-related deaths or clinical signs were observed in any of the animals treated with AgNPs. No treatment-related differences in maternal body weight, food consumption, gross findings, serum biochemistry, organ weight, gestation index, fetal deaths, fetal and placental weights, sex ratio, or morphological alterations were observed between the groups. The results show that repeated oral doses of AgNPs during pregnancy caused oxidative stress in hepatic tissues at >= 100 mg/kg/day, but did not cause developmental toxicity at doses of up to 1000 mg/kg/day. The no-observed-adverse-effect level of AgNPs is considered to be <100 mg/kg/day for dams and 1000 mg/kg/day for embryo-fetal development.