Effect of zinc oxide nanoparticles on dams and embryo–fetal development in rats

Jeong-Sup Hong,1,2 Myeong-Kyu Park,1 Min-Seok Kim,1 Jeong-Hyeon Lim,1 Gil-Jong Park,1 Eun-Ho Maeng,1 Jae-Ho Shin,3 Yu-Ri Kim,4 Meyoung-Kon Kim,4 Jong-Kwon Lee,5 Jin-A Park,2 Jong-Choon Kim,6 Ho-Chul Shin2 1Health Care Research Laboratory, Korea Testing and Research Institute, Gimpo, 2College of Veterinary Medicine, Konkuk University, Seoul, 3Department of Biomedical Laboratory Science, Eulji University, Seongnam-si, 4Department of Biochemistry and Molecular Biology, Korea University Medical School and College, Seoul, 5Toxicological Research Division, National Institute of Food and Drug Safety Evaluation, Chungcheongbuk-do, 6College of Veterinary Medicine, Chonnam National University, Gwangju, Korea Abstract: This study investigated the potential adverse effects of zinc oxide nanoparticles (ZnOSM20[-] NPs; negatively charged, 20 nm) on pregnant dams and embryo–fetal development after maternal exposure over the period of gestational days 5–19 with Sprague Dawley rats. ZnOSM20(-) NPs were administered to pregnant rats by gavage at 0 mg/kg/day, 100 mg/kg/day, 200 mg/kg/day, and 400 mg/kg/day. All dams were subjected to caesarean section on gestational day 20, and all the fetuses were examined for external, visceral, and skeletal alterations. Toxicity in the dams manifested as significantly decreased body weight at 400 mg/kg/day and decreased liver weight, and increased adrenal glands weight at 200 mg/kg/day and 400 mg/kg/day. However, no treatment-related difference in the number of corpora lutea, the number of implantation sites, the implantation rate (%), resorption, dead fetuses, litter size, fetal deaths, fetal and placental weights, and sex ratio were observed between the groups. Morphological examinations of the fetuses demonstrated no significant difference in the incidences of abnormalities between the groups. No significant difference was found in the Zn content of fetal tissue between the control and high-dose groups. These results showed that a 15-day repeated oral dose of ZnOSM20(-) was minimally maternotoxic at dose of 200 mg/kg/day and 400 mg/kg/day. Keywords: nanotoxicology, nanoparticles, zinc oxide, maternal toxicity, developmental toxicity, teratogenicity