Developmental and reproductive toxicity of PVP/PEI-coated silver nanoparticles to zebrafish

Cellular and molecular mechanisms of toxicity of silver nanoparticles (NPs) and their toxicity to fish embryos after waterborne exposure have been widely investigated, but much less information is available regarding the effect of Ag NPs on physiological functions such as growth or reproduction. In this work, the effects of waterborne exposure of adult zebrafish (Danio rerio) to PVP/PEI coated Ag NPs (~ 5 nm) on reproduction (fecundity) were investigated. Moreover, the development of the embryos after parental exposure was compared with the development of embryos after direct waterborne exposure to the NPs. For this, two experiments were run: 1) embryos from unexposed parents were treated for 5 days with Ag NPs (10 μg Ag L− 1-10 mg Ag L− 1) and development was monitored, and 2) selected breeding zebrafish were exposed for 3 weeks to 100 ng Ag L− 1 (environmentally relevant concentration) or to 10 μg Ag L− 1 of Ag NPs, fecundity was scored and development of resulting embryos was monitored up to 5 days. Waterborne exposure of embryos to Ag NPs resulted in being highly toxic (LC50 at 120 h = 50 μg Ag L− 1), causing 100% mortality during the first 24 h of exposure at 0.1 mg Ag L− 1. Exposure of adults, even at the environmentally relevant silver concentration, caused a significant reduction of fecundity by the second week of treatment and resulting embryos showed a higher prevalence of malformations than control embryos. Exposed adult females presented higher prevalence of vacuolization in the liver. These results show that Ag NPs at an environmentally relevant concentration are able to affect population level parameters in zebrafish.