Maternal Exposure to Silver Nanoparticles in Mice: Effects on Dams’ Reproductive Performance and Pups’ Neurobehavioral Ontogeny

Introduction: - Significant increase in usage of silver nanoparticles (AgNPs) in consumer products, has increased its exposures to human and animals. Although there are some reports regarding the effects of AgNPs on complex organisms, no report was found as to its effects on neurobehavioral ontogeny. Methods: To investigate the effects of maternal exposure to AgNPs on development of neurobehavioral reflexes as well as physical indexes of growthand development during preweaning period, virgin female NMRI mice were treated with zero, 5 and 50 μg/mouse AgNPs. AgNPs were injected subcutaneously (S.C) to female mice, immediately following male exposure and at once every three days until parturition. Reproductive performance of dams were assessed and home cage activity and developmental landmarks of all pups were observed daily. Gross necropsy was performed on the 28th day. Results: No significant differences were observed in dams' and pups' weight. Survival rate was decreased (p<0.05) in NP5 group and a clear hyperactivity was observed in NP50 group. Prenatal exposure to AgNPs delayed the development of the some pups' neurobehavioral reflexes which were supposed to take place during the first four days following birth. The weight of spleen was decreased in AgNPs treated mice and the weight of liver was increased in male offspring who was exposed to AgNPs before birth. Conclusion: This study revealed that prenatal exposure to AgNPs delayed neurobehavioral development during the early stages of the pre-weaning period. Furthermore, more attention should be paid to alteration of lymphoid organ and liver weights of offspring.