The endocrine disruptor effect of metal nanoparticles mainly depends on their capacity to release metal ions†

Throughout their lives, humans are constantly exposed to various pollutants that can affect our development and physiology. The growing list of pollutants include drugs, pesticides, cosmetics, plasticizers, and other organic molecules that have been found to disrupt endocrine activities. Endocrine disruptors can negatively impact our organism's development, metabolism, and sexual functions. Recently, it was discovered that exposure to silver nanoparticles (AgNP) inhibits specific liver nuclear receptors. Nuclear receptors are transcription factors that play a critical role in regulating important physiological functions including endocrine ones. To investigate further, we tested the impact of two types of metal nanoparticles: AgNP, which release metal ions, and titanium dioxide nanoparticles, which do not dissociate into ions. We found that AgNP significantly inhibited the thyroid and androgen pathways but had no effect on the aryl hydrocarbon pathway. On the other hand, titanium dioxide nanoparticles had little effect. Additionally, we observed that combining AgNP with antagonists led to cumulative inhibition of the thyroid and androgen pathways. Our previous data suggest that Ag(I) ions released from the NP trigger the inhibition of zinc finger-containing nuclear receptors. In conclusion, metal nanoparticles with a capacity to release metal ions are highly effective endocrine disruptors, and the impact caused by organic molecules co-transported with metal nanoparticles is minor.