Silver nanomaterials, which possess antimicrobial activity, have been used in many feminine hygiene products for contraception and anti-infection purposes. However, whether and how silver nanomaterials affect the female reproductive system remains an open scientific question, which researchers should be working to elucidate.
Recently, a joint research group led by Prof. Chunying Chen (National Center for Nanoscience and Technology, Beijing) and Prof. Xiaochun Wu (National Center for Nanoscience and Technology, Beijing) have demonstrated that gold nanorod core/silver shell nanostructures (Au@Ag NRs) are toxic to primary rat granulosa cells. In this study, primary rat granulosa cells were exposed to Au@Ag NRs and their effects were compared with the effects of primary rat granulosa cells exposed to gold nanorods (Au NRs).
Qualitative MMP assay after Au NRs or Au@Ag NRs exposure for 24 h (measured by CLSM). The scale bars in these images represent 50 µm.
Primary rat granulosa cells treated with Au@Ag NRs generated more reactive oxygen species, had reduced mitochondrial membrane potential and produced less adenosine triphosphate. Eventually, these cells underwent mitochondria-mediated apoptosis. Furthermore, it was found that Au@Ag NRs can promote the secretion of two steroids, namely progesterone and estradiol, by primary rat granulosa cells in a time and dose-dependent manner.
Interestingly, highest degree of apoptosis and steroidogenesis occurred simultaneously after 24h Au@Ag NRs exposure. This implies a correlation between apoptosis and elevated steroidogenesis induced by silver nanomaterials in primary rat granulosa cells. Lastly, the physical chemical properties of Au@Ag NRs were investigated to unveil the underlying mechanisms of these biological phenomena. Both the surface reactivity and intracellular silver ion release of Au@Ag NR contribute to the toxic response of granulosa cells.
This work shed more light on the mechanisms by which nanosilver mediates toxic effects in ovary granulosa cells. More importantly, caution should be taken when using nanosilver–containing feminine products.
