Nanotoxicology: Nanoparticles Versus the Placenta

Summary posted by Meridian on 5/6/2011

Source: Nature Nanotechnology

Author(s): Jeffrey A. Keelan

A recent study in the journal Nature Nanotechnology confirms that some nanoparticles can cross the placenta and accumulate in fetuses in pregnant mice.  The nanoparticles were also shown to restrict the growth of the fetus through damage to the placenta, although such effects could be prevented by changing the surface charge.  The increasing use of nanomaterials means the likelihood of humans being exposed to these substances is also increasing, and concern is growing about the effects of nanoparticles on pregnant women.  The researchers caution that while the mouse model is very useful for research, care must be taken when extrapolating the results to human pregnancy.  Still, the results do suggest that extreme caution is required when considering exposure of pregnant women to nanomaterials.  The research team did find that size is an important determinant of placental uptake, with particles larger than 80 nanometers being partially or totally excluded.  Additionally, the team found that the deleterious effects of the nanoparticles could be reversed by coating the surface with carboxyl or amino groups.  The study does raise a number of questions regarding size-dependent effects, the relationship between fetal exposure to nanomaterials and toxicity, and how nanoparticles are transported into fetal circulation.  The author states:"Answering these questions will help clarify the relationship between nanoparticle size, composition and fetoplacental toxicity, and give valuable guidance on the safety of nanomaterial exposure during pregnancy.”

The original article may still be available at http://www.nature.com/nnano/journal/v6/n5/full/nnano.2011.65.html