Kinetics of gold nanoparticles in the human placenta

Abstract

We studied the transfer of PEGylated gold nanoparticles through perfused human placenta. In ‘once-through’ perfusions using 15 and 30 nm nanoparticles both maternal and fetal outflows were collected. Recirculating perfusions using 10 or 15 nm nanoparticles lasted 6 h. The gold concentration in samples was analysed on ICP-MS. The reference compound antipyrine crossed the placenta rapidly, as expected. In open perfusions nanoparticles were detected in maternal but not in fetal outflow, suggesting the lack of placental transfer. During 6 h re-circulating perfusions, no particles were detected in fetal circulation. Using transmission electron microscopy (TEM) and silver enhancement, nanoparticles could be visualized in the placental tissue mainly in the trophoblastic cell layer. In in vitro experiments, nanoparticles were taken up by BeWo choriocarcinoma cells and retained inside the cells for an extended period of 48 h. In conclusion, PEGylated gold nanoparticles of the size 10–30 nm did not cross the perfused human placenta in detectable amounts into the fetal circulation within 6 h. Whether PEGylated gold nanoparticles eventually are able to cross placenta and whether nanoparticles affect placental functions needs to be further studied.