Barrier Capacity of Human Placenta for Nanosized Materials

TLDR

Humans have long been exposed to fine and ultrafine particles, and the rapid growth of nanotechnology has increased engineered nanoparticles with novel properties, raising concerns about potential adverse health effects, especially during pregnancy. The study aimed to determine whether nanoparticles can cross the human placental barrier and potentially affect the fetus. An ex vivo human placental perfusion model was employed to assess size‑dependent transplacental transfer of nanoparticles. Polystyrene beads up to 240 nm were taken up and crossed the placental barrier without harming placental viability, indicating that nanomaterials can transfer transplacentally.

Abstract

BackgroundHumans have been exposed to fine and ultrafine particles throughout their history. Since the Industrial Revolution, sources, doses, and types of nanoparticles have changed dramatically. In the last decade, the rapidly developing field of nanotechnology has led to an increase of engineered nanoparticles with novel physical and chemical properties. Regardless of whether this exposure is unintended or not, a careful assessment of possible adverse effects is needed. A large number of projects have been carried out to assess the consequences of combustion-derived or engineered nanoparticle exposure on human health. In recent years there has been a growing concern about the possible health influence of exposure to air pollutants during pregnancy, hence an implicit concern about potential risk for nanoparticle exposure in utero. Previous work has not addressed the question of whether nanoparticles may cross the placenta.ObjectiveIn this study we investigated whether particles can cross the placental barrier and affect the fetus.MethodsWe used the ex vivo human placental perfusion model to investigate whether nanoparticles can cross this barrier and whether this process is size dependent. Fluorescently labeled polystyrene beads with diameters of 50, 80, 240, and 500 nm were chosen as model particles.ResultsWe showed that fluorescent polystyrene particles with diameter up to 240 nm were taken up by the placenta and were able to cross the placental barrier without affecting the viability of the placental explant.ConclusionsThe findings suggest that nanomaterials have the potential for transplacental transfer and underscore the need for further nanotoxicologic studies on this important organ system.