Barrier Capacity of Human Placenta for Nanosized Materials

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.

Determination of the Transport Rate of Xenobiotics and Nanomaterials Across the Placenta using the <em>ex vivo</em> Human Placental Perfusion Model

“…Further representative results obtained with the ex vivo dual recirculating human placental perfusion model were published recently 11,19 . 19 .…”

“…Click here to view larger figure. 19 . The ratios between fetal and maternal concentrations of 14 C-antipyrine and polystyrene particles were calculated after 180 min of placenta perfusion.…”

“…Each data point represents the mean particle concentration to the given time point of at least 3 independent experiments. For polystyrene nanoparticles the placental transfer is size-dependent 19 . After 3 hr of placenta perfusion already 20-30% of the initially added 80 nm polystyrene particles were transferred from the maternal to the fetal circuit, while the 500 nm polystyrene particles were not appearing in the fetal circuit even after 6 hr of perfusion.…”

“…The ex vivo dual recirculating human placental perfusion model provides a controlled and reliable system for studying the placental transport of various endogenous and exogenous compounds 3,11,12,18,19 and a wide range of other functions of the placenta like mechanisms responsible for the development of pathological states like preeclampsia [20][21][22] . In this protocol we focus mainly on the set up, handling and method that allow the study of accumulation, effects and translocation rates of a broad set of xenobiotics or nanoparticles.…”

Transport of digoxin-loaded Polymeric Nanoparticles Across BeWo cells, an In Vitro Model of Human Placental Trophoblast

“…Our experiments have also confirmed that at concentrations up to 200 μg/ml, PEGylated PLGA nanoparticles are not cytotoxic to trophoblast cells, and are therefore an ideal drug delivery platform. It has previously been shown that polymeric particles approximately 100 nm in diameter can cross the placenta [12,35]. In this work, digoxin-loaded nanoparticles were synthesized by a modified solvent displacement method, which resulted in high encapsulation efficiency, narrow polydispersity and appropriate p article size to promote transplacental drug delivery.…”