Elemental fingerprint of human amniotic fluids and relationship with potential sources of maternal exposure

Abstract

Background-The impact of nanoparticles we are increasingly exposed to remains largely unknown. Of particular concern is the exposure of pregnant women and potential impact on fetal development. Indeed, many in vitro and in vivo animal studies have shown that nanoparticles are able to cross the placental barrier and induce toxic effects to the fetus. However, little is known in humans. Objective-The aim and originality of this study were to investigate the nanoparticle burden of amniotic fluids in pregnant women. Methods-To that purpose, 100 amniotic fluids collected for clinical purposes were used to determine the nanoparticle quantity and nature by inductively coupled plasma atomic emission spectroscopy (NAMIOTIC, ClinicalTrials.gov Identifier: NCT02720887). Results-The prevalence of patients with a substantial concentration for the essential trace elements Cu, Fe and Zn was high, while that of patients with a substantial concentration of Al, Ag, Be, Co, Cr, Ni, Si, Ti and W was relatively low (under 20%). It was generally higher in the fraction containing nanoparticles and ions than in the fraction containing micro-and submicroparticles. No correlation was found between the nanoparticle burden and the different potential sources of exposure to nanoparticles (smoking status of the patient, living area, heating source, mode of transport, leisure, use of hygiene products and cosmetics and occupational activities). Conclusion-Our results showing low concentrations and low prevalence of most of the assessed elements in amniotic fluids are reassuring. Further research is needed to draw firm conclusions on the developmental toxicity of engineered nanoparticles in humans but the present paper can provide a useful basis for further evaluation of the fetal toxicity of nanoparticles.

Translocation of (ultra)fine particles and nanoparticles across the placenta; a systematic review on the evidence of in vitro, ex vivo, and in vivo studies

“…Only 2 studies examined the maternal-fetal transfer of (ultra)fine particles and NPs under real-life exposure conditions [ 1 , 93 ] (Table 4 ). Bové et al performed a study on a subset of term placentae from 20 healthy, non-smoking mother-newborn pairs enrolled within the Belgian ENVIR ON AGE (ENVIRonmental influence ON early AGEing) birth cohort [ 94 ].…”

“…, under 20%). Nonetheless, the authors acknowledged that this does not necessarily indicate the presence of NPs since the used technique, ICP-OES, is not able to discriminate NPs from ions [ 93 ].…”

“…The most frequently used qualitative technique was TEM ( N = 22). Analytical tools, such as energy-dispersive X-ray spectroscopy (EDX) or Raman spectroscopy, can be coupled to electron microscopes for additional elemental composition analysis [ 45 , 47 , 75 , 80 , 93 ]. For example, Takeda et al used field emission-type SEM (FE-SEM)/EDX to show the transfer of nanosized TiO 2 from pregnant mice into the brain and testis of their offspring [ 80 ].…”

“…As visualized in Fig. 2 a, only 2 included studies examined the transplacental passage of (ultra)fine particles or NPs in a human population under real-life exposure conditions [ 1 , 93 ]. The majority of the cited studies investigated maternal-fetal particle transfer and distribution in animal models, hence, in biological systems under controlled conditions.…”

“…Alignment of rodent and lagomorph reproductive timelines with that of humans is based on Theiler (mouse) [ 138 ], Witschi (rat) [ 139 ], Edwards (rabbit) [ 140 ], and Carnegie (human) [ 141 ] stages of development. The included studies employed various gestational windows of NP exposure ranging from exposure during early or late gestation [ 60 , 67 , 70 , 71 , 74 , 85 , 89 ] to continuous exposure during the whole pregnancy [ 1 , 52 , 68 , 72 , 76 , 81 , 92 , 93 ] to assess the time-dependence of transplacental particle transfer. In this regard, polymeric NPs accumulated in different compartments of the rat conceptus during early (GD10), but not late (GD20) gestation, consistent with the lack of a developed placenta during early gestation [ 89 ].…”