Abstract

Background:

The first evidence of micro- and nanoplastic (MNP) exposure in the human placenta is emerging. However, the toxicokinetics and toxicity of MNPs in the placenta, specifically environmentally relevant particles, remain unclear.

Objectives:

We examined the transport, uptake, and toxicity of pristine and experimentally weathered MNPs in nonsyncytialized and syncytialized BeWo b30 choriocarcinoma cells.

Methods:

We performed untargeted chemical characterization of pristine and weathered MNPs using liquid chromatography high-resolution mass spectrometry to evaluate compositional differences following particle weathering. We investigated cellular internalization of pristine and weathered polystyrene (PS; $0.05–10\mathrm{\mu }\mathrm{m}$) and high-density polyethylene (HDPE; $0–80\mathrm{\mu }\mathrm{m}$) particles using high-resolution confocal imaging and three-dimensional rendering. We investigated the influence of particle coating with human plasma on the cellular transport of PS particles using a transwell setup and examined the influence of acute MNP exposure on cell viability, damage to the plasma membrane, and expression of genes involved in steroidogenesis.

Results:

Chemical characterization of MNPs showed a significantly higher number of unique features in pristine particles in comparison with weathered particles. Size-dependent placental uptake of pristine and weathered MNPs was observed in both placental cell types after 24 h exposure. Cellular transport was limited and size-dependent and was not influenced by particle coating with human plasma. None of the MNPs affected cell viability. Damage to the plasma membrane was observed only for $0.05\mathrm{\mu }\mathrm{m}$ PS particles in the nonsyncytialized cells at the highest concentration tested ($100\mathrm{\mu }\mathrm{g}/\mathrm{mL}$). Modest down-regulation of hsd17b1 was observed in syncytialized cells exposed to pristine MNPs.

Discussion:

Our results suggest that pristine and weathered MNPs are internalized and translocated in placental cells in vitro. Effects on gene expression observed upon pristine PS and HDPE particle exposure warrant further examination. More in-depth investigations are needed to better understand the potential health risks of MNP and chemicals associated with them under environmentally relevant exposure scenarios. https://doi.org/10.1289/EHP10873

中文翻译：

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人类胎盘细胞中原始和风化的微塑料和纳米塑料的摄取、运输和毒性

摘要

背景：

人类胎盘中暴露于微塑料和纳米塑料 (MNP) 的第一个证据正在出现。然而，胎盘中 MNPs 的毒代动力学和毒性，特别是与环境相关的颗粒，仍不清楚。

目标：

我们检查了非合胞和合胞 BeWo b30 绒癌细胞中原始和实验风化 MNP 的运输、摄取和毒性。

方法：

我们使用液相色谱高分辨率质谱法对原始和风化的 MNP 进行了非靶向化学表征，以评估粒子风化后的成分差异。我们研究了原始和风化聚苯乙烯（PS；$0.05–10\mathrm{\mu }\mathrm{米}$) 和高密度聚乙烯 (HDPE;$0–80\mathrm{\mu }\mathrm{米}$) 粒子使用高分辨率共焦成像和三维渲染。我们使用 transwell 装置研究了人血浆颗粒涂层对 PS 颗粒细胞转运的影响，并检查了急性 MNP 暴露对细胞活力、质膜损伤和类固醇生成相关基因表达的影响。

结果：

与风化颗粒相比，MNP 的化学表征表明原始颗粒的独特特征数量显着增加。在暴露 24 小时后，在两种胎盘细胞类型中都观察到原始和风化 MNP 的大小依赖性胎盘摄取。细胞运输是有限的并且依赖于尺寸，并且不受人类血浆颗粒涂层的影响。没有一个 MNP 影响细胞活力。仅观察到对质膜的损伤$0.05\mathrm{\mu }\mathrm{米}$最高浓度的非合胞细胞中的 PS 颗粒测试 ($100\mathrm{\mu }\mathrm{G}/\mathrm{毫升}$）。在暴露于原始 MNP 的合胞细胞中观察到 hsd17b1 的适度下调。

讨论：

我们的研究结果表明，原始的和风化的 MNP在体外被内化并转移到胎盘细胞中。在原始 PS 和 HDPE 颗粒暴露下观察到的对基因表达的影响需要进一步检查。需要进行更深入的调查，以更好地了解 MNP 及其相关化学品在环境相关暴露情景下的潜在健康风险。https://doi.org/10.1289/EHP10873