# Year 116 of the plastic age: a Pandora's box as a time bomb for pregnancy? Review of clinical and fundamental data on prenatal exposure to plastics

Bertrand Lefrere, Lea Poinsignon, Thierry Fournier, Gaëtane Lespes, Jean

Louis Beaudeux, Amal Zerrad Saadi

<figure><img src="image_1.png" /></figure>

## To cite this version:

Bertrand Lefrere, Lea Poinsignon, Thierry Fournier, Gaëtane Lespes, Jean Louis Beaudeux, et al. Year 116 of the plastic age: a Pandora's box as a time bomb for pregnancy? Review of clinical and fundamental data on prenatal exposure to plastics. Journal of Hazardous Materials, 2025, 499, pp.140018. 10.1016/j.jhazmat.2025.140018. hal-05368983

HAL Id: hal-05368983

https://hal.science/hal-05368983v1

Submitted on 18 Nov 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_2.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
<figure><img src="image_3.png" /></figure>

Review

Year 116 of the plastic age: a Pandora's box as a time bomb for pregnancy?
Review of clinical and fundamental data on prenatal exposure to plastics

Bertrand Lefrère<sup>a,b</sup>, Léa Poinsignon<sup>a,b</sup>, Thierry Fournier<sup>a,c</sup>, Gaëtane Lespes<sup>d,e</sup>, Jean-Louis Beaudeux<sup>a,b,f</sup>, Amal Zerrad-Saadi<sup>a,c,g</sup>

HIGHLIGHTS

* Plasticenta: MP (as polystyrene, polypropylene, polyethylene, and polyvinylchloride) in human placental tissue.

* MP can be associated with placental-driven dysfunction pathologies, such as IUGR and miscarriage.

* Analytical challenges: their ubiquity require plastic-free procedure for sampling and experiments.

* NP size, concentration, functionalization as key-factors for their biological fate.

* The unknown: chronic exposition? Cellular and molecular mechanisms for induced-IUGR/miscarriage?

GRAPHICAL ABSTRACT

<figure><img src="image_4.png" /></figure>

ARTICLE INFO

Keywords:

Exposome

Pregnancy

Placenta

Fetal development

Microplastics

Nanoplastics

Polystyrene

ABSTRACT

Plastics constitute an area of interest within the context of the placental exposome. A growing body of evidence now indicates that various micro- and nanoplastics — including notably polystyrene, polypropylene, polyethylene, and polyvinylchloride — are present in the human placenta, from the basal plate to the fetal membranes. Results from *in vitro* and *ex vivo* studies have shown that these environmental pollutants can enter the maternal bloodstream and reach the placenta, where they concentrate in the syncytiotrophoblast. These so-called "plasticenta" have been observed even in uncomplicated pregnancies, and to date, no longitudinal study has confirmed harmful long-term consequences for the newborn. However, plastics appear to alter placental functions and may therefore be associated with adverse outcomes such as miscarriage, intrauterine growth restriction and preterm birth. Findings from *ex vivo* human studies, *in vivo* murine models, and *in vitro* experiments with micro- and nanoplastics indicate that factors such as particle type, size, concentration, surface functionalization, route of exposure, and environmental conditions play key roles in cellular uptake and subsequent alterations in

<footnote><sup>a</sup> Université Paris Cité, INSERM UMR-S 1139, FPRM, Paris 75006, France</footnote>

<footnote><sup>b</sup> Service de Biochimie, Assistance Publique des Hôpitaux de Paris, Hôpital Necker Enfants-Malades, Paris 75015, France</footnote>

<footnote><sup>c</sup> FHU Prem'IMPACT, Paris, France</footnote>

<footnote><sup>d</sup> Université de Pau et des Pays de l'Adour / E2S UPPA, CNRS, Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux (IPREM), UMR 5254, Helioparc, 2 avenue Pierre Angot, Pau Cedex 09 64053, France</footnote>

<footnote>* Corresponding author at: Université Paris Cité, INSERM UMR-S 1139, FPRM, Paris 75006, France.
E-mail address: amal.zerrad-saadi@u-paris.fr (A. Zerrad-Saadi).</footnote>
cell function and phenotype. Consequently, various impairments in placental metabolic and immune functions may contribute to abnormal development of the placenta and the fetus. Maternal exposure to these ubiquitous environmental pollutants may induce prenatal and neonatal disease states. In this review, we examine the current clinical, *in vivo* and *in vitro* data on the occurrence, distribution and impact of micro- and nanoplastics in the placenta.

# 1. Introduction

The "Plastic Age" began in 1909 with the creation of Bakelite — the first synthetic polymer [1]. Although styrene had already been isolated from the styrax tree in the 19th century, the widespread use of poly-styrene (PS), along with other plastics, such as polyvinyl chloride (PVC), polyurethane (PU), nylon, and polyethylene (PE), mainly manufactured from petrochemicals, markedly accelerated in the 1950s [1]. By 2017, global annual plastic production had reached 8.3 billion metric tons, surpassing the world's recycling and incineration capacity by 79% [2].

Amplified by the surge in biomedical waste during the Covid-19 pandemic [3], plastic pollution has become a major concern for human health, affecting all terrestrial and marine ecosystems, as well as the entire food chain.

Application of a “One Health” approach to the plastics issue goes beyond the scientific sphere and raises social and political questions [4, 5]. Indeed, we are increasingly aware of the negative consequences of the very properties that make plastics so useful: their resistance to biodegradation leads to their accumulation in the environment, undergoing primary or, more frequently, secondary fragmentations into

<figure><img src="image_5.png" /><figcaption>**Fig. 1.** Chorionic villus at term, the structural and functional unit of placenta. Adapted from Evain-Brion D and Malassiné A, « Le placenta humain », Lavoisier, 2010.</figcaption></figure>
<figure><img src="image_6.png" /><figcaption>Fig. 2. Workflow for literature screening.</figcaption></figure>

particles that vary in appearance, size, degradation rate, and surface characteristics. In the absence of a consensus definition, plastic particles are typically categorized by size: macro- and mesoplastics, microplastics (MP), and nanoplastics (NP). In this review, we focus on MP (1 µm-5 mm) and NP (<1000 nm) [6]. These particles are also commonly used as microbeads and nanobeads in synthetic turf infill, plastic packaging, cosmetic products, and agricultural applications such as fertilizers and seed coatings. According to the European Chemicals Agency (ECHA), micro- and nanoplastics (MP/NP) that are intentionally added to manufactured products are released into the environment at an estimated rate of 42,000 tons per year [7]. Because of their omnipresence, MP/NP fall within the exposome concept and their contamination (by ingestion and inhalation mostly) cannot be escaped. Indeed, the meta-analysis by Senathirajah *et al.* in 2021 definitively confirmed the impact of the environmental presence of plastics and thus human exposure [8]. Recently, as reviewed by Prata *et al.* [4], individual daily exposure to MP was estimated at 107–143 particles via ingestion [9] and 26–130 particles via indoor inhalation [10].

Physiological “barriers” are demonstrably permeable to MP/NP, which exhibit cytotoxic, inflammatory and immune effects [11] as they can infiltrate various human tissues and deep organs [12], including the gonads. The ovaries are already exposed to MP/NP; exposure of rodents to supra-environmental doses (ranging from 0.015 to 30 mg/kg/day) has highlighted their passage into the gonads in general and into oocytes in particular through the blood-follicle barrier [13]. In utero exposure to MP/NP is therefore a continuum affecting the conceptus even before implantation and placental development.

The placenta is an ephemeral organ essential for the exchange of nutrients and gases between the maternal and fetal blood. Furthermore, the placenta offers the fetus a degree of protection against potentially harmful environmental elements, such as xenobiotics (drugs, pollutants) and germs. Readers may refer to an overview of its key-functions in Burton *et al.'s* elegant paper [14].

The human placenta is anchored in the uterine wall through an invasive and physiologically aggressive process, which remodels the spiral uterine arteries and results in a placental interface known as the haemochorial type, in which the maternal blood is separated from the

fetal blood by a layer of tissue called the chorion. On the fetal side, the chorionic surface is connected to the umbilical cord, which features rich vascular arborization (via umbilical vessels); on the maternal side, the basal surface is embedded in the maternal decidua, segmented into cotyledons, each made up of multiple chorionic villi that form the structural and functional unit of the placenta, as detailed in Fig. 1. The terminal floating chorionic villus consists of a mesenchymal axis containing fetal vessels, fibroblasts and macrophages (Hofbauer cells). At the periphery of the villus, the underlying epithelium of mononucleated villous cytotrophoblast (VCT) fuses to form a multinucleated syncytiotrophoblast (ST), which ensures the following functional triad:

a/ Maternal-fetal exchanges and permissive barrier: for xenobiotics that are not effluxed by active transporters of the ABC (ATP-binding cassette) family, but instead are captured by different transfer systems (passive, facilitated diffusion, active transport, endocytosis) used for nutrient exchanges. It holds a metabolic arsenal in order to limit fetal exposure. Endocytosis, the preferred mechanism for high molecular weight pollutants, may be mediated by clathrin-dependent invagination guided to an endosome along microtubular tracks, or even be caveolae-dependent, rich in cholesterol and sphingolipids.

b/ Endocrine function, via the synthesis and polarized secretion into the maternal circulation of steroid and glycoprotein hormones (such as hCG, i.e the human chorionic gonadotropin) in high concentrations from the first weeks of pregnancy, which ensures placental development, metabolic adaptation of the maternal organism and fetal growth until parturition is triggered.

c/ Angiogenic function, mainly mediated by VEGF (vascular endothelial growth factor) signaling pathways and their endothelial receptors.

Although the reprotoxic effects of plasticizers (such as phthalates and bisphenol A [15]) and eco-corona components (such as metals [16]) have been well characterized, those of MP/NP remain poorly understood. In the light of a research dealing with effects of nanopolystyrene on human primary cytotrophoblast [17], our research group has sought to address in this review several questions regarding the interaction between MP/NP and the placenta: (i) are the placenta's barrier properties impaired by exposure to MP/NP?; (ii) are its endocrine and
immune functions affected?; and (iii) what about the potential effects on fetal growth and the long-term metabolic consequences (in light of Barker's thrifty phenotype hypothesis, formulated in the 1990s, or the so-called DOHaD, which proposes that prenatal environment and altered fetal programming significantly influence chronic, childhood and adult-onset chronic diseases)?

Detailed reviews are available on environmental and food hygiene considerations (notably for pregnant women) [18], the characteristics of experimental models of the placenta and their use in assessing the impact of plastics [19], the mechanisms involved in placental transport and metabolism [20], reprotoxic effects on aquatic and terrestrial animals (albeit with a relatively limited focus on the human placenta) [21], data on postnatal exposure [22] and clinical data [23,24]. Built upon Panneerselvam's review [25], our present narrative literature review complements these works and focus especially on placental exposure and does not encompass data on preconceptional or strictly postnatal exposure.

Our narrative literature review is based on a search of the PubMed database up to February 2025 (Fig. 2). We focus on impairments of placental functions due to MP/NP and potential associations with fetal and/or neonatal diseases. First, we examine the clinical studies that have documented the presence of plastic in the human placenta. Second, we review studies of the human placenta's hemodynamic behavior *ex vivo*. We then explore possible responses to these issues by analyzing (i) *in vitro* data on the cellular and molecular mechanisms involved and (ii) *in vivo* data (restricted to murine models) on pregnancy and fetal outcomes). A table summarizing the strengths and weaknesses/limits of each study is available (Supplementary data). Several limitations in our literature review method should be noted: the use of a single database mainly focused on the biomedical field; a focus on cohorts dealing mainly with MP/NP detection, not on additives; and with one exception, these publications are dedicated to positive results, which may lead to a hypothetical overestimation of MP/NP effects.

## 2. Clinical insights into plastic exposure: from plasticemia to plasticenta

### 2.1. Plasticemia

The recent findings of MP in human blood (hereafter referred to as “plasticemia”) [26–28] raise a major epidemiological and toxicological issue.

Leslie *et al.* were the first to quantify MP/NP in the whole blood of 17 of the 22 (77%) apparently healthy study participants in the Netherlands. By a pyrolysis–gas chromatography–mass spectrometry (Pyr-GC-MS) method, the mean total MP/NP concentration in non-fasting total blood samples was 1.6 µg/mL [26]. In decreasing order of frequency, polyethylene terephthalate (PET), PS, PE, poly-methylmethacrylate (PMMA), and polypropylene (PP) were detected. MP/NP blood concentration was as high as 12 µg/mL in some participants, and the greatest value observed for PS was 4.8 µg/mL. The sampling conditions (notably the internal diameter of the needle and/or sample preparation steps, such as filtration before pyrolysis) have restricted the size range of the MP/NP determined (700 nm-500 µm). Given the limit of detection of Pyr-GC-MS and the lack of reproducibility of the analysis (possibly due to a matrix effect) [29], this study probably offers a partial view of the phenomenon of *plasticemia*.

Next, Leonard *et al.* measured MP in enzyme-digested blood samples from 20 apparently healthy volunteers, using micro-Fourier transform infrared spectroscopy (micro-FTIR) [28]. They detected a higher prevalence of blood MP (90%) prior to the quantification step (versus 40% after applying limit of quantification criteria). Possibly due to geographical differences, the MP pattern found in this Canadian population differed markedly from that observed by Leslie *et al.*: PE was the most abundant, followed by ethylene–vinyl acetate/ethylene vinyl alcohol (EVA/EVOH), ethylene propylene diene monomer (EPDM),

polyamide (PA) and EVA (ethylene vinyl-acetate). As a result, the total MP concentration estimated using an equation (better suited to fibers than fragments) was 0.66 ± 0.87 µg/mL. This was lower than (but broadly) consistent with Leslie *et al.*'s study.

In parallel, the presence of NP in peripheral blood has also been described qualitatively [27]. Here, an indirect approach, using lipophilic Nile Red flow cytometry, was used to study blood samples from 129 individuals in Barcelona (including 37 healthy individuals, 36 newborns, and patients with hematologic malignancies). Although lacking specificity, this technique may detect NP. All participants (including pregnant and non-pregnant women, non-pregnant women, as well as newborns) had detectable levels in their blood. This finding confirms the presence of subclinical levels of NP in their blood during pregnancy. In parallel, a study using a laser direct infrared (LDIR) and scanning electron microscopy identified nine types of MP (smaller than 184 µm) in blood samples from 15 patients undergoing cardiac surgery [30], with PET being was the most abundant plastic (as in Leslie *et al.*'s study), followed by PP and other MP. The MP were found in all samples, ranging from 20 to 184 µm. The smallest of these MP could have blocked blood capillaries.

Despite the bias inherent to the digestion process, these techniques provided precious insights into the size and shape of bloodborne MP – key variables for placental uptake and dissemination. Notably, no acute toxic event were reported in Leslie's and Leonard's studies. These pioneering studies did not report the level of exposure to plastics, the sex ratio, or whether any of the women were pregnant. MP/NP concentrations in pregnant women might be decreased by the typical hemodilution. Their findings are crucial, not only for the clinical relevance of MP/NP exposure in *in vitro* models, but also because they provide evidence of the need to monitor plastic pollution biological impact. Beyond the disparity among the analytical strategies, this reflects the high prevalence and heterogeneity of plasticemia in different parts of the Western world. The question of the correlation between peripheral and intratissular levels is open.

The presence of MP/NP in the bloodstream appears to result in their potential deposition in the vascular tree. Indeed, Rotchell *et al.* found NP (alkyl resin, polyvinyl propionate/acetate and nylon-EVA) of various sizes (ranging from 12 to 208 µm in length and from 7 to 300 µm in width) in saphenous explants [31]. Similarly, the discovery of PE-MP in a thrombus biopsy (using Raman spectroscopy) provided further indirect evidence of the passage of MP/NP through the bloodstream and their subsequent deposition in or near the vascular tree. Furthermore, other polymers (PA, PVC, and PP) were recently discovered in thrombi at several anatomically distinct sites [32]. The presence of MP in blood also raises the question of a possible effect on blood cells themselves (especially erythrocytes) and blood functions (including hemostasis, which is a particularly relevant feature for the highly perfused placenta). Gopinath *et al.* reported significant hemolysis in human blood exposed to 100 nm native or carboxylate PS-NP [33]. The effect appears to be particle-size-dependent because Pluciennik *et al.* did not observe any changes in erythrocytes exposed to smaller particles (30, 45 and 70 nm) [34]. Last but not least, plastic in blood can be derived from the indirect infusion into the bloodstream, since a study found PVC-MP/NP (down to 20 nm in size) released by intravenous infusion bags [35].

We shall now briefly give some background information on the clinical and epidemiological data on the interaction between MP/NP and the intestinal, pulmonary and skin barriers in the context of pregnancy.

i) With regard to the lungs, healthy participants can inhale plastic particles into the alveoli [36]. This phenomenon might be accentuated by hormonally-triggered ventilatory adaptations during pregnancy. Cox *et al.* estimated that women inhale an average of 132 MP per day [9]. Based on this estimate, Fournier *et al.* modeled the conversion of MP into NP and found a value of 6.67 × 10¹⁶ NP [37]. ii) With regard to the gastrointestinal tract, the estimated weekly ingestion of MP is 0.1–5 g [8]. The transfer of MP/NP into the portal vein (either directly or via the
lymph) remains to be characterized. Based on nutritional data from North America, a woman's estimated daily intake is approximately 126 MP [8]. The reduction in intestinal motility induced by progesterone during pregnancy might favor a longer residence time of MP/NP in the digestive tract. iii) Along with the dominant pulmonary and gastrointestinal routes, MP have been detected on the skin [38]. Cosmetics can be a source of exposure (e.g., glitter can contain PET) [39]. However, the dermis might constitute an entry route (primarily for NP), especially following changes in dermal structure during pregnancy-associated skin conditions [40]. With regard to the vaginal cavity, PU condoms and period products can also be sources of MP/NP (such as polyester, PP, PE, and nylon) that might reach the uterus or pass into the circulation [39]. In a recent study in China, 13 types of MP were discovered in the endometrium of 19 of 20 healthy nulliparous women [41]. With a median abundance of 21 MP/g, the IR method detected small MP (20–100 µm, notably ethylene-acrylic acid copolymers) and large MP (100–500 µm, such as PE and PVC). Intriguingly, their deposition was correlated with the consumption of carbonated beverages and chewing gum.

What about the excretion routes? Urinary excretion of colored MP was recently documented in one of the three women studied by Pironti et al. [42]. In parallel, two studies have reported on the presence of MP in breast milk [43,44] which constitutes one of the first sources of oral absorption of plastics in newborns.

With regard to the placenta, it is reasonable to consider that plastics in the mother's blood can reach the uterine arteries which perfuse the intervillous chambers (Fig. 1). The large surface area for gas and nutrient exchange in the placenta (around $14\ m^2$ in total) favors their deposition. Since MP are known to be present in tissues downstream of the vascular tree, they can also reach the highly vascularized placental parenchyma; this prompted Ragusa et al. to develop the "plasticenta" concept [45], as discussed below.

## 2.2. *Plasticenta*

The human placenta is the second most documented organ in terms of MP deposition [46]. This stems from the fact that access after childbirth is easy, practical, and non-invasive, and thereby minimizes ethical concerns. The characteristics and main findings of clinical observational studies (focused on the placenta) are summarized in Table 1 [43,45,47–58]. Let us examine the clinical, epidemiological, histological, and ultrastructural aspects of *plasticenta*.

In 2021, Ragusa et al. were the first to document the presence of compounds identified as MP in placental tissue [45]. The fourteen cohorts came from Europe [45,47,48,51], the Middle East [49], Asia [50, 54–56,43,59], North America [53,57,58], and the Pacific (from Hawaii) [52]. MP shapes and sizes varied greatly, ranging from 2 µm to over 200 µm, and were smaller than most of MP found in blood. All polymers detected by Leslie et al. [26] were also found in placental tissues. The studies probably underestimated the total placental deposition due to the nature of sampling. Furthermore, the small weight of the placental samples (which had to be filtered several times) might not have been representative of this large organ. For instance, in their study in Canada, Zurub et al. calculated that a full-term placenta contained 650–2 600 MP particles and (potentially) other non-plastic particles [53]. The types and abundances of plastics differed from one study to another and might reflect geographic differences in population exposure. Some of the numerous MP/NP found by Jochum et al. have been the subject of clustered analysis suggesting shared pathways of exposure [58]. The only retrospective study, the Hawaiian one, found an interesting trend towards an increase in the absolute and relative MP counts over the last two decades, although the same polymers were not always found during the study periods considered [52]. This study was not performed in an area close to petrochemical industry sites and confirmed the global presence of thus invisible MP exposure.

*Plasticenta* can be observed in pregnant women with both complication-free pregnancies and no significant medical history or

comorbidities (except gestational diabetes, hypothyroidism, or heavy smoking in some cases) as well as pathological pregnancies. The absence of longitudinal follow-up in most newborns precludes confirming or ruling out the occurrence of medium- or long-term toxicity later in life. Three clinical studies have examined the association between MP and pregnancy outcomes. The first highlighted the systematic presence of MP (mostly fragments) and a correlation with idiopathic intrauterine growth retardation (IUGR), which might suggest the presence of a hidden placental disorder [49]. Interestingly, the polymer found (mainly PE) was the same as that observed in maternal capillary blood, skin and saliva samples in another cohort of participants from the same city in Iran [38]. Although Halfar et al.'s study was not a comparative one, it is noteworthy that all preterm pregnancies had documented elevated MP in placenta and amniotic fluid [51]. The study of a small Chinese cohort indicated that the presence of PS in villous tissues might be a strong risk factor and could serve as a predictor for idiopathic recurrent miscarriage [54]. Jochum et al. showed by logistic regression that PVC and PC can be independent predictors of premature birth, in parallel with the elevation of PET and PU found in preeclampsia and gestational diabetes, two comorbidities associated with preterm birth [58].

In epidemiological terms, three questionnaire-based studies [43,49,56] demonstrated some interesting correlations or associations between the presence of some type of MP and hygiene and dietary behaviors: high consumption of bottled water, use of certain toothpastes, consumption of mead (hydromel), takeaway food, non-stick cookware, plastic food containers. Comparative studies involving large populations are needed to provide robust data, enabling the delivery of documented, relevant preventive advice to women in order to minimize their exposure [18].

In histological terms, numerous of the above-mentioned studies showed that the maternal and fetal sides of all the placental strata (including the chorioamniotic membranes) are affected by the deposition of MP. These data also suggest that the impairment of the placenta's selective barrier properties and the deep deposition of MP are related to *in utero* exposure and not external contamination during childbirth. The entire villous architecture appears to be affected by MP deposition, mostly in the ST which appears to contain a particularly high number of MP [45]. The MP/NP, sparing the nuclei, were found to be either "free" in the cytosol and/or located in organelles identified as lysosomes, peroxisomes, or even in lipid droplet and vacuoles. MP deposition has been associated with swollen/pyknotic mitochondria, dilated rough endoplasmic reticulum, and aggregosomes, reflecting multiple signs of intracellular stress [48,50]. MP were also detected in fetal capillaries (specifically in pericytes and the endothelial cells) [48].

Due to the nature of sampling, we lack data on whether *plasticenta* result from cumulative exposure during pregnancy or from acute absorption. The placenta undergoes structural modifications during pregnancy that might impact the toxicodynamics of MP/NP. Further studies of MP transport at earlier stages of development and during full-term delivery are needed. Jochum et al. found that despite shorter gestations, preterm placentas exhibited a counterintuitively 28 % higher cumulative concentration of most MP/NP, suggesting their influence on pregnancy duration [58].

A pilot clinical study of amniotic fluid samples (collected during premature rupture of membranes) highlighted the presence of MP (mainly chlorinated PE, CPE) and plastic additives in seven of the 10 patients [51]. The lower MP count and the broad range of components in amniotic fluid (compared with the placenta) suggest that the placental barrier is at least partially permissive. A study based on an original dual-analytical method reported an 80 % presence of various MP - polytetrafluoroethylene, PS and acrylonitrile-butadiene-styrene, mostly, in amniotic fluid, without immediate adverse pregnancy outcomes [60]. The timing of amniotic fluid sampling precludes identifying the source of the deposited MP. Indeed, the amniotic fluid emanates exclusively from maternal plasma ultrafiltrate until the 8th week, after which fetal urine dominates. In a study of a cohort of 40 healthy singleton pregnancies in Shanghai, there was an inverse correlation between the
amniotic fluid count of MP (mainly fragments of PE and CPE, ranging from 20 to 100 µm, detected using LDIR spectroscopy in 80 % of samples) and gestational age, suggesting that MP content diminishes with gestational age at delivery [61]. The authors suggested that MP (correlated with the consumption of plastic water bottles and seafood) might be associated with a shorter pregnancy [61].

The possibility of a transfer via the placenta-cord blood-meconium pathway has been reported recently by Zhu *et al.* for some polymers, shedding new light on direct fetal exposure. [50]. They show in a smaller cohort of nine pregnancies, an interesting correlation between the abundance of various MP in cord blood and placenta [59]. The *in utero* swallowing of amniotic fluid could lead to the substantial MP transfer, resulting in a diverse intrameconial MP content that may indicate long-term fetal accumulation [61]. MP have been detected in the fetal gastrointestinal tract and in meconium, although the data are somewhat contradictory and might be influenced by the differences in sampling and detection methods used [43,47,62]. Taken as a whole, these data indicate that (i) cumulative, prolonged placental exposure to MP likely can occur since 70–80 days of gestation, when the meconium starts to form, (ii) the fetus may excrete MP, as their quantity in the meconium can exceed that found in the placenta. A low degree of diversity in the so-called placental microbiota – whose existence is still debated – is significantly correlated with plasticenta (notably PS) [63].

Despite the meticulously plastic-free protocols used in these studies, the risk of environmental contamination is present, from sample collection to analysis. During childbirth, the lack of air filtration in the delivery room can be partly compensated for by isolating the placenta as early as possible. Specific negative controls cannot be performed at this stage. We do not know for sure whether the mode of delivery – vaginal or cesarean – influences external contamination [53]. Theoretically, cesarean surgery exposes women to many plastic medical devices (protective film prior to incision, syringes) which constitute a potential risk factor for exposure to MP. Also, the potential intravaginal content of MP can trigger a contamination. However, a recent study showed that the mode of delivery does not have a significant impact on the *plasticenta*; this finding suggests that MP deposition occurs during pregnancy and not at or after birth [53]. Differences in workflows challenge comparisons of these studies, some of which included a relatively small number of patients. Heterogeneity in sampling (e.g. the number and surface area), the sample digestion process (such as heating the sample, which can modify the physicochemical behavior of MP), the porosity of the filters (limiting the size range found), the analytical methods, and the completeness of the spectral databases all make comparisons very difficult. As opposed to non-destructive techniques such as Raman, which provide information on particle shape and size, it should be noted that destructive methods such as pyrolysis prior to GC/MS only allow detection of monomer compounds (such as styrene, propylene and ethylene...) as a proxy for the evaluation of chemicals used in plastic production, not MP/NP per se. However, the microscopic and spectroscopic technologies mentioned above might be very useful tools for documenting and monitoring intrauterine exposure to plastics, potentially through screening by the pathologist [64] and the medical biologist. In the future, a *plasticemia* assay (i.e. biomarkers of environmental plastic impregnation) might be epidemiologically relevant at birth.

### 3. When the human placenta encounters plastics: functional investigations

The placenta is highly species-specific. Among the various models of the human placenta developed to date, the *ex vivo* cotyledon perfusion model best mimics the hemodynamics of the cotyledon [65]. This model is valuable for studying transplacental passage, kinetics, and potential accumulation of NP as well as their functional impact on the placenta [66]. The maternal-fetal circulation is reproduced by inserting cannulas into the lobule's intervillous area, compensating for the lack of catheterizable maternal vessels. Several studies focused on PS-NP [67–71],

summarized in Table 2. The placentas from full-term pregnancies were obtained after cesarean sections or vaginal deliveries. None of the studies reported the age of the mother or the sex of the fetus. The placentas were exposed in a closed circuit to native NP and/or functionalized form at a supra-environmental dose (15–40 µg/mL), with clear bidirectional passage. The functionalization of NP involves surface modifications, such as carboxylation or amination (as performed in the manufacture of certain polymers).

The transfer of unlabeled PS-NP particles (25 µg/mL) into the maternal circulation compartment was size-dependent, with higher transfer rates observed for smaller nanoparticles. After 3 h, the NP concentrations in the fetal compartment were three to ten times lower for particle sized 50, 80 and 240 nm, and much lower for particles at 500 nm. This likely reflects either the placental barrier's relative impermeability to larger nanoparticles or retention of PS-NP in the *ex vivo* perfused uterine artery [69]. Functionalized (carboxyl) PS-NP also exhibited bidirectional placental transfer between maternal and fetal compartments, albeit less rapidly than unlabeled PS-NP [68]. While the exact mechanism of internalization remains uncharacterized, it is thought to involve an active, non-passive transport pathway. Given the small exchange surface area, anterograde transfer (towards the fetal unit) was significantly greater than retrograde transfer; suggesting that multiple transport systems and internalization mechanisms are at work on the maternal side [68].

Biocorona formation is a major determinant of the placental passage of MP/NP, as it also influences the surface reactivity and functionalization of these hydrophobic compounds in the circulatory system. Plasma proteins have an essential role in the formation and remodeling of the biocorona. By binding noncovalently to native NP, albumin forms a protein stratum that greatly increases PS-NP size [33]. The coalescence of NP can change the conformation of circulating albumin, with a functional impact that has not been established yet [33]. Using various culture media supplemented with plasma from women, the composition of the 80 nm NP corona was examined at various points in the circuit [71]. Proteomic analyses revealed profound quantitative changes in the composition of the corona, which was mainly composed of albumin and IgG. Given the changes in plasma levels of these proteins during pregnancy (due to hemodilution and/or changes in their synthesis or catabolism), the maternal-fetal transfer of NP might be enhanced. Unlabeled or functionalized NP were deposited throughout the villi, particularly in the ST [70]; this confirmed the results of Ragusa [48].

Several functional consequences of plastic accumulation in the placenta have been reported. Endocrine and metabolic functions are generally not impaired by exposure for less than 6 h. In contrast, 70 nm NP-PS (25 µg/mL) reportedly enhanced the expression of genes involved in cell cycle regulation (specifically the G2/M transition due to the proliferative nature of cytotrophoblast and mesenchymal cells), DNA repair, and the inflammatory response (chemotaxis and degranulation) in whole placenta samples [67]. This latter effect was confirmed by RTqPCR assays, with a trend towards overexpression of IL-6 (associated with infertility and pre-eclampsia). Overexpression of cytochromes CYP1A1 (involved in progesterone metabolism) and cytochrome CYP1B1 was also observed.

### 4. Plastics and cell-based *in vitro* models of the human placenta: data on acute exposure

#### 4.1. *Internalization and transport*

Cultures of human carcinoma lines are more readily available than freshly isolated primary cells. They provide specific data on the influence of the MP/NP physical characteristics (e.g., size, charge, etc.) and their passage across the placental barrier (Table 2).

Translocation of 50 nm PS into trophoblastic cells varied significantly across different cell lines, with values of 30 %, 40 % and 70 % for JAR, BeWo, and Swan 71, respectively [72–74]. These disparities might
be due to interindividual phenotypic variability of the original tumors and the trophoblast's state of differentiation. Experiments in a Transwell co-culture with trophoblastic BeWo b30 cells at the apical pole and fetal HPEC-2A endothelial cells at the basal pole highlighted the predominant role of key-cells of villi in maintaining barrier function [74,75]. Although NP transport in BeWo b30 appeared to be particularly low, the confluent barrier was impermeable. Wan et al. showed, in the same Transwell model, that Swan 71 cells' migration/ invasion was gradually suppressed with PS-NP (50–200 µg/mL, 50 nm) [55]. Cocktail experiments with PMMA and silicon dioxide nanoparticles at the same concentration (50 µg/mL) abolished the effect on Swan 71 migration/invasion phenotype, suggesting the importance of the chemical surface composition and the particle number in the mix. The degree of syncytialization is also determinant for the passage of PS-NP [76].

The importance of the plastic particle surface charge for internalization (mentioned above for the perfused cetylodon model) has been questioned. Inhibition of active ABC transporters (notably MRP-1) by the MK571 antagonist resulted in a moderate reduction in the basolateral passage of amino PS-NP (-NH2). None of the other inhibitors tested had an impact on particle transport, regardless of the surface charge [77]. One limitation is the distinct transporter expression profile in the BeWo cell line compared with cultured primary trophoblasts. Furthermore, NP-PS appear to be able to cross the placental barrier passively, and this might even be the main internalization mode. A passive "Trojan horse" mode appears to be favored by the protein corona. The mechanism of endocytosis remains obscure but might occur through a caveolae-/clathrin-dependent pathway, although inhibitors like chlorpromazine and methyl-β-cyclodextrin did not modify NP translocation [77]. These results also suggest a possible passive translocation of particles across cell membranes through the disruption of intercellular tight-junction permeability. After the internalization of 50 nm NP, transmission electron microscopy and confocal microscopy evidenced particles within several organelles (including endosomes, lysosomes and mitochondria). Based on their previous observation in human placenta, Ragusa et al. [48] showed by immunofluorescence and TEM that HTR8/SVneo cells can also internalize PS-NP, accumulating notably in lysosome-like structures, as well as others bilayer compartments, inducing similar stress phenotype with ultrastructural alterations (ER dilatation and vesication, mitochondrial ballooning) [78]. Moreover, PS-NP was also shown to accumulate and transit in Swan 71 migrasomes (i.e organelles with a vesicle-like structure produced during cell migration) through the downregulation of the SOX2-ROCK1 transcription, impairing their production and function in trophoblasts [54]. Worryingly, 100 nm PS-NP, after 48 h of exposure to supra-environmental dose, were able to reach the nuclei of HTR8/SVneo cells, raising the question of a genotoxic impact [79].

## 4.2. Cellular effects: cytotoxicity, oxidative stress, and inflammation

The cytotoxic effects of MP/NP on placental tissue have been studied in various villous (VCT) and extravillous (EVCT) cytotrophoblast models, as well as human umbilical vein endothelial cells (HUVEC) and, more rarely, in primary trophoblast and placental explants, with a focus on the cellular and subcellular impacts on the maternal-fetal barrier. These studies are summarized in Table 2.

Each cell line has a distinct phenotype and specific features regarding intercellular tight junctions, glucose transport, and hormone secretion. In the BeWo b30 villous trophoblastic line, no significant reduction in viability was observed upon exposure at environmental dose to neutral or negatively charged (e.g. carboxylated) PS-NP, whatever the particle size (between 50 and 500 nm) [77,80]. However, Shen et al. reported a ~50 % relative decrease in JEG3 cell viability after exposure to negatively charged (carboxylated) 25 nm NP but only at supra-environmental concentration [80]. In contrast, PS-NP cytotoxicity appears to correlate positively with positive surface charge. Following

exposure to 50 nm amine-conjugated PS, cell viability was reduced by 30 % at 10 µg/mL and by 90 % at 100 µg/mL [77]. At environmentally relevant doses (1–15 µg/mL), cytotoxicity seems to vary depending on both the cell line and NP surface charge.

To date, only one study has directly compared cytotoxicity in VCT isolated from term placentas (primary culture) with that in the immortalized 3A-Sub-E cell line [81]. The immortalized cells showed greater viability and resistance to apoptosis and senescence than the primary cells. In parallel, exposure to 40 nm PS-NP induced increased expression of the apoptosis marker caspase-3 in the 3A-Sub-E line (at 500 µg/mL) [81], Swan 71 cells (up to 50 µg/mL) [55], and primary cultured trophoblasts (from 50 µg/mL upwards) [81].

Effects of NP exposure on redox homeostasis and oxidative stress have been investigated mainly in extravillous trophoblast models (HTR8/SVneo and JEG3 cells) (Table 2). In both models, 100 µg/mL of 25 nm PS and (to a lesser extent) 100 nm PS were associated with increased production of reactive oxygen species. This oxidative stress was coupled with immune dysregulation, evidenced by enhanced release of pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor alpha) and decreased secretion of immunomodulatory cytokines (interleukins-4 and -10) after 48 h of exposure—even at relatively low doses of PS (10 µg/mL) [79]. Overall, MP/NP exposure in villous trophoblasts seems to promote inflammation in a size-dependent manner. Indeed, an inverse correlation between particle size and induction of inflammatory markers (CXCL1-ATF3) was reported in the JEG3 model [80]. Also, 72 h exposure of 40–200 nm carboxylated PS can trigger, with a differential uptake and effects, a concentration-dependent genotoxic damage, whereas a shorter, supra-environmental exposure with 40 nm down regulates several important actors implicated in the trophoblastic migration [82]. As for HTR8/SVneo cells, Ragusa et al. noted a striking decrease in viability from slightly supra-environmental doses (10 µg/mL), with a dose-effect up to 100 µg/mL of PS-NP during 24 and 48 h of exposure [78]. Intriguingly, 24–48 h exposure to PS-NP compromises the proliferation of HTR-8/SVneo cells in a time- and dose-dependent manner, and impacts the migration and invasion property after wound healing, whereas exposure to PS-MP promotes oxidative cell metabolic activity and at the same concentration and conditions, does not hamper invasion phenotype. In addition, 50 nm PS-NP at a high dose of 200 µg/mL triggers an impairment of the cycle arrest at the G0/G1 phase, impeding S-phase and inducing apoptosis [83]. As observed for certain plasticizers, exposure of trophoblasts to MP/NP has an impact on the cell cycle, with reduced cell proliferation and a greater number of cells in the G2 phase [80]. Interestingly, the genes that are most strongly overexpressed after exposure of *ex vivo* human placenta to 70 nm PS-NP are among those that regulate the cell cycle [67]. Similarly, reduced migration (in a wounding assay) and decreased cell invasion (in a Transwell assay) were observed after a 24-hour exposure of HTR8/SVneo extravillous trophoblasts to 100 nm particles at 100 µg/mL [79]. Taken as a hole, these NP can compromise early-pregnancy trophoblastic phenotype and key-functions.

Several studies have investigated the cellular and subcellular impact of exposure to MP on HUVEC [84–87], which constitute the last protective barrier before plastics reach the fetal compartment. The viability of HUVEC lines exposed to PS was around 20 % lower after exposure to 20 µg/mL PS ranging in size between 500 nm and 1 µm [84]. The overall cytotoxicity of MP was therefore rather moderate for exposures lasting up to 48 h. Likewise, large NP (100–500 nm in size) induced autophagy, as evidenced notably by greater expression of LC3-II/LC3-I autophagosome membrane proteins and the accumulation of particles in autophagosomes, which was caused by a suppression of the AKT pathway [86]. Lu et al. showed that in contrast to trophoblastic models, HUVEC did not present oxidative stress or inflammation. However, the researchers observed lysosomal dysfunction, with the underexpression of lysosomal membrane proteins and acid hydrolases (LAMP-2 and CTSB) [86]. In experiments on endothelial cells exposed to 500 nm PS, Lee et al. reported a low migration capacity (from 40 µg/mL upwards) and a
<figure><img src="image_7.png" /><figcaption>**Fig. 3.** Overview of molecular pathways induced by MP/NP exposure. After internalization in the chorionic villi (structure schematically shown on the left), MP/NP may be free in the cytoplasm or encapsulated in phagosome-like structures. Autophagosomes fuse with lysosomes, in which MP/NP can accumulate and thus may block the autophagic flux. The oxidative stress generated by these foreign bodies may be accompanied by genotoxicity and the triggering of a pro-inflammatory cascade (mediated by NF-κB), leading to cell death through apoptosis. Like the mechanisms of internalization, the mechanisms of efflux are still largely unknown, but may involve the MRP1 transporter. These cellular and metabolic alterations can lead to major functional impairments for the key cell type of the chorionic villi (right), which may be associated with pathological outcomes (right, bottom).</figcaption></figure>

significant (30%) relative decrease in tubulogenesis (from 20 µg/mL upwards) [84]. These antiangiogenic effects appeared to be mediated by the MAPK/SMAD2 pathways, because of reduced activity of the P38 and ERK pathways.

Lastly, one study dedicated to examining the impact of MP on fresh explants of chorionic villi, from 40 placentas at term with healthy pregnancies, provided valuable insights due to their accessibility and preserved tissue architecture [88]. Here, 5 µm PS at a supra-environmental dose (100 µg/mL) triggered cytotoxicity, oxidative damage and depletion of antioxidant defenses, leading to various biochemical disruptions in intermediary and energy metabolism favoring general mitochondrial dysfunction. Regarding primary cultured trophoblast — a particularly challenging model due to the complexity of sample collection and the technical difficulty of the trophoblast purification protocol [65] — our group has shown for the first time that exposure up to 48 h to NP-PS triggers size- (20 and 100 nm) and dose-dependent (10–100 µg/mL) lysosomal accumulation, cytotoxicity, inflammatory response and endocrine disruption for hCG [17].

The cellular and molecular mechanisms induced by MP/NP exposure mentioned above, and their consequences on placental functions, are summarized in Fig. 3.

## 5. In silico data

Data from *in silico* studies is sparse. Only one model (using predictive approaches such as molecular docking, density functional theory, and fractional factorial design) suggested that interactions between plastics and placental enzymes have a key role in the metabolization of xenobiotics [89]. PS, PC, and PET might strongly inhibit the enzymes epoxide hydrolase, uracil phosphoribosyltransferase, beta 1,3-glucuronyltransferase I, sulfotransferase, N-acetyltransferase 2, and cytochrome P450 1A1 [89]. Recognition at the enzyme active site is improved through pi- and alkyl interactions mediated by the plastic's aromatic rings [89].

However, it is difficult to predict the overall effect (toxic or not toxic) of this enzyme inhibition. This work needs to be confirmed by enzyme activity assays and highlights the complexity of studying xenobiotic metabolism in the context of “cocktail effects”.

## 6. Data in murine models: chronic exposure

### 6.1. Maternal-fetal passage of plastics

Although the mouse placenta is hemochorial, it differs significantly from the human placenta with regard to organogenesis and anatomy [90].

The murine placenta is composed of two main zones:

- Located between the maternal decidua and the labyrinthine zone, the junctional zone, composed of spongiotrophoblasts and glycogen cells, is mainly responsible for endocrine functions and growth hormone production.

- Parallel to the villous architecture in humans, the labyrinthine zone is responsible for fetomaternal exchanges.

The murine placenta is hemotrichorial because the labyrinthine zone is composed of three layers of trophoblastic cells in addition to the layer of fetal endothelial cells:

- Giant sinusoidal trophoblastic cell layer (CTSG): in direct contact with maternal blood, permeable to small molecules and low-molecular-weight solutes.

- Syncytiotrophoblast bilayer: multinucleated cells, between the CTSG layer and fetal endothelial cells, resulting from the fusion of underlying trophoblasts via the action of syncytins A and B (different from human syncytins but sharing the same fusogenic characteristics).

Multiparity offers an interesting model for establishing causal links between controlled exposure during a short gestation time and potential teratogenic, transgenerational, and/or epigenetic effects. Most of our knowledge of the mechanisms of plastic deposition and toxicity in the
placenta has been derived from mice. Studies with a focus on placenta are summarized in Table 3. [37,54,55,81,91–108].

With few exceptions [101,103,109–111], all these in vivo studies were based on exposure to spherical PS during gestation. Although this type of exposure is not representative of the diversity and complexity of plastic particles found in human *plasticenta*, it enhances interstudy comparability and reproducibility. However, the heterogeneity of study methodologies — including the route of administration, duration of exposure, particle size, surface functionalization, and detection techniques for PS-NP — complicates the overall interpretation of results. Acute administration methods varied across studies and included continuous administration through *via* the jugular vein, single caudal bolus injection, intratracheal instillation, and oral gavage. While parenteral administration (peritoneal or intravenous) allows for better control of the dose over the short gestation period, it does not reflect physiological exposure routes. Most studies investigated PS-NP ranging from 20 to 500 nm, whereas other studies examined PS-MP particles sized 5–20 µm. The physicochemical characteristics of the spherical PS particles were extensively characterized (Table 3).

Tissue deposition in the placenta and fetus has been explored in several studies. Several investigations involving exposure of pregnant mice to fluorescent PS nanobeads confirmed systemic distribution and accumulation within placental tissue. Complementary evidence from an *ex vivo* perfusion model further supported the maternal-to-fetal and umbilical transfer of nanoparticles [103]. Kenesei *et al.* observed the clearance of functionalized PS-NP from the placental tissue within 4 days post-administration, consistent with the known half-life of fluorescent NP [91]. The authors hypothesized renal excretion as the main elimination route, given the absence of detectable fluorescence in fetal tissues. Conversely, a study by Chen *et al.* reported similar MP distributions in both placenta and fetal tissues, suggesting direct placental transfer [97]. In contrast, Tang *et al.* did not observe significant presence of 80 nm unlabelled PS-NP in the placenta after exposure via repeated oropharyngeal aspiration, highlighting the importance of the exposure route and clearance mechanisms in particle biodistribution [99]. One limitation of these chronic studies relates to the potential for artefactual fluorescent probe leakage during prolonged tissue contact, which may confound interpretation of nanoparticle localization.

The hematogenous diffusion of PS-NP in pregnant mice was corroborated by their colocalization with red blood cells in the labyrinthine zone, including maternal vascular sinusoids and fetal blood vessels — major sites of exchange and trafficking — as well as the fetal endothelium [95]. Considering the fenestrated nature of fetal capillaries and the discontinuous nature of cytotrophoblasts, these data suggest that the tight junctions of the ST bilayer (which is less permissive than the human monochorionic placenta) may be impaired [95]. Recent evidence of tight junction disorganization, notably in ZO-1, 2 and claudins 1 and 2, provides further insights into MP entry mechanisms into placental cells [104]. Macrophages may play an essential role in the translocation and extravasation of plastics, as suggested by the clustered appearance of 20 nm PS-NP particles [95]. Indirect phenotypic observations in flow cytometry studies suggest that NPs are internalized by polarized macrophages [93].

With regard to hemodynamics, Dibbon *et al.* showed that maternal exposure to PS-MP can affect fetal-placental blood flow in the umbilical artery in a size-dependent manner [102]. In contrast, a cocktail of PE MP/NP did not lead to outcomes such as IUGR or fetal loss and did not impact umbilical cord length but was associated with increased in umbilical artery blood flow suggestive of a placental functional impairment [103]. Finally, differential passage of MP/NP across the placenta might influence fetal labyrinth capillary arborization, via effects ranging from adaptive, compensatory mechanisms to placental functional impairment.

## 6.2. The impact of MP exposure on the placenta structure and function

The histological evidence of NP toxicity is heterogeneous, ranging from the lack of any detectable damage to alterations in the depths of the vascular tree. The latter were evidenced by a reduced number and smaller diameter of arterioles several weeks after a peritoneal injection of MP [93]. This raises the question of whether the chronic ingestion of an environmental dose is associated with poor placental perfusion, underdevelopment of labyrinthine vascularization, and impaired angiogenesis, which could alter the redox balance and lead to oxidative stress in the suboptimally perfused tissues [97]. In spongiotrophoblast and giant trophoblastic cells, the glycogen content tends to decrease; this is associated with a significant reduction in placental sucrose levels and has been attributed by Chen *et al.* to a either a lack of uptake or a compensatory metabolic redistribution related to altered cholesterol uptake (which is essential for the synthesis of progesterone) [97]. These processes appear to be mediated by the deregulation of apolipoprotein ApoA-IV gene expression [97]. Furthermore, an observed impairment in the coagulation cascade might have prothrombotic effects on placental perfusion and contribute to IUGR and preeclampsia [97]. Disturbances in the placental metabolism of glucose, biotin and the essential amino acid lysine were also noted, confirming an earlier report [96], as well as altered expression of amino acid transporters [104]. With regard to pregnancy outcomes, the changes in the bioavailability of these major metabolic intermediates in the early stages of ontogenesis might have a role in the onset of fetal hypotrophy. Consistent with a pro-inflammatory induced-phenotype, placental inflammatory infiltrate with necrotic areas were observed following continuous gavage of PS-MP, along with an induction of pro-apoptotic and ER stress (via the GRP78/IRE1α/JNK pathway) [104]. In parallel, MP-PS exposure has been associated to placental apoptosis [104].

The deregulation of immune processes in the placenta may also induce fetal disease, such as IUGR. Changes in the number and/or phenotype (according to surface markers) of decidual immune cell populations involved in uterine receptivity have been observed and were associated with perturbations of arterial remodeling, trophoblastic invasion, immune tolerance and the epithelial-mesenchymal transition. In this context, a reduction in the natural killer cell count, macrophage polarization towards an M2 phenotype, and an increase in the pro/anti-inflammatory cytokine ratio might all contribute to the generation of a reprotoxic response and a correlated increase in fetal-placental resorption [93,104].

## 7. Reprotoxic effects

The teratogenic direct effects of MP/NP are difficult to distinguish from impairments caused by extraplacental maternal disturbances. Data on toxicity are mainly focused on the fetus. Some of the observed alterations might be associated with fetal hypotrophy [37,96,97,99,104,112], greater placental resorption [37,93,113,114] or might not significantly affect viability [96,102]. The main pathological features highlighted were IUGR (hypotrophy is currently one of the conditions correlated with plasticenta in humans as seen above) and dysmetabolic, neurotoxic, reprotoxic and miscarriage risks [55]. A study highlighted a significant induction of miscarriage in mice treated with PS-NP taken orally. This induction was linked to the promotion of trophoblastic apoptosis, mediated by the Bcl2/caspase pathway [55]. Transcriptional upregulation of allograft rejection genes has been highlighted, raising questions about systemic effects on the onset of miscarriage. This inability of the placenta to satisfy fetal needs is frequently encountered in obstetrics and has been observed in the majority of murine studies. IUGR induced by MP might be (i) dose- and sex-dependent, (ii) potentially correctable in the postnatal period (i.e. lacking a final clinical impact), and (iii) counteracted by compensatory mechanisms, because Cary *et al.* observed that a low placental weight was nevertheless associated with a normal fetal weight [95].
Several studies have focused on the impact of MP/NP on various organs in the progeny, affecting both somatic cells and gametes.

Concerning the liver, Luo *et al.* observed a long-term decrease in the transcription of carbohydrate-lipid metabolism genes in the F1 progeny on postnatal days (PND) 42 and 280 and F2 progeny on PND 42 after exposure to MP during gestation in mice [92]. Furthermore, Huang *et al.* observed greater oxidative stress and inflammation in liver tissue on PND 21 and 56 [94]. As for the digestive tract, Tang et. al found that maternal exposure of 80 nm-PS triggers ROS generation and initiates a ferroptotic process, with a digestive toxicity particularly marked in female offspring [99].

Brain lesions have also been described, including sex-specific structural changes in the blood-brain barrier during the sexual differentiation period. For example, poor visual cortex function (as evidenced by early eye opening, a clinical sign of IUGR) was observed in males but not in females [98]. After oral administration of fluorescent PS-NP to pregnant rats, fluorescence was observed within the hippocampal and cortical tissues on PND 7 [100]. This signal was associated with impaired hippocampal neurogenesis/gliogenesis, reduced ATP production by Ki67 + hippocampal cells, and impaired cognitive functions [100]. As for brain development, a maternal oral consumption of 50 nm PS disorganize brain metabolism as evidenced by decreased GABA, creatine, glucose, and, in a sex-dependent manner, asparagine [115]. In another study, exposure of mice to PE-MP during gestation generated autistic traits in the progeny [101], while PS-MP maternal exposure was accompanied by an impaired social novelty ability, although not found in the offspring brains and not associated with levels of genic/proteic expressions of some key brain cell/synaptic markers [116].

Furthermore, defective neural retinal development was observed following oral exposure to PS-NP (100 nm), with the impairment of retinal ganglion cells and bipolar cells, and reduced retinal vascular trophicity (oxidative stress, disturbances in key neurotransmitter metabolism, repression of Fos expression) [117].

Maternal exposure to MP/NP may also impair fetal cardiac function, as evidenced by an increase in fetal heart rate observed by doppler ultrasound [102]. This alteration could reflect a direct toxic effect on the myocardium, or an indirect consequence of placental hypoxemia and insufficient fetal oxygenation, prompting an adaptive vasculature response in the placenta, as previously described. In the case of oral exposure to PE, an adaptative regulation of oxygen delivery has been suggested, supported by the absence of adverse effects on pregnancy outcome and normal uterine artery pulsatility index (a clinical measure of feto-placental vascular resistance) [103].

Impairments in spermatogenesis (reflected by abnormal sperm morphology) following pre- and post-natal exposure to PS-NP have also been described and were possibly caused by increased oxidative stress on PND 21 and 56. The toxicity of plastics might thus extend into the second generation and opens up the possibility of an epigenetic, transgenerational effect [94]. Moreover, maternal exposure to PS-NP impaired female offspring fertility, notably, through a premature activation of primordial follicles, mediated by promotion of the AKT-FOXO3a signaling pathway [105]. Together with a diminished testosterone concentration, Ma *et al.*, based on both morphological and multiomics approaches have shown that oral maternal exposure to PS-NP (25–100 nm) impaired spermatogenesis with an irruption in undifferentiated spermatogonia increasing ROS levels, promoting inflammation [118]. Not only PS-NP, but also 5 µm PS-MP can, after an oral maternal absorption, cause a reversible mitochondrial damage (enhancement of ROS production, decrease of ATP content, autophagy) in testicular tissue leading to poor semen quality [119]. Taken together, these findings suggest that the maternal exposure to PS-MP/NP can have profound effects on the reproductive function of both male and female F1 offspring, raising serious concerns about their multigenerational impact.

## 8. Conclusion, scientific and political perspectives

Several clinical studies have confirmed that MP/NP are present in the placenta, mostly in ST which presents many subclinical histologic changes, and may be translocated to the fetus. Although accumulation has been demonstrated in meconium and amniotic fluid, there is no conclusive evidence of their presence in fetal blood or internal organs. Globally, a Targeted Risk Assessment of Environmental Chemicals modeling (TRAEC), combining experimental data and encompassing reliability, outcome fitness, correlation, on *in vitro* and *in vivo* data from forty articles, concludes to a moderate-to-low risk of reproductive toxicity associated with MP/NP [83]. The correlation between placental plastic exposure and IUGR, as well as miscarriage, observed in a limited number of human studies needs to be replicated in larger, prospective cohorts with standardized protocols. Could MP/NP also be associated with the onset of preterm/preeclampsia [58]? This hypothesis deserves further investigations, given the known links between oxidative stress, vascular dysfunction, and plastic-induced placental changes. What are the implications for the future of the infant in light of the DOHaD theory? The potential association between plasticenta and social determinants of health — such as geographic location, dietary habits, socioeconomic status, and access to prenatal care — will be key factors in understanding exposure disparities and in designing effective prevention strategies. What about studying the interplay between MP and other environmental changes in the setting of pregnancy.

At the cellular level, some poorly understood aspects warrant further investigations: how do MP/NP precisely enter the placental cells? What are the influx and efflux mechanisms involved? How do these particles trigger ER stress in both human and murine tissues? A pharmacological approach using inhibitors of specific MP/NP entry pathways and molecular targets could offer valuable mechanistic insights. We lack additional data about MP/NP impact on human fresh villous explants and primary cytotrophoblasts. Above all, assessing the impact of MP/NP using more advanced placental models appears essential, such as 3D organoid models or co-culture placenta-on-chip systems with trophoblast and endothelial cells. The former would allow investigation of the cellular and molecular effects of MP/NP while accounting for paracrine interactions within the placenta, whereas the latter would enable detailed modeling of blood flow and MP/NP transfer between different cell types. Another critical area of research concerns the impact of MP/NP on the migration and invasion capacities of extravillous cytotrophoblasts — key-functions for placental development and uterine remodeling. Furthermore, a major unresolved question is whether MP/NP can translocate directly across the fetal capillary endothelium. Addressing this issue will require ethically approved studies on tissues from elective terminations. To better understand the transport and effects of MP/NP in placental tissue, it is also necessary to investigate the influence of particle shape. Epidemiological studies cited in this review indicate that plastic particles accumulate predominantly in fibrous forms, whereas current experimental studies focus almost exclusively on spherical shapes. However, by analogy, in lung tissue, fibrous particles (such as asbestos or fiberglass) are known to be more toxic than spherical ones [120]. Indeed, a strong pro-oxidative and pro-inflammatory response can be triggered in macrophages, as a result of so-called "frustrated" phagocytosis [121]. This raises the question of the potential consequences of exposure to micro- and nanofibers on placental macrophage cells (Hofbauer cells) and the possible repercussions for microvilli fibrosis (microvillitis), similar to pulmonary fibrosis.

Important analytical challenges remain, particularly with regard to (i) detecting not just MP but also smaller-sized NP, whose concentrations in blood and in placenta have not been fully determined, (ii) standardizing protocols used to measure plastics and to avoid environmental (airborne) contamination in clinical setting and experimentation. Studies estimating human and placental exposure to MP/NP are currently not standardized and alternate between particle detection using Raman or IR spectrometry and mass quantification by Pyr-GC-MS.
<table><caption>**Table 1**
A summary of clinical studies dealing with the plasticenta.</caption><thead><tr><th>Author, study type</th><th>Subjects</th><th>Country, exposure</th><th>Maternal age (year)</th><th>Pregnancy outcome</th><th>Delivery</th><th>Placenta</th><th>Extraction-digestion</th><th>Technics & data support</th><th>Main findings</th><th>Type</th><th>Size (μm)</th></tr></thead><tbody><tr><td>Ragusa 2021 [45]<br>Prospective, pilot study</td><td>6 healthy women<br>No smoking.<br>No abrasive dental treatment &lt; 2w</td><td>Italy<br>Rome,<br>Bergamo<br>(based on author affiliations)</td><td>/</td><td>No special outcome reported</td><td>Vaginal, at term</td><td>Maternal, fetal, chorioamniotic membrane sections</td><td>KOH 10%, 1 week<br>1.6 μm filtration</td><td>Raman SLOPP Library of Microplastics, KnowItAll software.<br>Confidence &gt; 80<br>Hit quality index<br>European Chemical Agency data</td><td>12 pigmented MP detected/4 placentas: 5 in fetal side<br>4 in maternal side,<br>3 in chorioamniotic membranes<br>+ pigment or cosmetics (iron hydroxide oxide yellow, ultramarine blue); plastic-staining (copper phthalocyanine, phthalocyanine); textile (polyester) associated particle (violanthrone)</td><td>PP</td><td>5–10</td></tr><tr><td>Braun 2021 [47]<br>Prospective, pilot study</td><td>2 women</td><td>Berlin,<br>Germany</td><td>/</td><td>No special outcome reported</td><td>singleton “near-term” cesarean</td><td>a) Peripheral (n = 1) and central placenta (n = 1) tissue<br>+ 1 negative control<br>b) pieces of 1 cm³ (n = 3) with intense washing<br>+ 1 negative control<br>+ meconium (n = 2 + controls)</td><td>Triple sieving, 50 μm stainless H₂O₂ 30%, &gt; 7w NaOH<br>0.05 M<br>Final filtration<br>0.2 μm</td><td>FTIR<br>Spectrum IMAGE software (Perkin-Elmer)</td><td>Placenta:<br>a) PE, PU + with valid negative control<br>b) PP + for 1 placenta, negative for the other.<br>Invalid negative control for PS.<br>Airborne fallout control + for PU, suggesting a false-positive for placenta in a).<br>Meconium: 1 + for PE.<br>Negative control + for PP. The other + for PP, PS with valid negative control<br>No results shown for lifestyle study.</td><td>PE?<br>PP</td><td>&gt; 50</td></tr><tr><td>Liu 2023 [43]<br>Prospective, pilot study</td><td>18 healthy women (2021)<br>Median BMI 21.5 kg/m².<br>No paste/recent smokers</td><td>Shanghai,<br>China</td><td>32.5 (median)</td><td>No special outcome reported</td><td>Vaginal, at term</td><td>Placenta: immediately sectioned in portions.<br>12 meconium</td><td>Nitric acid (68%), 48 h Filtration 13 μm.<br>Anhydrous ethanol, sonication (40KHz). Filtration, 13 μm</td><td>IR imaging spectrometer<br>Concordance degree criteria<br>&gt; 65% to Agilent Clarity software database</td><td>Placenta: 16 types of plastics detected in all slices, median abundance at 18 particles/g<br>Meconium: 14 types of plastics, 51.4 particles/g, mainly PA ++ in a statistically superior proportion than for placenta, PU, PVC, PTFE.<br>Behavior study: significant positive</td><td>PA<br>PU<br>PE<br>PET<br>PVC<br>++</td><td>20–50</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 1 (continued)</caption><thead><tr><th>Author, study type</th><th>Subjects</th><th>Country, exposure</th><th>Maternal age (year)</th><th>Pregnancy outcome</th><th>Delivery</th><th>Placenta</th><th>Extraction-digestion</th><th>Technics & data support</th><th>Main findings</th><th>Type</th><th>Size (μm)</th></tr></thead><tbody><tr><td>Ragusa 2022 [48] Prospective, pilot study</td><td>10 patients. No severe disease 1 hypothyroidism 1 gestational diabetes 1 active smoker</td><td>Rome, Italy</td><td>33.4 (mean)</td><td>No special outcome reported</td><td>Half vaginal, Half cesarean</td><td>cutting the section from the maternal side, collecting exclusively from intraparenchymal portion (n = 3 × 10, size 5 mm)</td><td>Adapted from Braun Fixation 2.5 % glutaraldehyde, 48 h, 4°C 5 mm hydrated fragments</td><td>Variable pressure scanning electron microscope. Transmission, Electron Microscopy Dual energy dispersive X-rays spectroscopy</td><td>association with plastics, water intake > 2 L/day and PA, Scrub cleanser or toothpaste and PE, hydromel and PU.<br/>- MP in all placenta villi sides (surface, intracellular, extracellular) in syncytiotrophoblast + +, cytotrophoblast, stroma, fetal vessels (pericytes, endothelium).<br/>- intracellular localization: lysosomes + +, peroxisomes, vacuoles, lipid droplets.<br/>- Ultrastructural modifications + +: constant, rough, dilated ER; aggregosomes, altered mitochondria (ballooning, pyknosis, mitochondrial granules) No significant correlation for lifestyle habit</td><td>/</td><td>2,1–18.5</td></tr><tr><td>Amereh 2022 [49] Pilot, prospective comparative</td><td>43 healthy women (2021–2022)</td><td>Tehran, Iran</td><td>27.1 (mean) 27.7 (mean)</td><td>30 normal weight babies 13 idiopathic IUGR</td><td>Unknown Sex ratio H/F: 1.5 Sex ratio H/F: 1.6</td><td>cut in three portions: maternal, fetal and chorioamniotic membrane sides</td><td>Adapted from Ragusa</td><td>Light microscopy Raman SLOPP Library of Microplastics and KnowItALL, concordance degree > 80 Hit Quality Index</td><td>MP 49 % in maternal side, 33 % fetal side, 18 % chorioamniotic membrane Normal group: 13 %, mainly transparent fragments and film IUGR group: 100 % with fragments + +, fibers, pellets and films, mostly white or transparent. Lifestyle positive significant association: bottled sources, takeaway food Clinical negative significant association with birth weight, length, head</td><td>PE, PS PE, PS PET PP</td><td>7.3–27.6 2.9–34.5</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 1 (continued)</caption><thead><tr><th>Author, study type</th><th>Subjects</th><th>Country, exposure</th><th>Maternal age (year)</th><th>Pregnancy outcome</th><th>Delivery</th><th>Placenta</th><th>Extraction-digestion</th><th>Technics & data support</th><th>Main findings</th><th>Type</th><th>Size (µm)</th></tr></thead><tbody><tr><td>Zhu 2022 [50] Pilot prospective</td><td>17 healthy women</td><td>Beijing, Wuxi, China,</td><td>23–36</td><td>No special outcome reported</td><td>Unknown</td><td>Frozen placenta pieces, including the fetal and maternal sides, broken into small pieces.</td><td>Adapted from Ragusa Filtration 10 µm</td><td>Laser direct infrared Agilent Clarity analysis Degree of confidence > 90 %</td><td>circumference and 1-min Apgar score.<br>149 MP detected, average abundance 2.7 +/- 2.65 particles/g: 11 polymers identified, mainly PVC (43.27 %), followed by PP (14.55 %) and PBS (10.90 %).</td><td>PVC<br>PP<br>PBS<br>PC<br>PS<br>PA</td><td>20 to > 300</td></tr><tr><td>Halfar 2023 [51] Prospective</td><td>10 women with physiological pregnancies</td><td>Ostrava, Czech Republic</td><td>30.2 (mean)</td><td>Preterm</td><td>PPROM Between 24 + 0 and 36 + 6 weeks of gestation</td><td>Amniocentesis 0.5 g of placenta from the central part of basal plate</td><td>KOH, 4°C, 24 h Filtration 1 µm KOH, 37°C, 2 h, Filtration 1 µm</td><td>Olympus stereomicroscope FTIR-ATR Concordance degree criteria > 60 %</td><td>MP in 7 amniotic liquids, 1–8 particles/sample (0.2–1.6 MP or additives/mL)<br>MP in 9 placenta samples, 1–10 particles/sample (2–20 MP or additives/g).<br>7 patients with lower count in amnios than in placenta</td><td>PE<br>PE-HD<br>PET<br>CPE<br>PVC<br>PE, PE-HD</td><td>6.8–260 (mainly 10–50)</td></tr><tr><td>Weingrill 2023 [52] Retrospective & prospective</td><td>2006: 10 samples 2013: 10 samples 2021: 10 fresh placental cotyledons</td><td>Hawaii, US</td><td>Unknown Unknown</td><td>No pathological outcome No pathological outcome No special outcome reported</td><td>Unknown Unknown cesarean</td><td>/ / /</td><td>Adapted from Ragusa Filtration 1.6 µm</td><td>Light microscopy Raman Atomic force microscope SLOPP Library of Microplastics and library of KnowItALL</td><td>142 MP in total. Rare MP fibers in environmental blank Increase of MP per filter area toward years 2006: MP in 60 % of placentas.<br>4.1 + / - 1.3 particles/ 50 g of tissue All polymers identified. 2.2/area 2013: MP in 90 % of placentas.<br>7.1 + / - 0.9 particles/ 50 g of tissue 32 formerly identified among 38 MP. 3.8/area 2021: MP in 100 % of placentas.<br>15.5 + / - 3 particles/ 50 g of tissue 68 formally identified among 82 MP 8.2/area</td><td>PP>PE>PVC> PU<br>PP>PET>PVA> PES>PET>PVA>PP></td><td>2.82 ± 0.31</td></tr><tr><td>Zurub 2024 [53]</td><td>10 patients Non-smokers</td><td>Ottawa, Canada</td><td>34/33</td><td>Physiological singleton pregnancy</td><td>Term</td><td>5 cesarian (5 males) 5 vaginal (3 males)</td><td>From Jenner et al. Sci Total Environ (2022)</td><td>Raman</td><td>31 MP in all samples 1–11MP/placenta (1 +1.2 MP/g) + additional polymers</td><td>phthalocyanine > PE > PS, PVC > PP, PMMA > styrene-isoprene</td><td>2–60</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 1 (continued)</caption><thead><tr><th>Author, study type</th><th>Subjects</th><th>Country, exposure</th><th>Maternal age (year)</th><th>Pregnancy outcome</th><th>Delivery</th><th>Placenta</th><th>Extraction-digestion</th><th>Technics & data support</th><th>Main findings</th><th>Type</th><th>Size (μm)</th></tr></thead><tbody><tr><td></td><td></td><td></td><td></td><td></td><td></td><td>3 g /placenta (basal place, chorionic villous tissue, chorionic plate)</td><td>Filtration 0.7 μm</td><td></td><td>No significant difference for MP considering:<br/>- anatomical localization<br/>- mode of delivery</td><td></td><td></td></tr><tr><td>Wan 2024 [54,55]<br/>Comparative study</td><td>60 patients</td><td>China</td><td>25–30</td><td>n = 30 idiopathic miscarriage (RM)<br/>n = 30 matched healthy control (HC)</td><td>6–10 GW</td><td>villous tissue sample</td><td>Adapted from Zhao Q, Sci Total Enviro, 2023. KOH 10%, 48°C</td><td>Pyr-GC-MS</td><td>PS plastic fragments detected<br/>- Higher content in RM<br/>- Positive association with miscarriage<br/>- Good predictive capability for miscarriage</td><td>PS fragments (selective approach)</td><td>/ (destructive method)</td></tr><tr><td>Yun2024 [56]</td><td>50 women, 50% first pregnancy<br/>6% with history of natural miscarriage</td><td>China</td><td>32.12</td><td>uncomplicated pregnancy</td><td>NA</td><td>2 g villous tissue sample from central portion</td><td>Adapted from Zhu et al. KOH, 48 h centrifugation<br/>Filtration 0.8 cm²</td><td>Raman particle with one dimension<br/>&lt; 20μm; WiRE 5.5 software<br/>Pyr-GC-MS<br/>Histopathology</td><td>- 40 MP across 31 of 50 placentas - 2–5 MP detected/sample<br/>- no significant localized histological pathologic features<br/>- life-style habits: consumption of non-stick cookware (84%) and plastic food containers (100%)</td><td>PTFE* &gt; PS &gt; ABS<br/>&gt; PC* &gt; PP &gt; PE<br/>&gt; PVC</td><td>2.35 ± 1.25 μm</td></tr><tr><td>Zhu 2024 [59]</td><td>9 healthy women</td><td>Schenzen, China</td><td>32</td><td>no comorbidities</td><td>4 preterm<br/>5 full-term<br/>7 vaginal<br/>2 cesarian</td><td>cuboidal sections excised 4-cm equidistant from the cord insertion site<br/>Excision of maternal decidua and fetal chorion-annion</td><td>Adapted from Yan, Environ. Sci. Technol (2022)</td><td>Raman</td><td>Placenta<br/>- MP detection in all 9 samples<br/>- 3 fragments/placenta, mainly yellow or transparent<br/>- life-style habits: tendency to an increase of MP with consumption of plastic bottles/cup only<br/>Meconium<br/>- 14 types of MP</td><td>CEL &gt; PNB &gt; PB and PEA<br/>CEL, PB and PNB detected also in umbilical cord</td><td>Around 20–550 μm</td></tr><tr><td>Garcia 2024 [57]<br/>Prospective study</td><td>62 samples</td><td>USA</td><td>/</td><td>/</td><td>/</td><td>cuboidal sections excised 4-cm equidistant from the cord insertion site<br/>Excision of maternal decidua and fetal chorion-annion</td><td>KOH, 40°C, 72 h Ethanol</td><td>Pyr-GC-MS FTIR (detection limit of 20 μm)</td><td>- MP detection in half of placental biopsies<br/>- 126.8 ± 147.5 mg/g and the median of 85.8 mg/g,<br/>- 6.5–685 mg total MP/g of tissue</td><td>PE + +<br/>PS, PP, PVC, PS, PET</td><td>&gt; 1 μm</td></tr><tr><td>Jochum 2025 [58]</td><td>158 overall cohort</td><td>USA</td><td>31 + /– 7</td><td>87 term<br/>Vs<br/>71 preterm</td><td>Vaginal</td><td>circumferentially excision of 4 cm from the cord</td><td>Adapted from Garcia et al.</td><td>Pyr-GC-MS</td><td>12 types of polymers identified<br/>- Higher types in PTB –</td><td>PE, SBR, PVC PP, N66, PET, N6, PMMA, ABS, PU, PC, PS</td><td>MP-NP</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 1 (continued)</caption><thead><tr><th>Author, study type</th><th>Subjects</th><th>Country, exposure</th><th>Maternal age (year)</th><th>Pregnancy outcome</th><th>Delivery</th><th>Placenta</th><th>Extraction-digestion</th><th>Technics & data support</th><th>Main findings</th><th>Type</th><th>Size (μm)</th></tr></thead><tbody><tr><td>Prospective study</td><td></td><td></td><td></td><td>(more hypertension, social deprivation, preeclampsia) matched for smoking, gestational diabetes</td><td></td><td>insertion site, avoiding decidua</td><td></td><td></td><td>for PVC, PET, PU, but not ABS – (225 +/- 181 μg/g) vs. term (176 +/- 138 μg/g)<br/>- inverse correlation between birth weight with PU and PC<br/>- increase cumulative MP/NP with smoking history and preeclampsia, decreased with gestational diabetes<br/>- distinct clustering highlighting potential association of sources: PE, SBR; PMMA, N6, PU, ABS, PC; PET, N6, PP, PVC.</td><td></td><td></td></tr></tbody></table>

ABS: acrylonitrile butadiene styrene; CEL: microplastic cellulose; CPE: chlorinated polyethylene; N66: Nylon 66; PE-HD: high-density polyethylene; PA: polyamide; PB: polybutene isotactic; PC: polycarbonate; PBS: polyethylene succinate; PEA: polyethylene adipate; PTFE: Polytetrafluoroethylene; SBR: Styrene-butadiene rubber
<table><caption>Table 2 (continued)</caption><thead><tr><th>Author</th><th>Model</th><th>Polymer</th><th>Size (nm)</th><th>Size in culture medium (nm)</th><th>Functions</th><th>Surface load in culture medium (mV)</th><th>Shape</th><th>Doses (µg/mL)</th><th>Duration</th><th>Goal</th><th>Methods</th><th>Main results</th></tr></thead><tbody><tr><td>Gruber 2020 [71]</td><td>Human ex vivo placental perfusion</td><td>PS</td><td>80</td><td>107</td><td>fluorescent probe</td><td>-9.61 ± 0.91</td><td>S</td><td>40</td><td>up to 6 h</td><td>T</td><td>Zeta-potential, LC-MS/MS, TEM</td><td>Materno-fetal translocation of the particles. Plasma albumin enhanced particle translocation (albumin formed the corona).</td></tr><tr><td>Chortarea 2023 [67]</td><td>Human ex vivo placental perfusion</td><td>PS</td><td>70</td><td>501</td><td>Unmodified (-29.1)</td><td>NA</td><td>S</td><td>25</td><td>up to 6 h</td><td>E</td><td>SEM, zeta potential, DNA microarrays, RT-qPCR, WB</td><td>The top 10 most enriched pathways underlying particles responses related to: cell division and cell cycle, DNA repair, regulation of G2/M transition, regulation of signaling receptor activity, apoptosis, inflammatory response and iron homeostasis.</td></tr><tr><td>Grafmuller 2023 [70]</td><td>Human ex vivo placental perfusion</td><td>PS</td><td>80</td><td>NA</td><td>Fluorescent probe</td><td>NA</td><td>S</td><td>NA</td><td>up to 6 h</td><td>T</td><td>Fluorescence measurement</td><td>80 nm particles transported across the placenta to the fetal compartment (not 500 nm particles). 20-30% of the 80 nm particles translocated to fetal compartment after 3 h. No effects of both particles on glucose consumption, lactate production and hCG, leptin secretion.</td></tr><tr><td>de Sousa 2024 [88]</td><td>Villous chorionic villi explants from term placentas</td><td>PS</td><td>5000</td><td>NA</td><td>-COOH</td><td>NA</td><td>S</td><td>100</td><td>24 h</td><td>E</td><td>Raman, zeta-potential, MTT, LDH, ROS, antioxydant enzymes activity, M16, metabolomic</td><td>No effects on cell viability at 24 h but an increase of the LDH release after 72 h at 100 µg/mL. Decreased CAT and SOD activity, ROS overproduced (O₂ and H₂O₂). Lower ratio GSH/GSSG and increased amount of MDA and carbonylated proteins at 100 µg/mL. Metabolism altered - lowered level of alanine, formate, glutaric acid, maltotriose and increased level of valine and tyrosine-suggesting impairments in folate, amino-acids metabolisms and TCA cycle.</td></tr><tr><td>Poinsignon 2025 [17]</td><td>Primary culture of VCT from term placentas and chorionic villi</td><td>PS</td><td>20</td><td>110 ± 7</td><td>No</td><td>-10 ± 1</td><td>S</td><td>0, 0.01, 1, 10, 100</td><td>up to 48 h</td><td>C&E</td><td>TEM, DLS, Zeta-potential, WST1, Mito-Tracker CMXRos, ROS assay, RT-qPCR, WB</td><td>Internalization in human chorionic villi and primary VCT. Accumulation time/size dependent. Particles mostly accumulated in vesicles (lysosomes/ autophagosomes). Lower viability of VCT: from 1 µg/mL for 20 nm particles and from 100 µg/mL for 100 nm particles. ROS induction and antioxidant response for both</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 2 (continued)</caption><thead><tr><th>Author</th><th>Model</th><th>Polymer</th><th>Size (nm)</th><th>Size in culture medium (nm)</th><th>Functions</th><th>Surface load in culture medium (mV)</th><th>Shape</th><th>Doses (µg/mL)</th><th>Duration</th><th>Goal</th><th>Methods</th><th>Main results</th></tr></thead><tbody><tr><td></td><td></td><td></td><td>25</td><td>NA</td><td>Fluorescent probe green</td><td>NA</td><td></td><td>100</td><td></td><td>I</td><td></td><td>sizes. Autophagy flux induced but blocked with particles of 100 nm. Pro-inflammatory cytokines secreted: TNF-α and IL-6 at 100 µg/mL of 20 nm particles, and IL-1β from 1 µg/ mL of 100 nm particles. Down- secretion of hCG from 1 µg/mL of 100 nm particles.</td></tr><tr><td></td><td></td><td></td><td>100</td><td>130 ± 6</td><td>No</td><td>-7 ± 1</td><td></td><td>0, 0.01, 1, 10, 100</td><td></td><td>C&E</td><td></td><td></td></tr><tr><td></td><td></td><td></td><td>100</td><td>NA</td><td>Fluorescent probe green</td><td>NA</td><td></td><td>100</td><td></td><td>I</td><td></td><td></td></tr><tr><td>Huang 2015 [81]</td><td>3A-Sub-E and primary VCT from term placentas</td><td>PS</td><td>20</td><td>NA</td><td>-COOH and yellow-green fluorescent probe</td><td>NA</td><td>S</td><td>0, 50, 200</td><td>up to 4 h</td><td>E</td><td>TEM, Confocal microscopy, FC, WB, TUNEL assay, BrdU assay</td><td>The five types of particles internalized in trophoblastic cells (3A-Sub-E). Accumulation in lysosomes and mitochondria. Size-dependent internalization: greater for particles of 40, 100 and 200 nm. Apoptosis induced (cleaved-caspase 3) at high doses for 40 and 20 nm particles (500 and 200 µg/mL respectively) on 3A-Sub-E cells. VCT from primary cells more sensitive to cell death by apoptosis (cleaved-caspase 3 from 50 and 20 µg/mL of 40 and 20 nm particles respectively). Proliferation reduced on 3A- Sub-E cells exposed to 20 nm particles at 200 µg/mL.</td></tr><tr><td>Wan 2024 [54]</td><td>Swan 71 and Human villous tissues (normal and miscarriages)</td><td>PS</td><td>57</td><td>NA</td><td>No</td><td>NA</td><td>S</td><td>0, 50, 100, 150, 200</td><td>24 h</td><td>E</td><td>FTIR, TEM, Transwell migration/invasion assays, RT-qPCR, WB, FC, gene reporter Assay, HIC</td><td>Decreased invasion and migration of Swan 71, from 50 µg/mL. Decreased number of migrasomes. Autophagy induced and ROCK1-SOX2 pathway down-regulated. Down-expression of ROCK1-SOX2 in human miscarriages placentas.</td></tr><tr><td>Wan 2024 [55]</td><td>Swan 71 and Human villous tissues (normal and miscarriages)</td><td>PS</td><td>50</td><td>41 ± 7</td><td>No</td><td>NA</td><td>S</td><td>50, 100, 150, 200</td><td>24–48 h</td><td>E</td><td>TEM, CCK-8 viability assay, FC, TUNEL assay, Mito-Tracker Red CMXRos, ROS assay, RT-qPCR, WB</td><td>Lower viability from 400 µg/ mL. Apoptosis induction from 50 µg/mL (cleaved-caspase 2–3 up-regulated, Bcl-2 down- regulated). ROS production. Human tissues from miscarriages associated with a</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 2 (continued)</caption><thead><tr><th>Author</th><th>Model</th><th>Polymer</th><th>Size (nm)</th><th>Size in culture medium (nm)</th><th>Functions</th><th>Surface load in culture medium (mV)</th><th>Shape</th><th>Doses (µg/mL)</th><th>Duration</th><th>Goal</th><th>Methods</th><th>Main results</th></tr></thead><tbody><tr><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>TEM, FC, confocal microscopy</td><td>decrease of Bcl-2 and an increase of cleaved-Caspase. Particles internalized into Swan 71 (1 h) and stabilized at a constant content until 24 h.</td></tr><tr><td>Hu 2022 [79]</td><td>HTR8/SVneo</td><td>PS</td><td>100</td><td>NA</td><td>No</td><td>NA</td><td>S</td><td>0, 10, 50, 100</td><td>up to 48 h</td><td>E</td><td>TEM, IR, CCK-8 viability assay, EdU assay, FC, WB, Wound healing assay, invasion assay, ROS detection, cytokines assay, RT-q.PCR</td><td>Cell viability unchanged but lower proliferation (100 µg/mL) associated with cell cycle arrest in phase S. Migration and invasion significantly decreased at 100 µg/mL. Increased ROS production and inflammation (from 10 µg/mL, TNF-alpha and IFN-gamma increased while IL-4 and IL-10 decreased).</td></tr><tr><td>Lv 2024 [107]</td><td>HTR8/SVneo</td><td>PS</td><td>30</td><td>NA</td><td>No</td><td>NA</td><td>S</td><td>0, 10, 20, 50, 100</td><td>24 h</td><td>E</td><td>Zeta-pontial, CCK8 viability assay, migration assay, RT-q.PCR, WB</td><td>Decreased cell viability from 20 µg/mL (24 h exposure). Migration altered after 24 h exposure to 100 µg/mL, associated with a decrease activation MAPK pathway (MAPKK6).</td></tr><tr><td>Wan 2024 [83]</td><td>HTR8/SVneo</td><td>PS</td><td>50</td><td>NA</td><td>No</td><td>NA</td><td>S</td><td>0, 10, 50, 100, 200</td><td>0, 12 h, 24 h, 48 h</td><td>E</td><td>CCK-8 viability assay, wound healing assay, Transwell migration assay, FC, mitochondrial potential measurement</td><td>Cytotoxicity time and dose-dependent (significant from 50 µg/mL at 24 h for 50 nm particles against 10 µg/mL at 48 h for 200 nm particles). Migration and invasion decreased. Apoptosis induced after exposure to 50 nm and 200 nm particles.</td></tr><tr><td>Nacka-Aleksic, 2025 [82]</td><td>HTR8/SVneo</td><td>PS</td><td>40 200</td><td>NA</td><td>-COOH and fluorescent probe</td><td>NA</td><td>S</td><td>0, 10, 100</td><td>24, 48, 72 h</td><td>E</td><td>MTT, Crystal violet adherent cell number assay, Comet assay, RT-q.PCR, migration and invasion assay</td><td>No significant cytotoxicity (except 72 h at 100 µg/mL for 40 nm particles), apoptosis or loss of adherence after particles exposure. Significant DNA damages (size and dose dependent) for both sizes of particles at 10 and 100 µg/mL. Migration and invasion decreased at high doses of 40 nm particles, not for 200 nm particles. Decreased expression of proteins involved in extracellular matrix and migration/invasion (MMP2, MMP9, Integrin alpha5, migration inhibitory factor MIF)</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 2 (continued)</caption><thead><tr><th>Author</th><th>Model</th><th>Polymer</th><th>Size (nm)</th><th>Size in culture medium (nm)</th><th>Functions</th><th>Surface load in culture medium (mV)</th><th>Shape</th><th>Doses (µg/mL)</th><th>Duration</th><th>Goal</th><th>Methods</th><th>Main results</th></tr></thead><tbody><tr><td>Ragusa 2025 [78]</td><td>HTR8/Svneo</td><td>PS</td><td>50</td><td>NA</td><td>No</td><td>NA</td><td>S</td><td>0, 10, 25, 50, 75, 100</td><td>24 h and 48 h</td><td>E</td><td>TEM, CCK-8 viability assay</td><td>Dose and time dependent cytotoxicity (50 µg/mL, 40 % cell death). Histological changes (loss of adherence). Swollen and pyknotic mitochondria suggesting mitochondrial dysfunction.</td></tr><tr><td></td><td></td><td></td><td></td><td></td><td>Fluorescent probe</td><td></td><td></td><td></td><td></td><td>I</td><td>TEM and confocal microscopy</td><td>Internalization and aggregation of particles around 200 nm in cells. Particles encapsulated in lysosomal-like structure. Aggregations close to endoplasmic reticulum.</td></tr><tr><td>Rytting 2012 [73]</td><td>BeWo b30</td><td>PS</td><td>50 100</td><td>56 98</td><td>Fluorescent probe</td><td>NA</td><td>S</td><td>up to 1 mg/mL</td><td>up to 24 h</td><td>T &amp; E</td><td>MTT, transwell and TEER, confocal microscopy</td><td>No cytotoxicity up to 800 µg/mL. After 24 h, 0.6 % of 100nm-particles were transported to basal side against 3.5 % for 50nm-particles. Cell permeability dependent on particle size.</td></tr><tr><td>Kloet 2015 [77]</td><td>BeWo b30</td><td>PS</td><td>50 50 50</td><td>69 ± 10.1 57.6 ± 11.7 82.7 ± 30.91</td><td>- COOH (-58.3) - COOH (-55.5) - NH2 (+51)</td><td>- 11 ± 0.9 - 11 ± 0.2 - 12 ± 1.2</td><td>S</td><td>0, 0.01, 1, 10, 100</td><td>up to 24 h</td><td>C, T&amp; E</td><td>Zeta-potential, SEM, DLS, SDS-Page, MTT, Transwell translocation study, mechanisms of internalization</td><td>Adsorption of proteins around particles. Differences in the amount but not the nature of the proteins adsorbed in the corona of the three different charged particles (smaller amount of positively charged particles). Decreased viability of positively charged particles, significant at concentrations of 20 µg/mL. Time-dependent translocation of the three particles to the basolateral compartment of Transwell. Translocation of positively charged particles involved MRP-1 transporter. Negatively charged particles transport is still unclear: endocytosis, PgP, BCRP or MRP-1 inhibitors had no effects.</td></tr><tr><td>Dusza 2022 [76]</td><td>BeWo b30 (syncytialized and unsyncytialized)</td><td>PS HDPE</td><td>50 200 1000 Ranging from 0 to 80 µm</td><td>NA</td><td>Pristine (with or without fluorescent probe) or Weathered</td><td>NA</td><td>S Non uniformly shaped</td><td>0, 0.1, 1, 10, 100</td><td>NA</td><td>T&amp;E</td><td>Confocal microscopy, Transwell and TEERs, translocation study, ATP dosage (viability assay), LDH assay, RT.qPCR</td><td>PS particles crossed easier BeWo b30 unsyncytialized than BeWo b30 syncytialized. Size and dose-dependent translocation of PS particles (stronger for little size of particles and high concentration). Weathered particles more internalized than</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 2 (continued)</caption><thead><tr><th>Author</th><th>Model</th><th>Polymer</th><th>Size (nm)</th><th>Size in culture medium (nm)</th><th>Functions</th><th>Surface load in culture medium (mV)</th><th>Shape</th><th>Doses (µg/mL)</th><th>Duration</th><th>Goal</th><th>Methods</th><th>Main results</th></tr></thead><tbody><tr><td>Rothbauer 2017 [72]</td><td>BeWo b30, ACH-3P, JAR, Jeg-3</td><td>PS</td><td>50 490</td><td>NA</td><td>Fluorescent probe</td><td>NA</td><td>S</td><td>0, 125, 250, 500</td><td>up to 24 h</td><td>T&E</td><td>Transwell and TEER, MTT</td><td>No cytotoxicity up to 500 µg/mL on BeWo b30, ACH-3P, Jeg-3 and JAR. Particles transport most important with Jeg-3 and ACH-3P (75 %) than BeWo b30 and JAR (40 %). Transport of 50 nm particles increased compared to 490 nm particles.</td></tr><tr><td>Aengenheister 2018 [75]</td><td>Co-culture: BeWo b30 + HPEC-A2</td><td>PS</td><td>49 70 nm</td><td>43.3 ± 88.3 70.6 ± 109.8</td><td>Fluorescent probe</td><td>- 9.9 ± 1.1 - 9.3 ± 0.2</td><td>S</td><td>up to 100</td><td>up to 24 h</td><td>C, T&E</td><td>TEM, zeta-potential, HPLC, Transwell and TEER, ICC</td><td>Slight translocation of 49 nm particles across HPEC-A2 cells, BeWo b30 and co-culture (2 %, 1.2 %, 1.3 % respectively). No translocation of 70 nm particles. No permeability of the placental barrier to PS.</td></tr><tr><td>Hesler 2019 [74]</td><td>BeWo b30 (± co-culture with HPEC-A2)</td><td>PS</td><td>50 500 50 500</td><td>around 57 around 570 NA NA</td><td>COOH-fluorescent probe</td><td>around -10 around -9 NA</td><td>S</td><td>0, 0.01, 0.1, 1,5,10,25,50,100</td><td>up to 24 h</td><td>C, T&E</td><td>TEM, A4F, zeta potential measurements, WST-1 viability assay, Transwell and TEER, ICC, micronucleus assay</td><td>Increased metabolic activity from 5 µg/mL and 0.01 µg/mL for respectively 50 nm and 500 nm particles. No impact on TEER resistance. Translocation increased with 50 nm particles than 500 nm. Particles were internalized only in BeWo b30 cells, at the apical side. No internalization in HPEC-A2, at the basal side.</td></tr><tr><td>Shen 2022 [80]</td><td>JEG-3</td><td>PS</td><td>25 50 100 500</td><td>≈ 25 ≈ 53 ≈ 101 ≈ 510 -</td><td>unlabeled, -COOH and -NH2</td><td>Unmodified: around -40, -NH2: around 55, -COOH: around -52</td><td>S</td><td>0, 20, 78, 313, 1250, 5000</td><td>up to 24 h</td><td>C, E</td><td>DLS, zeta-potential, MTT, PKA activity assay, ROS, FC, RT-q. PCR</td><td>Size and dose-dependent cytotoxicity. Lower viability induced by positively charged particles compared to negatively or unmodified particles (from 78 µg/mL for 25 nm positively charged particles against 313 µg/mL for 25 nm unmodified or negatively charged particles). Increased PKA activity and ROS production for the three types of particles. Cell cycle affected only for 25 and 50 nm particles. Positively charged particles induced greater number of cells to undergo cell cycle arrest in G2 phase than negatively or unmodified particles.</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 2 (continued)</caption><thead><tr><th>Author</th><th>Model</th><th>Polymer</th><th>Size (nm)</th><th>Size in culture medium (nm)</th><th>Functions</th><th>Surface load in culture medium (mV)</th><th>Shape</th><th>Doses (µg/mL)</th><th>Duration</th><th>Goal</th><th>Methods</th><th>Main results</th></tr></thead><tbody><tr><td>Lee 2021 [84]</td><td>HUVEC</td><td>PS</td><td>500 1000</td><td>NA</td><td>No</td><td>NA</td><td>S</td><td>0, 20, 40, 60, 80, 100</td><td>up to 72 h</td><td>E</td><td>MTT, angiogenic tube formation assay, transwell migration/ invasion assay, ROS, WB, FC, IF</td><td>Size and time-dependent decrease of cell viability. 500 nm particles altered endothelial tube formation (from 20 µg/mL). Endothelial tube formation size-dependent repressed. Migration altered by 500 nm particles via MAPK deregulation (P38, ERK). Cell death linked to autophagy induction after 500 nm particles exposure (LC3-II increased).</td></tr><tr><td>Fu 2022 [85]</td><td>HUVEC</td><td>PS</td><td>50 NA</td><td>50 NA</td><td>No -NH2</td><td>-17 -3</td><td>irregular, cuboid</td><td>0, 5, 10, 15, 20, 25</td><td>12, 24 h</td><td>E</td><td>DLS, zeta-potential, MTT, LDH release, ROS, mitochondrial membrane potential detection, RT-q.PCR, ATP activity</td><td>Lower viability with -NH2 particles than unmodified particles (from 5 µg/mL after 24 h). Mitochondrial membrane potential altered for both types of particles (10 µg/mL). Mitochondrial dynamic modified (fusion induced) after -NH2 particles and a significant decrease of ATP synthesis.</td></tr><tr><td>Lu 2022 [87]</td><td>HUVEC</td><td>PS</td><td>1000</td><td>NA</td><td>No (fluorescent probe)</td><td>NA</td><td>S</td><td>0, 5, 10, 25</td><td>48 h</td><td>E</td><td>TEM, Raman, MTT, LDH release assay, FC, RT-q.PCR, WB, IF, ROS</td><td>Decreased cell viability after 48 h at 100 µg/mL (no effects on LDH release). No effects on adhesion molecules expression (ICAM-1 and VCAM-1). No induction of P62 expression, nor the autophagy pathway. No effect on ROS production and inflammation (constant expression of pro-inflammatory cytokines).</td></tr><tr><td>Lu 2022 [86]</td><td>HUVEC</td><td>PS</td><td>100 100 500 500</td><td>NA</td><td>No fluorescent probe No fluorescent probe</td><td>NA</td><td>S</td><td>0, 5, 10, 25, 50, 100</td><td>24, 48 h</td><td>E</td><td>MTT, FC, SEM, TEM, LDH assay, WB, IF, RT-q.PCR, ROS</td><td>Time and dose-dependent internalization for the both sizes of particles. Accumulation in intracellular vesicles. No decrease of viability after 100 nm particles exposure but an increased LDH release at 25 µg/mL. Increased cell death after 48 h exposure to 500 nm particles (from 50 µg/mL). Increased expression of LC3-II and BECN1 after 100 nm particles exposure, no effects of 500 nm particles. 100 nm particles blocked autophagic flux (LAMP-2 decreased). No effects on pro-inflammatory cytokines expression and ROS production.</td></tr></tbody></table>

C: characterization; S: spherical; T transport; E effect; I internalization
<table><caption>**Table 3**
A summary of in vivo studies in murine.</caption><thead><tr><th>Author</th><th>Rodent</th><th>Polymer</th><th>Size (nm)</th><th>Exposure</th><th>Duration</th><th>Techniques</th><th>Blood MP/ NP**</th><th>Goal</th><th>Main results</th></tr></thead><tbody><tr><td>Huang 2015 [94]</td><td>FVB/N mice</td><td>Fluorescent carboxylate PS (Eugene OR, USA)</td><td>20, 40, 100, 200, 500</td><td>IV, jugular vein after anesthesia with (chloral hydrate) 300 µg, 50 µL/min</td><td>16.5 GD- 4 h</td><td>Immunofluorescence Flow cytometry, Western blot TUNEL assay</td><td>150 µg/mL</td><td>D</td><td>Dams: PS in maternal blood 688.4 ± 243.0 ng/mL. Half-life 5.8 min. Placenta: NPs detected for 4/7, 4/9, 4/6, 7/9, 5/9 for each NP one respectively (500-20 nm) No histological alteration. Uptake ↑ for NP 40 nm. Fetus: Brain 3/6, 3/7, 3/6, 5/7, 3/6; Lung 2/ 6, 3/9, 1/6, 2/6, 1/8; Liver 3/7, 0/6, 1/6, 4/ 7, 2/6 respectively (500-20 nm)</td></tr><tr><td>Kenesei 2016 [91]</td><td>Mice</td><td>Fluorescent PS* with COOH/PEG</td><td>50 and 90</td><td>Tail-vein injection 7 µL/g bodyweight 33.3 µg/mL</td><td>10-15 GD- 5 min or 4 days</td><td>Spectral imaging fluorescence microscopy.</td><td>35 µg/mL</td><td>D</td><td>Placenta: PS-COOH NPs + + in lacuna, no PS-PEG NPs 5 min later; no NPs 4 days later Embryo: no NP detected 5 min or 4 days later</td></tr><tr><td>Hu 2021 [93]</td><td>Allogenic C57BL/6- mated BALB/ c</td><td>PS* (J&K Scientific, China)</td><td>10 µm</td><td>Intraperitoneal 250 µg in 200 µL</td><td>11.5</td><td>Density gradient centrifugation Flow cytometry, RT-qPCR</td><td>125 µg/mL</td><td>E</td><td>Placenta: ↓number and diameter of arterioles, ↓ CD45 + leukocytes and CD49b+ natural killers (not in maternal blood/spleen), ↓ decidual proportion of macrophages (F4/ 80 +CD11b+), M2 phenotype (CD206 +) dominance, ↑ LT CD4 + (not in maternal blood/spleen) transcriptional ↓ TNF-a, IL-2 (light), IFN-g (light), ↑ IL-4, and IL-6 (trend) Embryo: ↑ resorption rate, with no difference in viability</td></tr><tr><td>Aghaei 2022 [96]</td><td>Healthy CD-1 mice</td><td>Pristine PS (Microspheres- Nanospheres, NY)</td><td>5 µm, 50 nm</td><td>Oral, drinking water, ad libitum access 10<sup>2</sup> ng/L, 1.5 × 10<sup>3</sup> p (n = 12) 10<sup>4</sup> ng/L, 1.5 × 10<sup>5</sup> p (n = 11) 10<sup>6</sup> ng/L, 1.5 × 10<sup>13</sup> p (n = 11) filtered water Control: same water (n = 14)</td><td>0 GD to 17.5</td><td>High-resolution NMR MetaboAnalyst, KEGG</td><td>0.2 ng/mL- 45 µg/mL</td><td>E</td><td>↑ fetal-placental weight ratio in both treated groups Placenta: no effect on weight, shorter umbilical cords for both groups at all concentrations, ↓ of glucose and lysine concentration at 10<sup>6</sup> g/L, perturbation of glucose, lysine and biotin metabolism. Fetus: no effect on resorption, ↓ weight for both MP and NPs (dose effects at 10<sup>4</sup> and 10<sup>6</sup> ng/L),</td></tr><tr><td>Cary 2023 [95]</td><td>10 Sprague- Dawley rats</td><td>Pristine, carboxylated, red-fluorescent PS spheres (Thermo, Waltham)</td><td>20 nm*</td><td>Oral (n = 5), Gavage bolus during anesthesia (isoflurane 5 %) 10 g/kg, 250 µg/mL, sterile deionized water. Untreated control (n = 5)</td><td>At 20 GD</td><td>Darkfield hyperspectral microscopy</td><td>40 µg/mL</td><td>D E</td><td>Placenta: irregular clusters, up to 100 µm in the decidua, junctional and labyrinth zones, together with RBCs. No histological lesions. Fetus: ovate, irregular clusters, 10-25 µm in liver, kidney, lung, heart, and brain. No histological lesions. Placenta: ↓ weight, efficiency ↑ Fetus: NS weight</td></tr><tr><td>Fournier 2022 [37]</td><td>21 female Sprague- Dawley rats</td><td>Rhodamine-coupled PS (NanoCS, NY) beads</td><td>20* nm</td><td>Pulmonary (intratracheal) Anesthesia (5 % isoflurane), 2.64 × 10<sup>14</sup>, 300 µL, water, surfactant</td><td>at 20 GD</td><td>Fluorescent optical live (a) Darkfield hyperspectral microscopy (b) Spectrophotometry assay</td><td>1.5 mg/mL</td><td>D E</td><td>(a) significant for placenta, fetal abdomen, liver, and heart. (b) detection in fetal liver, lung, kidney, heart, and brain. Fetal and placenta weights ↓, number of resorptions ↑</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 3 (continued)</caption><thead><tr><th>Author</th><th>Rodent</th><th>Polymer</th><th>Size (nm)</th><th>Exposure</th><th>Duration</th><th>Techniques</th><th>Blood MP/ NP**</th><th>Goal</th><th>Main results</th></tr></thead><tbody><tr><td>Chen 2023 [97]</td><td>C57 BL/6 female mice</td><td>PS (Huge Biotechnology, Shanghai)</td><td>100</td><td>(n = 11)<br>Control: saline solution (n = 14)<br>Ex vivo placental IV, naïve rats, 900 µL, 7.92 × 10<sup>14</sup> p/mL</td><td>0–17 GD</td><td>RNA extraction, sequencing<br>UHPLC/MS-TOF, XCMS, KEGG<br>RT-qPCR</td><td>2–420 µg/mL</td><td>E</td><td>No histological changes in the placenta<br>Transfer through the maternal vasculature from the uterine artery within 10 min, peak at 20 min, elevated concentrations in the umbilical effluent within 90 min, ↑ 150–180 min.<br><br><b>Placenta:</b> upward trend for absolute and relative weights (10 mg/L), downward trend for glycogen in spongiotrophoblast and trophoblast giant cells, vascular underdevelopment in the labyrinth zone.<br>Lipid metabolism genes (steroids, cholesterol) ↑ (10 mg/L), confirmed by metabolomic analysis, and the coagulation cascade, ↑ JAK-STAT (both doses), ↓ sucrose. ApoA-IV ↑, as well as its transcription factors RORC, HNF4A, and CREBH<br><br><b>Fetus:</b> ↓ absolute and relative weights (10 mg/L), no significant increase in abortions, irregular alignments and morphologies in skeletal muscle, swelling, nuclear fragmentation (10 mg/L)<br>Lipid metabolism genes ↑ (10 mg/L), with the greatest metabolic significance in the PPAR pathway, ApoA-IV ↓, PPARα and PPARGC1A ↓</td></tr><tr><td>Wang 2023 [112]</td><td>C57BL/6 mice, 10 w</td><td>PS (Baseline Kromtech Research Centre, Tianjin, China))</td><td>71.09 ± 6.63 nm</td><td>inhalation of 0, 1, 5, and 25 µg µl−1: oropharingeal aspiraton (20 µl)</td><td>vaginal plug apparition to end of gestation</td><td>Histology,<br>Immunohistochemistry,<br>Biochemical analysis,<br>RTqPCR, WB</td><td>10 µg/mL - 5,2 mg/mL</td><td>E</td><td>Fetus: ↓ birth weight (F only, M, H), constant litter size and sex ratio Post-natal week 12: ↑ body weight (F and M, L), ASAT ↑ (H), ↑ hepatic oil-red staining (H), ↑ hepatic TG (F only, H), constant liver weight, ↑ hepatic transcription of CD36 (F, L, M, H), GPAT4 (F, H), DGAT 2, MTTP (F, H), ↑ hepatic expression</td></tr><tr><td>Tang 2023 [99]</td><td>32 C57BL/6 J mice (6–8 w)</td><td>PS beads* (Base Line Chrom Tech Research Centre (Tianjin))</td><td>80</td><td>Oropharyngeal aspiration,<br>a. 7.52 × 10<sup>11</sup> p/d,<br>25 µg/µL (n = 8)<br>b. 3.76 × 10<sup>12</sup> p/d,<br>5 µg/µL (n = 8)<br>c. 1.88 × 10<sup>13</sup> p/d,<br>1 µg/µL (n = 8)<br>d. 0 for control (n = 8)</td><td>3/weeks during gestation</td><td>In vivo fluorescence imaging<br>Enzymatic assay<br>Western blot<br>Immunohistochemistry<br>RT-PCR</td><td>25 µg/mL - 5.6 mg/mL</td><td>D & E</td><td><b>Placenta:</b> no significant signal found. ↓ weight (especially in females). Vascular space impairment, ↓ placental erythrocytes. ↓ mRNA 1 β-hydroxysteroid dehydrogenase (in females)<br><b>Fetus:</b> no significant signal found. ↓ weight (especially in females).<br><b>Offspring:</b> ↓ weight only at a low dose.<br>Lipogenesis markers ↑ (CD36, MOGAT2, DGAT2).<br>. Duodenum: ↓ villus height (b), ↑ crypt height (all). MDA activity ↑ (b-c, F), SOD activity ↓ (c, M).<br>Ferroptosis: ↓ expression GPx4 (b,c), FTH1, FTL (b,c), SLC7A11.<br>. Jejunum: ↑ villus height (a, F; c), MDA activity ↑ (c, F), GSH-Px ↑ (b, F), SOD activity ↑ (c, M)</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 3 (continued)</caption><thead><tr><th>Author</th><th>Rodent</th><th>Polymer</th><th>Size (nm)</th><th>Exposure</th><th>Duration</th><th>Techniques</th><th>Blood MP/ NP**</th><th>Goal</th><th>Main results</th></tr></thead><tbody><tr><td>Moreno 2024 [109]</td><td>6 Sprague-Dawley rat</td><td>polyamide-12 (PA-12), Arkema (King of Prussia, Pennsylvania), spheroid shape</td><td>5 µm (30.7 nm and 3.81 µm mainly after dispersion)</td><td>Custom rodent inhalation facility (n = 3), 11.46 ± 3.78 mg/m3, 4 h/day</td><td>6-19 GD (10 days non consecutive)</td><td>hyperspectral dark-field microscopy</td><td>150 µg/mL - 1,5 mg/mL</td><td>D</td><td>Fetus: constant litter size, tendency to diminished weight. PND14 for n = 2 (1 M, 1 F): omnipresence in tissues</td></tr><tr><td>Dibbon 2023 [102]</td><td>28 healthy CD-1 mice (6-14 w)</td><td>PS (microspheres-nanospheres, NY)</td><td>5 µm or 50 nm</td><td>Oral Drinking water 10<sup>6</sup> ng/mL n = 9 (MP) n = 10 (NP) n = 9 controls</td><td>17.5</td><td>High-frequency ultrasound: Umbilical artery pulsatility ("brain-sparing effect in Doppler ultrasound)</td><td>2.5 µg/mL - 45 µg/mL</td><td>E</td><td>No effect on maternal weight, litter size, fetal resorption, F/M ratio: Overall fetal weight MP/NP: NS; ↓ fetal weight, F. Overall placenta weight MP/NP: NS; ↑ placenta weight M vs F. ↓ FPWR for M, NPs vs. control MP: ↑ UA blood flow; NS for pulsatility. NP: ↓ UA blood flow; ↑ for pulsatility MP & NPs: ↓ middle cerebral artery blood flow; Significant impact on ductus venosus artery on a-wave ratio. Velocity ratio ↓ MP. vs NP</td></tr><tr><td>Zhang 2024 [114]</td><td>28 C57BL/6 mice, 6-8 w</td><td>PS (Baseline Kromtech Research Centre, Tianjin, China))</td><td>1 µm</td><td>0, 0.1 (L), 1 (M), and 10 (H) mg/L (n = 4 each) in deionized water</td><td>18 days 0.5-18.5</td><td>Histology, Immunohistochemistry, Biochemical analysis, RTqPCR</td><td>0,25 µg/mL - 450 µg/mL</td><td>E</td><td>Placenta: ↓ weight (L, M, H), ↓ placental junctional zones (H) without structural damage. Fetus: ↓ weight (M, H), ↑ embryo resorption, hypotrophy (L, M, H),</td></tr><tr><td>Hanrahan 2024 [103]</td><td>25 CD-1 mice (6-18 w)</td><td>PE with Tween 20 surfactant</td><td>740 nm- 5 µm</td><td>Oral Drinking water 10<sup>6</sup> ng/mL N = 12 (MP) n = 12 controls (surfactant) n = 11 controls (filtered water)</td><td>0.5-17.5 GD</td><td>Artery ultrasound Uterine artery (velocity, pulsatility) Middle cerebral artery (velocity, pulsatility)</td><td>2.5 µg/mL - 40 µg/mL</td><td>E</td><td>Placenta No significant effect on weight Embryo/fetus No significant effect on weight or umbilical cord length ↓ Fetal-placental blood flow (uterine artery) in the PE group only. No significant difference in UA pulsatility. No significant difference in cerebral blood flow</td></tr><tr><td>Wan 2024 [55]</td><td>C57 BL/6 mice (6-8 w)</td><td>PS (Shanghai Huge Biotechnology)</td><td>50</td><td>Daily oral gavage n = 9, 25 mg/kg/d n = 9, 50 mg/kg/d n = 9, 100 mg/kg/d n = 9 controls</td><td>1-14 GD</td><td>TUNEL assay Western-blot</td><td>370 µg/mL - 20 mg/mL</td><td>D &amp; E</td><td>↑ embryo adsorption, ↑ miscarriage rate, with dose dependence Placenta, for > 50 mg/kg: ↑ apoptosis and ROS, with dose dependence, ↓ Bcl2, ↑ cleaved caspases-2 and -3</td></tr><tr><td>Wan 2024 [54]</td><td>C57 BL/6 mice (6-8 w)</td><td>PS (Shanghai Huge Biotechnology)</td><td>50</td><td>Daily oral gavage 100 mg/kg/day . SOX2 group a) PS-NP b) PS-NP + IP vector pcDNA3.1, c) PS-NP + IP vector pcDNA3.1-SOX2 . ROCK1: same principle</td><td>1-13 GD</td><td>Dual-Luciferase reporter assays, WB, RTqPCR</td><td>370 µg/mL - 20 mg/mL</td><td>E</td><td>↑ miscarriage rate Impairment of ROCK-1-mediated invasion/ migration and migrasome, by repressing his transcription factor SOX2 (promotion of its autophagic degradation)</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 3 (continued)</caption><thead><tr><th>Author</th><th>Rodent</th><th>Polymer</th><th>Size (nm)</th><th>Exposure</th><th>Duration</th><th>Techniques</th><th>Blood MP/ NP**</th><th>Goal</th><th>Main results</th></tr></thead><tbody><tr><td>Bai 2024 [104]</td><td>C57BL/6 J mice (7 weeks)</td><td>PS (Huafukang Bioscience Co.)</td><td>5 µm</td><td>Gavages<br>25 mg/kg n = 8<br>50 mg/kg n = 8<br>100 mg/kg n = 8<br>Normal saline n = 8</td><td>1–14 GD</td><td>Histopathology<br>Western-blot &<br>immunofluorescence<br>qRT-PCR</td><td>370 µg/mL - 20 mg/mL</td><td>E</td><td><b>Placenta:</b> ↓ placental weight;<br>inflammatory cell infiltration and necrotic foci<br>↑ concentrations MDA, CAT, MOP and H₂O₂,<br>↓ T-AOC SOD<br>↑ <i>transcription</i> IL1α, Il-6 and Tnf-α<br>↓ expression ZO-1, ZO-2, claudin-1, claudin 3;<br>↓ <i>transcription</i> Aa transporters (<i>Slc36a1</i>, <i>Slc36a4</i>, and <i>Slc38a1</i>), fatty acid transporteur (<i>Slc2a1</i>), glucose (<i>Slc2a1</i>); Vegf, Vegfr and <i>Atp1a1</i><br>↑ expression Bax, cleaved caspase-3, ↓ Bcl2 and Bcl-xL<br><b>Fetus:</b> trend of decreasing in number</td></tr><tr><td>Chen [110]</td><td>C57BL/6 J mice</td><td>Released MP from a brand of disposable paper cup, in hot water + associated toxins</td><td>6–706–62,6–154um</td><td>Oral gavage, 200 µL<br>Equivalent to 0, 1, 10, 100 cups/day in human</td><td>3, 6, 9, 12, and 15 d</td><td>Raman<br>Transcriptomic<br>ELISA</td><td>2 µg/mL - 1 mg/mL</td><td>D &amp; E</td><td><b>Placenta</b><br>High amount of MP 171,573 ± 92,071 n/g<br>Dose-dependant ↓ in adhesion junction pathways and autophagy gene expression, ↑ N-glycan biosynthesis, ↑ pathway of allograft rejection<br><b>Fetus</b><br>High amount of MP 190,436 ± 99,103 n/g</td></tr><tr><td>Luo 2019 [92]</td><td>ICR mice [7w]</td><td>Pristine PS (NY)</td><td>5 µm</td><td>Oral, drinking water <i>ad libitum</i>, including during lactation<br>100 (a) and 1000 µg/L (b)<br>Control: normal water</td><td>19 GD-all gestation &amp; lactation</td><td></td><td>0.25–105 µg/mL</td><td>E</td><td><b>Dams</b>: pyruvate, triglycerides, fatty acids ↓, liver mRNA Glut2, GK, PK, chrebp ↓, Cs, CoAs, Coa-r<br>Significant gene overexpression in all groups, impairing insulin secretion and energetic process, lipid biosynthesis, regulation of neoglucogenesis confirmed in KEGG, including PPAR, CYP450 F1(PND 42):<br><b>Hepatic</b>: ↓ carbohydrate metabolism (Gk, Chrebp), ↓ citric acid metabolism (Cs, CoA-s, CoA-r), ↓ β-oxidation: PPAR-α, Acox, Cpt1α, Mcad, ↓ triglyceride synthesis and transport (Dgat2, Gpat2)<br><b>Intestinal</b>: Male: ↓'a-diversity (microbiota).<br>Dysbiosis (female: Lachnospiraceae ++ // male: Ambiguous Taxa ++)<br>F1 (PND 280): No differences in mouse body weight. Female: lipid accumulation in the liver</td></tr><tr><td>Han 2021 [111]</td><td>5 mice</td><td>PE (Cospheric, Santa Barbara, CA, USA)</td><td>10–45</td><td>0, 6, 60 µg/mice (n = 3 each), seven intratacheal instillation during exposure</td><td>GD9-PND7</td><td>Histopathology<br>Biochemical assays</td><td>3–360 µg/mL</td><td>D &amp; E</td><td><b>Fetus</b><br>No effect in the number of offspring and body weight<br>Birth No effect on TG levels, acetylcholinesterase, glutathione peroxidase activity. Kidney and lung examination without pathologic features.<br><b>PND7:</b> accumulation in kidney at high dose only</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 3 (continued)</caption><thead><tr><th>Author</th><th>Rodent</th><th>Polymer</th><th>Size (nm)</th><th>Exposure</th><th>Duration</th><th>Techniques</th><th>Blood MP/ NP**</th><th>Goal</th><th>Main results</th></tr></thead><tbody><tr><td>Huang 2022 [94]</td><td>32 healthy female Kunming mice (7 w)</td><td>PS (Sigma-Aldrich)</td><td>100</td><td>Oral, 0, 0.1, 1, and 10 mg/L water</td><td>Until weaning</td><td>Hematocytometer Enzyme assays RT-PCR Targeted metabolomics</td><td>20 µg/mL- 10 mg/mL</td><td>E</td><td>Offspring: No abortions, no effect on litter size, ↓ weight at birth, PND21, PND56 (1, 10 mg/L)<br/>* Liver: ↓ size, absolute weight PND D21 (1, 10 mg/L); transient severe histologic lesions at PDN21, with sinusoid congestion, inflammatory cell infiltrate D12; ROS: ↑ MDA generation, ↓ CAT and SOD activity at D21 and D56, (10 mg/L); transient ↑ Il-6, TNF-α and Il-1β expression PND21 (> 0.1 mg/L); ↓ DHAP, F6Ptase, AMP, G6Ptase, TPP at high dose.<br/>* Kidney and small intestine: normal Testis: ↓ absolute weight, D21-56, 1-10 mg/L; dysmorphogenesis, ↓ epididymal count, disordered arrangement, germ cell detachment from seminiferous epithelium, D56 (1, 10 mg/L); ↑ MDA generation D21-D56, ↓ CAT (1 mg/L) and SOD activities, D21, (1-10 mg/L), ↓ CAT and SOD activity at D56 (10 mg/L).</td></tr><tr><td>Harvey 2023 [98]</td><td>20 healthy CD-1 female mice (8-15 w)</td><td>Plain PS (Microspheres-Nanospheres, NY)</td><td>50 nm*</td><td>Oral, ad libitum access 10<sup>6</sup> ng/L, filtered water (n = 10) Control (n = 10)</td><td>until weaning</td><td>Behavioral tests Ex vivo magnetic resonance imaging</td><td>2.5-100 µg/mL</td><td>E</td><td>Fetus: No difference in size at birth (the same sex ratio as controls), ↑ postnatal growth in males and in controls. No impact on offspring motor function (PD 2-6) but earlier eye opening in males<br/>Focal structural differences in the absolute volume in grey and white matter regions. Decrease in the hypothalamus, medial septum, medulla (only in females), olfactory bulb, visual cortex (only in males); increase in the corpus callosum, cortex areas (only the visual cortex in females), fornix, hippocampus, inferior colliculus, lateral ventricle, mammillothalamic tract, and striatum</td></tr><tr><td>Jeong 2022 [100]</td><td>C57BL/6 Pregnant mice</td><td>conjugated PS, plain or carboxylated (Polyscience, Warrington, PA)</td><td>50, 100</td><td>Oral Agarose jelly cube, once a day 0.5, 10, 100, 1000 µg/d Control: water</td><td>7.5 GD- 2 weeks after birth</td><td>TEM Transcriptome Electrophys HPLC/UV, Western blot, Protein Network</td><td>0.3 µg/mL - 16 mg/mL</td><td>D &amp; E</td><td>Embryo: no signal in any embryonic organ, umbilical cord at E14<br/>Placenta: PS lightly ↑ in the labyrinth, clearly ↑ in the decidua<br/>Offspring PND7: ↑ body &amp; brain weight (> 10 µg/d consumption), PS in intestines, blood, brain. ↓ Ki67 + proliferative cells in hippocampus. ↑ astrocyte count and abnormal gliogenesis<br/>PND14: no morphological changes or weight gain<br/>↓ Neun + cells in the hippocampal striatum radiatum, ↓ corpus callosum, ↑ FAP+ cells in the corpus callosum and internal capsule. Structural changes in males and females but</td></tr></tbody></table>

(continued on next page)
<table><caption>Table 3 (continued)</caption><thead><tr><th>Author</th><th>Rodent</th><th>Polymer</th><th>Size (nm)</th><th>Exposure</th><th>Duration</th><th>Techniques</th><th>Blood MP/ NP**</th><th>Goal</th><th>Main results</th></tr></thead><tbody><tr><td>Zaheer 2022 [101]</td><td>C57BL/6 J &amp; CD-1 mice</td><td>PE (Cospheric LLC, USA) in Tween-80</td><td>10-20 µm</td><td>Oral 100 ppm-100 µL/ d (syringe), 2 weeks Control: PBS</td><td>2 weeks during pregnancy and 2 weeks postnatal for 5-6 weeks of age F1</td><td>Behavior study 2-chamber test SAP score Biochemical assays</td><td>5 µg/mL- 75 µg/mL</td><td>E</td><td>severe cognitive impairment ++ in females only<br>Offspring, 5-6 weeks of age<br>↓ social interaction/novelty seeking<br>↓ spatial working memory<br>Repetitive and compulsive behaviors<br>↓ GSH, GABA, glycerophosphocholine and phosphocholine</td></tr><tr><td>Lu 2024 [108]</td><td>18 ICR mice, 8 w</td><td>PS (Tianjin Baseline ChromTech Research Centre, China)</td><td>5 µm, 50 nm</td><td>0, 10 mg/L/day in drinking water</td><td>vaginal plug - PND21</td><td>Histology, 16S RNA, LC-MS/ MS targeted metabolomics</td><td>25 µg/mL - 1 mg/mL</td><td>D<br>E</td><td>No significant variation in body weight following both MP/NP. ↑ liver, kidney, spleen, heart, brain index. MP and NP found in blood. NP found in all organs, contrary to MP (heart and spleen only). Size-dependent disturbance of glucolipidic metabolism, hepatotoxicity, microbiota composition and metabolic response.</td></tr><tr><td>Ma 2025 [118]</td><td>80 Kunmig mice, 6 w</td><td>PS (mini-emulsion polymerization)</td><td>25</td><td>0, 1 mg/day by oral gavage</td><td>GD1-PND21</td><td>Histology, RNA seq, proteomics, RTq-PCR, TEM, WB</td><td>50 µg/mL - 2 mg/mL</td><td>E</td><td>Fetus: constant litter size and sex ratio, ↓birth weight (M). PND7: Testis: ↓ weight, ↑ MDA, SOD activity, ↓ SOD. PND 7/21: structural dizorganisation and ↓ spermatogonic and spermatozoa cells. Inflammation in undifferentiated spermatogonia via ↑ Tnfsf18/Nlrp6, Prdm14 transcription and expression, reduction in autophagic flux</td></tr><tr><td>Jeong 2024 [106]</td><td>C57BL/6 J mice</td><td>COOH-PS (Polyscience, Warrington, PA, US) and PP (Environmental Disease Research Center)</td><td>50<br>500</td><td>0-500 µg/day ingestion</td><td>Gestation and lactation GD 8-PND14</td><td>Metagenomic, WB, biochemassays</td><td>250 µg/mL - 10 mg/mL</td><td>E</td><td>↑ body weight at 1 w (PS), at 3 w (PS, PP), at 6 w (M, PS) with no food-effect. At 6 w, ↑ Fat ratio (fat tissue/lean tissue) (PS, PP), ↑ plasma cholesterol at 3w (PS), dysregulation of PLA2- induced lipid metabolism (PS) and changes in microbiota tax (PS) correlated to altered lysophosphatidylcholine/phosphatidylcholine ratio in breast milk.</td></tr><tr><td>Cheng 2025 [105]</td><td>30 Kunming female mice, 8 w</td><td>PS (Beijing Zhongkeleiming Technology)</td><td>50</td><td>Gastric perfusion 30 mg/kg/d, 200 µL (NaCl for controls)</td><td>0,5 GW-PND7/ 21</td><td>Immunofluoresenc qRT-PCR Transcriptomic Western-blot</td><td>450 µg/mL - 18 mg/mL</td><td>D &amp; E</td><td>↓ fertility, ↓ growing follicles and oocytes↓ pregnancy duration,<br>Fetus: ↑ abortion rate, ↓ number of implantation<br>Fluorescent NP in digestive tract, ↓ body weight at birth<br>Female offspring: ↑ estrous phase and ↓ diestrus duration. ↓ AMH, E2, FSH NS↓ fertility, litter size, scarcity of secondary follicles and absence of antral follicles ↓ primordial and growing follicles, ↓ ovarian AKT, FOXO3a, mTORC1 ↓ transzonal projection, ↓ mRNA and expression of CAMKIIb)</td></tr></tbody></table>

D: deposition, E: effect, GD: gestational day; PND: postnatal day; p: particle; MP: microplastic; NP: nanoplastic; ↓ or ↑: significantly lower or higher concentrations. * physical characterization prior to the experiment.

** Blood concentration estimation based on the following physiological characteristics: for mice, weight 30 g, blood volume 2 mL, water consumption/day 5 mL; for rats, weight 200 g, blood volume 13 mL. For each study, the minimum concentration is calculated with the hypothesis of 100 % absorption and no accumulation, and the maximum concentration is calculated with the hypothesis of 100 % absorption and 100 % accumulation over time (repeated doses).
In the former case, exposure to NP is overlooked, as the sensitivity is limited to the micrometer scale. In the latter case, sample destruction tends to underestimate the amount of MP/NP present and prevents any distinction between MP and NP. Studies report MP/NP impregnation either as mass concentration or as particle concentration. Since mass concentration depends on particle size and density (which vary greatly between polymers: 0.01 g/cm³ for PP vs. 1.38 g/cm³ for PVC), it cannot accurately reflect the particle concentration. Developing sensitive, standardized detection methods will be essential to clarify whether fetal systemic exposure occurs and, if so, at what level, which could have major implications for clinical practice. New methods should therefore allow (i) the identification, localization, and quantification of MP/NP by distinguishing the proportion of each polymer in terms of number, size, and shape, (ii) the assessment of pregnant women's exposure to MP/NP, including their organic, organometallic, and metallic additives, and (iii) the quantification of mother-to-fetus transfer of particles in human placentas, maternal blood, and cord blood. A gentle enzymatic tissue digestion method that releases compounds into an aqueous medium appears to be the least destructive [122]. Detection and quantification of plastics will require complementary methods: counting and characterization of their chemical nature using nano-Raman and IR spectroscopy, in addition to mass quantification by Pyr-GC-MS and inductively coupled plasma mass spectrometry (ICP-MS).

With a few exceptions, research has primarily focused on the effects of polystyrene. When combined with plasticizers, PS has a wide range of uses: in insulation and padding in its expanded form, and in packaging (particularly food packaging) as well as in toys, electronic circuits, car parts, etc. in its solid form. However, more studies investigating other polymers, alternative particle shapes, native vs. degradation products, and both acute and chronic exposure scenarios are needed to better understand the *plasticenta*. Aqueous suspensions of purified PE, PP and PVC spheres are now commercially available and could be used in models of co-exposure or comparative exposure. In parallel, one could also use “real-world” polymers and their plasticizers to better mimic everyday exposure.

These high-profile research topics will be inspiring for public decision-makers and authorities. At the European Union scale, in 2023, the REACH committee, responsible for regulating the manufacture and use of chemical substances in European industry, voted in favor of a regulation for manufactured MP/NP, with the aim of reducing MP environmental emissions by 30 % in the next ten years. MP at a concentration equal to or greater than 0.01 % of the overall mass of the mixture are also affected by the regulations; below this concentration, they remain authorized. Any organic, insoluble, resistant polymer, less than 5 mm in size — including NP — will be banned when used as microbead. Paradoxically, this transitional period is particularly long for some products despite their immediate contamination of soils or their immediate contact with skin. However, as for NP, their fate remains very unclear, particularly regarding a temporary exemption from regulation due to the absence of effective detection, identification and precise quantification in complex matrices.

The exploration of *plasticenta* has only just begun. This “terra incognita” is as vast as the “sixth continent” of plastic drifting in the Pacific Ocean. In 1957, at the time when conventional plastics were emerging, the prospects for vascular surgery prompted the French philosopher Roland Barthes to say that "life itself could be plasticized" [123]. No one foresaw that these polymers might escape from the Pandora’s box nor that “life before life” could be plasticized. Let us ensure that through research and political action, the box begins to close.

## Environmental implication

The impact of MP/NP is a major public health issue. This growing interest is highly relevant with regard to the placental exposome. A body of evidence now indicates that various micro-nanoplastics (including

polystyrene, polypropylene, polyethylene...) are present notably in the human placenta. These “plasticcentas” appear to be linked to changes in placental function and might therefore be associated with the occurrence of miscarriage or intrauterine growth retardation. Maternal exposure of the placenta and fetus to these environmental pollutants might induce prenatal and neonatal disease states. In our opinion, it represents, better than any other, the concept of One Health.

## CRediT authorship contribution statement

**Thierry Fournier:** Writing – review & editing. **Léa Poinsignon:** Writing – original draft, Investigation, Conceptualization. **Bertrand Lefrère:** Writing – original draft, Methodology, Investigation, Data curation, Conceptualization. **Jean-Louis Beaudeux:** Writing – review & editing, Validation, Supervision, Methodology, Conceptualization. **Amal Zerrad-Saadi:** Writing – review & editing, Visualization, Validation, Supervision, Conceptualization. **Gaetane Lespes:** Writing – review & editing.

## Funding

This work was funded by the French National Agency for Environmental and Occupational Health (grant reference: ANSES-21-EST-121).

## Declaration of Competing Interest

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Dr Zerrad-Saadi reports financial support was provided by French National Agency for Environmental and Occupational Health. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

## Appendix A. Supporting information

Supplementary data associated with this article can be found in the online version at doi:10.1016/j.jhazmat.2025.140018.

## Data availability

No data was used for the research described in the article.

## References

[1] Thompson, R.C., Swan, S.H., Moore, C.J., vom Saal, F.S., 2009 Jul 27. Our plastic age. Philos Trans R Soc B 364 (1526), 1973–1976.

[2] Geyer, R., de, Jambeck, J.R., Law, K.L., 2017 Jul 7. Production, use, and fate of all plastics ever made. Sci Adv 3 (7), e1700782.

[3] Masud, R.I., Suman, K.H., Tasnim, S., Begum, M.S., Sikder, M.H., Uddin, M.J., et al., 2023 Jan. A review on enhanced microplastics derived from biomedical waste during the COVID-19 pandemic with its toxicity, health risks, and biomarkers. Environ Res 216, 114434.

[4] Prata, J.C., Da Costa, J.P., Lopes, I., Andrady, A.L., Duarte, A.C., Rocha-Santos, T., 2021 Jul. A one health perspective of the impacts of microplastics on animal, human and environmental health. Sci Total Environ 777, 146094.

[5] Nielsen, T.D., Hasselbalch, J., Holmberg, K., Stripple, J., 2020 Jan. Politics and the plastic crisis: a review throughout the plastic life cycle. WIREs Energy Environ [Internet 9 (1).] (https://onlinelibrary.wiley.com/doi/10.1002/wene.360), cited 2023 Jul 31.

[6] Allan, J., Belz, S., Hoeveler, A., Hugas, M., Okuda, H., Patri, A., et al., 2021 Jun. Regulatory landscape of nanotechnology and nanoplastics from a global perspective. Regul Toxicol Pharm 122, 104885.

[7] (https://echa.europa.eu/de/-/rac-backs-restricting-intentional-uses-of-microp lastics).

[8] Senathirajah, K., Attwood, S., Bhagwat, G., Carbery, M., Wilson, S., Palanisami, T., 2021 Feb. Estimation of the mass of microplastics ingested – a pivotal first step towards human health risk assessment. J Hazard Mater 404, 124004.

[9] Cox, K.D., Coverton, G.A., Davies, H.L., Dower, J.F., Juanes, F., Dudas, S.E., 2019 Jun 18. Human consumption of microplastics. Environ Sci Technol 53 (12), 7068–7074.
[10] Prata, J.C., 2018 Mar. Airborne microplastics: consequences to human health? Environ Pollut 234, 115–126.

[11] Sangkham, S., Faikhaw, O., Munkong, N., Sakunkoo, P., Arunlertaree, C., Chavali, M., et al., 2022 Aug. A review on microplastics and nanoplastics in the environment: their occurrence, exposure routes, toxic studies, and potential effects on human health. Mar Pollut Bull 181, 113832.

[12] Barceló, D., CPIC, Y., Alfarhan, A.H., 2023 Aug. Microplastics: detection in human samples, cell line studies, and health impacts. Environ Toxicol Pharmacol 101, 104204.

[13] Yang, J., Kamstra, J., Legler, J., Aardema, H., 2023. The impact of microplastics on female reproduction and early life. Anim Reprod 20 (2), e20230037.

[14] Burton, G.J., Fowden, A.L., 2015 Mar 5. The placenta: a multifaceted, transient organ. Philos Trans R Soc Lond B Biol Sci 370 (1663), 20140066.

[15] Vrachnis, N., Loukas, N., Vrachnis, D., Antonakopoulos, N., Zygouris, D., Kolialexi, A., et al., 2021 Jul 15. A systematic review of bisphenol a from dietary and Non-Dietary sources during pregnancy and its possible connection with fetal growth restriction: investigating its potential effects and the window of fetal vulnerability. Nutrients 13 (7), 2426.

[16] Stosavljević, A., Perović, M., Nešić, A., Miković, Ž., Manojlović, D., 2022 Jun. Levels of non-essential trace metals and their impact on placental health: a review. Environ Sci Pollut Res 29 (29), 43662–43674.

[17] Poinsignon, L., Lefrère, B., Ben Azzouz, A., Chissey, A., Colombel, J., Djelidi, R., et al., 2025 Jun 15. Exposure of the human placental primary cells to nanoplastics induces cytotoxic effects, an inflammatory response and endocrine disruption. J Hazard Mater 490, 137713.

[18] Ragusa, A., Principi, G., Matta, M., 2022 Sep 21. Pregnancy in the era of the environmental crisis: plastic and pollution. Clin Exp Obstet Gynecol 49 (10), 216.

[19] Dusza, H.M., Van Boxel, J., Van Duursen, M.B.M., Forsberg, M.M., Legler, J., Vähäkangas, K.H., 2023 Feb. Experimental human placental models for studying uptake, transport and toxicity of micro- and nanoplastics. Sci Total Environ 860, 160403.

[20] Medley, E.A., Spratlen, M.J., Yan, B., Herbstman, J.B., Deyssenroth, M.A., 2023 Feb 27. A systematic review of the placental translocation of Micro- and nanoplastics. Curr Envir Health Rpt [Internet] cited 2023 Jun 26; Available from: (https://link.springer.com/10.1007/s40572-023-00391-x).

[21] Jaafarzadeh Haghighi Fard, N., Mohammadi, M.J., Jahedi, F., 2023 Aug. Effects of nano and microplastics on the reproduction system: in vitro and in vivo studies review. Food Chem Toxicol 178, 113938.

[22] Paul, I., Mondal, P., Haldar, D., Halder, G., 2024 May 5. Beyond the cradle - amidst microplastics and the ongoing peril during pregnancy and neonatal stages: a holistic review. J Hazard Mater 469, 133963.

[23] Sharma, R.K., Kumari, U., Kumar, S., 2024 May. Impact of microplastics on pregnancy and fetal development: a systematic review. Cureus 16 (5), e60712.

[24] Hunt, K., Davies, A., Fraser, A., Burden, C., Howell, A., Buckley, K., et al., 2024 Apr. Exposure to microplastics and human reproductive outcomes: a systematic review. BJOG 131 (5), 675–683.

[25] Panneerselvam, D., Murugesan, A., Raveendran, S.K., Kumar, J.S., Venkataraman, P., 2025 Jan. Examining the hidden dangers: understanding how microplastics affect pregnancy. Eur J Obstet Gynecol Reprod Biol 304, 53–62.

[26] Leslie, H.A., Van Velzen, M.J.M., Brandsma, S.H., Vethaak, A.D., Garcia-Vallejo, J.J., Lamoree, M.H., 2022 May. Discovery and quantification of plastic particle pollution in human blood. Environ Int 163, 107199.

[27] Salvia, R., Rico, L.G., Bradford, J.A., Ward, M.D., Olszowy, M.W., Martínez, C., et al., 2023. Fast-screening flow cytometry method for detecting nanoplastics in human peripheral blood. MethodsX 10, 102057.

[28] Leonard, V.L., Diddle, S., Atherall, C.R., Chapman, C.A., Watkins, E., D J M., et al., 2024 Jun 21. Microplastics in human blood: polymer types, concentrations and characterisation using µFTIR. Environ Int 188, 108751.

[29] Kuhlman, R.L., 2022 Sep. Letter to the editor, discovery and quantification of plastic particle pollution in human blood. Environ Int 167, 107400.

[30] Yang, Y., Xie, E., Du, Z., Peng, Z., Han, Z., Li, L., et al., 2023 Aug 1. Detection of various microplastics in patients undergoing cardiac surgery. Environ Sci Technol 57 (30), 10911–10918.

[31] Rotchell, J.M., Jenner, L.C., Chapman, E., Bennett, R.T., Bolanle, I.O., Loubani, M., et al., 2023 Feb 1. Detection of microplastics in human saphenous vein tissue using µFTIR: a pilot study. In: Mukherjee, A. (Ed.), PLoS ONE 18, e0280594.

[32] Wang, T., Yi, Z., Liu, X., Cai, Y., Huang, X., Fang, J., et al., 2024 May. Multimodal detection and analysis of microplastics in human thrombi from multiple anatomically distinct sites. eBioMedicine 103, 105118.

[33] Gopinath, P.M., Saranya, V., Vijayakumar, S., Mythili Meera, M., Ruprekha, S., Kunal, R., et al., 2019 Jun 20. Assessment on interactive prospectives of nanoplastics with plasma proteins and the toxicological impacts of virgin, coronated and environmentally released-nanoplastics. Sci Rep 9 (1), 8860.

[34] Pluciennik, K., Sicińska, P., Duchnowicz, P., Bonarska-Kujawa, D., Męczarska, K., Solarska-Ściuk, K., et al., 2023 Sep. The effects of non-functionalized polystyrene nanoparticles with different diameters on human erythrocyte membrane and morphology. Toxicol Vitr 91, 105634.

[35] Li, P., Li, Q., Lai, Y., Yang, S., Yu, S., Liu, R., et al., 2023 Dec. Direct entry of micro (nano)plastics into human blood circulatory system by intravenous infusion. iScience 26 (12), 108454.

[36] Jenner, L.C., Rotchell, J.M., Bennett, R.T., Cowen, M., Tentzeris, V., Sadofsky, L. R., 2022 Jul. Detection of microplastics in human lung tissue using µFTIR spectroscopy. Sci Total Environ 831, 154907.

[37] Fournier, S.B., D'Errico, J.N., Adler, D.S., Kollontzi, S., Goedken, M.J., Fabris, L., et al., 2020 Dec. Nanopolystyrene translocation and fetal deposition after acute lung exposure during late-stage pregnancy. Part Fibre Toxicol 17 (1), 55.

[38] Abbasi, S., 2021 Feb. Human exposure to microplastics: a study in Iran. J Hazard Mater 403, 123799.

[39] Ramsperger, A.F.R.M., Bergamaschi, E., Panizzolo, M., Fenoglio, I., Barbero, F., Peters, R., et al., 2023 Jan. Nano- and microplastics: a comprehensive review on their exposure routes, translocation, and fate in humans. NanoImpact 29, 100441.

[40] Xie, F., Agrawal, S., Johnson, E.F., Wieland, C.N., Davis, D.M.R., Theiler, R.N., et al., 2023 May. Updates on the dermatopathology of pregnancy-associated skin conditions. Hum Pathol, S0046817723001168.

[41] Sun, J., Sui, M., Wang, T., Teng, X., Sun, J., Chen, M., 2024 Jan 1. Detection and quantification of various microplastics in human endometrium based on laser direct infrared spectroscopy. Sci Total Environ 906, 167760.

[42] Pironti, C., Notarstefano, V., Ricciardi, M., Motta, O., Giorgini, E., Montano, L., 2022 Dec 30. First evidence of microplastics in human urine, a preliminary study of intake in the human body. Toxics 11 (1), 40.

[43] Liu, S., Guo, J., Liu, X., Yang, R., Wang, H., Sun, Y., et al., 2023 Jan. Detection of various microplastics in placentas, meconium, infant feces, breastmilk and infant formula: a pilot prospective study. Sci Total Environ 854, 158699.

[44] Ragusa, A., Notarstefano, V., Svelato, A., Belloni, A., Gioacchini, G., Blondeel, C., et al., 2022 Jun 30. Raman microspectroscopy detection and characterisation of microplastics in human breastmilk. Polymers 14 (13), 2700.

[45] Ragusa, A., Svelato, A., Santacroce, C., Catalano, P., Notarstefano, V., Carnevali, O., et al., 2021 Jan. Plasticenta: first evidence of microplastics in human placenta. Environ Int 146, 106274.

[46] Roslan, N.S., Lee, Y.Y., Ibrahim, Y.S., Tuan Anuar, S., Yusof, K.M.K.K., Lai, L.A., et al., 2024 Aug 23. Detection of microplastics in human tissues and organs: a scoping review. J Glob Health 14, 04179.

[47] Braun, T., Ehrlich, L., Henrich, W., Koeppel, S., Lomako, I., Schwabl, P., et al., 2021 Jun 22. Detection of microplastic in human placenta and meconium in a clinical setting. Pharmaceutics 13 (7), 921.

[48] Ragusa, A., Matta, M., Cristiano, L., Matassa, R., Battagliae, O., Svelato, A., et al., 2022 Sep 14. Deeply in plasticenta: presence of microplastics in the intracellular compartment of human placentas. IJERPH 19 (18), 11593.

[49] Amereh, F., Amjadi, N., Mohseni-Bandpei, A., Isazadeh, S., Mehrabi, Y., Esami, A., et al., 2022 Dec. Placental plastics in young women from general population correlate with reduced foetal growth in IUGR pregnancies. Environ Pollut 314, 120174.

[50] Zhu, L., Zhu, J., Zuo, R., Xu, Q., Qian, Y., An, L., 2023 Jan. Identification of microplastics in human placenta using laser direct infrared spectroscopy. Sci Total Environ 856, 159060.

[51] Halfar, J., Cabanová, K., Vávra, K., Delongová, P., Motyka, O., Špaček, R., et al., 2023 Dec. Microplastics and additives in patients with preterm birth: the first evidence of their presence in both human amniotic fluid and placenta. Chemosphere 343, 140301.

[52] Weingrill, R.B., Lee, M.J., Benny, P., Riel, J., Saiki, K., Garcia, J., et al., 2023. Temporal trends in microplastics accumulation in placentas from pregnancies in Hawai'i. Environ Int 180, 108220.

[53] Zurub, R.E., Bainbridge, S., Rahman, L., Halappanavar, S., El-Chaar, D., Wade, M. G., 2024 Oct. Particulate contamination of human placenta: plastic and non-plastic. Environ Adv 17, 100555.

[54] Wan, S., Wang, X., Chen, W., Xu, Z., Zhao, J., Huang, W., et al., 2024 Jan 30. Polystyrene nanoplastics activate autophagy and suppress trophoblast cell Migration/Invasion and migrasome formation to induce miscarriage. ACS Nano 18 (4), 3733–3751.

[55] Wan, S., Wang, X., Chen, W., Wang, M., Zhao, J., Xu, Z., et al., 2024 Mar 7. Exposure to high dose of polystyrene nanoplastics causes trophoblast cell apoptosis and induces miscarriage. Part Fibre Toxicol 21 (1), 13.

[56] Yun, X., Liang, L., Tian, J., Li, N., Chen, Z., Zheng, Y., et al., 2024 Sep 15. Raman-guided exploration of placental microplastic exposure: unraveling the polymeric tapestry and assessing developmental implications. J Hazard Mater 477, 135271.

[57] Garcia, M.A., Liu, R., Nihart, A., El Hayek, E., Castillo, E., Barrozo, E.R., et al., 2024 Apr 29. Quantitation and identification of microplastics accumulation in human placental specimens using pyrolysis gas chromatography mass spectrometry. Toxicol Sci 199 (1), 81–88.

[58] Jochum, M., Garcia, M., Hammerquist, A., Howell, J., Stanford, M., Liu, R., et al., 2025 Feb 3. Elevated Micro- and nanoplastics detected in preterm human placentae. Res Sq rs.3.rs-5903715.

[59] Zhu, M., Li, X., Lin, W., Zeng, D., Yang, P., Ni, W., et al., 2024 Nov 26. Microplastic particles detected in fetal cord blood, placenta, and meconium: a pilot study of nine Mother-Infant pairs in south China. Toxics 12 (12), 850.

[60] Tian, J., Liang, L., Li, Q., Li, N., Zhu, X., Zhang, L., 2025 Jan 15. Association between microplastics in human amniotic fluid and pregnancy outcomes: detection and characterization using Raman spectroscopy and pyrolysis GC/MS. J Hazard Mater 482, 136637.

[61] Xue, J., Xu, Z., Hu, X., Lu, Y., Zhao, Y., Zhang, H., 2024 Apr 10. Microplastics in maternal amniotic fluid and their associations with gestational age. Sci Total Environ 920, 171044.

[62] Li, Z., Wang, J., Gao, X., Du, J., Sui, H., Wu, J., et al., 2023 Mar 27. Investigation of microplastics (≥10 µm) in meconium by Fourier transform infrared microspectroscopy. Toxics 11 (4), 310.

[63] Liu, S., Liu, X., Guo, J., Yang, R., Wang, H., Sun, Y., et al., 2022 Oct 21. The association between microplastics and microbiota in placentas and meconium: the first evidence in humans. Environ Sci Technol acs. est.2c04706.
[64] Schukow, C.P., Macknis, J.K., 2024 Oct 1. The surgical Pathologist's (Potential) role in placental microplastic detection. Arch Pathol Lab Med 148 (10), 1080-1081.

[65] Deval, G., Boland, S., Fournier, T., Ferecatu, I., 2021 Nov 12. On placental toxicology studies and cerium dioxide nanoparticles. IJMS 22 (22), 12266.

[66] Aengenheister, L., Favaro, R.R., Morales-Prieto, D.M., Furer, L.A., Gruber, M., Wadsack, C., et al., 2021 Jan. Research on nanoparticles in human perfused placenta: state of the art and perspectives. Placenta 104, 199-207.

[67] Chortarea, S., Gupta, G., Saarimäki, L.A., Netkueakul, W., Manser, P., Aengenheister, L., et al., 2023 Jul. Transcriptomic profiling reveals differential cellular response to copper oxide nanoparticles and polystyrene nanoplastics in perfused human placenta. Environ Int 177, 108015.

[68] Grafmueller, S., Manser, P., Diener, L., Diener, P.A., Maeder-Althaus, X., Maurizi, L., et al., 2015 Dec. Bidirectional transfer study of polystyrene nanoparticles across the placental barrier in an ex vivo human placental perfusion model. Environ Health Perspect 123 (12), 1280-1286.

[69] Wick, P., Malek, A., Manser, P., Meili, D., Maeder-Althaus, X., Diener, L., et al., 2010 Mar. Barrier capacity of human placenta for nanosized materials. Environ Health Perspect 118 (3), 432-436.

[70] Grafmüller, S., Manser, P., Krug, H.F.P., Wick, P., Von Mandach, U., 2013 Jun 18. Determination of the transport rate of xenobiotics and nanomaterials across the placenta using the ex vivo human placental perfusion model. JOVE (76), 50401.

[71] Gruber, M.M., Hirschmugl, B., Berger, N., Holter, M., Radulović, S., Leitinger, G., et al., 2020 Dec. Plasma proteins facilitates placental transfer of polystyrene particles. J Nanobiotechnol. 18 (1), 128.

[72] Rothbauer, M., Patel, N., Gondola, H., Siwetz, M., Huppertz, B., Ertl, P., 2017 Jul 19. A comparative study of five physiological key parameters between four different human trophoblast-derived cell lines. Sci Rep 7 (1), 5892.

[73] Rytting, Cartwright, E., Poulsen, Nielsen, Pojana, Knudsen, et al., 2012 Jan. In vitro placental model optimization for nanoparticle transport studies. IJN 497.

[74] Hesler, M., Aengenheister, L., Ellinger, B., Drexel, R., Straskraba, S., Jost, C., et al., 2019 Dec. Multi-endpoint toxicological assessment of polystyrene nano- and microparticles in different biological models in vitro. Toxicol Vitr 61, 104610.

[75] Aengenheister, L., Keevend, K., Muoth, C., Schönenberger, R., Diener, L., Wick, P., et al., 2018 Dec. An advanced human in vitro co-culture model for translocation studies across the placental barrier. Sci Rep 8 (1), 5388.

[76] Dusza, H.M., Katrukha, E.A., Nijmeijer, S.M., Akhmanova, A., Vethaak, A.D., Walker, D.I., et al., 2022 Sep. Uptake, transport, and toxicity of pristine and weathered Micro- and nanoplastics in human placenta cells. Environ Health Perspect 130 (9), 97006.

[77] Kloet, S.K., Walczak, A.P., Louisse, J., Van Den Berg, H.H.J., Bouwmeester, H., Tromp, P., et al., 2015 Oct. Translocation of positively and negatively charged polystyrene nanoparticles in an in vitro placental model. Toxicol Vitr 29 (7), 1701-1710.

[78] Ragusa, A., Cristiano, L., Di Vinci, P., Familiari, G., Nottola, S.A., Macchiarelli, G., et al., 2025. Artificial plasticity: how polystyrene nanoplastics affect in-vitro cultured human trophoblast cells. Front Cell Dev Biol 13, 1539600.

[79] Hu, J., Zhu, Y., Zhang, J., Xu, Y., Wu, J., Zeng, W., et al., 2022 Oct. The potential toxicity of polystyrene nanoplastics to human trophoblasts in vitro. Environ Pollut 311, 119924.

[80] Shen, F., Li, D., Guo, J., Chen, J., 2022 Sep. Mechanistic toxicity assessment of differently sized and charged polystyrene nanoparticles based on human placental cells. Water Res 223, 118960.

[81] Huang, J.P., Hsieh, P.C.H., Chen, C.Y., Wang, T.Y., Chen, P.C., Liu, C.C., et al., 2015 Dec. Nanoparticles can cross mouse placenta and induce trophoblast apoptosis. Placenta 36 (12), 1433-1441.

[82] Nacka-Aleksić, M., Vilotić, A., Pirković, A., Živanović, M., Ljujić, B., Jovanović Krivokuća, M., 2025 Jan 5. Nano-scale dangers: unravelling the impact of nanoplastics on human trophoblast invasion. Chem Biol Inter 405, 111137.

[83] Wan, D., Liu, Y., Chang, Q., Liu, Z., Wang, Q., Niu, R., et al., 2024 Jul 30. Micro-/Nanoplastic exposure on placental health and adverse pregnancy risks: novel assessment system based upon targeted risk assessment environmental chemicals strategy. Toxics 12 (8), 553.

[84] Lee, H.S., Amarakoon, D., Wei, C. i, Choi, K.Y., Smolensky, D., Lee, S.H., 2021 Aug. Adverse effect of polystyrene microplastics (PS-MPs) on tube formation and viability of human umbilical vein endothelial cells. Food Chem Toxicol 154, 112356.

[85] Fu, Y., Fan, M., Xu, L., Wang, H., Hu, Q., Jin, Y., 2022 Apr 25. Amino-Functionalized polystyrene Nano-Plastics induce mitochondria damage in human umbilical vein endothelial cells. Toxics 10 (5), 215.

[86] Lu, Y.Y., Li, H., Ren, H., Zhang, X., Huang, F., Zhang, D., et al., 2022 Jan 5. Size-dependent effects of polystyrene nanoplastics on autophagy response in human umbilical vein endothelial cells. J Hazard Mater 421, 126770.

[87] Lu, Y.Y., Cao, M., Tian, M., Huang, Q., 2023 Feb. Internalization and cytotoxicity of polystyrene microplastics in human umbilical vein endothelial cells. J Appl Toxicol 43 (2), 262-271.

[88] de Sousa, A.K.A., Pires, K.S.N., Cavalcante, I.H., Cavalcante, I.C.L., Santos, J.D., Queiroz, M.I.C., et al., 2024. Polystyrene microplastics exposition on human placental explants induces time-dependent cytotoxicity, oxidative stress and metabolic alterations. Front Endocrinol (Lausanne) 15, 1481014.

[89] Enyoh, C.E., Duru, C.E., Ovuoraye, P.E., Wang, Q., 2023 Mar. Evaluation of nanoplastics toxicity to the human placenta in systems. J Hazard Mater 446, 130600.

[90] Georgiades, P., Ferguson-Smith, A.C., Burton, G.J., 2002 Jan. Comparative developmental anatomy of the murine and human definitive placentae. Placenta 23 (1), 3-19.

[91] Kenesei, K., Murali, K., Czéh, Á., Piella, J., Puntes, V., Madarász, E., 2016 Dec. Enhanced detection with spectral imaging fluorescence microscopy reveals tissue- and cell-type-specific compartmentalization of surface-modified polystyrene nanoparticles. J Nanobiotechnol. 14 (1), 55.

[92] Luo, T., Wang, C., Pan, Z., Jin, C., Fu, Z., Jin, Y., 2019 Sep 17. Maternal polystyrene microplastic exposure during gestation and lactation altered metabolic homeostasis in the dams and their F1 and F2 offspring. Environ Sci Technol 53 (18), 10978-10992.

[93] Hu, J., Qin, Z., Zhang, J., Zhu, Y., Zeng, W., Lin, Y., et al., 2021 Dec. Polystyrene microplastics disturb maternal-fetal immune balance and cause reproductive toxicity in pregnant mice. Reprod Toxicol 106, 42-50.

[94] Huang, T., Zhang, W., Lin, T., Liu, S., Sun, Z., Liu, F., et al., 2022 Feb. Maternal exposure to polystyrene nanoplastics during gestation and lactation induces hepatic and testicular toxicity in Male mouse offspring. Food Chem Toxicol 160, 112803.

[95] Cary, C.M., DeLoid, G.M., Yang, Z., Bitounis, D., Polunas, M., Goedken, M.J., et al., 2023 Feb 14. Ingested polystyrene nanospheres translocate to placenta and fetal tissues in pregnant rats: potential health implications. Nanomaterials 13 (4), 720.

[96] Aghaei, Z., Mercer, G.V., Schneider, C.M., Sled, J.G., Macgowan, C.K., Baschat, A. A., et al., 2022 Dec 20. Maternal exposure to polystyrene microplastics alters placental metabolism in mice. Metabolomics 19 (1), 1.

[97] Chen, G., Xiong, S., Jing, Q., Van Gestel, C.A.M., Van Straalen, N.M., Roelofs, D., et al., 2023 Jan. Maternal exposure to polystyrene nanoparticles retarded fetal growth and triggered metabolic disorders of placenta and fetus in mice. Sci Total Environ 854, 158666.

[98] Harvey, N.E., Mercer, G.V., Stapleton, D., Steeves, K.L., Hanrahan, J., Cui, M., et al., 2023. Maternal exposure to polystyrene nanoplastics impacts developmental milestones and brain structure in mouse offspring. Environ Sci Adv 2 (4), 622-628.

[99] Tang, J., Bu, W., Hu, W., Zhao, Z., Liu, L., Luo, C., et al., 2023 Feb 14. Ferroptosis is involved in Sex-Specific small intestinal toxicity in the offspring of adult mice exposed to polystyrene nanoplastics during pregnancy. ACS Nano 17 (3), 2440-2449.

[100] Jeong, B., Baek, J.Y., Koo, J., Park, S., Ryu, Y.K., Kim, K.S., et al., 2022 Mar. Maternal exposure to polystyrene nanoplastics causes brain abnormalities in progeny. J Hazard Mater 426, 127815.

[101] Zaheer, J., Kim, H., Ko, I.O., Jo, E.K., Choi, E.J., Lee, H.J., et al., 2022 Mar. Pre-/post-natal exposure to microplastic as a potential risk factor for autism spectrum disorder. Environ Int 161, 107121.

[102] Dibbon, K.C., Mercer, G.V., Maekawa, A.S., Hanrahan, J., Steeves, K.L., Ringer, L. C.M., et al., 2023 Sep 19. Polystyrene micro- and nanoplastics cause placental dysfunction in mice. Biol Reprod ioad216.

[103] Hanrahan, J., Steeves, K.L., Locke, D.P., O'Brien, T.M., Maekawa, A.S., Amiri, R., et al., 2024 Jan 3. Maternal exposure to polyethylene micro- and nanoplastics impairs umbilical blood flow but not fetal growth in pregnant mice. Sci Rep 14 (1), 399.

[104] Bai, J., Wang, Y., Deng, S., Yang, Y., Chen, S., Wu, Z., 2024 Sep 11. Microplastics caused embryonic growth retardation and placental dysfunction in pregnant mice by activating GRP78/IRE1α/JNK axis induced apoptosis and endoplasmic reticulum stress. Part Fibre Toxicol 21 (1), 36.

[105] Cheng, X., Xue, Y., Wang, H., Ma, Z., Hu, N., Zhang, C., et al., 2025 Jan 1. Maternal exposure to polystyrene nanoplastics during gestation and lactation caused fertility decline in female mouse offspring. Ecotoxicol Environ Saf 289, 117632.

[106] Jeong, B., Kim, J.S., Kwon, A.R., Lee, J., Park, S., Koo, J., et al., 2024 Mar. Maternal nanoplastic ingestion induces an increase in offspring body weight through altered lipid species and microbiota. Environ Int 185, 108522.

[107] Lv, J., He, Q., Yan, Z., Xie, Y., Wu, Y., Li, A., et al., 2024 May 17. Inhibitory impact of prenatal exposure to nano-polystyrene particles on the MAP2K6/p38 MAPK axis inducing embryonic developmental abnormalities in mice. Toxics 12 (5), 370.

[108] Lu, H., Xu, P., Sun, G., Chen, B., Zheng, Y., Zhang, J., et al., 2024 Dec 10. Early-life exposure to polystyrene micro- and nanoplastics disrupts metabolic homeostasis and gut microbiota in juvenile mice with a size-dependent manner. Sci Total Environ 955, 176802.

[109] Moreno, G.M., Brunson-Malone, T., Adams, S., Nguyen, C., Seymore, T.N., Cary, C.M., et al., 2024 Nov 15. Identification of micro- and nanoplastic particles in postnatal sprague-dawley rat offspring after maternal inhalation exposure throughout gestation. Sci Total Environ 951, 175350.

[110] Chen, Q., Peng, C., Xie, R., Xu, H., Su, Z., Yilihan, G., et al., 2024 Oct 5. Placental and fetal enrichment of microplastics from disposable paper cups: implications for metabolic and reproductive health during pregnancy. J Hazard Mater 478, 135527.

[111] Han, Y., Song, Y., Kim, G.W., Ha, C., Lee, J., Kim, M., et al., 2021 Oct. No prominent toxicity of polyethylene microplastics observed in neonatal mice following intratracheal instillation to dams during gestational and neonatal period. Toxicol Res 37 (4), 443-450.

[112] Wang, Zhao, X., Wang, Z., Hu, X., Chao Luo null, W., Chu, X., et al., 2023 May. Effects of polystyrene nanoplastic gestational exposure on mice. Chemosphere 324, 138255.

[113] Zhang, Y.P., Tian, L., Xie, X.Q., Wang, Y.T., Lyu, P., Xi, Z.G., 2022 Nov. Effects of nanopolystyrene nanoplastic exposure on the development and neurotoxicity of
fetal rats during gestation. Zhongguo Ying Yong Sheng Li Xue Za Zhi 38 (6), 760–765.

[114] Zhang, R., Feng, Y., Nie, P., Wang, W., Wu, H., Wan, X., et al., 2024 Jul 1. Polystyrene microplastics disturb maternal glucose homeostasis and induce adverse pregnancy outcomes. Ecotoxicol Environ Saf 279, 116492.

[115] Mercer, G.V., Harvey, N.E., Steeves, K.L., Schneider, C.M., Sled, J.G., Macgowan, C.K., et al., 2023 Nov 21. Maternal exposure to polystyrene nanoplastics alters fetal brain metabolism in mice. Metabolomics 19 (12), 96.

[116] So, Y.H., Shin, H.S., Lee, S.H., Moon, H.J., Jang, H.J., Lee, E.H., et al., 2023 Dec. Maternal exposure to polystyrene microplastics impairs social behavior in mouse offspring with a potential neurotoxicity. Neurotoxicology 99, 206–216.

[117] Xiong, S., He, J., Qiu, H., van Gestel, C.A.M., He, E., Qiao, Z., et al., 2024 Mar. Maternal exposure to polystyrene nanoplastics causes defective retinal development and function in progeny mice by disturbing metabolic profiles. Chemosphere 352, 141513.

[118] Ma, S., Li, S., Jiang, S., Wang, L., Zhan, D., Xiong, M., et al., 2025 Jan 21. Maternal exposure to polystyrene nanoplastics disrupts spermatogenesis in mouse

offspring by inducing Prdm14 overexpression in undifferentiated spermatogonia. ACS Nano 19 (2), 2148–2161.

[119] Liu, T., Hou, B., Zhang, Y., Wang, Z., 2022 Oct 28. Determination of biological and molecular attributes related to polystyrene Microplastic-Induced reproductive toxicity and its reversibility in Male mice. Int J Environ Res Public Health 19 (21), 14093.

[120] Barlow, C.A., Grespin, M., Best, E.A., 2017 Dec 6. Asbestos fiber length and its relation to disease risk. Inhal Toxicol 29 (12–14), 541–554.

[121] Qi, Y.T., Zhang, F.L., Tian, S.Y., Wu, H.Q., Zhao, Y., Zhang, X.W., et al., 2024 Apr. Nanosensor detection of reactive oxygen and nitrogen species leakage in frustrated phagocytosis of nanofibres. Nat Nanotechnol 19 (4), 524–533.

[122] Geppner, L., Ramer, G., Tomasetig, D., Grundhöfer, L., Küss, J., Kaup, M., et al., 2023 Nov. A novel enzymatic method for isolation of plastic particles from human blood. Environ Toxicol Pharmacol 104, 104318.

[123] Barthes, R., 1957. Mythologies. Editions du Seuil, pp. 159–161.