Barrier capacity of human placenta for nanosized materials

Nervous system exposure of different classes of nanoparticles: A review on potential toxicity and mechanistic studies

Nanoparticles (NPs) are generally defined as very small particles in the size range of 1-100 nm. Due to the rapid development of modern society, many new materials have been developed. The widespread use of NPs in medical applications, the food industry and the textile industry has led to an increase in NPs in the environment and the possibility of human contact, which poses a serious threat to human health. The nervous system plays a leading role in maintaining the integrity and unity of the body and maintaining a harmonious balance with the external environment. Therefore, based on two categories of organic and inorganic NPs, this paper systematically summarizes the toxic effects and mechanisms of NPs released into the nervous system. The results showed that exposure to NPs may damage the nervous system, decrease learning and cognitive ability, and affect embryonic development. Finally, a remediation scheme for NPs entering the body via the environment is also introduced. This scheme aims to reduce the neurotoxicity caused by NPs by supplementing NPs with a combination of antioxidant and anti-inflammatory compounds. The results provide a valuable reference for future research in this field.

Investigating Exposure and Hazards of Micro- and Nanoplastics During Pregnancy and Early Life (AURORA Project): Protocol for an Interdisciplinary Study

BACKGROUND

Micro- and nanoplastics (MNPs) are emerging pollutants of concern with ubiquitous presence in global ecosystems. MNPs pose potential implications for human health; however, the health impacts of MNP exposures are not yet understood. Recent evidence suggests that MNPs can cross the placental barrier, underlying the urgent need to understand their impact on reproductive health and development.

OBJECTIVE

The Actionable eUropean ROadmap for early-life health Risk Assessment of micro- and nanoplastics (AURORA) project will investigate MNP exposures and their biological and health effects during pregnancy and early life, which are critical periods due to heightened vulnerability to environmental stressors. The AURORA project will enhance exposure assessment capabilities for measuring MNPs, MNP-associated chemicals, and plastic additives in human tissues, including placenta and blood.

METHODS

In this interdisciplinary project, we will advance methods for in-depth characterization and scalable chemical analytical strategies, enabling high-resolution and large-scale toxicological, exposure assessment, and epidemiological studies. The AURORA project performs observational studies to investigate determinants and health impacts of MNPs by including 800 mother-child pairs from 2 existing birth cohorts and 110 women of reproductive age from a newly established cohort. This will be complemented by toxicological studies using a tiered-testing approach and epidemiological investigations to evaluate associations between maternal and prenatal MNP exposures and health perturbations, such as placental function, immune-inflammatory responses, oxidative stress, accelerated aging, endocrine disruption, and child growth and development. The ultimate goal of the AURORA project is to create an MNP risk assessment framework and identify the remaining knowledge gaps and priorities needed to comprehensively assess the impact of MNPs on early-life health.

RESULTS

In the first 3 years of this 5-year project (2021-2026), progress was made toward all objectives. This includes completion of recruitment and data collection for new and existing cohorts, development of analytical methodological protocols, and initiation of the toxicological tiered assessments. As of September 2024, data analysis is ongoing and results are expected to be published starting in 2025.

CONCLUSIONS

As plastic pollution increases globally, it is imperative to understand the impact of MNPs on human health, particularly during vulnerable developmental stages such as early life. The contributions of the AURORA project will inform future risk assessment.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/63176.

Nanomedicine for Maternal and Fetal Health

Conception, pregnancy, and childbirth are complex processes that affect both mother and fetus. Thus, it is perhaps not surprising that in the United States alone, roughly 11% of women struggle with infertility and 16% of pregnancies involve some sort of complication. This presents a clear need to develop safe and effective treatment options, though the development of therapeutics for use in women's health and particularly in pregnancy is relatively limited. Physiological and biological changes during the menstrual cycle and pregnancy impact biodistribution, pharmacokinetics, and efficacy, further complicating the process of administration and delivery of therapeutics. In addition to the complex pharmacodynamics, there is also the challenge of overcoming physiological barriers that impact various routes of local and systemic administration, including the blood-follicle barrier and the placenta. Nanomedicine presents a unique opportunity to target and sustain drug delivery to the reproductive tract and other relevant organs in the mother and fetus, as well as improve the safety profile and minimize side effects. Nanomedicine-based approaches have the potential to improve the management and treatment of infertility, obstetric complications, and fetal conditions.

Air pollution-linked epigenetic modifications in placental DNA: Prognostic potential for identifying future foetal anomalies

Prenatal exposure to air pollution is a significant risk factor for the mother and the developing foetus. The accumulation of pollutants in the placenta can cause a self-cascade loop of pro-inflammatory cytokine responses and DNA double-strand breaks. Previous research has shown that airborne particulate matter can damage the epigenome and disturb mitochondrial machinery, ultimately impairing placental function. Mitochondria are essential for preserving cellular homeostasis, energy metabolism, redox equilibrium, and epigenetic reprogramming. As these organelles are subtle targets of environmental exposures, any disruption in the signaling pathways can result in epigenomic instability, which can impact gene expression and mitochondrial function. This, in turn, can lead to changes in DNA methylation, post-translational histone modifications, and aberrant expression of microRNAs in proliferating trophoblast cells. The placenta has two distinct layers, cytotrophoblasts, and syncytiotrophoblasts, each with its mitochondria, which play important roles in preeclampsia, gestational diabetes, and overall health. Foetal nucleic acids enter maternal circulation during placental development because of necrotic, apoptotic, and inflammatory mechanisms. These nucleic acids reflect normal or abnormal ongoing cellular changes during prenatal foetal development. Detecting cell-free DNA in the bloodstream can be a biomarker for predicting negative pregnancy-related outcomes and recognizing abnormalities in foetal growth. Hence, a thorough understanding of how air pollution induces epigenetic variations within the placenta could offer crucial insights into underlying mechanisms and prolonged repercussions on foetal development and susceptibility in later stages of life.

The Application of Engineered Nanomaterials in Perinatal Therapeutics

Pregnancy is a vulnerable life stage for the mother and developing fetus. Because of this dual concern, approved therapeutic options for pre-existing conditions or pregnancy-induced pathologies, placental deformities, or fetal concerns are extremely limited. These cases often leave patients and clinicians having to choose between maternal health and fetal development. Recent advancements in nanomedicine and nanotherapeutic devices have made the development of perinatal therapeutics an attractive objective. However, perinatal medicine requires a multifaceted approach given the interactions between maternal, placental, and fetal physiology. Maternal-fetal interactions are centralized to the placenta, a specialized transient barrier organ, to allow for nutrient and waste exchange. Perinatal nanotherapeutics must be designed for placental avoidance or uptake. In this review, pregnancy-related conditions, experimental models, and modes of drug delivery during pregnancy are discussed.

COVID-19 Vaccine mRNA Biodistribution: Maternal and Fetal Exposure Risks

SARS-CoV-2 infection during pregnancy has severe consequences on maternal and neonatal health. Presently, vaccination stands as a critical preventive measure for mitigating infection-related risks. Although the initial clinical trials for the COVID-19 vaccines excluded pregnant women, subsequent investigations have indicated mRNA vaccinations' effectiveness and short-term safety during pregnancy. However, there is a lack of information regarding the potential biodistribution of the vaccine mRNA during pregnancy and lactation. Recent findings indicate that COVID-19 vaccine mRNA has been detected in breast milk, suggesting that its presence is not confined to the injection site and raises the possibility of similar distribution to the placenta and the fetus. Furthermore, the potential effects and responses of the placenta and fetus to the vaccine mRNA are still unknown. While potential risks might exist with the exposure of the placenta and fetus to the COVID-19 mRNA vaccine, the application of mRNA therapies for maternal and fetal conditions offers a groundbreaking prospect. Future research should leverage the unique opportunity provided by the first-ever application of mRNA vaccines in humans to understand their biodistribution and impact on the placenta and fetus in pregnant women. Such insights could substantially advance the development of safer and more effective future mRNA-based therapies during pregnancy.

Identification and analysis of microplastics in para-tumor and tumor of human prostate

BACKGROUND

While microplastics are widely found in various human organs and tissues, the relationship between microplastics and human health, especially prostate health, remains unclear. This study aims to identify and quantify the properties, types, and abundance of microplastics in paired para-tumor and tumor tissues of human prostate. Additionally, the potential correlation between microplastics abundance and prostate cancer are investigated.

METHODS

Paired para-tumor and tumor samples of the prostate were collected from 22 patients who underwent robot-assisted radical prostatectomy. A combination of laser direct infrared spectroscopy, scanning electron microscopy and pyrolysis-gas chromatography-mass spectrometry was utilized to analyse the properties, type and abundance of microplastics. Correlations between microplastics abundance, demographic characteristics and clinical features of patients were also examined.

FINDINGS

Laser direct infrared analysis revealed the presence of microplastics, including polyamide, polyethylene terephthalate, and polyvinyl chloride, in both para-tumor and tumor tissues of human prostate. However, polystyrene was exclusively detected in tumor tissues. The particle size distribution in the prostate tissue mainly ranged from 20 to 100 μm. Approximately 31.58% of para-tumor samples exhibited sizes between 20 and 30 μm, while 35.21% of tumor samples displayed sizes between 50 and 100 μm. The shapes of these microplastics varied considerably with irregular forms being predominant. Additionally, microplastics were detected by pyrolysis-gas chromatography-mass spectrometry in 20 paired prostate tissues. The mean abundance of microplastics was found to be 181.0 μg/g and 290.3 μg/g in para-tumor and tumor of human prostate samples, respectively. Among the 11 target types microplastics polymers, only polystyrene, polypropylene, polyethylene, and polyvinyl chloride were detected. Notably, polystyrene, polyethylene, and polyvinyl chloride, except for polypropylene, demonstrated significantly higher abundance in tumor tissues compared to their respective paired para-tumor. Furthermore, a positive correlation was observed between polystyrene abundance in the tumor samples of human prostate and frequency of take-out food consumption.

INTERPRETATION

This research provides both qualitative and quantitative evidence of the microplastics presence as well as their properties, types, and abundance in paired para-tumor and tumor samples of human prostate. Correlations between microplastics abundance, demographics, and clinical characteristics of patients need to be further validated in future studies with a larger sample size.

FUNDING

This work was supported by the National Key Research and Development Program of China (2022YFC2702600) and the National Natural Science Foundation of China (Grant No. 82071698, No. 82101676, and No. 82271630).

Microplastics caused embryonic growth retardation and placental dysfunction in pregnant mice by activating GRP78/IRE1α/JNK axis induced apoptosis and endoplasmic reticulum stress

Microplastics (MPs), a brand-new class of worldwide environmental pollutant, have received a lot of attention. MPs are consumed by both humans and animals through water, food chain and other ways, which may cause potential health risks. However, the effects of MPs on embryonic development, especially placental function, and its related mechanisms still need to be further studied. We investigated the impact on fetal development and placental physiological function of pregnant mice by consecutive gavages of MPs at 0, 25, 50, 100 mg/kg body weight during gestational days (GDs 0-14). The results showed that continuous exposure to high concentrations of MP significantly reduced daily weight gain and impaired reproductive performance of pregnant mice. In addition, MPs could significantly induce oxidative stress and placental dysfunction in pregnant mice. On the other hand, MPs exposure significantly decreased placental barrier function and induced placental inflammation. Specifically, MPs treatment significantly reduced the expression of tight junction proteins in placentas, accompanied by inflammatory cell infiltration and increased mRNA levels of pro-inflammatory cytokines and chemokines in placentas. Finally, we found that MPs induced placental apoptosis and endoplasmic reticulum (ER) stress through the GRP78/IRE1α/JNK axis, leading to placental dysfunction and decreased reproductive performance in pregnant mice. We revealed for the first time that the effects of MPs on placental dysfunction in pregnant animals. Blocking the targets of MPs mediated ER stress will provide potential therapeutic ideas for the toxic effects of MPs on maternal pregnancy.

Thyroid and parathyroid function disorders induced by short-term exposure of microplastics and nanoplastics: Exploration of toxic mechanisms and early warning biomarkers

Human exposure to micro- and nano-plastics (MNPs) primarily occurs through respiration and diet in the environment. However, the early effects and warning signs of MNPs exposure on vertebrates are unclear. Here we used intratracheal instillation and intragastric infusion to establish mouse models for MNPs exposure to systematically investigate the toxic mechanisms of MNPs on endocrine organs. Results showed that MNPs induced endocrine disruptions in short-term exposure by both dietary and respiratory pathways. Microplastics (MPs) exposed through dietary route were more toxic to thyroid gland, whereas nanoplastics (NPs) exhibited the highest level of toxicity to parathyroid gland through respiration. The transcriptome and validation of related functional genes revealed that MNPs affected the synthesis of thyroglobulin by interfering with the expressions of PAX8 and CREB. MNPs also impacted the levels of thyroid stimulating hormone, further mediating the secretion of thyroid hormones. Moreover, MNPs modulate the expression of Mafb, thereby exerting regulatory effects on parathyroid hormone (PTH) synthesis and growth development in parathyroid cells. Meanwhile, MNPs interfered with the expression of IP3R in the calcium signaling pathway, indirectly affecting the secretion of PTH. This study reveals the effects and mechanisms of MNPs on thyroid and parathyroid and highlights the significance of early warning of MNPs exposure.

Prenatal exposure to particulate matter and infant birth outcomes: Evidence from a population-wide database

There are growing concerns about the impact of pollution on maternal and infant health. Despite an extensive correlational literature, observational studies which adopt methods that seek to address potential biases due to unmeasured confounders draw mixed conclusions. Using a population database of births in Northern Ireland (NI) linked to localized geographic information on pollution in mothers' postcodes (zipcodes) of residence during pregnancy, we examine whether prenatal exposure to PM2.5 is associated with a comprehensive range of birth outcomes, including placental health. Overall, we find little evidence that particulate matter is related to infant outcomes at the pollution levels experienced in NI, once we implement a mother fixed effects approach that accounts for time-invariant factors. This contrasts with strong associations in models that adjust for observed confounders but without fixed effects. While reducing ambient air pollution remains an urgent public health priority globally, our results imply that further improvements in short-run levels of prenatal PM2.5 exposure in a relatively low-pollution, higher-income country context, are unlikely to impact on birth outcomes at the population level.

Expanding horizons in cancer therapy by immunoconjugates targeting tumor microenvironments

Immunoconjugates are promising molecules combining antibodies with different agents, such as toxins, drugs, radionuclides, or cytokines that primarily aim to target tumor cells. However, tumor microenvironment (TME), which comprises a complex network of various cells and molecular cues guiding tumor growth and progression, remains a major challenge for effective cancer therapy. Our review underscores the pivotal role of TME in cancer therapy with immunoconjugates, examining the intricate interactions with TME and recent advancements in TME-targeted immunoconjugates. We explore strategies for targeting TME components, utilizing diverse antibodies such as neutralizing, immunomodulatory, immune checkpoint inhibitors, immunostimulatory, and bispecific antibodies. Additionally, we discuss different immunoconjugates, elucidating their mechanisms of action, advantages, limitations, and applications in cancer immunotherapy. Furthermore, we highlight emerging technologies enhancing the safety and efficacy of immunoconjugates, such as antibody engineering, combination therapies, and nanotechnology. Finally, we summarize current advancements, perspectives, and future developments of TME-targeted immunoconjugates.

The Impact of Maternal Nanoplastic and Microplastic Particle Exposure on Mammal's Offspring

The issue of environmental nanoplastic (NPl) particle and microplastic (MPl) particle pollution is becoming increasingly severe, significantly impacting ecosystems and biological health. Research shows that NPl/MPl can penetrate the placental barrier and enter the fetus, leading to transgenerational effects. This review integrates the existing literature on the effects of prenatal NPl/MPl exposure on mammalian offspring, focusing particularly on its negative impacts on the central nervous system, liver, intestinal health, reproductive function, and skeletal muscles. The vast majority of previous studies on prenatal NPl/MPl in mammals have used polystyrene material. Future research should explore the effects of other prenatal NPl/MPl materials on offspring to better reflect the realities of the human environment. It is also essential to investigate the potential harm and underlying mechanisms associated with prenatal NPl/MPl exposure to offspring in greater depth. This will aid in developing appropriate prevention and treatment strategies in the future.

Effects of nanoplastic exposure during pregnancy and lactation on neurodevelopment of rat offspring

Microplastics have emerged as a prominent global environmental contaminant, and they have been found in both human placenta and breast milk. However, the potential effects and mechanisms of maternal exposure to microplastics at various gestational stages on offspring neurodevelopment remain poorly understood. This investigation delves into the potential neurodevelopmental ramifications of maternal exposure to polystyrene nanoplastics (PS-NPs) during distinct phases of pregnancy and lactation. Targeted metabolomics shows that co-exposure during both pregnancy and lactation primarily engendered alterations in monoamine neurotransmitters within the cortex and amino acid neurotransmitters within the hippocampus. After prenatal exposure to PS-NPs, fetal rats showed appreciably diminished cortical thickness and heightened cortical cell proliferation. However, this exposure did not affect the neurodifferentiation of radial glial cells and intermediate progenitor cells. In addition, offspring are accompanied by disordered neocortical migration, typified by escalated superficial layer neurons proliferation and reduced deep layer neurons populations. Moreover, the hippocampal synapses showed significantly widened synaptic clefts and diminished postsynaptic density. Consequently, PS-NPs culminated in deficits in anxiolytic-like behaviors and spatial memory in adolescent offspring, aligning with concurrent neurotransmitter and synaptic alterations. In conclusion, this study elucidates the sensitive windows of early-life nanoplastic exposure and the consequential impact on offspring neurodevelopment.

A review on micro- and nanoplastics in humans: Implication for their translocation of barriers and potential health effects

As emerging contaminants, micro- and nanoplastics (MNPs) can absorb and leach various toxic chemicals and ultimately endanger the health of the ecological environment and humans. With extensive research on MNPs, knowledge about MNPs in humans, especially their translocation of barriers and potential health effects, is of utmost importance. In this review, we collected literature published from 2000 to 2023, focusing on MNPs on their occurrence in humans, penetrating characteristics in the placental, blood-brain, and blood-testis barriers, and exposure effects on mammalian health. The characteristics and distributions of MNPs in human samples were analyzed, and the results demonstrated that MNPs were ubiquitous in most human samples, except for kidneys and cerebrospinal fluid. In addition, the phenomenon of MNPs crossing barriers and their underlying mechanisms were discussed. We also summarized the potential factors that may affect the barrier crossing and health effects of MNPs, including characteristics of MNPs, exposure doses, administration routes, exposure durations, co-exposure to other pollutants, and genetic predisposition. Exposure to MNPs may cause cytotoxicity, neurotoxicity, and developmental and reproductive toxicity in mammals. People are encouraged to reduce their exposure to MNPs to prevent these adverse health effects. Finally, we discussed the shortcomings of current research on MNPs in humans, providing a valuable reference for understanding and evaluating the potential health risks from MNP exposure in mammals, including humans.

Micro/Nanoplastic Exposure on Placental Health and Adverse Pregnancy Risks: Novel Assessment System Based upon Targeted Risk Assessment Environmental Chemicals Strategy

Micro/nanoplastics (MNPs), as emerging pollutants, have been detected in both the maternal and fetal sides of the placenta in pregnant women, and their reproductive toxicity has been demonstrated in in vivo and in vitro experimental models. The Targeted Risk Assessment of Environmental Chemicals (TRAEC) strategy has been innovatively devised to facilitate valid risk assessment, encompassing a comprehensive evaluation of reliability, correlation, outcome fitness, and integrity across four dimensions based on the included published evidence and our own findings. This study serves as an application case of TRAEC, with 40 items of research evidence on the toxicity of MNPs to the placenta, which were rigorously screened and incorporated into the final scoring system. The final score for this TRAEC case study is 5.63, suggesting a moderate-to-low risk of reproductive toxicity associated with MNPs in the placenta, which may potentially increase with decreasing particle size. It is essential to emphasize that the findings also report original data from assays indicating that exposure to high-dose groups (100 μg/mL, 200 μg/mL) of 50 nm and 200 nm polystyrene nanoplastics (PS-NPs) induces HTR8/SVneo cell cycle arrest and cell apoptosis, which lead to reproductive toxicity in the placenta by disrupting mitochondrial function. Overall, this study employed the TRAEC strategy to provide comprehensive insight into the potential reproductive health effects of ubiquitous MNPs.

Size-classifiable quantification of nanoplastic by rate zonal centrifugation coupled with pyrolysis-gas chromatography-mass spectrometry

Particle size is an important indicator to evaluate the environmental risk and biotoxicity of nanoplastic (NP, particle diameter <1000 nm). The methods available to determine size classes of NP in environmental samples are few and are rare to achieve efficient separation and recycling of NP with close particle sizes. Here, we show that rate-zonal centrifugation (RZC) can quickly and efficiently collect NP of different sizes based on their sedimentation coefficients. When combined with cloud-point extraction (CPE) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), our method can quantify three NP particle-size classes separately (including 100 nm, 300 nm, and 600 nm) in aqueous samples with high recovery (81.4 %-89.4 %), limits of detections (LODs, 33.5-53.4 μg/L), and limits of quantifications (LOQs, 110.6-167.2 μg/L). Compared with the conventional sample pretreatment process, our method can effectively extract and determine the NP with different sizes. Our approach is highly scalable and can be effectively applied to NP in a wide range of aquatic environments. Meanwhile, our approach is highly scalable to incorporate diverse assays to study the environmental behaviours and ecological risks of NP.

The potential of micro- and nanoplastics to exacerbate the health impacts and global burden of non-communicable diseases

Non-communicable diseases (NCD) constitute one of the highest burdens of disease globally and are associated with inflammatory responses in target organs. There is increasing evidence of significant human exposure to micro- and nanoplastics (MnPs). This review of environmental MnP exposure and health impacts indicates that MnP particles, directly and indirectly through their leachates, may exacerbate inflammation. Meanwhile, persistent inflammation associated with NCDs in gastrointestinal and respiratory systems potentially increases MnP uptake, thus influencing MnP access to distal organs. Consequently, a future increase in MnP exposure potentially augments the risk and severity of NCDs. There is a critical need for an integrated one-health approach to human health and environmental research for assessing the drivers of human MnP exposure and their bidirectional links with NCDs. Assessing these risks requires interdisciplinary efforts to identify and link drivers of environmental MnP exposure and organismal uptake to studies of impacted disease mechanisms and health outcomes.

Down to size: Exploring the influence of plastic particle Dimensions on physiological and nervous responses in early-stage zebrafish

The chorion is the first protective barrier set to prevent numerous pollutants from damaging the developing embryo. However, depending on their size, some nanoplastics (NPs) can pass through this barrier and reach the embryo, while all microplastics (MPs) remain on the outside. This study brings a straight approach to compare MPs and NPs, and assess their direct and indirect effects on zebrafish embryos and larvae. Zebrafish eggs were exposed before 2 h post fertilization (hpf) to polystyrene MPs (5 μm) and NPs (250 nm) at a concentration of 1000 μg/L until 96 hpf. Physiotoxicity and neurotoxicity were assessed prior and post-hatching through several biomarkers. Response to hypoxia (upregulation of hif-1aa and hif-1ab) were found in embryos exposed to MPs, and partly found in those exposed to NPs. Embryos exposed to NPs showed significant tachycardia, reduced O2 consumption and increased apoptosis in the eyes, whereas MPs affected the expressions of all genes related to the neurodevelopment of embryos (elavl3, pax2a, pax6a, act1b). Post-hatching, physiological responses were muted. MPs and NPs exposures ended by evaluating larval behaviours during dark-and-light cycles. Both sizes of plastic particles negatively affected the visual motor response (VMR) and vibrational startle response (VSR). Thigmotaxis levels were significantly increased by NPs whereas MPs showed anxiolytic properties. This study shows that both MPs and NPs affect the physiology and neurodevelopment of zebrafish at different levels, before and after hatching.

The potential impact of nano- and microplastics on human health: Understanding human health risks

Plastics are used all over the world. Unfortunately, due to limited biodegradation, plastics cause a significant level of environmental pollution. The smallest recognized to date are termed nanoplastics (1 nm [nm] up to 1 μm [μm]) and microplastics (1 μm-5 mm). These nano- and microplastics can enter the human body through the respiratory system via inhalation, the digestive tract via consumption of contaminated food and water, or penetration through the skin via cosmetics and clothes contact. Bioaccumulation of plastics in the human body can potentially lead to a range of health issues, including respiratory disorders like lung cancer, asthma and hypersensitivity pneumonitis, neurological symptoms such as fatigue and dizziness, inflammatory bowel disease and even disturbances in gut microbiota. Most studies to date have confirmed that nano- and microplastics can induce apoptosis in cells and have genotoxic and cytotoxic effects. Understanding the cellular and molecular mechanisms of plastics' actions may help extrapolate the risks to humans. The article provides a comprehensive review of articles in databases regarding the impact of nano- and microplastics on human health. The review included retrospective studies and case reports of people exposed to nanoplastics and microplastics. This research highlights the need for further research to fully understand the extent of the impact of plastics on human health.

Exposure to pollution during the first thousand days and telomere length regulation: A literature review

Telomere length (TL) is a biomarker for cellular senescence and TL erosion is predictive of the risk for age-related diseases. Despite being genetically determined at birth, TL may be susceptible to modifications through epigenetic mechanisms. Pollutant agents are considered one of the major threats to both human and planetary health. Their ability to cross the placental barrier and induce oxidative stress in fetal cells is particularly concerning and it may be associated with early TL erosion. In consideration of the timely relevance of this topic, we conducted a literature review on the impact of prenatal exposure to pollutant agents on newborn TL. The search yielded a total of 1099 records, of which only 32 met the inclusion criteria for the review. These criteria included the participation of human subjects, a longitudinal design or collection of longitudinal data, reporting of original TL data, and a focus on exposure to pollutant agents. The majority of the studies reported a significant inverse association between prenatal exposure to pollutant agents and TL. Furthermore, the second trimester of pregnancy emerged as a special sensitive period for the occurrence of pollutant agent-driven TL modifications. Sex differences were inconsistently reported across studies. This review contributes to highlighting biochemical pathways for the threats of environmental pollution to human health. Future research is warranted to further highlight potential buffering mechanisms.

ROS-dependent degeneration of human neurons induced by environmentally relevant levels of micro- and nanoplastics of diverse shapes and forms

Our study explores the pressing issue of micro- and nanoplastics (MNPs) inhalation and their subsequent penetration into the brain, highlighting a significant environmental health concern. We demonstrate that MNPs can indeed penetrate murine brain, warranting further investigation into their neurotoxic effects in humans. We then proceed to test the impact of MNPs at environmentally relevant concentrations, with focusing on variations in size and shape. Our findings reveal that these MNPs induce oxidative stress, cytotoxicity, and neurodegeneration in human neurons, with cortical neurons being more susceptible than nociceptors. Furthermore, we examine the role of biofilms on MNPs, demonstrating that MNPs can serve as a vehicle for pathogenic biofilms that significantly exacerbate these neurotoxic effects. This sequence of investigations reveals that minimal MNPs accumulation can cause oxidative stress and neurodegeneration in human neurons, significantly risking brain health and highlights the need to understand the neurological consequences of inhaling MNPs. Overall, our developed in vitro testing battery has significance in elucidating the effects of environmental factors and their associated pathological mechanisms in human neurons.

Impact of Microplastics on Pregnancy and Fetal Development: A Systematic Review

Microplastic (MP) pollution is a growing global concern because of its potential to impair human health, particularly with regard to fetal development. However, the origins of prenatal MP exposure and its effects on fetal development have not been well studied. This study aimed to provide a systematic review of the literature regarding the impact of microplastics on pregnancy and fetal development. PubMed, Embase, ScienceDirect, Web of Science, Scopus, and Google Scholar were searched from 2010 until March 2024. Original publications exploring the impact of microplastics on pregnancy and fetal development were included in the study. After selecting papers, two independent reviewers extracted data regarding study characteristics, microplastics identified, and reproductive impacts. The quality of studies was assessed using the Critical Appraisal Checklists for Studies created by the Joanna Briggs Institute (JBI). Twelve studies, including 234 subjects, were selected from a total of 2,809 citations for the final qualitative analysis. Articles were published between 2021 and 2024, and most were conducted in China. The results of the included studies confirmed the existence of microplastics with varying sizes (2.1 to 100 micrometers) in the placenta and the fetal body. Studies revealed correlations between lifestyle choices and the presence of microplastics in the placenta. They also reported correlations between the level of microplastics and diminished microbiome diversity, reduced birthweights, affected gestational age, and fetal growth and development. Microplastics may be detrimental to a developing fetus during pregnancy. Nonetheless, more thorough research is required to comprehend the impact of microplastic exposure on pregnancy and fetal development.

Microplastics in maternal amniotic fluid and their associations with gestational age

Microplastics (MPs) pollution is a growing global concern due to its potential threat to human health, particularly concerning fetal health. Nevertheless, few studies have examined the sources of fetal MPs exposure and its impact on fetal development. In this study, MPs levels in maternal amniotic fluid (AF) and their associations with measures of fetal growth were investigated. Specifically, 40 human AF samples were collected to determine the presence and characteristics of MPs using laser direct infrared (LD-IR) spectroscopy. MPs were found in 32 out of 40 AF samples, with an average abundance of 2.01 ± 4.19 particles/g. Polyethylene (PE, 38.80 %) and chlorinated polyethylene (CPE, 26.98 %) were the most prevalent polymers. The majority of MPs (87.56 %) were 20-100 μm in size, and fragments (71.23 %) evidently prevailed in morphology. Additionally, a questionnaire was designed to explore the associations between MPs levels in the AF and maternal dietary habits, aiming at unveiling the potential sources of MPs in AF. The MPs levels in the AF were positively associated with the frequency of seafood consumption (r = 0.781, P < 0.001) and bottled water intake (r = 0.386, P = 0.014). Moreover, the associations between MPs levels in maternal AF and measures of fetal growth were evaluated. The abundance of total MPs in maternal AF were significantly negatively associated with gestational age (β = -0.44, 95 % CI, -0.83, -0.05). This study confirms the presence of MPs in human AF and provides compelling evidence linking them to gestational age, while highlighting the potential risks associated with dietary habits. These findings underscore the need for further investigation into the mechanisms of MPs transmission from mother to fetus and the potential health implications during fetal development, offering valuable insights for future policies aimed at safeguarding maternal and fetal health.

Exploring the potential and challenges of developing physiologically-based toxicokinetic models to support human health risk assessment of microplastic and nanoplastic particles

Microplastics (MPs) and nanoplastics (NPs) pollution has emerged as a significant and widespread environmental issue. Humans are inevitably exposed to MPs and NPs via ingestion, inhalation, and dermal contacts from various sources. However, mechanistic knowledge of their distribution, interaction, and potency in the body is still lacking. To address this knowledge gap, we have undertaken the task of elucidating the toxicokinetic (TK) behaviors of MPs and NPs, aiming to provide mechanistic information for constructing a conceptual physiologically based toxicokinetic (PBTK) model to support in silico modeling approaches. Our effort involved a thorough examination of the existing literature and data collation on the presence of MPs in the human body and in vitro/ex vivo/in vivo biodistribution across various cells and tissues. By comprehending the absorption, distribution, metabolism, and excretion mechanisms of MPs and NPs in relation to their physicochemical attributes, we established a foundational understanding of the link between external exposure and internal tissue dosimetry. We observed that particle size and surface chemistry have been thoroughly explored in previous experimental studies. However, certain attributes, such as polymer type, shape, and biofilm/biocorona, warrant attention and further examination. We discussed the fundamental disparities in TK properties of MPs/NPs from those of engineered nanoparticles. We proposed a preliminary PBTK framework with several possible modeling approaches and discussed existing challenges for further investigation. Overall, this article provides a comprehensive compilation of existing TK data of MPs/NPs, a critical overview of TK processes and mechanisms, and proposes potential PBTK modeling approaches, particularly regarding their applicability to the human system, and outlines future perspectives for developing PBTK models and their integration into human health risk assessment of MPs and NPs.

Pathogenesis of PM2.5-Related Disorders in Different Age Groups: Children, Adults, and the Elderly

The effects of PM2.5 on human health fluctuate greatly among various age groups, influenced by a range of physiological and immunological reactions. This paper compares the pathogenesis of the disease caused by PM2.5 in people of different ages, focusing on how children, adults, and the elderly are each susceptible to it because of differences in their bodies. Regarding children, exposure to PM2.5 is linked to many negative consequences. These factors consist of inflammation, oxidative stress, and respiratory problems, which might worsen pre-existing conditions and potentially cause neurotoxicity and developmental issues. Epigenetic changes can affect the immune system and make people more likely to get respiratory diseases. On the other hand, exposures during pregnancy can change how the cardiovascular and central nervous systems develop. In adults, the inhalation of PM2.5 is associated with a wide range of health problems. These include respiratory difficulties, reduced pulmonary function, and an increased susceptibility to illnesses such as asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. In addition, exposure to PM2.5 induces systemic inflammation, cardiovascular diseases, insulin resistance, and neurotoxic consequences. Evident disturbances in the immune system and cognitive function demonstrate the broad impact of PM2.5. The elderly population is prone to developing respiratory and cardiovascular difficulties, which worsen their pre-existing health issues and raise the risk of cognitive decline and neurological illnesses. Having additional medical conditions, such as peptic ulcer disease, significantly increases the likelihood of being admitted to hospital.

Polystyrene Nano- and Microplastic Particles Induce an Inflammatory Gene Expression Profile in Rat Neural Stem Cell-Derived Astrocytes In Vitro

Microplastics are considered an emerging environmental pollutant due to their ubiquitous presence in the environment. However, the potential impact of microplastics on human health warrants further research. Recent studies have reported neurobehavioral and neurotoxic effects in marine and rodent models; however, their impact on the underlying cellular physiology in mammals remains unclear. Herein, we exposed neural stem cells and neural stem cell-derived astrocytes, oligodendrocytes, and neurons to various sizes and concentrations of polystyrene nano- and microplastics. We investigated their cellular uptake, impact on cytotoxicity, and alteration of gene expression through transcriptome profiling. The cell type most affected by decreased viability were astrocytes after 7 days of repeated exposure. Transcriptional analysis showed that 1274 genes were differentially expressed in astrocytes exposed to 500 nm microplastics, but only 531 genes were altered in astrocytes exposed to 50 nm nanoplastics. Both canonical pathway and Kyoto Encyclopedia of Genes and Genomes analysis showed that upregulated pathways were involved in neuroinflammation, innate and adaptive immunity, cell migration, proliferation, extracellular matrix remodeling, and cytoskeleton structures. The downregulated pathways were involved in lipid metabolism, specifically fatty acid oxidation and cholesterol metabolism. Our results show that neural stem cell-derived astrocytes repeatedly exposed to nano- and microplastics for 7 days undergo changes that are hallmarks of astrogliosis.

Unraveling the threat: Microplastics and nano-plastics' impact on reproductive viability across ecosystems

Plastic pollution pervades both marine and terrestrial ecosystems, fragmenting over time into microplastics (MPs) and nano-plastics (NPs). These particles infiltrate organisms via ingestion, inhalation, and dermal absorption, predominantly through the trophic interactions. This review elucidated the impacts of MPs/NPs on the reproductive viability of various species. MPs/NPs lead to reduced reproduction rates, abnormal larval development and increased mortality in aquatic invertebrates. Microplastics cause hormone secretion disorders and gonadal tissue damage in fish. In addition, the fertilization rate of eggs is reduced, and the larval deformity rate and mortality rate are increased. Male mammals exposed to MPs/NPs exhibit testicular anomalies, compromised sperm health, endocrine disturbances, oxidative stress, inflammation, and granulocyte apoptosis. In female mammals, including humans, exposure culminates in ovarian and uterine deformities, endocrine imbalances, oxidative stress, inflammation, granulosa cell apoptosis, and tissue fibrogenesis. Rodent offspring exposed to MPs experience increased mortality rates, while survivors display metabolic perturbations, reproductive anomalies, and weakened immunity. These challenges are intrinsically linked to the transgenerational conveyance of MPs. The ubiquity of MPs/NPs threatens biodiversity and, crucially, jeopardizes human reproductive health. The current findings underscore the exigency for comprehensive research and proactive interventions to ameliorate the implications of these pollutants.

Microplastics in oral healthcare products (OHPs) and their environmental health risks and mitigation measures

The environmental input of microplastics from personal care products has received significant attention; however, less focus has been paid to oral healthcare products. The present study assessed the occurrence of microplastics in commercially available oral healthcare products such as toothbrushes, toothpastes, toothpowder, mouthwash, dental floss, and mouth freshener spray that have a pan-India distribution. The extracted microplastics were quantified and characterised using a microscope and ATR-FTIR. All products showed microplastic contamination, where toothbrushes showed the maximum particles (30-120 particles/brush) and mouth freshener sprays (0.2-3.5 particles/ml) had the least abundance. Fragments, fibres, beads, and films were the various shapes of microplastics observed, where fragments (60%) were dominant. Various colours such as pink, green, blue, yellow, black, and colourless were observed, where colourless (40%) particles were dominant. Microplastics were categorized into three sizes: <0.1 mm (63%), 0.1-0.3 mm (35%), and >0.3 mm (2%). Four major types of polymers, such as polyethylene (52%), polyamide (30%), polyethylene terephthalate (15%), and polybutylene terephthalate (3%), were identified. Risk assessment studies such as Daily Microplastics Emission (DME), Annual Microplastics Exposure (AME), and Polymer Hazard Index (PHI) were carried out. The DME projection for India was the highest for mouthwash (74 billion particles/day) and the least for mouth freshener sprays (0.36 billion particles/day). The AME projection for an individual was the highest in toothbrushes (48,910 particles ind.-1 yr.-1) and the least in mouth freshener sprays (111 particles ind.-1 yr.-1). PHI shows that the identified polymers fall under the low-to high-risk categories. This study forecasts the community health risks linked to microplastics in oral healthcare products and suggests mitigation strategies. It has the potential to shape environmental policy development in response.

A comprehensive review on the source, ingestion route, attachment and toxicity of microplastics/nanoplastics in human systems

Microplastics (MPs)/nanoplastics (NPs) are widely found in the natural environment, including soil, water and the atmosphere, which are essential for human survival. In the recent years, there has been a growing concern about the potential impact of MPs/NPs on human health. Due to the increasing interest in this research and the limited number of studies related to the health effects of MPs/NPs on humans, it is necessary to conduct a systematic assessment and review of their potentially toxic effects on human organs and tissues. Humans can be exposed to microplastics through ingestion, inhalation and dermal contact, however, ingestion and inhalation are considered as the primary routes. The ingested MPs/NPs mainly consist of plastic particles with a particle size ranging from 0.1 to 1 μm, that distribute across various tissues and organs within the body, which in turn have a certain impact on the nine major systems of the human body, especially the digestive system and respiratory system, which are closely related to the intake pathway of MPs/NPs. The harmful effects caused by MPs/NPs primarily occur through potential toxic mechanisms such as induction of oxidative stress, generation of inflammatory responses, alteration of lipid metabolism or energy metabolism or expression of related functional factors. This review can help people to systematically understand the hazards of MPs/NPs and related toxicity mechanisms from the level of nine biological systems. It allows MPs/NPs pollution to be emphasized, and it is also hoped that research on their toxic effects will be strengthened in the future.

Trophoblast stem cell-based organoid models of the human placental barrier

Human placental villi have essential roles in producing hormones, mediating nutrient and waste exchange, and protecting the fetus from exposure to xenobiotics. Human trophoblast organoids that recapitulate the structure of villi could provide an important in vitro tool to understand placental development and the transplacental passage of xenobiotics. However, such organoids do not currently exist. Here we describe the generation of trophoblast organoids using human trophoblast stem (TS) cells. Following treatment with three kinds of culture medium, TS cells form spherical organoids with a single outer layer of syncytiotrophoblast (ST) cells that display a barrier function. Furthermore, we develop a column-type ST barrier model based on the culture condition of the trophoblast organoids. The bottom membrane of the column is almost entirely covered with syndecan 1-positive ST cells. The barrier integrity and maturation levels of the model are confirmed by measuring transepithelial/transendothelial electrical resistance (TEER) and the amount of human chorionic gonadotropin. Further analysis reveals that the model can be used to derive the apparent permeability coefficients of model compounds. In addition to providing a suite of tools for the study of placental development, our trophoblast models allow the evaluation of compound transfer and toxicity, which will facilitate drug development.

Maternal PM2.5 exposure is associated with preterm birth and gestational diabetes mellitus, and mitochondrial OXPHOS dysfunction in cord blood

Maternal exposure to fine particulate matter (PM2.5) is associated with adverse pregnancy and neonatal health outcomes. To explore the mechanism, we performed mRNA sequencing of neonatal cord blood. From an ongoing prospective cohort, Air Pollution on Pregnancy Outcome (APPO) study, 454 pregnant women from six centers between January 2021 and June 2022 were recruited. Individual PM2.5 exposure was calculated using a time-weighted average model. In the APPO study, age-matched cord blood samples from the High PM2.5 (˃15 ug/m3; n = 10) and Low PM2.5 (≤ 15 ug/m3; n = 30) groups were randomly selected for mRNA sequencing. After selecting genes with differential expression in the two groups (p-value < 0.05 and log2 fold change > 1.5), pathway enrichment analysis was performed, and the mitochondrial pathway was analyzed using MitoCarta3.0. The risk of preterm birth (PTB) increased with every 5 µg/m3 increase of PM2.5 in the second trimester (odds ratio 1.391, p = 0.019) after adjusting for confounding variables. The risk of gestational diabetes mellitus (GDM) increased in the second (odds ratio 1.238, p = 0.041) and third trimester (odds ratio 1.290, p = 0.029), and entire pregnancy (odds ratio 1.295, p = 0.029). The mRNA-sequencing of cord blood showed that genes related to mitochondrial activity (FAM210B, KRT1, FOXO4, TRIM58, and FBXO7) and PTB-related genes (ADIPOR1, YBX1, OPTN, NFkB1, HBG2) were upregulated in the High PM2.5 group. In addition, exposure to high PM2.5 affected mitochondrial oxidative phosphorylation (OXPHOS) and proteins in the electron transport chain, a subunit of OXPHOS. These results suggest that exposure to high PM2.5 during pregnancy may increase the risk of PTB and GDM, and dysregulate PTB-related genes. Alterations in mitochondrial OXPHOS by high PM2.5 exposure may occur not only in preterm infants but also in normal newborns. Further studies with larger sample sizes are required.

Connecting the Dots: Livestock Animals as Missing Links in the Chain of Microplastic Contamination and Human Health

Plastic pollution is a global diffuse threat, especially considering its fragmentation into microplastics (MPs) and nanoplastics (NPs). Since the contamination of the aquatic environment is already well studied, most studies have now focused on the soil. Moreover, the number of studies on the exposure routes and toxic effects of MNPs in humans is continuously increasing. Although MNPs can cause inflammation, cytotoxicity, genotoxicity and immune toxicity in livestock animals, which can accumulate ingested/inhaled plastic particles and transfer them to humans through the food chain, research on this topic is still lacking. In considering farm animals as the missing link between soil/plant contamination and human health effects, this paper aims to describe their importance as carriers and vectors of MNP contamination. As research on this topic is in its early stages, there is no standard method to quantify the amount and the characteristics of MNPs in different matrices. Therefore, the creation of a common database where researchers can report data on MNP characteristics and quantification methods could be helpful for both method standardization and the future training of an AI tool for predicting the most abundant/dangerous polymer(s), thus supporting policy decisions to reduce plastic pollution and perfectly fitting with One Health principles.

Microplastics exposure: implications for human fertility, pregnancy and child health

Plastics found in our everyday environment are becoming an increasing concern for individual and population-level health, and the extent of exposure and potential toxic effects of these contaminants on numerous human organ systems are becoming clear. Microplastics (MPs), tiny plastic particles, appear to have many of the same biological effects as their plastic precursors and have the compounded effect of potential accumulation in different organs. Recently, microplastic accumulation was observed in the human placenta, raising important questions related to the biological effects of these contaminants on the health of pregnancies and offspring. These concerns are particularly heightened considering the developmental origins of health and disease (DOHaD) framework, which postulates that in utero exposure can programme the lifelong health of the offspring. The current review examines the state of knowledge on this topic and highlights important avenues for future investigation.

The potential impacts of micro-and-nano plastics on various organ systems in humans

Humans are exposed to micro-and-nano plastics (MNPs) through various routes, but the adverse health effects of MNPs on different organ systems are not yet fully understood. This review aims to provide an overview of the potential impacts of MNPs on various organ systems and identify knowledge gaps in current research. The summarized results suggest that exposure to MNPs can lead to health effects through oxidative stress, inflammation, immune dysfunction, altered biochemical and energy metabolism, impaired cell proliferation, disrupted microbial metabolic pathways, abnormal organ development, and carcinogenicity. There is limited human data on the health effects of MNPs, despite evidence from animal and cellular studies. Most of the published research has focused on specific types of MNPs to assess their toxicity, while other types of plastic particles commonly found in the environment remain unstudied. Future studies should investigate MNPs exposure by considering realistic concentrations, dose-dependent effects, individual susceptibility, and confounding factors.

Honeycomb-like AgNPs@TiO2 array SERS sensor for the quantification of micro/nanoplastics in the environmental water samples

There has been a growing concern over the micro/nanoplastics pollution and treatment. The fast qualitative and quantitative analysis of these small plastic particles is the crucial issues. Herein, a novel honeycomb-like AgNPs@TiO2 array-based surface-enhanced Raman scattering (SERS) sensor was developed for efficient identification and analysis of the micro/nanoplastics in the environmental water samples. The plasmonic AgNPs were uniformly anchored within the periodic TiO2 nanocage arrays to form a AgNPs@TiO2 array. The dual enhancement mechanisms in the AgNPs@TiO2 hybrid structure endow the SERS sensor high sensitivity to detect trace amount of micro/nanoplastics down to 50 μg/mL with a hand-held Raman spectrometer. Further, this SERS sensor successfully discerns two-component mixtures of the micro/nanoplastics due to the fingerprint feature. In addition, the superior reproducibility (RSD of 9.69%) of the SERS sensor assures the quantitative detection reliability, realizing quantitative analysis of Polystyrene (PS) microplastics in tap water, lake water, soil water and seawater with detection limits of 100 μg/mL, 100 μg/mL, 100 μg/mL, 100 μg/mL and 250 μg/mL, respectively. The recovery rates of PS microspheres in four water environments ranged from 97.6% to 109.7%, with the RSD ranging from 0.49% to 10.23%. This honeycomb AgNPs@TiO2 array sensor provides a promising application prospect in the detection of micro/nanoplastics contaminants from the environmental water.

Folate-mediated Transport of Nanoparticles across the Placenta

BACKGROUND

In this study, a prototype of a targeted nanocarrier for drug delivery for prenatal therapy of the developing fetus was developed and examined in vitro and ex vivo. The folate transport mechanism in the human placenta was utilized as a possible pathway for the transplacental delivery of targeted nanoparticles.

METHODS

Several types of folic acid-decorated polymeric nanoparticles were synthesized and characterized. During transport studies of targeted and non-targeted fluorescent nanoparticles across the placental barrier, the apparent permeability values, uptake, transfer indices, and distribution in placental tissue were determined.

RESULTS

The nanoparticles had no effect on BeWo b30 cell viability. In vitro, studies showed significantly higher apparent permeability of the targeted nanoparticles across the cell monolayers as compared to the nontargeted nanoparticles (Pe = 5.92 ± 1.44 ×10-6 cm/s for PLGA-PEG-FA vs. 1.26 ± 0.31 ×10-6 cm/s for PLGA-PEG, P < 0.05), and the transport of the targeted nanoparticles was significantly inhibited by excess folate. Ex vivo placental perfusion showed significantly greater accumulation of the targeted nanoparticles in the placental tissue (4.31 ± 0.91%/g for PLGA-PEG-FA vs. 2.07 ± 0.26%/g for PLGA-PEG).

CONCLUSION

The data obtained suggested different mechanisms for the uptake and transplacental transfer of targeted versus nontargeted nanoparticles. This targeted nanoformulation may be a promising strategy for fetal drug therapy.

The reproductive and transgenerational toxicity of microplastics and nanoplastics: A threat to mammalian fertility in both sexes

Microplastics (MPs) and nanoplastics (NPs) are extensively distributed in the environment. However, a comprehensive review and in-depth discussion on the effects of MPs and NPs to reproductive capacity and transgenerational toxicity on mammals, especially on humans, is lacked. It is suggested that microplastics and nanoplastics could accumulate in mammalian reproductive organs and exert toxic effects on the reproductive system for both sexes. For males, the damage of microplastics consists of abnormal testicular and sperm structure, decreased sperm vitality, and endocrine disruption, which were caused by oxidative stress, inflammation, apoptosis of testicular cells, autophagy, abnormal cytoskeleton, and abnormal hypothalamic-pituitary-testicular axis. For females, the damage of microplastics includes abnormal ovary and uterus structure and endocrine disruption, which were caused by oxidative stress, inflammation, granulosa cell apoptosis, hypothalamic-pituitary-ovary axis abnormalities, and tissue fibrosis. For transgenerational toxicity, premature mortality existed in the rodent offspring after maternal exposure to microplastics. Among the surviving offspring, metabolic disorders, reproductive dysfunction, immune, neurodevelopmental, and cognitive disorders were detected, and these events directly correlated with transgenerational translocation of MPs and NPs. Studies on human-derived cells or organoids demonstrated that transgenerational toxicity studies for both sexes are yet in the phase of exploring suitable experimental models, and more detailed research on the threat of MPs and NPs to human fertility is still urgently needed. Further studies will help assess the MPs and NPs threat to public fertility and reproductive health risks.

Tissue distribution, placental transfer and excretion of silver nanoparticles in pregnant rats after a single oral dose

A quantitative assessment of silver nanoparticles (AgNPs) in fluids and some organs of pregnant rats as well as their fetal blood were carried out in this study. A single oral dose (1mg/kg) of AgNPs with a size range of 4-20 nm was administered to pregnant rats on the 19th of gestation. Five groups were euthanized after 10 min, 1, 6, 12, and 24 hr as well as the control group. Total Silver (Ag) contents were measured in bloods (maternal and fetal) and several organs using Inductive Coupled Plasma Optical Emission Spectroscopy (ICP-OES) followed by acid digestion. In maternal blood, AgNPs were found to increase time-dependently after 12 and 24 hr into 0.135 and 0.224 μg/ml, but it was slightly higher in fetal blood (0.32 and 0.31 μg/ml) after 10 min and 1 hr. In other samples: kidneys, liver, spleen, placenta, and uterus the data indicated that NPs were rapidly absorbed from the dosing site (gastrointestinal tract) as evidenced by the detection of Ag in the analyzed samples (fluids and tissues). On the other hand, the cumulative percentages of excretion level in urine was 8.25% which was higher than in feces (4.77%) after 24 hr. These findings indicate the ability of AgNPs to accumulate in pregnant rats and transfer to their fetus imposing adverse outcomes and male formation. Thus, further investigations must be followed for direct and/or indirect exposure to such NPs before decision for their practices.

Nanoparticles at the maternal-fetal interface

The increasing production of intentional and unintentional nanoparticles (NPs) has led to their accumulation in the environment as air and ground pollution. The heterogeneity of these particles primarily relies on the NP physicochemical properties (i.e., chemical composition, size, shape, surface chemistry, etc.). Pregnancy represents a vulnerable life stage for both the woman and the developing fetus. The ubiquitous nature of these NPs creates a concern for developmental fetal exposures. At the maternal-fetal interface lies the placenta, a temporary endocrine organ that facilitates nutrient and waste exchange as well as communication between maternal and fetal tissues. Recent evidence in human and animal models identifies that gestational exposure to NPs results in placental translocation leading to local effects and endocrine disruption. Currently, the mechanisms underlying placental translocation and cellular uptake of NPs in the placenta are poorly understood. The purpose of this review is to assess the current understanding of the physiochemical factors influencing NP translocation, cellular uptake, and endocrine disruption at the maternal-fetal interface within the available literature.

The Association Between Microplastics and Microbiota in Placentas and Meconium: The First Evidence in Humans

Pregnancy and infancy are vulnerable times for detrimental environmental exposures. However, the exposure situation of microplastics (MPs) for mother-infant pairs and the adverse health effect of MPs are largely unknown. Therefore, we explored MP exposure in placentas and meconium samples, and the potential correlation of MP exposure with microbiota in placentas and meconium. A total of 18 mother-infant pairs were effectively recruited from Shanghai, China. The study required pregnant women to provide placentas and meconium samples. An Agilent 8700 laser infrared imaging spectrometer (LDIR) was applied to identify MPs. Microbiota detection was identified by 16S rRNA sequencing. Sixteen types of MPs were found in all matrices, and polyamide (PA) and polyurethane (PU) were the major types we identified. MPs detected in samples with a size of 20-50 μm were more than 76.46%. At the phylum level, both placenta and meconium microbiota were mainly composed of Proteobacteria, Bacteroidota, and Firmicutes. We also found some significant differences between placenta and meconium microbiota in β-diversity and gut composition. Additionally, we found polystyrene was inversely related with the Chao index of meconium microbiota. Polyethylene was consistently inversely correlated with several genera of placenta microbiota. The total MPs, PA, and PU consistently impacted several genera of meconium microbiota. In conclusion, MPs are ubiquitous in placentas and meconium samples, indicating the wide exposure of pregnant women and infants. Moreover, our findings may support a link between high concentration of MPs and microbiota genera in placentas and meconium. Additionally, there were several significant associations between the particle size of MPs in 50-100 μm and meconium microbiota.

Atmospheric Microplastics: Perspectives on Origin, Abundances, Ecological and Health Risks

Microplastic (MP) pollution has aroused a tremendous amount of public and scientific interest worldwide. MPs are found widely ranging from terrestrial to aquatic ecosystems primarily due to the over-exploitation of plastic products and unscientific disposal of plastic waste. There is a large availability of scientific literature on MP pollution in the terrestrial and aquatic ecosystems, especially the marine environments; however, only recently has greater scientific attention been focused on the presence of MPs in the air and its retrospective health implications. Besides, atmospheric transport has been reported to be an important pathway of transport of MPs to the pristine regions of the world. From a health perspective, existing studies suggest that airborne MPs are priority pollutant vectors, that may penetrate deep into the body through inhalation leading to adverse health impacts such as neurotoxicity, cancer, respiratory problems, cytotoxicity, and many more. However, their effects on indoor and outdoor air quality, and on human health are not yet clearly understood due to the lack of enough research studies on that and the non-availability of established scientific protocols for their characterization. This scientific review entails important information concerning the abundance of atmospheric MPs worldwide within the existing literature. A thorough comparison of existing sampling and analytical protocols has been presented. Besides, this review has unveiled the areas of scientific concern especially air quality monitoring which requires immediate attention, with the information gaps to be filled have been addressed.

Indoor air pollution exposure and early childhood development in the Upstate KIDS Study

BACKGROUND

Limited human studies have investigated the impact of indoor air pollution on early childhood neurodevelopment among the US population. We aimed to examine the associations between prenatal and postnatal indoor air pollution exposure and early childhood development in a population-based birth cohort.

METHODS

This analysis included 4735 mother-child pairs enrolled between 2008 and 2010 in the Upstate KIDS Study. Indoor air pollution exposure from cooking fuels, heating fuels, and passive smoke during pregnancy, and at 12 and 36 months after birth were assessed by questionnaires. Five domains of child development were assessed by the Ages and Stages Questionnaire at 4, 8, 12, 18, 24, 30, and 36 months. Generalized estimating equations were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for potential confounders.

RESULTS

Exposure to unclean cooking fuels (natural gas, propane, or wood) throughout the study period was associated with increased odds of failing any development domain (OR = 1.28, 95% CI 1.07, 1.53), the gross motor domain (OR = 1.52, 95% CI: 1.09, 2.13), and the personal-social domain (OR = 1.36, 95% CI: 1.00, 1.85), respectively. Passive smoke exposure throughout the study period increased the odds of failing the problem-solving domain by 71% (OR = 1.71, 95% CI 1.01, 2.91) among children of non-smoking mothers. No association was found between heating fuel use and failing any or specific domains.

CONCLUSION

Unclean cooking fuel use and passive smoke exposure during pregnancy and early life were associated with developmental delays in this large prospective birth cohort.

Prenatal ambient air pollution exposure and child weight trajectories from the 3rd trimester of pregnancy to 2 years of age: a cohort study

BACKGROUND

Prenatal air pollution exposure may increase risk for childhood obesity. However, few studies have evaluated in utero growth measures and infant weight trajectories. This study will evaluate the associations of prenatal exposure to ambient air pollutants with weight trajectories from the 3rd trimester through age 2 years.

METHODS

We studied 490 pregnant women who were recruited from the Maternal and Development Risks from Environmental and Social Stressors (MADRES) cohort, which comprises a low-income, primarily Hispanic population in Los Angeles, California. Nitrogen dioxide (NO2), particulate matter < 10 µm (PM10), particulate matter < 2.5 µm (PM2.5), and ozone (O3) concentrations during pregnancy were estimated from regulatory air monitoring stations. Fetal weight was estimated from maternal ultrasound records. Infant/child weight measurements were extracted from medical records or measured during follow-up visits. Piecewise spline models were used to assess the effect of air pollutants on weight, overall growth, and growth during each period.

RESULTS

The mean (SD) prenatal exposure concentrations for NO2, PM2.5, PM10, and O3 were 16.4 (2.9) ppb, 12.0 (1.1) μg/m3, 28.5 (4.7) μg/m3, and 26.2 (2.9) ppb, respectively. Comparing an increase in prenatal average air pollutants from the 10th to the 90th percentile, the growth rate from the 3rd trimester to age 3 months was significantly increased (1.55% [95%CI 1.20%, 1.99%] for PM2.5 and 1.64% [95%CI 1.27%, 2.13%] for NO2), the growth rate from age 6 months to age 2 years was significantly decreased (0.90% [95%CI 0.82%, 1.00%] for NO2), and the attained weight at age 2 years was significantly lower (- 7.50% [95% CI - 13.57%, - 1.02%] for PM10 and - 7.00% [95% CI - 11.86%, - 1.88%] for NO2).

CONCLUSIONS

Prenatal ambient air pollution was associated with variable changes in growth rate and attained weight from the 3rd trimester to age 2 years. These results suggest continued public health benefits of reducing ambient air pollution levels, particularly in marginalized populations.

Creating mini-pregnancy models in vitro with clinical perspectives

During the last decade, organs-on-chips or organoids microphysiological analysis platforms (MAP) have garnered attention in the practical applications of disease models, drug discovery, and developmental biology. Research on pregnant women has firm limitations due to ethical issues; thus, remodelling human pregnancy in vitro is highly beneficial for treatment modality development via disease remodelling or drug monitoring. This review highlights current efforts in bioengineering devices to reproduce human pregnancy and emphasises the significant convergence of biology, engineering, and maternal-foetal medicine. First, we review recent achievements in culturing cells from tissues involved in pregnancy; specifically, trophoblasts from the placenta. Second, we highlight developments in the reconstitution of pregnancy-related female reproductive organs across several structural and functional interpretations. Last, we examine research on the fundamental comprehension of pregnancy-associated diseases to find bioengineering solutions. Recreating human pregnancy through an engineered model is naturally complex; nevertheless, challenges are inevitable to progress precision medicine.

Sources, Degradation, Ingestion and Effects of Microplastics on Humans: A Review

Celluloid, the predecessor to plastic, was synthesized in 1869, and due to technological advancements, plastic products appear to be ubiquitous in daily life. The massive production, rampant usage, and inadequate disposal of plastic products have led to severe environmental pollution. Consequently, reducing the employment of plastic has emerged as a pressing concern for governments globally. This review explores microplastics, including their origins, absorption, and harmful effects on the environment and humans. Several methods exist for breaking down plastics, including thermal, mechanical, light, catalytic, and biological processes. Despite these methods, microplastics (MPs, between 1 and 5 mm in size) continue to be produced during degradation. Acknowledging the significant threat that MPs pose to the environment and human health is imperative. This form of pollution is pervasive in the air and food and infiltrates our bodies through ingestion, inhalation, or skin contact. It is essential to assess the potential hazards that MPs can introduce. There is evidence suggesting that MPs may have negative impacts on different areas of human health. These include the respiratory, gastrointestinal, immune, nervous, and reproductive systems, the liver and organs, the skin, and even the placenta and placental barrier. It is encouraging to see that most of the countries have taken steps to regulate plastic particles. These measures aim to reduce plastic usage, which is essential today. At the same time, this review summarizes the degradation mechanism of plastics, their impact on human health, and plastic reduction policies worldwide. It provides valuable information for future research on MPs and regulatory development.

Toxicity of microplastics and nanoplastics: invisible killers of female fertility and offspring health

Microplastics (MPs) and nanoplastics (NPs) are emergent pollutants, which have sparked widespread concern. They can infiltrate the body via ingestion, inhalation, and cutaneous contact. As such, there is a general worry that MPs/NPs may have an impact on human health in addition to the environmental issues they engender. The threat of MPs/NPs to the liver, gastrointestinal system, and inflammatory levels have been thoroughly documented in the previous research. With the detection of MPs/NPs in fetal compartment and the prevalence of infertility, an increasing number of studies have put an emphasis on their reproductive toxicity in female. Moreover, MPs/NPs have the potential to interact with other contaminants, thus enhancing or diminishing the combined toxicity. This review summarizes the deleterious effects of MPs/NPs and co-exposure with other pollutants on female throughout the reproduction period of various species, spanning from reproductive failure to cross-generational developmental disorders in progenies. Although these impacts may not be directly extrapolated to humans, they do provide a framework for evaluating the potential mechanisms underlying the reproductive toxicity of MPs/NPs.

'Spikeopathy': COVID-19 Spike Protein Is Pathogenic, from Both Virus and Vaccine mRNA

The COVID-19 pandemic caused much illness, many deaths, and profound disruption to society. The production of 'safe and effective' vaccines was a key public health target. Sadly, unprecedented high rates of adverse events have overshadowed the benefits. This two-part narrative review presents evidence for the widespread harms of novel product COVID-19 mRNA and adenovectorDNA vaccines and is novel in attempting to provide a thorough overview of harms arising from the new technology in vaccines that relied on human cells producing a foreign antigen that has evidence of pathogenicity. This first paper explores peer-reviewed data counter to the 'safe and effective' narrative attached to these new technologies. Spike protein pathogenicity, termed 'spikeopathy', whether from the SARS-CoV-2 virus or produced by vaccine gene codes, akin to a 'synthetic virus', is increasingly understood in terms of molecular biology and pathophysiology. Pharmacokinetic transfection through body tissues distant from the injection site by lipid-nanoparticles or viral-vector carriers means that 'spikeopathy' can affect many organs. The inflammatory properties of the nanoparticles used to ferry mRNA; N1-methylpseudouridine employed to prolong synthetic mRNA function; the widespread biodistribution of the mRNA and DNA codes and translated spike proteins, and autoimmunity via human production of foreign proteins, contribute to harmful effects. This paper reviews autoimmune, cardiovascular, neurological, potential oncological effects, and autopsy evidence for spikeopathy. With many gene-based therapeutic technologies planned, a re-evaluation is necessary and timely.

Determinants and mechanisms of inorganic nanoparticle translocation across mammalian biological barriers

Biological barriers protect delicate internal tissues from exposures to and interactions with hazardous materials. Primary anatomical barriers prevent external agents from reaching systemic circulation and include the pulmonary, gastrointestinal, and dermal barriers. Secondary barriers include the blood-brain, blood-testis, and placental barriers. The tissues protected by secondary barriers are particularly sensitive to agents in systemic circulation. Neurons of the brain cannot regenerate and therefore must have limited interaction with cytotoxic agents. In the testis, the delicate process of spermatogenesis requires a specific milieu distinct from the blood. The placenta protects the developing fetus from compounds in the maternal circulation that would impair limb or organ development. Many biological barriers are semi-permeable, allowing only materials or chemicals, with a specific set of properties, that easily pass through or between cells. Nanoparticles (particles less than 100 nm) have recently drawn specific concern due to the possibility of biological barrier translocation and contact with distal tissues. Current evidence suggests that nanoparticles translocate across both primary and secondary barriers. It is known that the physicochemical properties of nanoparticles can affect biological interactions, and it has been shown that nanoparticles can breach primary and some secondary barriers. However, the mechanism by which nanoparticles cross biological barriers has yet to be determined. Therefore, the purpose of this review is to summarize how different nanoparticle physicochemical properties interact with biological barriers and barrier products to govern translocation.

Effects of nano and microplastics on the reproduction system: In vitro and in vivo studies review

Microplastics (MPs) and nanoplastics (NPs), as their name suggest, are tiny plastic particles. The negative impact of MPs as an emerging pollutant on humans is not hidden from anyone. Recent research on how this pollutant affects the reproductive system and how it enters the blood, placenta, and semen has attracted the attention of scientists. This review study deals with the reproductive toxicity of MPs particles in terrestrial animals, aquatic animals, soil fauna, human cells, and human placenta. In vitro and in vivo animal studies showed that MPs can lead to reduced fertility in men, reduced ovarian capacity, apoptosis of granulosa cells, or even reduced sperm motility. They cause oxidative stress and cell apoptosis and inflammatory effects. The results of these animal studies show that MPs may have similar effects on the human reproductive system. However, not much research has been done on human reproductive toxicity by MPs. Therefore, special attention should be paid to the toxicity of the reproductive system by MPs. The purpose of this comprehensive study is to express the importance of the impact of MPs on the reproductive system. These results provide new insight into the potential dangers of MPs.