Toxic effects of nanoplastics with different sizes and surface charges on epithelial-to-mesenchymal transition in A549 cells and the potential toxicological mechanism

Mechanism of nano-plastics induced inflammation injury in vascular endothelial cells

Nano-plastics, emerging pollutants in the environment, have raised global concern due to their widespread presence in daily life and the potential toxicity to human health. Upon entering human body, nano-plastics can readily interact with vascular endothelial cells within the bloodstream, potentially leading to endothelial dysfunction. However, our understanding of the toxic impact of nano-plastics on vascular endothelial cells remains insufficient, and the underlying mechanism are yet to be elucidated. This study investigated the toxicological effects of nano-plastics on EA.hy 926 endothelial cells. Exposure to different types of nano-plastics such as polystyrene (PS), amino-modified PS or carboxyl-modified PS, resulted in suppress cell activity, damage to the cell membrane, oxidative stress and significantly inhibit cell migration. RNA sequencing (RNA-seq) and small RNA-seq analyses revealed that numbers of genes and miRNAs were differentially expressed after nano-plastics treatment. CEBPB, a gene within the inflammation-related tumor necrosis factor signaling pathway, was confirmed to be a target of miR-1908-5p, indicating that nano-plastics induced activation of CEBPB might promote inflammatory injury to vascular endothelial cells. These results enhance our understanding of the biological effects of nano-plastics and their potential impact on inflammation injury.

Exploring toxicological pathways of microplastics and nanoplastics: Insights from animal and cellular models

Microplastics (MPs) and nanoplastics (NPs) represent an emerging issue for human and animal health. This review critically examines in vitro and in vivo studies to elucidate their mechanisms of action and toxicological effects. Key objectives included: providing a comprehensive overview of MP-NPs studies in literature, assessing experimental conditions relative to real environmental scenarios, and identifying toxicological pathways at the molecular level. The findings revealed significant progress in understanding MP-NPs impacts. In particular, it has been observed the promotion of inflammation, oxidative stress, apoptosis, autophagy, and endoplasmic reticulum (ER) stress via specific signaling axes. Reproductive toxicity emerged as the primary research focus, particularly in male models, whereas effects on gastrointestinal, neurological, and cardiovascular systems were insufficiently studied, especially for the molecular pathways affected. Most studies disproportionately focused on polystyrene particles, neglecting other prevalent polymers such as polyethylene and polypropylene. Furthermore, reliance on synthetic microspheres and non-realistic experimental concentrations limits relevance to real-world conditions. Limited long-term exposure studies further constrain the understanding of MP-NPs persistence and risks. In view of this, future research should integrate environmentally relevant conditions for particles doses, size and composition, long-term exposure assessments, and advanced methodologies such as omics and computational modeling. In addition, therapeutic interventions targeting oxidative and ER stress, inflammation and apoptosis may be an excellent solution to mitigate MP-NPs toxicity. At the same time, a standardized global approach is needed to fully understand the risks posed by MP-NPs, attempting to safeguard public and environmental health.

Exposure of the human placental primary cells to nanoplastics induces cytotoxic effects, an inflammatory response and endocrine disruption

Humans are inevitably exposed to micro- and nanoplastics (MP/NP). These particles are able to cross the biological barriers and enter the bloodstream with levels close to 1.6 µg mL-1; MP/NP have been detected in placentas and meconium of newborns. However, the consequences of this exposure on the integrity, development and functions of the human placenta are not documented. In this study, trophoblasts purified from human placentas at term were exposed for 48 h, to two different sizes of polystyrene nanoparticles (PS-NP) of 20 nm (PS-NP20) and 100 nm (PS-NP100), at environmental and supra-environmental concentrations (0.01-100 µg mL-1). Cell viability, oxidative stress, mitochondrial dynamics, lysosomal degradation processes, autophagy, inflammation/oxidative responses and consequences for placental endocrine and angiogenic functions were assessed. PS-NP size determines their internalization rate and their behavior in trophoblasts. Indeed, PS-NP20 are more rapidly translocated, and accumulated in lysosomes as shown by confocal and TEM imaging. They induce higher cytotoxicity than PS-NP100, as early as 1 µg mL-1 (p < 0.05). In addition, they induce a pro-inflammatory cytokines response: IL-1ß is induced from 0.01 µg mL-1 for the both nanoparticle sizes; IL-6, and TNF-α are overexpressed at 100 µg mL-1 only for PS-NP20 (p < 0.05). For the first time, we report that PS-NP disrupt endocrine function, as observed by a decreased hCG release at concentrations found in human blood. This work, provides an in-depth in vitro assessment of the effects of PS-NP on the human placenta.

In vitro effects of aged low-density polyethylene micro(nano)plastic particles on human airway epithelial cells

Airborne micro(nano)plastic (MNP) pollution has emerged as a major global concern due to its increasingly worrying adverse health effects. Environmental weathering and UV irradiation of plastic waste, together with tire wear, generate airborne MNPs with irregular shapes and varied sizes, with low-density polyethylene (LDPE) being the predominant plastic type. However, knowledge of MNPs' toxicological effects remains scarce, as current in vitro research mainly focuses on commercial polystyrene beads. In this study, we investigated for the first time the toxicological effects of environmentally relevant aged LDPE MNPs on human bronchial epithelial cells (BEAS-2B). UV-aged LDPE fragments of irregular sizes and shapes were used to mimic real atmospheric particles, and BEAS-2B cells were exposed to 10-1000 μg/cm2 of LDPE MNPs. Our results showed that MNPs were internalized by BEAS-2B cells and promoted epithelial-to-mesenchymal transition (EMT), characterized by reduced β-catenin and increased vimentin expression, enhanced motility, and disturbed cell cycle. Moreover, exposure to aged LDPE MNPs significantly increased intracellular ROS levels and reduced cell proliferation rate at the highest dose. LDPE MNPs triggered oxidative stress in BEAS-2B cells through activation of the NRF2 signaling pathway, with impaired autophagic flux indicated by increased expression of p62 and LC3A/B. Importantly, LDPE MNP exposure significantly increased the secretion of pro-inflammatory mediators (CD62E, CD62P, ICAM-1, IL-6, IL-8), accompanied by suppressive effects on mitochondrial respiration and glycolytic function at 1000 μg/cm2. Taken together, our findings suggest that inhalation of LDPE MNPs could impact the morphology and function of the human airway epithelium and respiratory health in general.

Pulmonary hazards of nanoplastic particles: a study using polystyrene in in vitro models of the alveolar and bronchial epithelium

BACKGROUND

Nanoplastics (NPs) are released into the environment through the degradation of plastic objects, leading to human exposure. Due to their small size, concerns have been raised about the potential hazards to the respiratory tract, as ultrafine and nanoparticles are known to penetrate till the alveolar regions of the lungs, potentially impairing their functions. Thus, in the present study, we used model polystyrene nanoparticles doped with the fluorescent metal europium (PS-Eu) to enhance the understanding of NPs hazard and investigate adverse outcomes associated with exposure in human lungs using alveolar (A549) and bronchial (Calu-3) cell models grown in 2D and 3D submerged conditions or quasi air-liquid interface (ALI) conditions (3D).

RESULTS

Briefly, after in-dept physicochemical characterization of the particles, we assessed their impact on ROS production, cell viability (AlamarBlue and lactate dehydrogenase assays) and barrier integrity (lucifer yellow assay and TEER measurement), finding no negative effects in either model. However, in alveolar cells, particles increased acidic organelle activity. Transmission electron microscopy and Raman microscopy showed, in both models, a dose- and cell-dependent particle uptake with PS-Eu accumulating in numerous and large endo-lysosomes, which, in transwells-grown A549 cells, often contained also lamellar bodies (LBs), organelles involved in surfactants storage and secretion. After extensively quantifying surfactant proteins (SP) in the pellet and supernatant fractions of treated A549 cells, we observed a significant reduction in several members of this family, including surfactant protein B, which is crucial for lamellar body formation and surface tension regulation in the lungs. In quasi-ALI Calu-3 cultures instead, PS-Eu significantly upregulated interleukin 6 (IL-6) and increased transforming growth factor beta β (TGF-β), zonula occludens 1 (ZO-1), and mucin (MUC) 5B mRNA expressions causing a moderate proinflammatory response.

CONCLUSION

Our results show that PS-Eu exposure does not induce acute cytotoxicity in these models, but affects cell-specific functions like surfactant, mucin, and cytokine production. This underscores the limitations of relying solely on standard cytotoxicity tests for particle hazard assessment and highlights the importance of investigating cell function-specific signaling pathways. To support researchers in hazard assessment, we propose specific classes of biomarkers to test in in vitro lung models.

Toxicity of Engineered Nanoparticles in Food: Sources, Mechanisms, Contributing Factors, and Assessment Techniques

The increasing prevalence of engineered nanoparticles (ENPs) in food systems has raised concerns about their toxicity and potential health risks. To provide a comprehensive evaluation, a structured literature search was conducted using databases such as Web of Science and PubMed, focusing on studies published in the past ten years that examine ENP exposure pathways, toxicity mechanisms, contributing factors, and risk assessment strategies. This review first explores the diverse sources of ENPs, including food additives, nanocarriers, packaging, agricultural practices, and environmental contamination. Upon ingestion, ENPs undergo complex transformations within the human gastrointestinal tract (GIT), causing oxidative stress, cellular dysfunction, inflammation, and gut microbiota dysbiosis, potentially leading to systemic toxicity in vital organs. The toxicity of ENPs is influenced by their physicochemical properties, food matrix effects, GIT conditions, and host-specific factors. This review further discusses current toxicity assessment methodologies, including in silico, in vitro, in vivo, and emerging technologies. Finally, we identify critical research gaps, such as the lack of long-term exposure studies and limited evaluations of organic ENPs. By providing a comprehensive analysis of ingested ENP toxicity, this review aims to guide safer ENP applications and mitigate potential health risks.

Mechanism of S-Palmitoylation in Polystyrene Nanoplastics-Induced Macrophage Cuproptosis Contributing to Emphysema through Alveolar Epithelial Cell Pyroptosis

More than microplastics, nanoplastics may pose a greater toxic effect on humans due to their unique physicochemical properties. Currently, research on lung diseases caused by respiratory exposure to nanoplastics is scarce, with epigenetic mechanisms warranting further investigation. In the present study, we exposed rats to polystyrene nanoplastics (PS-NPs) via an oral-nasal exposure system and found that PS-NPs exposure resulted in emphysema. Mechanistically, PS-NPs entered macrophages and competitively bound to sigma nonopioid intracellular receptor 1 (SIGMAR1), leading to an increase in free zDHHC palmitoyltransferase 14 (zDHHC14). This, in turn, caused elevated palmitoylation of solute carrier family 31 member 1 (SLC31A1) in macrophages, inhibiting its ubiquitination and degradation, thereby enhancing SLC31A1 expression. The increased expression of SLC31A1 promoted cuproptosis of macrophages and elevated tumor necrosis factor-α (TNF-α) secretion, which activated the NLR family pyrin domain containing 3/matrix metallopeptidase 9 (NLRP3/MMP-9) pathway in alveolar epithelial cells (AECs). This process mediated pyroptosis and degradation of extracellular matrix (ECM), resulting in the destruction of alveolar structure and development of emphysema. The findings demonstrate a previously unknown molecular mechanism by which PS-NPs induce emphysema. The findings have implications for the prevention and treatment of respiratory system damage caused by nanoparticles.

Assessing the Impact of Nanoplastics in Biological Systems: Systematic Review of In Vitro Animal Studies

Nanoplastic (NP) pollution has emerged as a growing concern due to its potential impact on human health, although its adverse effects on different organ systems are not yet fully understood. This systematic scoping review, conducted in accordance with international guidelines, aimed to map the current evidence on the biological effects of NPs. In vitro animal studies assessing cellular damage caused by exposure to any type of NP were searched on PubMed, Web of Science, and Scopus. Data on primary outcomes related to genotoxicity and cytotoxicity (cell viability, oxidative stress, inflammation, DNA and cytoplasmic damage, apoptosis) were extracted from the included studies, and overall reporting quality was assessed. A total of 108 articles published between 2018 and 2024, mostly by China (54%), Spain (14%), and Italy (9%), were included. Polystyrene (PS) was the most frequently studied polymer (85%). NP sizes in solution ranged from 15 to 531 nm, with a higher prevalence in the 40-100 nm range (38%). The overall quality of studies was rated as moderate (60%), with many lacking essential details about cell culture conditions (e.g., pH of the medium, passage number, substances used). A higher frequency of negative effects from NP exposure was observed in respiratory cell lines, while immune, digestive, and hepatic cell lines showed greater resistance. Nervous, urinary, and connective tissue systems were impacted by NPs. Positively charged and smaller PS particles were consistently associated with higher toxicity across all systems. In summary, this review highlights the multifactorial nature of NP toxicity, influenced by size, surface charge, and polymer type. It also reveals a significant knowledge gap, stemming from the predominant use of immortalized monocultures exposed to commercially available PS NPs, the limited use of environmentally relevant particles, and the underutilization of advanced experimental models (e.g., organ-on-chip systems) that better mimic physiological conditions.

Nanoplastics Chronic Toxicity in Mice: Disturbing the Homeostasis of Tryptophan Metabolism in Gut-Lung-Microbiota Axis

Long-term exposure to nanoplastics causes chronic toxicity in mammals, particularly in the gut and lung tissues. The gut-lung-microbiota axis plays a pivotal role in organisms through the management of gut bacteria amino acid metabolic homeostasis. However, chronic toxicity of nanoplastics from gut to lungs have yet to be fully elucidated. In this study, nanoplastics exposure not only causes colon inflammation but also results in lung fibrosis. The abundance of Akkermansia muciniphila (AKK) is decreased after nanoplastics exposure. Interestingly, a positive correlation is observed between AKK and indole-3-lactic (ILA). Supplementation with AKK or ILA ameliorated nanoplastics-induced gut-derived lung injury by restoring the balance of tryptophan metabolism. Furthermore, knocking down indoleamine 2,3-dioxygenase 1 (ido1) upregulated ILA levels, contributing to defense against damage from nanoplastics. These results suggest that regulating ido1 expression and AKK abundance, involved in tryptophan metabolic homeostasis (especially ILA production), maybe a strategy to reduce the biological toxicity induced by nanoplastics. Mogroside V, a natural product, is found to promote AKK growth and inhibit ido1, thereby ameliorating chronic toxicity induced by nanoplastics. The study offers a new understanding of how nanoplastics cause chronic toxicity by dysregulating gut-lung-microbiota axis, as well as strategies for preventing and treating nanoplastics.

Pulmonary fibrosis: from mechanisms to therapies

Pulmonary fibrosis (PF) is a chronic, progressive interstitial lung disease characterized by excessive deposition of extracellular matrix (ECM) and abnormal fibroblast proliferation, which is mainly caused by air pollution, smoking, aging, occupational exposure, environmental pollutants exposure, and microbial infections. Although antifibrotic agents such as pirfenidone and nintedanib, approved by the United States (US) Food and Drug Administration (FDA), can slow the decline in lung function and disease progression, their side effects and delivery inefficiency limit the overall prognosis of PF. Therefore, there is an urgent need to develop effective therapeutic targets and delivery approaches for PF in clinical settings. This review provides an overview of the pathogenic mechanisms, therapeutic drug targeting signaling pathways, and promising drug delivery strategies for treating PF.

Protein corona as a mediator in antibiotic adsorption onto microplastics: Mechanisms and implications

Microplastics are emerging pollutants capable of adsorbing antibiotics in the environment through interactions mediated by biological molecules such as proteins, ultimately posing risks to human health. However, direct evidence demonstrating that microplastics and antibiotics form chemical-adsorption products has not been explored. One key mechanism contributing to their co-exposure risks during their transmission is biofilm formation, particularly the development of a protein corona, which may also serve as a potential virulence mechanism. In this study, the interactions and adsorption processes among microplastics, proteins, and antibiotics within biofilm formation were innovatively analysed using molecular docking. Hydrophobic interactions contributing to the formation of a stable protein corona have been evidenced even in vitro digestive simulations. Notably, the presence of a protein corona on microplastics enhances the maximum adsorption capacity of antibiotics by 51.9 ± 2.7 %-64.7 ± 3.5 %, without affecting the chemical adsorption mode on Site II or the heterogeneous diffusion mechanism. Furthermore, compared to previous studies, this research provides compelling evidence that sulfamethoxazole interacts with Glu 166 in Site II of bovine serum albumin with high accuracy. Overall, this study addresses a previously overlooked aspect of toxicological research by offering new insights into pollutant adsorption facilitated by the protein corona on microplastics.

Mechanistic insight on nanomaterial-induced reactive oxygen species formation

Reactive oxygen species (ROS) are closely related to cell death, proliferation and inflammation. However, excessive ROS levels may exceed the cellular oxidative capacity and cause irreversible damage. Organisms are often inadvertently exposed to nanomaterials (NMs). Therefore, elucidating the specific routes of ROS generation induced by NMs is crucial for comprehending the toxicity mechanisms of NMs and regulating their potential applications. This paper provides a comprehensive review of the toxicity mechanisms and applications of NMs from three perspectives: (1) Organelle perspective. Investigating the impact of NM-mediated ROS on mitochondria, unraveling mechanisms at the organelle level. (2) NMs' perspective. Exploring the broad applications and biosafety considerations of Nanozymes, a unique class of NMs. (3) Cellular system. Examining the toxic effects and mechanisms of NMs in cells at a holistic cellular level. Expanding on these perspectives, the paper scrutinizes the regulation of Fenton reactions by NMs in organisms. Furthermore, it introduces diseases resulting from NM-mediated ROS at the organism level. This comprehensive review aims to provide valuable insights for studying NM-mediated mechanisms at both cellular and organism levels, offering considerations for the safe design of nanomaterials.

Microplastics/nanoplastics contribute to aging and age-related diseases: Mitochondrial dysfunction as a crucial role

The pervasive utilization of plastic products has led to a significant escalation in plastic waste accumulation. Concurrently, the implications of emerging pollutants such as microplastics (MPs) and nanoplastics (NPs) on human health are increasingly being acknowledged. Recent research has demonstrated that MPs/NPs may contribute to the onset of human aging and age-related diseases. Additionally, MPs/NPs have the potential to induce mitochondrial damage, resulting in mitochondrial dysfunction. Mitochondrial dysfunction is widely recognized as a hallmark of aging; thus, it is necessary to elucidate the relationship between them. In this article, we first elucidate the distribution of MPs/NPs in various environmental media, their pathways into the human body, and their subsequent distribution within human tissues and organs. Subsequently, we examine the interplay between MPs/NPs, mitochondrial dysfunction, and the aging process. We aspire that this article will enhance awareness regarding the toxicity of MPs/NPs while also offering a theoretical framework to support the development of improved regulatory policies in the future.

Maternal exposure to phthalates and nanoplastics, isolated or combined: Impacts on placental structure, development, and antioxidant defense as a trigger for maternal-fetal adversities

The placenta is an essential maternal-fetal organ for the healthy development of the fetus, linking maternal and fetal circulations. Endocrine disrupting chemicals (EDCs), such as phthalates derived from plastic residues, may impair offspring development and increase the risk of metabolic disorders. Plastics also degrade into microplastics (MPs) and nanoplastics (NPs), which can cross the placenta, carrying EDCs and impacting fetal development. The objective of this study was to investigate whether gestational exposure to a phthalate mixture (PM) and NPs interferes with the maternal-fetal interface, altering female reproductive efficiency and placental morphophysiology. Pregnant SD rats were divided into 6 groups: CTR(control; vehicle), T1(20 μg/kg/day-PM), T2(200 mg/kg/day-PM), T3(1 mg/kg/day NPs-100nm), T4(20 μg/kg/dayPM+1 mg/kg/day-NPs-100nm), and T5(200 mg/kg/day-PM+1 mg/kg/day-NPs-100 nm). Treatment was administered orally from gestational day 5 (GD5) to GD20. At GD20, 5-8 rats from each group were anesthetized and underwent laparotomy, and blood, ovaries, uterus, and placentas were analyzed. There was an increase in pre-implantation loss in T3, T4 and T5 groups, a reduction in placental weight, and an increase in placental efficiency in male offspring in T3 group. An increase in the number of fetuses small for gestational age was observed in T3 and T5 vs. C. Furthermore, the treatment caused an increase in the expression of targets related to trophoblast cell differentiation in T5, and growth factors related to angiogenesis in the placenta in T3 and T4 groups. There was a decrease in TBARS, SOD, and GSTpi levels in T2, while CAT increased in T3, suggesting that these pollutants modulate placental gene expression and energy metabolism.

Dissection of the potential mechanism of polystyrene microplastic exposure on cardiomyocytes

Microplastics (MPs) are ubiquitous in the global biosphere, have widespread contact with humans, and increase exposure risks. Increasing evidence indicates that MPs exposure increases the risks of cardiovascular disease, however, a comprehensive exploration of the fundamental cellular mechanisms has yet to be undertaken. In this study, we used AC16 cells as a model and exposed them to 10 to 50 μg/mL of polystyrene MPs (PS-MPs), chosen based on the average daily intake and absorption of MPs by humans, to investigate their roles and mechanisms in cell injury. Proteomic analysis reveals that PS-MP-induced differentially expressed genes were enriched on endoplasmic reticulum (ER) stress and autophagy-related entries. The findings from immunofluorescence and western blotting provided further verification of the activation of ER stress by PS-MPs. Although the expression of LC3-II, a canonical autophagy marker was increased, PS-MPs inhibited autophagic flux instead of inducing autophagy. Importantly, ER stress not only contributes to PS-MPs-induced cell injury but also involved in PS-MPs-induced autophagic flux inhibition. Furthermore, the inhibition of autophagy, and the partial restoration of cell injury induced by PS-MPs was achieved through the activation of autophagy. Overall, the results reveal that activation of ER stress and inhibition of autophagic flux plays a significant role in the cell injury caused by PS-MPs in human cardiomyocytes, offering a novel perspective on the mechanism behind MPs-induced cardiomyocyte toxicity.

Life cycle exposure to differentially charged polystyrene nanoplastics leads to gender-specific particle accumulation and neurotoxicity in zebrafish (Danio rerio)

Nanoplastics (NPs) have been widely detected in freshwater environments and photodegradation, as well as physical and chemical breakdown, lead to different surface charges on the plastics. Although evidence in the literature highlights the importance of NPs surface charge to neurotoxicity, substantial gaps in mechanistic understanding remain. In the current study, zebrafish (Danio rerio) were exposed to differentially charged NPs (PS, PS-NH2, PS-COOH) at environmentally relevant concentration (10 μg/L). After full life cycle exposure, the potential neurotoxicity, brain damage, and the altered brain metabolism was investigated through light sheet microscopy 3-dimensional imaging, histopathology, Evans blue dye (EBD) extravasation, gene expression, and untargeted and targeted metabolomics of brain tissue in zebrafish. Exposure to PS, PS-NH2, PS-COOH caused adverse effects on the performance of neurobehaviors, blood-brain-barrier (BBB) permeability, amino acid metabolism, damage to the BBB and mitochondria, and overt inflammatory response. PS-NH2 (4.56-fold) and PS-COOH (3.59-fold) accumulated in the reticular formation (RF) of the male brain, while only PS-NH2 was detected in the RF (6.57-fold) and ventral hypothalamus (Hv) (3.08-fold) of female brains. Several important biological pathways were negatively impacted in a charge- and gender-specific fashion. This study provides novel insights into the underlying toxicity mechanisms of differentially charged NPs in a model aquatic species, as well as the associated environmental risks of this important group of emerging contaminants.

Micro- and Nano-Plastic-Induced Adverse Health Effects on Lungs and Kidneys Linked to Oxidative Stress and Inflammation

Micro- and nano-plastics (MNPs) are small plastic particles that result from the breakdown of larger plastics. They are widely dispersed in the environment and pose a threat to wildlife and humans. MNPs are present in almost all everyday items, including food, drinks, and household products. Air inhalation can also lead to exposure to MNPs. Research in animals indicates that once MNPs are absorbed, they can spread to various organs, including the liver, spleen, heart, lungs, thymus, reproductive organs, kidneys, and even the brain by crossing the blood-brain barrier. Furthermore, MPs can transport persistent organic pollutants or heavy metals from invertebrates to higher levels in the food chain. When ingested, the additives and monomers that comprise MNPs can disrupt essential biological processes in the human body, thereby leading to disturbances in the endocrine and immune systems. During the 2019 coronavirus (COVID-19) pandemic, there was a significant increase in the global use of polypropylene-based face masks, leading to insufficient waste management and exacerbating plastic pollution. This review examines the existing research on the impact of MNP inhalation on human lung and kidney health based on in vitro and in vivo studies. Over the past decades, a wide range of studies suggest that MNPs can impact both lung and kidney tissues under both healthy and diseased conditions. Therefore, this review emphasizes the need for additional studies employing multi-approach analyses of various associated biomarkers and mechanisms to gain a comprehensive and precise understanding of the impact of MNPs on human health.

Metabolic landscape of human alveolar type II epithelial cells undergoing epithelial-mesenchymal transition induced directly by silica exposure

Epithelial-mesenchymal transition (EMT) plays an irreplaceable role in the development of silicosis. However, molecular mechanisms of EMT induced by silica exposure still remain to be addressed. Herein, metabolic profiles of human alveolar type II epithelial cells (A549 cells) exposed directly to silica were characterized using non-targeted metabolomic approaches. A total of 84 differential metabolites (DMs) were identified in silica-treated A549 cells undergoing EMT, which were mainly enriched in metabolisms of amino acids (e.g., glutamate, alanine, aspartate), purine metabolism, glycolysis, etc. The number of DMs identified in the A549 cells obviously increased with the elevated exposure concentration of silica. Remarkably, glutamine catabolism was significantly promoted in the silica-treated A549 cells, and the levels of related metabolites (e.g., succinate) and enzymes (e.g., α-ketoglutarate (α-KG) dehydrogenase) were substantially up-regulated, with a preference to α-KG pathway. Supplementation of glutamine into the cell culture could substantially enhance the expression levels of both EMT-related markers and Snail (zinc finger transcription factor). Our results suggest that the EMT of human alveolar epithelial cells directly induced by silica can be essential to the development of silicosis.

The wheel of time: The environmental dance of aged micro- and nanoplastics and their biological resonance

The aging of micro- and nanoplastics (MNPs) significantly affects their environmental behavior and ecological impacts in both aquatic and terrestrial ecosystems. This review explored the known effects of aging on MNPs and identified several key perspectives. Firstly, aging can alter the environmental fate and transport of MNPs due to changes in their surface properties. This alteration accelerates their accumulation in specific habitats like oceans and soils, resulting in increased bioaccumulation by organisms. In addition, aged MNPs interact differently with living organisms than their pristine counterparts by influencing the attachment of biofilms and other microorganisms in aquatic ecosystems. Moreover, the aging processes of MNPs exhibit adverse effects on aquatic and terrestrial organisms via increasing the bioavailability and potential toxicity of MNPs as degradation products are released. Last but not least, the biodegradation potential of MNPs can be altered by the aging process, thus affecting their degradation rates and pathways in the environment. However, there are still knowledge gaps regarding the natural aging behaviors of MNPs, such as the aging mechanisms of different types of plastic, the influence of environmental factors, the release of pollutants, and even the effects of aging on their transformation in different ecosystems. Therefore, a great contribution can be made to sustainable plastic use and environmental preservation by studying the natural aging of common MNPs and their subsequent biological effects.

Exposure to Nanoplastics During Pregnancy Induces Brown Adipose Tissue Whitening in Male Offspring

BACKGROUND

Polystyrene nanoplastics (PSNPs) have been recognized as emerging environmental pollutants with potential health impacts, particularly on metabolic disorders. However, the mechanism by which gestational exposure to PSNPs induces obesity in offspring remains unclear. This study, focused on the whitening of brown adipose tissue (BAT), aims to elucidate the fundamental mechanisms by which prenatal exposure to PSNPs promotes obesity development in mouse offspring.

METHODS AND RESULTS

Pregnant dams were subjected to various doses of PSNPs (0 µg/µL, 0.5 µg/µL, and 1 µg/µL), and their offspring were analyzed for alterations in body weight, adipose tissue morphology, thermogenesis, adipogenesis, and lipophagy. The findings revealed a notable reduction in birth weight and an increase in white adipocyte size in adult offspring mice. Notably, adult male mice exhibited BAT whitening, correlated with a negative dose-dependent downregulation of UCP1 expression, indicating thermogenesis dysfunction. Further investigation revealed augmented lipogenesis evidenced by the upregulation of FASN, SREBP-1c, CD36, and DGAT2 expression, coupled with the inhibition of lipophagy, indicated by elevated levels of mTOR, AKT, and p62 proteins and reduced levels of LC3II/LCI and Lamp2 proteins in male offspring.

CONCLUSIONS

These findings indicate that gestational PSNP exposure plays a role in the development of obesity in offspring through the whitening of brown adipose tissue, which is triggered by lipogenesis and lipophagy inhibition, providing a novel insight into the metabolic risks associated with gestational PSNPs exposure.

Mitochondria-Targeted Biomaterials-Regulating Macrophage Polarization Opens New Perspectives for Disease Treatment

Macrophage immunotherapy is an emerging therapeutic approach designed for modulating the immune response to alleviate disease symptoms. The balance between pro-inflammatory and anti-inflammatory macrophages plays a pivotal role in the progression of inflammatory diseases. Mitochondria, often referred to as the "power plants" of the cell, are essential organelles responsible for critical functions such as energy metabolism, material synthesis, and signal transduction. The functional state of mitochondria is closely linked to macrophage polarization, prompting interest in therapeutic strategies that target mitochondria to regulate this process. To this end, biomaterials with excellent targeting capabilities and effective therapeutic properties have been developed to influence mitochondrial function and regulate macrophage polarization. However, a comprehensive summary of biomaterial-driven modulation of mitochondrial function to control macrophage phenotypes is still lacking. This review highlights the critical role of mitochondrial function in macrophage polarization and discusses therapeutic strategies mediated by biomaterials, including mitochondria-targeted biomaterials. Finally, the prospects and challenges of the use of these biomaterials in disease modulation have been explored, emphasizing their potential to be translated to the clinic. It is anticipated that this review will serve as a valuable resource for materials scientists and clinicians in the development of next-generation mitochondria-targeted biomaterials.

Biotransport and toxic effects of micro- and nanoplastics in fish model and their potential risk to humans: A review

The growing body of scientific evidence suggests that micro- and nanoplastics (MPs/NPs) pose a significant threat to aquatic ecosystems and human health. These particles can enter organisms through ingestion, inhalation, dermal contact, and trophic transfer. Exposure can directly affect multiple organs and systems (respiratory, digestive, neurological, reproductive, urinary, cardiovascular) and activate extensive intracellular signaling, inducing cytotoxicity involving mechanisms such as membrane disruption, extracellular polymer degradation, reactive oxygen species (ROS) production, DNA damage, cellular pore blockage, lysosomal instability, and mitochondrial depolarization. This review focuses on current research examining the in vivo and in vitro toxic effects of MPs/NPs on aquatic organisms, particularly fish, in relation to particulate toxicity aspects (such as particle transport mechanisms and structural modifications). Meanwhile, from the perspectives of the food chain and environmental factors, it emphasizes the comprehensive threats of MPs/NPs to human health in terms of both direct and indirect toxicity. Additionally, future research needs and strategies are discussed to aid in mitigating the potential risks of particulate plastics as carriers of toxic trace elements to human health.

Chronic environmental exposure to polystyrene microplastics increases the risk of nonalcoholic fatty liver disease

Microplastics (MPs), as the crucial environmental pollutants, can be easily transported into the human body and accumulate in the liver. However, current studies mainly focus on acute exposure to MPs, investigations on long-term interactions with MPs alone remain limited. Thereby, we examined noxious properties of MPs and selected the most common polystyrene (PS) MPs as the research object, including unmodified PS MPs (PS-MPs) and positive-charged PS MPs (PS-NH2) at 10 mg/L employing oral drinking water methods in mice for six consecutive months in vivo. In vitro, we treated the human hepatocyte cells with MPs at 25 μg/mL to explore involved mechanisms. The results revealed that six-month MPs exposure led to nonalcoholic fatty liver disease (NAFLD) including impaired liver functions, extensive lipid depositions accompanied by abnormal levels of metabolic genes and PS-NH2 MPs exerted a stronger effect than PS-MPs. Concurrently, mice treated with MPs revealed the accumulation of senescent hepatocytes, leading to increased secretions of senescent phenotypes in the liver. We also discovered that MPs initiated the HO-1/Nrf2 axis consequently inducing ferroptosis in vivo and in vitro, as shown by massive iron deposition, extensive lipid peroxidation along with significant protein expressions in ferroptosis-related markers. Additionally, targeting the HO-1/Nrf2 pathway to further alleviate ferroptosis with corresponding inhibitors could efficiently alleviate cell senescence. Therefore, our study reveals new evidence of the relationship between chronic exposure to MPs and NAFLD and furthers the understanding of how plastic pollution affects human health.

Rising Concern About the Carcinogenetic Role of Micro-Nanoplastics

In recent years, awareness regarding micro-nanoplastics' (MNPs) potential effects on human health has progressively increased. Despite a large body of evidence regarding the origin and distribution of MNPs in the environment, their impact on human health remains to be determined. In this context, there is a major need to address their potential carcinogenic risks, since MNPs could hypothetically mediate direct and indirect carcinogenic effects, the latter mediated by particle-linked chemical carcinogens. Currently, evidence in this field is scarce and heterogeneous, but the reported increased incidence of malignant tumors among younger populations, together with the ubiquitous environmental abundance of MNPs, are rising a global concern regarding the possible role of MNPs in the development and progression of cancer. In this review, we provide an overview of the currently available evidence in eco-toxicology, as well as methods for the identification and characterization of environmental MNP particulates and their health-associated risks, with a focus on cancer. In addition, we suggest possible routes for future research in order to unravel the carcinogenetic potential of MNP exposure and to understand prognostic and preventive implications of intratumoral MNPs.

The whole life journey and destination of microplastics: A review

Recent reports indicate that ubiquitous microplastics (MPs) in the environment can infiltrate the human body, posing significant health risks and garnering widespread attention. However, public understanding of the intricate processes through which microplastics are transferred to humans remains limited. Consequently, developing effective strategies to mitigate the escalating issue of MPs pollution and safeguard human health is still challenging. In this review, we elucidated the sources and dynamic migration pathways of MPs, examined its complex interactions with other pollutants, and identified primary routes of human exposure. Subsequently, the events and alterations of gut microbiota, gut microbiota metabolism, and intestinal barrier after MPs enter the gut of organisms are unclosed. Additionally, it highlighted the ease with which MPs translocate from the intestine to other organs along with their biological toxicities. Finally, we also emphasized the knowledge gaps in the current research field and proposes future research directions. This review aims to enhance public awareness regarding microplastic pollution and provide valuable references for forthcoming research endeavors as well as policy formulation related to this pressing issue.

Unmasking the Invisible Threat: Biological Impacts and Mechanisms of Polystyrene Nanoplastics on Cells

Polystyrene nanoplastics (PS-NPs), a pervasive component of plastic pollution, have emerged as a significant environmental and health threat due to their microscopic size and bioaccumulative properties. This review systematically explores the biological effects and mechanisms of PS-NPs on cellular systems, encompassing oxidative stress, mitochondrial dysfunction, DNA damage, inflammation, and disruptions in autophagy. Notably, PS-NPs induce multiple forms of cell death, including apoptosis, ferroptosis, necroptosis, and pyroptosis, mediated through distinct yet interconnected molecular pathways. The review also highlights various factors that influence the cytotoxicity of PS-NPs, such as particle size, surface modifications, co-exposure with other pollutants, and protein corona formation. These complex interactions underscore the extensive and potentially hazardous impacts of PS-NPs on cellular health. The findings presented here emphasize the need for continued research on the mechanisms underlying PS-NP toxicity and the development of effective strategies for mitigating their effects, thereby informing regulatory frameworks aimed at minimizing environmental and biological risks.

Airborne micro- and nanoplastics: emerging causes of respiratory diseases

Airborne micro- and nanoplastics (AMNPs) are ubiquitously present in human living environments and pose significant threats to respiratory health. Currently, much research has been conducted on the relationship between micro- and nanoplastics (MNPs) and cardiovascular and gastrointestinal diseases, yet there is a clear lack of understanding regarding the link between AMNPs and respiratory diseases. Therefore, it is imperative to explore the relationship between the two. Recent extensive studies by numerous scholars on the characteristics of AMNPs and their relationship with respiratory diseases have robustly demonstrated that AMNPs from various sources significantly influence the onset and progression of respiratory conditions. Thus, investigating the intrinsic mechanisms involved and finding necessary preventive and therapeutic measures are crucial. In this review, we primarily describe the fundamental characteristics of AMNPs, their impact on the respiratory system, and the intrinsic toxic mechanisms that facilitate disease development. It is hoped that this article will provide new insights for further research and contribute to the advancement of human health.

Integrin A5B1-mediated endocytosis of polystyrene nanoplastics: Implications for human lung disease and therapeutic targets

The extensive use of plastic products has exacerbated micro/nanoplastic (MPs/NPs) pollution in the atmosphere, increasing the incidence of respiratory diseases and lung cancer. This study investigates the uptake and cytotoxicity mechanisms of polystyrene (PS) NPs in human lung epithelial cells. Transcriptional analysis revealed significant changes in cell adhesion pathways following PS-NPs exposure. Integrin α5β1-mediated endocytosis was identified as a key promoter of PS-NPs entry into lung epithelial cells. Overexpression of integrin α5β1 enhanced PS-NPs internalization, exacerbating mitochondrial Ca2+ dysfunction and depolarization, which induced reactive oxygen species (ROS) production. Mitochondrial dysfunction triggered by PS-NPs led to oxidative damage, inflammation, DNA damage, and necrosis, contributing to lung diseases. This study elucidates the molecular mechanism by which integrin α5β1 facilitates PS-NPs internalization and enhances its cytotoxicity, offering new insights into potential therapeutic targets for microplastic-induced lung diseases.

Polystyrene microplastics exposition on human placental explants induces time-dependent cytotoxicity, oxidative stress and metabolic alterations

Introduction

Microplastics (MPs) are environmental pollutants that pose potential risks to living organisms. MPs have been shown to accumulate in human organs, including the placenta. In this study, we investigated the biochemical impact of 5 μm polystyrene microplastics (PS-MPs) on term placental chorionic villi explants, focusing on cytotoxicity, oxidative stress, metabolic changes, and the potential for MPs to cross the placental barrier.

Methods

Term placental chorionic explants were cultured for 24 hours with varying concentrations of PS-MPs, with MTT assays used to determine the appropriate concentration for further analysis. Cytotoxicity was assessed using the lactate dehydrogenase (LDH) release assay over a period of up to 72 hours. Reactive oxygen species formation and antioxidant activity were evaluated using biochemical assays. Metabolomic profiling was performed using proton nuclear magnetic resonance (1H NMR).

Results

Placental explants exposed to 100 μg/mL of PS-MPs showed a significant increase in cytotoxicity over time (p < 0.01). Levels of mitochondrial and total superoxide anion (p < 0.01 and p < 0.05, respectively) and hydrogen peroxide (p < 0.001) were significantly elevated. PS-MP exposure resulted in a reduction in total sulfhydryl content (p < 0.05) and the activities of antioxidant enzymes superoxide dismutase (p < 0.01) and catalase (p < 0.05), while glutathione peroxidase activity increased (p < 0.05), and the oxidized/reduced glutathione ratio decreased (p < 0.05). Markers of oxidative damage, such as malondialdehyde and carbonylated proteins, also increased significantly (p < 0.001 and p < 0.01, respectively), confirming oxidative stress. Metabolomic analysis revealed significant differences between control and PS-MP-exposed groups, with reduced levels of alanine, formate, glutaric acid, and maltotriose after PS-MP exposure.

Discussion

This study demonstrates that high concentrations of PS-MPs induce time-dependent cytotoxicity, oxidative stress, and alterations in the TCA cycle, as well as in folate, amino acid, and energy metabolism. These findings highlight the need for further research to clarify the full impact of MP contamination on pregnancy and its implications for future generations.

Recent advances on transport and transformation mechanism of nanoplastics in lung cells

Microplastics (MPs) are solid plastic particles less than or equal to 5 mm in size that are insoluble in water, and when the diameter is further reduced to <1 micrometer (μm), we call them nanoplastics (NPs). MPs and NPs are widely present in the atmosphere, and plastic particles have also been detected in the sputum of patients with respiratory diseases. This warns us that these tiny plastic particles are a potential threat to human respiratory health. The lungs, as the main organs of the respiratory system, are more likely to be adversely affected by inhaled NPs. However, the mechanism of transport and transformation of NPs in the lung is not clear, so our review mainly focuses on a series of effects and mechanisms of NPs on lung cells through absorption, distribution, metabolism, excretion (ADME) after inhalation into the human body. The most commonly used models in these experimental studies we focus on are A549 and BEAS-2B cells, which are used to model the lung cell response to plastic particles. In addition, we also summarize some shortcomings of these experiments and prospects for future studies, hoping to provide further clues for future studies and contribute to the prevention of related hazards and diseases.

Multi-omics reveal toxicity mechanisms underpinning nanoplastic in redclaw crayfish (Cherax quadricarinatus)

We investigated the effects of different nanoplastic (NP, size = 100 nm) concentrations on red crayfish (Cherax quadricarinatus) and examined toxicity mechanisms. We established four concentration groups (control (CK): 0 μg/L; Low: 100 μg/L; Medium: 500 μg/L; and High: 1000 μg/L) and analyzed toxicity effects in C. quadricarinatus hepatopancreas using histopathological, transcriptomic, metabolomic, and fluorescence methods. NP exposure caused histological lesions and oxidative stress in hepatopancreas, and also significantly decreased glutathione (GSH) (P < 0.05) but significantly increased malondialdehyde content (MDA) (P < 0.05) in NP-treated groups. By analyzing different metabolic indicators, total cholesterol (T-CHO) content significantly increased (P < 0.05) and triglyceride (TG) content significantly decreased in Medium and High (P < 0.05). Transcriptomic analyses revealed that NPs influenced apoptosis, drug metabolism-cytochrome P450, and P53 signaling pathways. Metabolomic analyses indicated some metabolic processes were affected by NPs, including bile secretion, primary bile acid biosynthesis, and cholesterol metabolism. Caspase 3, 8, and 9 distribution levels in hepatopancreatic tissues were also determined by immunofluorescence; positive caspase staining increased with increased NP concentrations. Additionally, by examining relative Bcl-2, Bax, Apaf-1, and p53 mRNA expression levels, Bcl-2 expression was significantly decreased with increasing NP concentrations; and the expression of Bcl-2 was increasing significantly with the NPs concentration increasing. Bax expression in Low, Medium, and High groups was also significantly higher when compared with the CK group (P < 0.05); with High group levels significantly higher than in Low and Medium groups (P < 0.05). P53 expression was significantly increased in Low, Medium, and High groups (P < 0.05). Thus, NPs induced apoptosis in C. quadricarinatus hepatopancreatic cells, concomitant with increasing NP concentrations. Therefore, we identified mechanisms underpinning NP toxicity in C. quadricarinatus and provide a theoretical basis for exploring NP toxicity in aquatic organisms.

Nanoparticles in drinking water: Assessing health risks and regulatory challenges

Nanoparticles (NPs) pose a significant concern in drinking water due to their potential health risks and environmental impact. This review provides a comprehensive analysis of the current understanding of NP sources and contamination in drinking water, focusing on health concerns, mitigation strategies, regulatory frameworks, and future perspectives. This review highlights the importance of nano-specific pathways, fate processes, health risks & toxicity, and the need for realistic toxicity assessments. Different NPs like titanium dioxide, silver, nanoplastics, nanoscale liquid crystal monomers, copper oxide, and others pose potential health risks through ingestion, inhalation, or dermal exposure, impacting organs and potentially leading to oxidative stress, inflammatory responses, DNA damage, cytotoxicity, disrupt intracellular energetic mechanisms, reactive oxygen species generation, respiratory and immune toxicity, and genotoxicity in humans. Utilizing case studies and literature reviews, we investigate the health risks associated with NPs in freshwater environments, emphasizing their relevance to drinking water quality. Various mitigation and treatment strategies, including filtration systems (e.g., reverse osmosis, and ultra/nano-filtration), adsorption processes, coagulation/flocculation, electrocoagulation, advanced oxidation processes, membrane distillation, and ultraviolet treatment, all of which demonstrate high removal efficiencies for NPs from drinking water. Regulatory frameworks and challenges for the production, applications, and disposal of NPs at both national and international levels are discussed, emphasizing the need for tailored regulations to address NP contamination and standardize safety testing and risk assessment practices. Looking ahead, this review underscores the necessity of advancing detection methods and nanomaterial-based treatment technologies while stressing the pivotal role of public awareness and tailored regulatory guidelines in upholding drinking water quality standards. This review emphasizes the urgency of addressing NP contamination in drinking water and provides insights into potential solutions and future research directions. Lastly, this review worth concluded with future recommendations on advanced analytical techniques and sensitive sensors for NP detection for safeguarding public health and policy implementations.

Effects of polystyrene nano- and microplastics on human breast epithelial cells and human breast cancer cells

The continuous littering of the environment with plastic and the resulting nano- and microplastics produced from various processes are ever-increasing problems. These materials also affect humans, as the absorption and accumulation of nano- and microplastics and their effects on health have thus far been rarely researched, which also applies to cancer. In the present study, the absorption of different sizes of polystyrene (PS) nano- and microplastics (PS particles) into human breast epithelial cells and human breast cancer cells was investigated. Subsequently, how the proliferation, colony and mammosphere formation abilities, cell fusion and migration of the cells were influenced by the PS particles were investigated. Our data revealed granularity-, dose- and cell line-dependent absorption of the PS particles, with the highest absorption observed in the MDA-MB-231-DSP1-7 cells and the lowest in the M13SV1_Syn1-DSP8-11 cells. Neither the colony-forming ability nor the cell fusion activity increased with the addition of PS particles. In contrast, slight, partially significant stimulatory effects on both proliferation and cell migration were observed, although these effects depended on the particle quantity and size and the cell line used. In summary, PS particles are absorbed by human breast epithelial and human breast cancer cells and influence cells that may be associated with cancer progression.

Nasal instillation of polystyrene nanoplastics induce lung injury via mitochondrial DNA release and activation of the cyclic GMP-AMP synthase-stimulator of interferon genes-signaling cascade

Nanoplastics (NPs) are a common type of degraded plastic material associated with adverse health effects such as pulmonary injury. However, the molecular mechanism(s) underlying lung injury as caused by NPs remains uncertain. Thus, we herein investigated the pulmonary toxicity of NPs on RAW264.7 cells and C57BL/6 mice. Our in vitro study indicated that NPs induced oxidative stress, cell death, inflammation, and the activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-signaling pathway. Mice in our in vivo study displayed significant pulmonary fibrosis, inflammation, apoptosis, necrosis, and excessive double-stranded DNA release into serum and bronchoalveolar lavage fluid. Our mechanistic exploration uncovered cGAS-STING-signaling activation as the leading cause of NPs-induced pulmonary fibrosis. The current study opens an avenue toward elucidating the role of the cGAS-STING-signaling pathway in NPs-induced pulmonary injury.

A review on advancements in atmospheric microplastics research: The pivotal role of machine learning

Microplastics (MPs), recognized as emerging pollutants, pose significant potential impacts on the environment and human health. The investigation into atmospheric MPs is nascent due to the absence of effective characterization methods, leaving their concentration, distribution, sources, and impacts on human health largely undefined with evidence still emerging. This review compiles the latest literature on the sources, distribution, environmental behaviors, and toxicological effects of atmospheric MPs. It delves into the methodologies for source identification, distribution patterns, and the contemporary approaches to assess the toxicological effects of atmospheric MPs. Significantly, this review emphasizes the role of Machine Learning (ML) and Artificial Intelligence (AI) technologies as novel and promising tools in enhancing the precision and depth of research into atmospheric MPs, including but not limited to the spatiotemporal dynamics, source apportionment, and potential health impacts of atmospheric MPs. The integration of these advanced technologies facilitates a more nuanced understanding of MPs' behavior and effects, marking a pivotal advancement in the field. This review aims to deliver an in-depth view of atmospheric MPs, enhancing knowledge and awareness of their environmental and human health impacts. It calls upon scholars to focus on the research of atmospheric MPs based on new technologies of ML and AI, improving the database as well as offering fresh perspectives on this critical issue.

Polyethylene Micro/Nanoplastics Exposure Induces Epithelial-Mesenchymal Transition in Human Bronchial and Alveolar Epithelial Cells

Micro/nanoplastics (MNPs), which are widely spread in the environment, have gained attention because of their ability to enter the human body mainly through ingestion, inhalation, and skin contact, thus representing a serious health threat. Several studies have reported the presence of MNPs in lung tissue and the potential role of MNP inhalation in triggering lung fibrosis and tumorigenesis. However, there is a paucity of knowledge regarding the cellular response to MNPs composed of polyethylene (PE), one of the most common plastic pollutants in the biosphere. In this study, we investigated the effects of low/high concentrations of PE MNPs on respiratory epithelial cell viability and migration/invasion abilities, using MTT, scratch, and transwell assays. Morphological and molecular changes were assessed via immunofluorescence, Western blot, and qRT-PCR. We demonstrated that acute exposure to PE MNPs does not induce cellular toxicity. Instead, cells displayed visible morphological changes also involving actin cytoskeleton reorganization. Our data underlined the role of epithelial-mesenchymal transition (EMT) in triggering this process. Moreover, a remarkable increase in migration potential was noticed, in absence of a significant alteration of the cell's invasive capacity. The present study highlights the potential impact of PE MNPs inhalation on the human respiratory epithelium, suggesting a possible role in carcinogenesis.

Protein corona alleviates adverse biological effects of nanoplastics in breast cancer cells

Pollution from micro- and nanoplastics (MNPs) has long been a topic of concern due to its potential impact on human health. MNPs can circulate through human blood and, thus far, have been found in the lungs, spleen, stomach, liver, kidneys and even in the brain, placenta, and breast milk. While data are already available on the adverse biological effects of pristine MNPs (e.g. oxidative stress, inflammation, cytotoxicity, and even cancer induction), no report thus far clarified whether the same effects are modulated by the formation of a protein corona around MNPs. To this end, here we use pristine and human-plasma pre-coated polystyrene (PS) nanoparticles (NPs) and investigate them in cultured breast cancer cells both in terms of internalization and cell biochemical response to the exposure. It is found that pristine NPs tend to stick to the cell membrane and inhibit HER-2-driven signaling pathways, including phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathways, which are associated with cancer cell survival and growth. By contrast, the formation of a protein corona around the same NPs can promote their uptake by endocytic vesicles and final sequestration within lysosomes. Of note is that such intracellular fate of PS-NPs is associated with mitigation of the biochemical alterations of the phosphorylated AKT (pAKT)/AKT and phosphorylated ERK (pERK)/ERK levels. These findings provide the distribution of NPs in human breast cancer cells, may broaden our understanding of the interactions between NPs and breast cancer cells and underscore the crucial role of the protein corona in modulating the impact of MNPs on human health.

Integrated multilevel investigation of photosynthesis revealed the algal response distinction to differentially charged nanoplastics

Nanoplastics (NPs), especially those with different charges, as one of emerging contaminants pose a threat to aquatic ecosystems. Although differentially charged NPs could induce distinct biological effects, mechanistic understanding of the critical physiological processes of aquatic organisms from an integrated multilevel perspective on aquatic organisms is still uncertain. Herein, multi-effects of differentially charged nanosized polystyrene (nPS) including neutral nPS, nPS-COOH, and nPS-NH2 on the photosynthesis-related physiological processes of algae were explored at the population, individual, subcellular, protein, and transcriptional levels. Results demonstrated that both nPS and nPS-COOH exhibited hormesis to algal photosynthesis but nPS-NH2 triggered severe inhibition. As for nPS-NH2, the integrity of algal subcellular structure, chlorophyll biosynthesis, and expression of photosynthesis-related proteins and genes were interfered. Intracellular NPs' content in nPS treatment was 25.64 % higher than in nPS-COOH treatment, and the content of chloroplasts in PS and nPS-COOH treatment were 3.09 % and 4.56 % higher than control, respectively. Furthermore, at the molecular levels, more photosynthesis-related proteins and genes were regulated under nPS-COOH exposure than those exposed to nPS. Light-harvesting complex II could be recognized as an underlying explanation for different effects between nPS and nPS-COOH. This study first provides a novel approach to assess the ecological risks of NPs at an integrated multilevel.

Plastic takeaway food containers may cause human intestinal damage in routine life usage: Microplastics formation and cytotoxic effect

The microplastics and organic additives formed in routine use of plastic takeaway food containers may pose significant health risks. Thus, we collected plastic containers made of polystyrene, polypropylene, polyethylene terephthalate, polylactic acid and simulated two thermal usages, including hot water (I) and microwave treatments (M). Nile Red fluorescence staining was developed to improve accurate counting of microplastics with the aid of TEM and DLS analysis. The quantity of MPs released from thermal treatments was determined ranging from 285.7 thousand items/cm2 to 681.5 thousand items/cm2 in containers loaded with hot water with the following order: IPS>IPP>IPET>IPLA, while microwave treatment showed lower values ranging from 171.9 thousand items/cm2 to 301.6 thousand items/cm2. In vitro toxicity test using human intestinal epithelial Caco-2 cells indicated decrease of cell viability in raw leachate, resuspended MPs and supernatants, which might further lead to cell membrane rupture, ROS production, and decreased mitochondrial membrane potential. Moreover, the leachate inhibited the expression of key genes in the electron transport chain (ETC) process, disrupted energy metabolism. For the first time, we isolate the actually released microplastics and organic substances for in vitro toxicity testing, and demonstrate their potential impacts to human intestine. SYNOPSIS: Plastic take-out containers may release microplastics and organic substances during daily usage, both of which can cause individual and combined cytotoxic effects on human colon adenocarcinoma cells Caco-2.

Nanoparticle-Based Drug Delivery Systems in Inhaled Therapy: Improving Respiratory Medicine

Inhaled nanoparticle (NP) therapy poses intricate challenges in clinical and pharmacodynamic realms. Recent strides have revolutionized NP technology by enabling the incorporation of diverse molecules, thus circumventing systemic clearance mechanisms and enhancing drug effectiveness while mitigating systemic side effects. Despite the established success of systemic NP delivery in oncology and other disciplines, the exploration of inhaled NP therapies remains relatively nascent. NPs loaded with bronchodilators or anti-inflammatory agents exhibit promising potential for precise distribution throughout the bronchial tree, offering targeted treatment for respiratory diseases. This article conducts a comprehensive review of NP applications in respiratory medicine, highlighting their merits, ranging from heightened stability to exacting lung-specific delivery. It also explores cutting-edge technologies optimizing NP-loaded aerosol systems, complemented by insights gleaned from clinical trials. Furthermore, the review examines the current challenges and future prospects in NP-based therapies. By synthesizing current data and perspectives, the article underscores the transformative promise of NP-mediated drug delivery in addressing chronic conditions such as chronic obstructive pulmonary disease, a pressing global health concern ranked third in mortality rates. This overview illuminates the evolving landscape of NP inhalation therapies, presenting optimistic avenues for advancing respiratory medicine and improving patient outcomes.

Lung microbiota participated in fibrous microplastics (MPs) aggravating OVA-induced asthma disease in mice

Environmental pollution is one of the risk factors for asthma. Currently, whether micro-plastics could aggravate asthma, is still unclear. In the air, fibrous MPs are the predominant shape. Since fibrous micro-plastics are reported to be detected in the lower respiratory tract and other body parts, the relationship of fibrous MP and asthma, as well as the potential mechanism is not well investigated. In this study, we produced fibrous MPs, whose lengths and widths were in accordance with the natural environment, and further, investigated the potential adverse effect of which on the asthma in a OVA (ovalbumin)-induced mice model, aiming at exploring the true life hazard of MP to the respiratory system. Following nasal exposure to fibrous MPs, the airway inflammation, mucus hypersecretion and fibrosis were aggravated in asthmatic mice. Fibrous MPs exposure also significantly increased the levels of total IgE, and, cardinal Th2 and Th1 pro-inflammatory cytokines participated in the etiopathogenesis of allergic airway inflammation. In addition, MP fibers exposure induced lung epithelial cells apoptosis, disruption of epithelial barrier integrity and activation of NLRP3 related signaling pathways. Moreover, fibrous MPs significantly altered the bacterial composition at the genus level. Compared to the control group, the relative abundance of Escherichia-Shigella and Uncultured were decreased to 4.47% and 0.15% in OVA group, while Blautia and Prevotella were elevated to 4.96% and 2.94%. For the OVA + MPs group, the relative abundance of Blautia and Uncultured were decreased to 2.27% and 0.006%, while Prevotella was increased to 3.05%. Our study highlights the detrimental effect of fibrous MPs on asthmatic population and facilitates an indication of the latent mechanisms of fibrous MPs induced airway pathology.

Plastic Fly: What Drosophila melanogaster Can Tell Us about the Biological Effects and the Carcinogenic Potential of Nanopolystyrene

Today, plastic pollution is one of the biggest threats to the environment and public health. In the tissues of exposed species, micro- and nano-fragments accumulate, leading to genotoxicity, altered metabolism, and decreased lifespan. A model to investigate the genotoxic and tumor-promoting potential of nanoplastics (NPs) is Drosophila melanogaster. Here we tested polystyrene, which is commonly used in food packaging, is not well recycled, and makes up at least 30% of landfills. In order to investigate the biological effects and carcinogenic potential of 100 µm polystyrene nanoparticles (PSNPs), we raised Oregon [R] wild-type flies on contaminated food. After prolonged exposure, fluorescent PSNPs accumulated in the gut and fat bodies. Furthermore, PSNP-fed flies showed considerable alterations in weight, developmental time, and lifespan, as well as a compromised ability to recover from starvation. Additionally, we noticed a decrease in motor activity in DNAlig4 mutants fed with PSNPs, which are known to be susceptible to dietary stressors. A qPCR molecular investigation of the larval intestines revealed a markedly elevated expression of the genes drice and p53, suggesting a response to cell damage. Lastly, we used warts-defective mutants to assess the carcinogenic potential of PSNPs and discovered that exposed flies had more aberrant masses than untreated ones. In summary, our findings support the notion that ingested nanopolystyrene triggers metabolic and genetic modifications in the exposed organisms, eventually delaying development and accelerating death and disease.

Hazard assessment of nanoplastics is driven by their surface-functionalization. Effects in human-derived primary endothelial cells

During plastic waste degradation into micro/nanoplastics (MNPLs) their physicochemical characteristics including surface properties (charge, functionalization, biocorona, etc.) can change, potentially affecting their biological effects. This paper focuses on the surface functionalization of MNPLs to determine if it has a direct impact on the toxicokinetic and toxicodynamic interactions in human umbilical vein endothelial cells (HUVECs), at different exposure times. Pristine polystyrene nanoplastics (PS-NPLs), as well as their carboxylated (PS-C-NPLs) and aminated (PS-A-NPLs) forms, all around 50 nm, were used in a wide battery of toxicological assays. These assays encompassed evaluations on cell viability, cell internalization, induction of intracellular reactive oxygen species (iROS), and genotoxicity. The experiments were conducted at a concentration of 100 μg/mL, chosen to ensure a high internalization rate across all treatments while maintaining a sub-toxic concentration. Our results show that all PS-NPLs are internalized by HUVECs, but the internalization dynamic depends on the particle's functionalization. PS-NPLs and PS-C-NPLs internalization modify the morphology of the cell increasing its inner complexity/granularity. Regarding cell toxicity, only PS-A-NPLs reduced cell viability. Intracellular ROS was induced by the three different PS-NPLs but at different time points. Genotoxic damage was induced by the three PS-NPLs at short exposures (2 h), but not for PS-C-NPLs at 24 h. Overall, this study suggests that the toxicological effects of PSNPLs on HUVEC cells are surface-dependent, highlighting the relevance of using human-derived primary cells as a target.

Research Progress on Micro(nano)plastic-Induced Programmed Cell Death Associated with Disease Risks

Due to their robust migration capabilities, slow degradation, and propensity for adsorbing environmental pollutants, micro(nano)plastics (MNPs) are pervasive across diverse ecosystems. They infiltrate various organisms within different food chains through multiple pathways including inhalation and dermal contact, and pose a significant environmental challenge in the 21st century. Research indicates that MNPs pose health threats to a broad range of organisms, including humans. Currently, extensive detection data and studies using experimental animals and in vitro cell culture indicate that MNPs can trigger various forms of programmed cell death (PCD) and can induce various diseases. This review provides a comprehensive and systematic analysis of different MNP-induced PCD processes, including pyroptosis, ferroptosis, autophagy, necroptosis, and apoptosis, based on recent research findings and focuses on elucidating the links between PCD and diseases. Additionally, targeted therapeutic interventions for these diseases are described. This review provides original insights into the opportunities and challenges posed by current research findings. This review evaluates ways to mitigate various diseases resulting from cell death patterns. Moreover, this paper enhances the understanding of the biohazards associated with MNPs by providing a systematic reference for subsequent toxicological research and health risk mitigation efforts.

Realistic Nanoplastics Induced Pulmonary Damage via the Crosstalk of Ferritinophagy and Mitochondrial Dysfunction

The smaller size fraction of plastics may be more substantially existing and detrimental than larger-sized particles. However, reports on nanoplastics (NPs), especially their airborne occurrences and potential health hazards to the respiratory system, are scarce. Previous studies limit the understanding of their real respiratory effects, since sphere-type polystyrene (PS) nanoparticles differ from NPs occurring in nature with respect to their physicochemical properties. Here, we employ a mechanical breakdown method, producing NPs directly from bulk plastic, preserving NP properties in nature. We report that among four relatively high abundance NP materials PS, polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polyethylene (PE) with a size of 100 nm, PVC induced slightly more severe lung toxicity profiles compared to the other plastics. The lung cytotoxicity of NPs is higher than that of commercial PS NPs and comparable to natural particles silicon dioxide (SiO2) and anatase titanium dioxide (TiO2). Mechanistically, BH3-interacting domain death agonist (Bid) transactivation-mediated mitochondrial dysfunction and nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy or ferroptosis are likely common mechanisms of NPs regardless of their chemical composition. This study provides relatively comprehensive data for evaluating the risk of atmospheric NPs to lung health.

Transforming pollution into solutions: A bibliometric analysis and sustainable strategies for reducing indoor microplastics while converting to value-added products

Microplastics (MPs), as emerging indoor contaminants, have garnered attention due to their ubiquity and unresolved implications for human health. These tiny particles have permeated indoor air and water, leading to inevitable human exposure. Preliminary evidence suggests MP exposure could be linked to respiratory, gastrointestinal, and potentially other health issues, yet the full scope of their effects remains unclear. To map the overall landscape of this research field, a bibliometric analysis based on research articles retrieved from the Web of Science database was conducted. The study synthesizes the current state of knowledge and spotlights the innovative mitigation strategies proposed to curb indoor MP pollution. These strategies involve minimizing the MP emission from source, advancements in filtration technology, aimed at reducing the MP exposure. Furthermore, this research sheds light on cutting-edge methods for converting MP waste into value-added products. These innovative approaches not only promise to alleviate environmental burdens but also contribute to a more sustainable and circular economy by transforming waste into resources such as biofuels, construction materials, and batteries. Despite these strides, this study acknowledges the ongoing challenges, including the need for more efficient removal technologies and a deeper understanding of MPs' health impacts. Looking forward, the study underscores the necessity for further research to fill these knowledge gaps, particularly in the areas of long-term health outcomes and the development of standardized, reliable methodologies for MP detection and quantification in indoor settings. This comprehensive approach paves the way for future exploration and the development of robust solutions to the complex issue of microplastic pollution.

Micro-and nano-plastics induce kidney damage and suppression of innate immune function in zebrafish (Danio rerio) larvae

Aquatic environments serve as critical repositories for pollutants and have significantly accumulated micro- and nanoplastics (MNPs) due to the extensive production and application of plastic products. While the disease resistance and immunity of fish are closely linked to the condition of their aquatic habitats, the specific effects of nanoplastics (NPs) and microplastics (MPs) within these environments on fish immune functions are still not fully understood. The present study utilized zebrafish (Danio rerio) embryos and larvae as model organisms to examine the impacts of polystyrene NPs (100 nm) and MPs (5 μm) on fish immune responses. Our findings reveal that NPs and MPs tend to accumulate on the surfaces of embryos and within the intestines of larvae, triggering oxidative stress and significantly increasing susceptibility to Edwardsiella piscicida infection in zebrafish larvae. Transmission electron microscopy examined that both NPs and MPs inflicted damage to the kidney, an essential immune organ, with NPs predominantly inducing endoplasmic reticulum stress and MPs causing lipid accumulation. Transcriptomic analysis further demonstrated that both NPs and MPs significantly suppress the expression of key innate immune pathways, notably the C-type lectin receptor signaling pathway and the cytosolic DNA-sensing pathway. Within these pathways, the immune factor interleukin-1 beta (il1b) was consistently downregulated in both exposure groups. Furthermore, exposure to E. piscicida resulted in restricted upregulation of il1b mRNA and protein levels, likely contributing to diminished disease resistance in zebrafish larvae exposed to MNPs. Our findings suggest that NPs and MPs similarly impair the innate immune function of zebrafish larvae and weaken their disease resistance, highlighting the significant environmental threat posed by these pollutants.

Probing Long-Term Impacts: Low-Dose Polystyrene Nanoplastics Exacerbate Mitochondrial Health and Evoke Secondary Glycolysis via Repeated and Single Dosing

Nanoplastics (NPs) are omnipresent in the environment and contribute to human exposure. However, little is known regarding the long-term effects of NPs on human health. In this study, human intestinal Caco-2 cells were exposed to polystyrene nanoplastics (nanoPS) in an environmentally relevant concentration range (102-109 particles/mL) under two realistic exposure scenarios. In the first scenario, cells were repeatedly exposed to nanoPS every 2 days for 12 days to study the long-term effects. In the second scenario, only nanoPS was added once and Caco-2 cells were cultured for 12 days to study the duration of the initial effects of NPs. Under repeated dosing, initial subtle effects on mitochondria induced by low concentrations would accrue over consistent exposure to nanoPS and finally lead to significant impairment of mitochondrial respiration, mitochondrial mass, and cell differentiation process at the end of prolonged exposure, accompanied by significantly increased glycolysis over the whole exposure period. Single dosing of nanoPS elicited transient effects on mitochondrial and glycolytic functions, as well as increased reactive oxygen species (ROS) production in the early phase of exposure, but the self-recovery capacity of cells mitigated these effects at intermediate culture times. Notably, secondary effects on glycolysis and ROS production were observed during the late culture period, while the cell differentiation process and mitochondrial mass were not affected at the end. These long-term effects are of crucial importance for comprehensively evaluating the health hazards arising from lifetime exposure to NPs, complementing the extensively observed acute effects associated with prevalent short-term exposure to high concentrations. Our study underlines the need to study the toxicity of NPs in realistic long-term exposure scenarios such as repeated dosing.

Polystyrene microplastics induce pulmonary fibrosis by promoting alveolar epithelial cell ferroptosis through cGAS/STING signaling

Polystyrene microplastics (PS-MPs) are new types of environmental pollutant that have garnered significant attention in recent years since they were found to cause damage to the human respiratory system when they are inhaled. The pulmonary fibrosis is one of the serious consequences of PS-MPs inhalation. However, the impact and underlying mechanisms of PS-MPs on pulmonary fibrosis are not clear. In this study, we studied the potential lung toxicity and PS-MPs-developed pulmonary fibrosis by long-term intranasal inhalation of PS-MPs. The results showed that after exposing to the PS-MPs, the lungs of model mouse had different levels of damage and fibrosis. Meanwhile, exposing to the PS-MPs resulted in a markedly decrease in glutathione (GSH), an increase in malondialdehyde (MDA), and iron overload in the lung tissue of mice and alveolar epithelial cells (AECs). These findings suggested the occurrence of PS-MP-induced ferroptosis. Inhibitor of ferroptosis (Fer-1) had alleviated the PS-MPs-induced ferroptosis. Mechanically, PS-MPs triggered cell ferroptosis and promoted the development of pulmonary fibrosis via activating the cGAS/STING signaling pathway. Inhibition of cGAS/STING with G150/H151 attenuated pulmonary fibrosis after PS-MPs exposure. Together, these data provided novel mechanistic insights of PS-MPs-induced pulmonary fibrosis and a potential therapeutic paradigm.

The interactions of subcellular organelles in pulmonary fibrosis induced by carbon black nanoparticles: a comprehensive review

Owing to the widespread use and improper emissions of carbon black nanoparticles (CBNPs), the adverse effects of CBNPs on human health have attracted much attention. In toxicological research, carbon black is frequently utilized as a negative control because of its low toxicity and poor solubility. However, recent studies have indicated that inhalation exposure to CBNPs could be a risk factor for severe and prolonged pulmonary inflammation and fibrosis. At present, the pathogenesis of pulmonary fibrosis induced by CBNPs is still not fully elucidated, but it is known that with small particle size and large surface area, CBNPs are more easily ingested by cells, leading to organelle damage and abnormal interactions between organelles. Damaged organelle and abnormal organelles interactions lead to cell structure and function disorders, which is one of the important factors in the development and occurrence of various diseases, including pulmonary fibrosis. This review offers a comprehensive analysis of organelle structure, function, and interaction mechanisms, while also summarizing the research advancements in organelles and organelle interactions in CBNPs-induced pulmonary fibrosis.