Effects Of Polystyrene Nanoplastics Research Articles

Polystyrene nanoplastics decrease molting and induce oxidative stress in adult Macrobrachium nipponense

The widespread occurrence and accumulation of plastic waste have been globally recognized as a critical issue. However, few researches have evaluated the adverse effects of nanoplastics to freshwater organisms. Thus, here, the effects of polystyrene nanoplastics (PS-NP) on the physiological changes (i.e., molting) and enzyme activity of oxidative stress were investigated in the adult freshwater prawn Macrobrachium nipponense. Based on a previous study and environmental microplastic concentrations, the prawn was exposed to 0, 0.04, 0.4, 4, and 40 mg/L waterborne PS-NP for 21 days. The results showed that growth and survival-related parameters were not affected by all PS-NP groups, while the molting rate were significantly decreased in the 4 and 40 mg/L PS-NP group. Meanwhile, the expression of molting-related gene (calcium–calmodulin-dependent protein kinase I, ecdysteroid receptor, and leucine-rich repeat-containing G-protein-coupled receptor 2) were significantly decreased. H2O2 content was significantly increased in all PS-NP groups relative to the control. Lower concentrations of PS-NP increased the activity of superoxide dismutase (SOD), glutathione S-transferase (GST), and glutathione peroxidase (GSH-Px), whereas increased concentrations, decreased SOD, GST, and GSH-Px activity. These results suggest that chronic exposure to PS-NP at an environmental concentration impaired molting and induced oxidative stress in the adult river prawn Macrobrachium nipponense. The findings provided basic information for assessing the risk assessment of nanoplastics and revealing the molecular mechanisms of nanoplastics toxicity.

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

As a newly emerging hazardous material, airborne nanoplastics are easily inhaled and accumulated in human and animal alveoli. We previously found that polystyrene nanoplastics (PS-NPs) induced apoptosis and inflammation of human alveolar epithelial A549 cells, implying they increase the risk of pulmonary fibrosis. In this study, we investigated whether PS-NPs induce epithelial-to-mesenchymal transition (EMT), the prelude to lung fibrosis, in A549 cells. A549 cells treated with PS-NPs of different sizes and surface charges exhibited increased migration and EMT markers accompanied with up-regulation of reactive oxygen species (ROS) and NADPH oxidase 4 (NOX4), an ROS generator located in the mitochondria and endoplasmic reticulum (ER). Moreover, PS-NPs caused mitochondrial dysfunction as demonstrated by membrane potential changes and impaired cellular energy metabolism. PS-NPs also activated ER stress as indicated by the up-regulated ER stress markers. As expected, smaller PS-NPs with a positive surface charge had stronger effects. Furthermore, the effects of PS-NPs on A549 cells were reversed by NOX4 gene knock-down, which verified the involvement of NOX4. Our results suggest that PS-NPs induce EMT in A549 cells through multiple mechanisms, and NOX4 is a key mediator in this process. Our findings contribute to understanding the toxicological mechanisms of nanoplastics on the respiratory system.

Effects of polystyrene nanoplastics on the bioaccumulation, distribution and parental transfer of ethylhexyl salicylate

In this study, the accumulation and distribution of ethylhexyl salicylate (EHS) and polystyrene nanoplastics (PS-NPs) in parental zebrafish (Danio rerio) and offspring and the effects of PS-NPs on EHS bioavailability were investigated.

Effects of polystyrene nanoplastics (PSNPs) on the physiology and molecular metabolism of corn (Zea mays L.) seedlings

The effects of polystyrene nanoplastics (PSNPs) on the physiological and molecular metabolism of corn seedlings were examined by treating corn (Zea mays L.) seedlings with 100, 300, and 500 nm diameter PSNPs and examining plant photosynthetic characteristics, antioxidant enzyme systems, and molecular metabolism. After 15 days of exposure to PSNPs with different particle sizes (50 mg·L−1), the photosynthetic characteristics of the plant remained stable, and the maximum photochemical quantum yield (Fv/Fm) and non-photochemical quenching coefficient (NPQ) had no significant effects. The root microstructure was damaged and the antioxidant enzyme system was activated, and the content of malondialdehyde (MDA) was significantly increased by 2.25–4.50-fold. In addition, 100 nm and 300 nm PSNPs exposure caused root superoxide dismutase (SOD) activity to increase 1.28-fold and 1.53-fold, and glutathione-peroxidase (GSH-PX) activity increased 1.30-fold and 1.58-fold. Non-targeted metabolomics analysis identified a total of 304 metabolites. Exposure to 100, 300, and 500 nm PSNPs led to the production of 85 (upregulated: 85, downregulated: 0), 73 (upregulated: 73, downregulated: 0), and 86 (upregulated: 84, downregulated: 2) differentially expressed metabolites, respectively, in the plant roots. Co-expressed differential metabolites accounted for 38.2% of the metabolites and indicated a metabolic imbalance primarily in organic acids and derivatives in the root system. The most significant enrichment pathways were those of alanine, aspartate, and glutamate metabolism. Overall, exposure to PSNPs of different particle sizes activated the root antioxidant enzyme system and interfered with plant basic metabolism. The alanine, aspartate, and glutamate metabolic pathways appear to be closely related to plant mechanisms for tolerance/detoxification of PSNPs.

Effects of Nanoplastics on the Dinoflagellate Amphidinium carterae Hulburt from the Perspectives of Algal Growth, Oxidative Stress and Hemolysin Production.

Recently, the effects of nanoplastics (NPs) on aquatic organisms have attracted much attention; however, research on the toxicity of NPs to microalgae has been insufficient. In the present study, the effects of polystyrene nanoplastics (nano-PS, 50 nm) on growth inhibition, chlorophyll content, oxidative stress, and algal toxin production of the marine toxigenic dinoflagellate Amphidinium carterae Hulburt were investigated. Chlorophyll synthesis was promoted by nano-PS on day 2 but was inhibited on day 4; high concentrations of nano-PS (≥50 mg/L) significantly inhibited the growth of A. carterae. Moreover, despite the combined effect of superoxide dismutase (SOD) and glutathione (GSH), high reactive oxygen species (ROS) level and malondialdehyde (MDA) content were still induced by nano-PS (≥50 mg/L), indicating severe lipid peroxidation. In addition, the contents of extracellular and intracellular hemolytic toxins in nano-PS groups were significantly higher than those in control groups on days 2 and 8, except that those of extracellular hemolytic toxins in the 100 mg/L nano-PS group decreased on day 8 because of severe adsorption of hemolytic toxins to the nano-PS. Hence, the effects of nano-PS on A. carterae are closely linked to nano-PS concentration and surface properties and exposure time. These findings provide a deep understanding of the complex effects of NPs on toxigenic microalgae and present valuable data for assessing their environmental risks.

Effects of polystyrene nanoplastics on extracellular polymeric substance composition of activated sludge: The role of surface functional groups.

Here we investigated the acute effects (12h exposure) of three polystyrene nanoplastics (PS NPs, including PS, PS-COOH and PS-NH2) on extracellular polymeric substance (EPS) composition of activated sludge. Three PS NPs exhibited the significant inhibition in total EPS and protein (PRO) production. The functional groups involved in the interactions between PS NPs and EPS were C-(C, H), and those between PS-NH2 NPs and EPS were CO and O-C-O. In addition, the dewaterability of activated sludge were optimized by three PS NPs, especially PS-NH2 NPs. Three PS NPs caused nonnegligible cellular oxidative stress and cell membrane damage in activated sludge (PS NPs exposure concentration: 100mg/L). Among them, the cell membrane damage caused by PS-NH2 was the most significant. Overall, the degree of influence on EPS and cytotoxicity of activated sludge varies with the surface functional groups of PS NPs.

Effects of polystyrene nanoplastics on Ctenopharyngodon idella (grass carp) after individual and combined exposure with zinc oxide nanoparticles

The toxicity of polystyrene nanoparticles (PS NPs) and ZnO nanoparticles (ZnO NPs), in combination is poorly known. Thus, the aim of the current study was to evaluate the effects of PS NPs (760 μg/L) on Ctenopharyngodon idella exposed to it, both in separate and in combination with ZnO NPs (760 μg/L), based on behavioral, biochemical and genotoxic biomarkers. Current data have indicated that PS NPs, for a short exposure period (3 days), both in separate and in combination with nanoparticles, have affected animals’ response to the mirror test. On the other hand, all treatments have equally induced C. idella inactivity towards alarm substances and DNA damage. There was increased oxidative stress, mainly in groups exposed to PS NPs (in combination, or not, with nanoparticles); although increased, the evaluated antioxidant levels did not appear to be enough to inhibit the effects of treatment-induced production of free radicals. Together, these results are likely co-responsible for the observed changes. The current study did not observe antagonistic, synergistic or additive effect on animals exposed to the combination between PS NPs and ZnO NPs; however, this outcome should not discourage the performance of similar studies focused on assessing the (eco)toxicity of pollutant mixtures comprising nanomaterials.

Platform to study intracellular polystyrene nanoplastic pollution and clinical outcomes.

Increased pollution by plastics has become a serious global environmental problem, but the concerns for human health have been raised after reported presence of microplastics (MPs) and nanoplastics (NPs) in food and beverages. Unfortunately, few studies have investigate the potentially harmful effects of MPs/NPs on early human development and human health. Therefore, we used a new platform to study possible effects of polystyrene NPs (PSNPs) on the transcription profile of preimplantation human embryos and human induced pluripotent stem cells (hiPSCs). Two pluripotency genes, LEFTY1 and LEFTY2, which encode secreted ligands of the transforming growth factor-beta, were downregulated, while CA4 and OCLM, which are related to eye development, were upregulated in both samples. The gene set enrichment analysis showed that the development of atrioventricular heart valves and the dysfunction of cellular components, including extracellular matrix, were significantly affected after exposure of hiPSCs to PSNPs. Finally, using the HiPathia method, which uncovers disease mechanisms and predicts clinical outcomes, we determined the APOC3 circuit, which is responsible for increased risk for ischemic cardiovascular disease. These results clearly demonstrate that better understanding of NPs bioactivities and its implications for human health is of extreme importance. Thus, the presented platform opens further aspects to study interactions between different environmental and intracellular pollutions with the aim to decipher the mechanism and origin of human diseases.

The influence of nanoplastics on the toxic effects, bioaccumulation, biodegradation and enantioselectivity of ibuprofen in freshwater algae Chlorella pyrenoidosa

Plastic pollution has become a pressing issue due to its persistence in the environment. Smaller plastics are more easily ingested, potentially exerting greater influences on organisms. In this study, the effects of polystyrene nanoplastics (NP) on the toxic effects, bioaccumulation, biodegradation and enantioselectivity of ibuprofen (IBU) in algae Chlorella pyrenoidosa were explored. The influences on the growth rate, chlorophyll a, total antioxidant capacity (T-AOC), reactive oxygen species (ROS) and lipid peroxidation (MDA) were evaluated after 96 h of exposure to a combination of polystryene NP (1 mg L−1) and IBU (5–100 mg L−1). The results indicated that the inhibitory effect of IBU on C. pyrenoidosa growth was alleviated in the presence of NP. For instance, the 96 h-IC50 value for rac-IBU in the treatment lacking NP was 45.7 mg L−1, and the corresponding value in the treatment containing NP was 63.9 mg L−1. The co-exposure of NP led to a significant enhancement of T-AOC and slight reduction of ROS and MDA compared with the individual exposure (IBU) group, suggesting a decreased oxidative stress. In addition, treatment with NP led to a decreased bioaccumulation and accelerated biodegradation of IBU in C. pyrenoidosa and enhanced removal in the medium. The enantioselective toxicity, bioaccumulation and biodegradation of IBU were observed both in the absence and presence of NP. S-IBU exhibited a greater toxicity, and R-IBU was preferentially accumulated and degraded in C. pyrenoidosa. No interconversion of the two enantiomers occurred regardless of the presence of NP. This consequence implied that the influence of coexistent NP should be considered in the environmental risk assessment of pharmaceuticals and personal care products in aquatic environments.

Nanoplastics: From tissue accumulation to cell translocation into Mytilus galloprovincialis hemocytes. resilience of immune cells exposed to nanoplastics and nanoplastics plus Vibrio splendidus combination

Plastic litter is an issue of global concern. In this work Mytilus galloprovincialis was used to study the distribution and effects of polystyrene nanoplastics (PS NPs) of different sizes (50 nm, 100 nm and 1 μm) on immune cells. Internalization and translocation of NPs to hemolymph were carried out by in vivo experiments, while endocytic routes and effects of PS NPs on hemocytes were studied in vitro. The smallest PS NPs tested were detected in the digestive gland and muscle. A fast and size-dependent translocation of PS NPs to the hemolymph was recorded after 3 h of exposure. The internalization rate of 50 nm PS NPs was lower when caveolae and clathrin endocytosis pathways were inhibited. On the other hand, the internalization of larger particles decreased when phagocytosis was inhibited. The hemocytes exposed to NPs had changes in motility, apoptosis, ROS and phagocytic capacity. However, they showed resilience when were infected with bacteria after PS NP exposure being able to recover their phagocytic capacity although the expression of the antimicrobial peptide Myticin C was reduced. Our findings show for the first time the translocation of PS NPs into hemocytes and how their effects trigger the loss of its functional parameters.

Impact of polystyrene nanoplastics (PSNPs) on seed germination and seedling growth of wheat (Triticum aestivum L.)

Microplastics and nanoplastics are emerging pollutants of global concern. However, the understanding of their ecological effects on terrestrial plants is still limited. We conducted the systematic research to reveal the impact of polystyrene nanoplastics (PSNPs) (0.01–10 mg/L) on seed germination and seedling growth of wheat (Triticum aestivum L.). The results showed that PSNPs had no discernible effect on seed germination rate whereas significantly (p < 0.01) increased root elongation by 88.6 %–122.6 % when compared with the control. Similarly, remarkable increases in carbon, nitrogen contents, and plant biomass were also observed after exposure to PSNPs. Moreover, PSNPs could reduce the shoot to root biomass ratio (S:R ratio) of wheat seedlings. Furthermore, the imagings of a 3D laser confocal scanning microscopy (LCSM) and scanning electron microscopy (SEM) indicated that PSNPs were taken up and subsequently down-top transported to shoot. The absorption and accumulation of four micronutrients (Fe, Mn, Cu and Zn) in wheat were generally reduced in varying degrees. Notably, metabolomics analysis revealed that all PSNPs treatments altered the leaf metabolic profiles mainly by regulating energy metabolisms and amino acid metabolisms. These findings are expected to provide new insights into the effects of PSNPs on crop plants.

Effects of Polystyrene Nanoplastics on Goldfish Olfactory Function

Increased plastic pollution has begun to affect aquatic environments from oceans to freshwater streams with little signs of it slowing down since plastics are a cheap and durable resource to use for manufacturing. Due to increased plastic material waste in natural aquatic ecosystems, fish are threatened by the natural break down of these plastics into sizes and molecules that can be easily ingested and absorbed by tissue. When plastics are broken down and are present in the water, the absorption of these molecules becomes less regulated by tissue. Most of the studies regarding plastic effects at this point in time on aquatic organisms are focused on the transfer of plastic particles through generation. We hypothesized that polystyrene nanoplastic (PS NP) particles on Carassius auratus are incorporated through the nose to the brain, dampening olfaction and compromising several physiological responses associated with the sense of smell. We analyzed the physiological effect PS NPs have on the brain and olfactory system of C. auratus. After the fish were exposed to Nanocs 20 nm Fluorescein isothiocyanate (FITC) labeled PS NPs in water for 24 hours in a dark aquarium, or injected directly in the nose, several organs were dissected. The brain, nose, intestines, kidney, liver, and gills were all snap frozen, mounted in OCT and immediately cut at 20 μm on a cryotome before organs were viewed with fluorescent microscopy. PS NP fluorescence was observed mainly in the nose, brain and intestines while the other organs are still in the process of being analyzed. Accumulation of nanoparticles in the brain was stronger in hypothalamic and olfactory bulb areas. Behavioral and electrophysiology studies of olfactory function after nanoplastic exposure are under development to more closely look at the direct possible effects that nanoplastic materials in the brain might have on behavior. The observed fluorescence supported the existence and ability of PS NPs to infiltrate nervous tissues in C. auratus and points to a possible interference with the sense of smell.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Polystyrene nanoplastics alter the cytotoxicity of human pharmaceuticals on marine fish cell lines

There is an increasing concern on the consequences of the presence of micro(nano)plastics to marine organisms. The present study aimed to provide information on the effects of polystyrene nanoplastics (PSNPs) to fish cells alone and combined with human pharmaceuticals, other emerging contaminants, using as biological models marine fish cell lines SAF-1 and DLB-1. Cells were exposed for 24 h to 100 nm PSNPs, starting at 0.001 up to 10 mg/L, to assess effects on viability and activity of catalase (antioxidant defense) and glutathione S-transferases (phase II biotransformation and antioxidant defense). The viability of cells was also evaluated after exposure to human pharmaceuticals alone and combined with PSNPs. Overall, PSNPs failed to be cytotoxic but data proved their ability to alter the toxicity of human pharmaceuticals. DLB-1 was the most sensitive cell line to PSNPs. Data support the use of marine fish cell lines in the study of the effects of micro(nano)plastics.

Bioaccumulation of polystyrene nanoplastics and their effect on the toxicity of Au ions in zebrafish embryos.

As nano- and micro-sized plastics accumulate in the environment and the food chain of animals, including humans, it is imperative to assess the effects of nanoplastics in living organisms in a systematic manner, especially because of their ability to adsorb potential toxicants such as pollutants, heavy metals, and organic macromolecules that coexist in the environment. Using the zebrafish embryo as an animal model, we investigated the bioaccumulation and in vivo toxicity of polystyrene (PS) nanoplastics individually or in combination with the Au ion. We showed that smaller PS nanoplastics readily penetrated the chorion and developing embryos and accumulated throughout the whole body, mostly in lipid-rich regions such as in yolk lipids. We also showed that PS nanoplastics induced only marginal effects on the survival, hatching rate, developmental abnormalities, and cell death of zebrafish embryos but that these effects were synergistically exacerbated by the Au ion in a dose- and size-dependent manner. Such exacerbation of toxicity was well correlated with the production of reactive oxygen species and the pro-inflammatory responses synergized by the presence of PS, supporting the combined toxicity of PS and Au ions. The synergistic effect of PS on toxicity appeared to relate to mitochondrial damage as determined by ultrastructural analysis. Taken together, the effects of PS nanoplastics were marginal but could be a trigger for exacerbating the toxicity induced by other toxicants such as metal ions.