Polystyrene Nanoplastics Research Articles

Distinctive toxic repercussions of polystyrene nano plastic towards aquatic non target species Nitrobacter vulgaris, Scenedesmus sp and Daphnia magna.

The widespread application of plastics and its eventual degradation to micro-sized or nano-sized plastics has led to several environmental concerns. Moreover, nanoplastics can easily cascade through the food chain accumulating in the aquatic organisms. Thus, our study focussed on investigating the hazardous impact of nano-sized plastics on aquatic species including Nitrobacter vulgaris, Scenedesmus sp, and Daphnia magna. Various concentrations of polystyrene nanoplastics ranging from 0.01 mg/L to 100 mg/L were tested against Nitrobacter vulgaris, Scenedesmus sp, and Daphnia magna. The minimum inhibitory concentration of polystyrene nanoplastics in Nitrobacter vulgaris was found to be 25 mg/L, and in Daphnia magna, the median lethal concentration 50 was observed to be 64.02 mg/L. Exposure of Scenedesmus sp with increasing nanoplastic concentrations showed a significant decrease in total protein (p < 0.001), and chlorophyll content (p < 0.01), whereas the lipid peroxidation increased (p < 0.001) significantly. Similarly, Nitrobacter vulgaris and Daphnia magna showed a significant decrease in catalase activity (p < 0.001) and an increase in lipid peroxidation levels (p < 0.01). Concomitant with lipid peroxidation results, decreased superoxide dismutase levels (p < 0.01) and protein concentrations (p < 0.01) were observed in Daphnia magna. Besides, the increasing concentration of polystyrene nanoplastics displayed an elevated mortality rate in Scenedesmus sp (p < 0.001) and Nitrobacter vulgaris (p < 0.01). Further, scanning electron microscopy analysis substantiated the morphological alterations in Nitrobacter vulgaris and Scenedesmus sp on exposure to polystyrene nanoplastics.

Plasmonic Coacervate as a Droplet-Based SERS Platform for Rapid Enrichment and Microanalysis of Hydrophobic Payloads.

A novel and simple coacervate microdroplet-based detection platform for the quantification of trace hydrophobic analytes is presented. Herein, taking advantage of the effective encapsulation and enrichment performance of the condensed coacervates, plasmonic metallic silver nanoparticles (AgNPs) and target hydrophobic analytes are simultaneously concentrated into a single microdroplet. The coencapsulation of AgNPs within coacervates promotes the formation of aggregates with a lot of "hot spots" for surface-enhanced Raman scattering (SERS) enhancement, facilitating the sensitive analysis of hydrophobic analytes by SERS technology. Such plasmonic coacervates are easily prepared and exhibit good reproducibility and signal uniformity. Optimized SERS performance by modulating the volume of encapsulated AgNPs enables quantitative determination of hydrophobic analytes of Nile Red, chlorpyrifos, benzo[e]pyrene, 20 and 50 nm polystyrene nanoplastics with low detection limits of 10-12 M, 10-9 M, 10-10 M, 0.05 ppb, and 0.5 ppb, and an approximately linear correlation between SERS signals and the analytical concentrations. This study opens a new convenient SERS platform for the ultrasensitive detection of hydrophobic hazardous substances, potentially becoming a rapid analysis method for extensive applications ranging from food safety to environment monitoring.

The effect and mechanism of exposure to polystyrene nanoplastics on lipid metabolism in mice liver

Objective: To investigate the effect and potential mechanism of exposure to 20 nm polystyrene nanoplastics (PS-NPs) on lipid metabolism in mice liver. Methods: An animal experimental model was designed, which was completed from September 2022 to July 2023 on the exposure omics platform of the School of Public Health at Capital Medical University and the Key Laboratory of Environment and Population Health at the Chinese Center for Disease Control and Prevention.1 mg/kg and 10 mg/kg PS-NPs tail vein mice exposure models were constructed. After exposure 7 d, serum was collected to measure the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and air flow assisted desorption electrospray ionization-mass spectrometry imaging (AFADESI-MSI) analysis were used to analyze the mRNA levels of fatty acid esterification related genes (Dgat1 and Dgat2) and lipid transport related genes (ApoB, Cd36, ApoE and Mttp) and metabolites' spatial changes in liver tissue. In vivo imaging system (IVIS) and tissue shake sections were employed to observe the fluorescence biological distribution of PS-NPs. t-test or one-way ANOVA was used to explore the difference between groups. Results: The serum ALT levels were (83.97±4.58), (91.17±13.69) and (142.43±6.09) U/L in the control group, 1 mg/kg PS-NPs exposure group and 10 mg/kg PS-NPs exposure group respectively (F=37.281, P<0.05). The relative mRNA levels of Dgat1, Dgat2, ApoB, Cd36 and ApoE were (1.49±0.63, 2.53±0.32, 2.45±0.54), (1.07±0.38, 1.86±0.83, 2.23±0.73), (1.01±0.13, 1.58±0.43, 2.03±0.52), (1.01±0.14, 1.55±0.37, 1.52±0.51), (1.01±0.17, 2.11±0.27, 2.39±0.93) in these three groups respectively. The differences were statistically significant (F=11.54, 6.95, 14.90, 5.98 and 14.68, P<0.05). AFADESI-MSI analysis found that PS-NPs exposure led to a significant decrease in the levels of glutarylcarnitine and O-Linoleoylcarnitine (t=4.12 and 3.35, P<0.05), which were associated with lipid beta oxidation. The content of triglycerides (TG) (m/z 921.726 4, t=8.69, P<0.05; m/z 919.711 4, t=3.20, P<0.05), phosphatidylic acid (PA) (m/z 895.712 3, t=3.60, P<0.05; m/z 821.526 6, t=3.36, P<0.05), lysophosphatidylcholine (LysoPC) (m/z 560.310 6, t=3.35, P<0.05; m/z 582.295 3, t=6.28, P<0.05), phosphatidylcholine (PC) (m/z 778.533 9, t=3.53, P<0.05; m/z 804.549 6, t=3.60, P<0.05; m/z 820.523 1, t=3.37, P<0.05), phosphatidylethanolamine (PE) (m/z 772.523 3, t=3.08, P<0.05) showed a significant increase in the PS-NPs exposure group. In vivo and in vitro imaging and in situ cell localization revealed that PS-NPs were mainly enriched in hepatic stellate cells and hepatic Kupffer cells in liver tissue. Conclusion: Exposure to PS-NPs induces disorder of liver lipid metabolism, which may be related to the accumulation of PS-NPs in hepatic stellate cells and hepatic Kupffer cells, providing basis for searching early biomarkers of PS-NPs exposure and further mechanism research.

The combined effects of polystyrene nanoplastics and dissolved organic matter on the environmental bioavailability of carbamazepine

The bioavailability of active pharmaceutical ingredients (APIs) plays a crucial role in determining the toxicity and risk of contaminants in the environment. However, the bioavailability of APIs in complex environmental matrices is still unclear. In this study, the combined effects of polystyrene nanoplastics (PS NPs) with various particle sizes (50, 100, and 1000 nm) and fulvic acid (FA) on the bioavailability of carbamazepine (CBZ) were investigated via negligible depletion solid-phase microextraction (nd-SPME) and Daphnia magna (D. magna) accumulation. The uptake kinetic study revealed that both PS NPs and FA reduced the elimination rate (k2) in most cases. The availability of CBZ to nd-SPME was determined by the hydrodynamic particle size of PS NPs, whereas the bioavailability to D. magna depended on the intrinsic particle size. The CBZ bioavailability was greater in co-exposed matrices due to the attenuated sorption of PS NPs to CBZ by FA modification. Notably, co-exposure of PS NPs and FA resulted in a higher bioaccumulation factor (BAF) of CBZ, probably due to the desorption and reabsorption of particle-associated CBZ. This study demonstrated that both PS NP particle size and FA binding affect the bioavailability of CBZ, and nd-SPME can mimic only the bioaccumulation of CBZ via diffusion.

Preferred Lung Accumulation of Polystyrene Nanoplastics with Negative Charges.

With the increasing presence of nanoplastics (NPs) in the human bloodstream, it is urgent to investigate their tissue accumulation and potential health risks. This study examines the effects of the size and surface charges of polystyrene (PS) NPs on lung accumulation. Using magnetic separation, we identified the protein corona composition on iron-core PS NPs, revealing the enrichment of vitronectin and fibrinogen. The corona promotes integrin αIIbβ3 receptor-mediated uptake by lung endothelial cells, explaining that both the corona composition and protein structure determine preferred localization of negatively charged PS NPs in the lung. This study uncovers the role of protein corona in NP uptake and the way NPs enter the lung, emphasizing the need to consider interactions between nanoplastics with varying surface characteristics and biological molecules in the nanotoxicological field.

Polystyrene nanoplastics induce apoptosis, histopathological damage, and glutathione metabolism disorder in the intestine of juvenile East Asian river prawns (Macrobrachium nipponense)

Nanoplastics (NPs) are widely distributed in the aquatic environment and have become a global concern as a new type of pollutant. Many researchers have studied the physiological effects of NPs on aquatic organisms, but relatively little is known about their effects on intestinal immune function in crustaceans. Therefore, we used NPs concentrations of 0, 5, 10, 20, 40 mg/L for 28 days of stress, evaluated the effects of NPs exposure on intestinal cell apoptosis, histopathological damage, and glutathione (GSH) metabolism of juvenile East Asian river prawns (Macrobrachium nipponense). As NPs concentration increased, the contents of total GSH and oxidized glutathione decreased gradually (P < 0.05), the concentration of GSH first increased and then decreased (P < 0.05), and the activities of lysozyme, acid phosphatase, phenoloxidase, and alkaline phosphatase first increased and then decreased (P < 0.05). Additionally, intestinal tissue structure was damaged, and the apoptosis rate significantly increased (P < 0.05). The expression of intestinal autophagy genes (CTL, ALF, Crustin, ATG8, and BCL-2) increased at first and then decreased, the expression levels of TNF and Wnt4 significantly decreased, and the expression of Beclin significantly increased with increasing NPs concentration. We also found that AP-1 and PTEN were highly expressed in the hepatopancreas and were involved in intestinal immune responses. Our results showed that exposure to NPs may induce apoptosis of intestinal tissue cells, induce autophagy, and inhibit GSH metabolism, thereby reducing intestinal immune function of M. nipponense. These findings provide a reference for healthy aquaculture and ecological risk assessment of prawns.

Cytotoxic effect of polystyrene nanoplastics in human umbilical vein endothelial cells (HUVECs) and normal rat kidney cells (NRK52E)

Plastics play a crucial role in nearly each aspect of societal production and everyday life, therefore making them one of the most widespread pollutants on a global scale. Because synthetic plastics are not entirely biodegradable, they often remain in the environment and fragment into micro- and nanoplastic particles. The detrimental impacts of nanoplastics on the environment and human health have received substantial worldwide interest in recent years. However, the effects of nanoplastics on human health have not yet been fully explored. Our study aimed to investigate the cytotoxic effects of polystyrene nanoplastics on two distinct mammalian cell lines: normal rat kidney cells (NRK52E) and human umbilical vein endothelial cells (HUVECs). Results showed that polystyrene nanoplastics generate cytotoxicity in both NRK52E and HUVECs in a concentration- and time-dependent manner. Additionally, polystyrene nanoplastics induced pro-oxidant levels (e.g., reactive oxygen species and hydrogen peroxide) and reduced antioxidants (glutathione content and glutathione peroxidase enzyme activity) in both types of cells. We also found that polystyrene nanoplastics cause apoptosis in both NRK52E and HUVECs, as shown by the activation of the caspase-3 enzyme and the loss of mitochondrial membrane potential. Interestingly, it was noticed that the vulnerability of HUVECs cells against polystyrene nanoplastics was a little higher than that of NRK52E cells. Also, the cell toxicity caused by polystyrene nanoplastics in NRK52E and HUVECs was effectively alleviated by co-exposure to a reactive oxygen species inhibitor, N-acetyl-cysteine. This suggests that oxidative stress might be one of the pathways that polystyrene nanoplastics cause cell toxicity. The present work warrants future study to explore the toxicity mechanisms of polystyrene nanoplastics in appropriate in vivo models.

Algal EPS modifies the toxicity potential of the mixture of polystyrene nanoplastics (PSNPs) and triphenyl phosphate in freshwater microalgae Chlorella sp.

Triphenyl phosphate (TPP) and polystyrene nanoplastics (PSNPs) are prevalent freshwater contaminants obtained mainly from food packaging, textiles and electronics. Algal extracellular polymeric substances (EPS), a part of natural organic matter, may influence these pollutants' behaviour and toxicity. The presence of EPS can enhance the aggregation of TPP-PSNP mixtures, and reduce the bioavailability, and thus the toxicity potential. Understanding the mutual interactions between TPP, PSNPs, and EPS in the aquatic environment is a prerequisite for the environmental risk assessment of these chemicals. The study examines the toxicity effects of various surface-modified PSNPs (1 mg/L of plain, animated, and carboxylated) and TPP (0.05, 0.5, and 5 mg/L) in pristine and combined forms on freshwater microalgae, Chlorella sp., as a model organism. The physical-chemical interactions of algal EPS (10 mg/L) with PSNPs and TPP and their mixtures were studied. The toxicity potential of the PSNPs was estimated by quantifying growth inhibition, oxidative stress, antioxidant activity, and photosynthesis in the cells. TPP toxicity increased in the presence of the PSNPs, however the addition of algal EPS reduced the combined toxic effects. EPS plays a protective role by reducing oxidative stress and enhancing photosynthetic efficiency in the algal cells. The Pearson modeling analysis indicated a positive correlation between growth inhibition, and reactive oxygen species, malondialdehyde production. The cluster heatmap and correlation mapping revealed a strong correlation among the oxidative stress, growth inhibition, and photosynthetic parameters. The study clearly highlights the potential of EPS in mitigating the risk of mixed emerging pollutants in the aquatic environment.

Maternal exposure to polystyrene nanoplastics induces sex-specific cardiotoxicity in offspring mice

Globally, plastic pollution threatens human health, particularly affecting the hearts of offspring exposed to maternal environmental factors early in development. Few studies have specifically addressed sex-specific cardiac injury in offspring resulting from maternal exposure to polystyrene nanoplastics (PS-NPs). This study investigates the potential cardiac injury in offspring following maternal exposure to 1 mg/L PS-NPs. Pregnant C57BL/6J mice were exposed to PS-NPs until 3 weeks postpartum to establish a maternal exposure model. Heart tissues were collected and weighed, and the transcriptomes of the offspring hearts were sequenced and analyzed using high-throughput RNA sequencing. Immunohistochemical staining was performed to assess the effects of PS-NPs on cardiac immune infiltration, fibrosis, and apoptosis in the offspring. PS-NPs caused a significant reduction in heart and body weight in female offspring compared to males. Additionally, PS-NPs induced sex-specific transcriptional reprogramming and metabolic disruptions in the offspring. PS-NPs also induced significant fibrosis, apoptosis, and increased CD68+ macrophage infiltration in offspring hearts. Notably, PS-NPs induced distinct cardiovascular diseases in the offspring. Fluid shear stress and atherosclerosis were significantly enriched in PS-NP-treated male offspring, while viral myocarditis was predominantly enriched in PS-NP-treated females. Our findings suggest that PS-NPs induce cardiotoxicity in offspring by disrupting metabolism, impairing immunity, and triggering fibrosis and apoptosis, with sex-specific differences. This study provides novel insights and a foundation for understanding sex-specific pharmacological differences and interventions in PS-NP-induced cardiovascular disease in offspring.

Trophic transfer induced gut inflammation, dysbiosis, and inflammatory pathways in zebrafish via Artemia franciscana: A differential analysis of nanoplastic toxicity

Rising glbal population and plastic consumption have caused a dramatic increase in plastic waste, leading to micro- and nanoplastic ingestion by aquatic organisms and subsequent bioaccumulation in their tissues. This transfer to higher trophic levels raises nanoplastic concentrations and bioavailability, potentially harming organisms' health and development. This poses a risk to human health via seafood. To address these issues, this study assesses the toxicological impacts of nanoplastics (NPs) on brine shrimp (Artemia franciscana) and their trophic transfer to zebrafish. The research unveiled concentration-dependent bioaccumulation of NPs in zebrafish and Artemia franciscana (A. franciscana). Polystyrene nanoplastics (PS-NPs) exhibited higher accumulation in A. franciscana whereas PP-NPs showed greater accumulation in zebrafish gut. Histopathological analysis under PS-NPs exposure revealed significant tissue alterations, indicative of inflammatory responses and impaired mucosal barrier integrity. Gene expression analyses confirmed these findings, showing activation of the P38-MAPK pathway by PS-NPs, which correlated with increased inflammatory cytokines. Additionally, PE-NPs activated the JNK-MAPK pathway, while PP-NPs exposure triggered the NOD-like receptor signaling pathway. Moreover, the composition of gut microbiota shifted to a dysbiotic state, characterized by an increase in pathogenic bacteria in the PS-NPs and PP-NPs groups, elevating the risk of developing Inflammatory Bowel Disease (IBD). PS-NPs were regarded as the most toxic due to their lower stability and higher aggregation tendencies, followed by PP-NPs and PE-NPs. Taken together, the overall study highlighted the complex interactions between NPs, gut microbiota, and host health, emphasizing the importance of thoroughly assessing the ecological and physiological impacts of nanoplastic pollution.

Modeling Polystyrene Nanoplastics Degradation in Water via Photo-Fenton Treatment: A Shrinking-Particle Approach

In this study, kinetic models for the photo-Fenton oxidation of polystyrene nanoplastics (NPs) in water were developed, considering particles with decreasing diameters. Various reaction parameters affecting the oxidation rate, such as particle size (140−909nm), agitation speed (250−1000rpm), and operating temperature (25 and 60 °C) were investigated. Oxidation progress was evaluated through turbidity measurements, TEM, and FTIR analysis, while leached intermediates were identified via Pyr-GC-MS and IC. Due to changes in NPs surface reactivity, the overall reaction rate was divided into two stages, following a free-radical mechanism. Using equations derived from the classic Shrinking Core Model, the oxidation of NPs was determined to proceed under chemical reaction control, with negligible mass transfer limitations. Additionally, the Prout-Tompkins model was found to accurately represent the degradation process. The proposed mechanisms and models provide valuable insights for describing and predicting the advanced oxidation of NPs under different operating conditions and treatment methods.

Intergenerational neurotoxicity of polystyrene nanoplastics in offspring mice is mediated by dysfunctional microbe-gut-brain axis

Nanoplastics (NPs) are ubiquitous in daily life, posing potential risks to the environment and human. While their negative effects on parental organisms have been extensively studied, intergenerational effects are still in the early stages of investigation. Here, we aimed to investigate the impact of maternal exposure to an environmentally relevant level of polystyrene NPs (PSNPs, 100 nm) during gestation and lactation (∼32 days, 50 μg/mouse/day) on neurotoxicity mediated by the microbe-gut-brain axis in offspring mice. Maternal PSNPs exposure significantly increased brain TNF-α level and microglia by 1.43 and 1.48 folds respectively, compared to control, accompanied by nuclear pyknosis and cell vacuolization in cortex and hippocampus. Targeted neurotransmitter metabolomics analysis revealed dysregulation in dopamine and serotonin metabolism. Specifically, dopamine levels increased significantly from 0.007 ng/L to 0.015 ng/L, while N-acetylseroton and 3,4-dihydroxyphenylacetic acid decreased significantly from 0.002 and 0.929 ng/L to 0.001 and 0.680 ng/L, respectively. Through a combination of 16S rRNA sequencing and biochemical analysis, we discovered that maternal PSNPs exposure led to a depletion of anti-inflammatory bacteria and an enrichment of pro-inflammatory bacteria resulting in intestinal barrier damage, elevated levels of lipopolysaccharide in blood, and subsequent activation of neuroinflammation. Meanwhile, gut bacteria dysbiosis interfered with communication between gut and brain by dysregulating neurotransmitter synthesis, as evidenced by significant associations between neurotransmitter-related bacteria (Akkermansia, Family_XIII_AD3011_group, Lachnoclostridium) and dopamine/serotonin related metabolites. Furthermore, transcriptional alterations in dopamine and serotonin related pathways were observed in the enteric nervous system, suggesting abnormal signal transduction from gut to brain contributes to neurotoxicity. This study provides new insights into NPs-induced neurotoxicity within the context of microbe-gut-brain axis and highlights the risk of cerebral dysfunction in offspring with maternal NPs exposure.

Polystyrene nanoplastics mediate skeletal toxicity through oxidative stress and the BMP pathway in zebrafish (Danio rerio)

The widespread presence of micro(nano)plastics (MNPs) has generated public concern. Studies have indicated that MNPs can accumulate in mammalian bones; however, research on the skeletal toxicity and underlying molecular mechanisms of MNPs in aquatic organisms remains limited. We subjected zebrafish embryos to three varying levels (1, 10, 100 μg/mL) of polystyrene nanoplastics (PSNPs) exposure over a period of 7 days in our research. The results revealed that PSNPs significantly reduced the body length and hatching rate of zebrafish, leading to skeletal deformities. mRNA level analysis showed significant upregulation of sp7, sparc, and smad1 genes transcription by PSNPs. Moreover, PSNPs markedly downregulated the mRNA levels associated with runx2a, bmp2a, and bmp4. Further investigations demonstrated that PSNPs dramatically increased ROS levels in zebrafish larvae, with significant downregulation of transcription levels of sod1 and cat genes, resulting in a sharp increase in transcription levels of apoptosis-related regulatory genes bcl-2 and bax. Furthermore, PSNPs led to a marked rise in Caspase 3 activity in zebrafish larvae, suggesting the initiation of apoptosis. PSNPs also notably inhibited alkaline phosphatase (AKP) activity. Compared to a 4-day exposure, a 7-day exposure to PSNPs intensified abnormalities across multiple indicators. In summary, our research indicates that PSNPs cause significant oxidative stress in zebrafish larvae, resulting in apoptosis. Moreover, PSNPs disrupt the transcription of genes related to skeletal development through the bone morphogenetic protein (BMP) pathway, further disrupting skeletal development processes and ultimately resulting in skeletal deformities in zebrafish larvae. This study provides new insights into the skeletal toxicity of MNPs.

Airborne polystyrene nanoplastics exposure leads to heart failure via ECM-receptor interaction and PI3K/AKT/BCL-2 pathways

Environmental contamination has been recognized as a significant threat to human well-being, and recent findings of microplastic presence in human cardiac tissues have raised concerns. However, research on the effects of airborne nanoplastics (NPs) on cardiac physiology remains limited. We utilized a comprehensive body exposure apparatus to simulate the impact of airborne polystyrene NPs pollution, focusing on understanding how airborne NPs affect cardiac morphology and function. Following two weeks of NPs exposure, mice exhibited a 23.89 ± 8.30 % reduction in heart mass, a 20.05 ± 2.97 % decrease in heart rate as detected, and a myocardial electrical conduction block. Echocardiography showed significant changes in cardiac contractility, with increases in cardiac ejection fraction and stroke volume of 13.00 ± 3.00 % and 43.00 ± 17.00 %, respectively. In addition, histologic assessments revealed signs of ventricular hypertrophy, ventricular myocardial hypertrophy, and myocardial necrotic fibrosis. Of particular interest, our mechanistic investigations highlighted the harmful effects of NPs on cardiac structure and function, mediated through extracellular matrix (ECM) receptor interactions and the PI3K/AKT/BCL-2 signaling pathway. The insights gained provide a foundation for understanding the risks posed by airborne NPs to human cardiac health, emphasizing the need for increased vigilance and implementation of mitigation strategies in environmental management.

ACFs-NH2 developed for dispersive solid phase extraction combined with Py-GC/MS for nanoplastic analysis in ambient water samples

Accurate determination of nanoplastics (NPs) in aquatic ecosystems constitutes a challenge for which highly sensitive analytical methods are necessitated. Herein, a sample pretreatment based on self-made amino-functionalized activated carbon fibers (ACFs-NH2) dispersive solid-phase extraction (DSPE) allows for high-recovery, followed by high-sensitivity detection of NPs by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The developed methodology allowed low detection limits (20–100 μg/L) to be achieved quickly in a few steps. Under optimal conditions, ACFs-NH2 (12.5 mg) was able to recover ≥98.45 % of polystyrene (PS) nanoplastics at high concentration (100 mg/L) in 10 mL seawater. Based on the high adsorption performance of materials, the adsorption dynamics and isotherms were determined to infer the interaction mechanism of PSNPs on ACFs-NH2. After adsorption, the target on the surface of the adsorbent can be directly pyrolyzed, which can simplify the operation steps and avoid the elution of organic solvents, making the process more environmentally friendly. This strategy is feasible for the analysis of trace NPs in water systems.

Nanoplastics exposure-induced mitochondrial dysfunction contributes to disrupted stem cell differentiation in human cerebral organoids

Nanoplastics are ubiquitous in our daily lives, raising concerns about their potential impact on the human brain. Many studies reported that nanoplastics permeate the blood-brain barrier and influence cellular processes in mouse models. However, the neurotoxic effects of ingesting nanoplastics on human brain remain poorly understood. Here, we treated cerebral organoids with polystyrene nanoplastics to model the effects of nanoplastic exposure on human brain. Importantly, we found that mitochondria might be the significant organelles affected by polystyrene nanoplastics using immunostaing and RNA-seq analysis. Subsequently, we observed the increased cell death and decreased cell differentiation in our cerebral organoids. In conclusion, our findings shed insights on the mechanisms underlying the toxicity of nanoplastics on human brain organoids, providing an evaluation system in detection potential environmental toxicity on human brain.

Pseudomonas Stutzeri may alter the environmental fate of polystyrene nanoplastics by trapping them with increasing extracellular polymers

Pseudomonas Stutzeri (P. stutzeri) is a denitrifying bacterium that is essential in biological nitrogen removal. To study the interaction between P. stutzeri and polystyrene nanoplastics (PS-NPs), the effects of PS-NPs posed on P. stutzeri were evaluated in terms of bacterial growth, physiology, denitrification function and extracellular polymers (EPS) secretion. Results of confocal laser scanning microscopy (LCSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and flow cytometry confirmed that PS-NPs were trapped by P. stutzeri. Exposure to PS-NPs inhibited bacterial growth and expression of denitrification-related genes, but unaffected the denitrifying enzyme activities. The enhanced secretion of EPS caused PS-NPs and bacterial aggregation. And the enzyme activity of SOD in P. stutzeri was increased while that of CAT was decreased. The results of flow cytometry showed that high concentrations of PS-NPs increased the complexity of P. stutzeri cells. These results reveal that P. stutzeri may be affected after trapping PS-NPs and alter their environmental fate as well. SynopsisThis study contributes to the understanding of the possible effect of P. stutzeri on the distribution of PS-NPs and illustrates the potential impact of PS-NPs on P. stutzeri.

Polystyrene nanoplastics: optimized removal using magnetic nano-adsorbent and toxicity assessment in zebrafish embryos.

The presence of microplastics (MPs) and nanoplastics (NPs) in aquatic ecosystems has raised serious environmental and health concerns. Polystyrene is one of the most abundant plastic polymers found in the environment. Polystyrene MPs/NPs have harmful implications for human health and their removal from the environment has become a serious challenge. In this study, we investigated the adsorptive uptake of polystyrene nanoplastics (PS NPs) from aqueous solutions using fly ash-loaded magnetic nanoparticles (FAMNPs) as the magnetic nano-adsorbent. During the factor screening study, the adsorption process was studied as a function of four variables namely pH (5-10), adsorption time (30-120min), amount of FAMNPs (0.01-0.04g), and stirring speed (50-200rpm). Central composite design (CCD) and response surface methodology (RSM) were employed to establish the relationship between the variables. Furthermore, toxicity assessments of PS NPs were checked on a zebrafish model, shedding light on its potential ecological effects. Two variables namely the pH and amount of FAMNPs significantly influenced the adsorption capacity of FAMNPs and were further optimized for subsequent analysis. The optimum operational readings proposed by the model were pH (8.5), and the amount of FAMNPs (0.03g), resulting in a good adsorption capacity of 29.12mg/g for PS NPs. The adequacy of the proposed model was evaluated by analysis of variance (ANOVA). Zebrafish embryos exposed to PS NPs revealed physical deformations such as pericardial edema and malformed notochord. The study demonstrates the effectiveness of FAMNPs in the adsorption of PS NPs from aqueous solutions, with optimal conditions identified at pH 8.5 and 0.03g of FAMNPs using RSM. The adequacy of the model was confirmed through ANOVA analysis. Toxicity assessments on zebrafish embryos exposed to PS NPs revealed significant mortality and physical deformations, highlighting the importance of PS NPs removal for environmental health.

Impacts of polystyrene nanoplastics on microgel formation from effluent organic matter

Municipal effluents discharged from wastewater treatment plants (WWTPs) are considered major contributors of nanoplastics (NPs) and dissolved effluent organic matter (dEfOM) to environments. Due to their small sizes, NPs can travel easily in waterways and evade wastewater treatment processes, and may directly interact with dEfOM, altering their environmental fates. However, although much research has examined the impact of natural organic matter on NPs, the interactions between NPs and dEfOM remain unexplored. This study investigated the influences of NPs on the behavior and capacity of dEfOM aggregation and surface granularity, and identified the possible aggregation mechanism. We also adjusted the salinity of water samples to simulate scenarios based on WWTP–sea continuums. Our data suggest that dEfOM can self-assemble with 55 nm polystyrene NPs to form microgels, particularly under high salinity conditions. NPs accelerates the formation speed and number of dEfOM aggregates, but the sizes of the aggregates remain largely unchanged. The relative particle counts at a salinity of 34 psu increased by 300 % compared to the control group. The potential mechanism behind NPs-microgels aggregation is likely driven by the synergistic effect of the divalent ion crosslinking and hydrophobic interactions between EfOM and NPs. Notably, NPs incorporation into microgels decreases the surface granularity, thereby possibly affecting settling velocity and colonization of aggregates, as well as microbial attachment and community diversity. Overall, our findings demonstrate the potential influence of NPs on dEfOM assembly and surface properties following effluent discharge, and can inspire further relevant studies on microorganism interactions, removal technologies, and the environmental transport of NPs.

Uncovering the performance and intrinsic mechanism of different hydrolyzed AlTi species in polystyrene nanoplastics coagulation

Hydrolyzed AlTi species are essential metal-based coagulants in a coagulation process to remove nanoplastics (NPs). Understanding the molecular interactions between hydrolyzed AlTi species and NPs is key to promoting coagulation efficiency. In this study, the coagulation performance and intrinsic mechanism of different AlTi species (including monomeric AlTi and polymeric AlTi species-Al13Ti13) for NPs removal were systematically investigated. We found that the polymeric AlTi species exhibited higher turbidity removal (95.0 %) and lower residual Al content (20.67 μg/L) at a low dosage over monomeric AlTi species. Al13 and Al13Ti13 formed by in situ hydrolysis were the dominant species to destabilize and aggregate NPs at pH 6. Main coagulation mechanisms were dominated by charge neutralization, complexation between the aliphatic CH of NPs and Al/Ti-OH, and cation-π interaction between polycations and the aromatic structure of NPs. The preformed Al13Ti13 showed multiple positive charge binding sites assisting its easy adsorption on NPs by electrostatic attraction, and then formed microscale aggregates through charge neutralization or intermolecular interaction. The preformed Al13Ti13 demonstrated a high stability and coagulation performance with respect to pH changes in raw water, whereas the promotion of μ-OH bridges dissociation by OH− and the presence of electrostatic repulsion significantly decreased the NPs removal by monomeric AlTi at high pH. This study provides valuable theoretical insights into the interaction between NPs and various hydrolyzed AlTi species.