Effects of photoaged polystyrene microplastics and nanoplastics on the extracellular aggregation and intracellular accumulation of ZnO nanoparticles to algae.

Hydrophobicity-driven self-assembly of nanoplastics and silver nanoparticles for the detection of polystyrene microspheres using surface enhanced Raman spectroscopy

High sensitivity in quantitative analysis of mixed-size polystyrene micro/nanoplastics in one step

Polystyrene nanoplastics shape microbiome and functional metabolism in anaerobic digestion

The occurrence of nanoplastics (NPs) and microplastics (MPs) in aquatic ecosystems and their capacity to sorb hydrophobic pollutants is nowadays an issue of great concern. This study aimed to assess the potential bioavailability and acute toxicity of polystyrene (PS) NPs (50 and 500 nm) and of MPs (4.5 µm), alone and with sorbed benzo(a)pyrene (B(a)P), in the embryo/larval stages of brine shrimps and zebrafish. Exposure to pristine plastics up to 50.1 mg PS/L did not cause significant impact on brine shrimp survival, while some treatments of plastics-B(a)P and all concentrations of B(a)P (0.1–10 mg/L) resulted acutely toxic. In zebrafish, only the highest concentrations of MPs-B(a)P and B(a)P caused a significant increase of malformation prevalence. Ingestion of NPs was observed by 24–48 h of exposure in the two organisms (from 0.069 to 6.87 mg PS/L). In brine shrimps, NPs were observed over the body surface and within the digestive tract, associated with feces. In zebrafish, NPs were localized in the eyes, yolk sac, and tail at 72 h, showing their capacity to translocate and spread into the embryo. MP ingestion was only demonstrated for brine shrimps. In zebrafish embryos exposed to plastics-B(a)P, B(a)P appeared in the yolk sac of the embryos. The presence of B(a)P was also noticeable in brine shrimps exposed to 500 nm NPs-B(a)P. In conclusion, NPs entered and spread into the zebrafish embryo and PS NPs, and MPs were successful vectors of B(a)P to brine shrimp and zebrafish embryos. Particle size played a significant role in explaining the toxicity of plastics–B(a)P. Our study provides support for the idea that plastics may pose a risk to aquatic organisms when combined with persistent organic pollutants such as B(a)P.

Toxicity assessment of environmental MPs and NPs and polystyrene NPs on the bivalve Corbicula fluminea using a multi-marker approach

Development of hydroxyapatite-enhanced membrane for nanoplastics removal: Multiple scenarios and mechanism exploration.

Adsorption kinetics of different mercury species on three kinds of micro-/nano-plastics in micro-polluted aquatic environments and their combined toxicity.

Nanoplastics (NPs) have been widely detected in soil-groundwater systems. However, to date, the effect of real groundwater on the fate and transport of NPs has been poorly understood. In this study, the transport and retention behaviors of both polystyrene and poly(lactic-co-glycolic acid) NPs (PS NPs and PLGA NPs) in different real groundwaters from three coastal cities in China were explored using column experiments. PS (0.51 and 1.1 μm) and PLGA (1 μm) NPs with a low concentration of 2 mg L-1 were employed. Close observation showed that the transport of PS NPs was much higher than PLGA NPs in different groundwaters, with an average breakthrough curve plateau (C/Co) of ∼0.81 for PS NPs and ∼0.19 for PLGA NPs, respectively. As observed for PLGA, the plastic shape- and size-induced straining may be the reason for the minimal transport. Interestingly, we found that although the physicochemical characteristics of different real groundwaters varied significantly, the transport of certain NPs in real groundwater was similar with negligible differences. Closer inspection indicated that similar pHs of different groundwaters may be the reason contributing to these findings. Further investigation revealed that the transport behaviors of PS and PLGA NPs in real groundwater did not follow the classical DLVO theory. These findings suggest that the fate and transport of NPs in real soil-groundwater systems are much more comprehensive than the prediction based on DLVO theory and need intensive investigation.

The fate and toxicity of nanoplastics (NPs) in the environment is largely determined by their stability. We explored how water composition, nanoplastic size, and surface carboxyl group density influenced the aggregation of polystyrene (PS) NPs in fresh water. Unfunctionalized 200, 300, 500, and 1000nmPS NPs and 310nm carboxylated PS NPs with carboxyl group densities of 0.35 and 0.6mmolg-1 were used to simulate pristine and aged NPs. Natural water matrices tested in this study include synthetic surface water (SSW), water from the Schie canal (Netherlands) and tap water. Suwannee River Natural Organic Matter (SRNOM) was included to mimic organic matter concentrations. In CaCl2, we found PS NPs are more stable as their size increases with the increase of the critical coagulation concentration (CCC) from 44mM to 59mM and 77mM for NP sizes of 200nm, 300nm and 500nm. Conversely, 1000nmPS NPs remained stable even at 100mM CaCl2. Increasing the carboxyl group density decreased the stability of NPs as a result of the interaction between Ca2+ and the carboxyl group. These results were consistent with the mass of Ca2+ adsorbed per mass of NPs. The presence of SRNOM decreased the stability of PS NPs via particle bridging facilitated by SRNOM. However, in SSW, Schie water and tap water with low divalent cation concentrations, the hydrodynamic size of PS NPs did not change, even at prolonged durations up to one week. We concluded that PS NPs are unlikely to aggregate in water with low divalent cation concentrations, like natural freshwater bodies. Ecotoxicologists and water treatment engineers will have to consider treating PS NPs as colloidally stable particles as the lack of aggregation in fresh surface water bodies will affect their ecotoxicity and may pose challenges to their removal in water treatment.

Effects of nanoplastics exposure on ingestion, life history traits, and dimethyl sulfide production in rotifer Brachionus plicatilis

In this work we studied the ability of polystyrene (PS) nanoplastics (NPs) and microplastics (MPs) to transfer benzo(a)pyrene (BaP) to mussel hemocytes and to produce toxic effects in vitro. For this, intracellular fate and toxicity of PS NPs (0.05 μm) and MPs (0.5 and 4.5 μm) alone or with BaP and of BaP alone were assessed. Particles of 0.05 and 0.5 µm largely aggregated in the exposure medium whereas presence of BaP reduced particle aggregation. Cells internalized PS NPs and MPs alone or with BaP and these were found inside and outside lysosomes, depending on their size. PS particles alone or with BaP were cytotoxic to hemocytes only at the highest concentrations tested. The same was true for most sublethal endpoints except for increased phagocytic activity provoked by NPs and 0.5 μm MPs at lower concentrations. Plastic particles appeared to be the main drivers for reduced plasma membrane integrity and increased phagocytic and lysosomal activities whereas BaP appeared to contribute more to reduced cell viability and phagocytosis and increased ROS production and genotoxicity. Overall, PS NPs and MPs can act as carriers of BaP to mussel hemocytes, rising concerns about risks plastics associated to pollutants may pose to aquatic organisms.

Photoreactive bromide ions as overlooked regulators of nanoplastic surface chemistry and aggregation in sunlit seawater.

Micro- and nano-plastics (NPs) are found in human milk, blood, tissues, and organs and associate with aberrant health outcomes including inflammation, genotoxicity, developmental disorders, onset of chronic diseases, and autoimmune disorders. Yet, interfacial interactions between plastics and biomolecular systems remain underexplored. Here, we have examined experimentally, in vitro, in vivo, and by computation, the impact of polystyrene (PS) NPs on a host of biomolecular systems and assemblies. Our results reveal that PS NPs essentially abolished the helix-content of the milk protein β-lactoglobulin (BLG) in a dose-dependent manner. Helix loss is corelated with the near stoichiometric formation of β-sheet elements in the protein. Structural alterations in BLG are also likely responsible for the nanoparticle-dependent attrition in binding affinity and weaker on-rate constant of retinol, its physiological ligand (compromising its nutritional role). PS NP-driven helix-to-sheet conversion was also observed in the amyloid-forming trajectory of hen egg-white lysozyme (accelerated fibril formation and reduced helical content in fibrils). Caenorhabditis elegans exposed to PS NPs exhibited a decrease in the fluorescence of green fluorescent protein-tagged dopaminergic neurons and locomotory deficits (akin to the neurotoxin paraquat exposure). Finally, in silico analyses revealed that the most favorable PS/BLG docking score and binding energies corresponded to a pose near the hydrophobic ligand binding pocket (calyx) of the protein where the NP fragment was found to make nonpolar contacts with side-chain residues via the hydrophobic effect and van der Waals forces, compromising side chain/retinol contacts. Binding energetics indicate that PS/BLG interactions destabilize the binding of retinol to the protein and can potentially displace retinol from the calyx region of BLG, thereby impairing its biological function. Collectively, the experimental and high-resolution in silico data provide new insights into the mechanism(s) by which PS NPs corrupt the bimolecular structure and function, induce amyloidosis and onset neuronal injury, and drive aberrant physiological and behavioral outcomes.

Short term exposure to polystyrene nanoplastics in mice evokes self-regulation of glycolipid metabolism

Nanoplastics (NPs) in aquatic environments raise concerns as carriers that alter the bioavailability of co-occurring pollutants, such as cadmium (Cd), affecting combined toxicity. Precision toxicology now demands single-cell assessments to provide novel insights into pollutant interactions. In this study, we utilized a 3D-printed droplet microfluidic platform integrated with time-resolved analysis (TRA)─inductively coupled plasma mass spectrometry (ICP-MS)─to investigate the uptake behavior of single algal cells exposed to Cd and Eu-containing polystyrene (PS) NPs. 3D printing enables rapid prototyping and design flexibility for optimized microfluidic chips, while the monolithic structure eliminates assembly errors, reduces dead volume, and supports large-scale production. The droplet platform offers high-throughput single-cell encapsulation; coupled with TRA-ICP-MS, it minimizes cross-contamination and enhances sensitivity for multielement single-cell analysis. Single-cell analysis revealed that coexposure increased both the proportion of Eu/Cd-containing cells and the uptaken Eu/Cd content. The adsorption of Cd2+ imparted a more positive surface charge to PS NPs. This promoted heterogeneous aggregation between algal cells and PS NPs, thereby enhancing the bioavailability of PS/Cd2+ to the algae. Complementing these single-cell measurements, bulk-cell assays were conducted to evaluate the toxicological impacts of coexposure to Cd and PS NPs on microalgae. The results demonstrate that coexposure to PS NPs and Cd2+ resulted in synergistic effects, including enhanced growth inhibition, photosynthetic impairment, membrane damage, and increased secretion of extracellular polymers. These findings highlight the increased ecological risks posed to aquatic organisms by the coexposure to PS NPs and Cd2+, emphasizing the need for comprehensive assessments of nanoplastic-pollutant interactions in aquatic ecosystems.