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Environmental Toxicology and... Apr 2023Micro and nanoplastics are ubiquitous pollutants that can cause adverse health effects even in humans. Effects of virgin and oxidised (simulating the aging processes)...
Micro and nanoplastics are ubiquitous pollutants that can cause adverse health effects even in humans. Effects of virgin and oxidised (simulating the aging processes) polystyrene nano (nPS) and micro particles (mPS) with diameters of 0.1 and 1 µm were studied on human professional phagocytes (i.e., monocyte cells THP-1 and macrophage-like mTHP-1 cells). After characterization by ATR-FTIR, UV-Vis spectroscopy, SEM and dynamic light-scattering analyses, the particles were FITC functionalised to quantify cellular uptake. Changes in the cell compartments were studied by acrydine orange and the pro-oxidant, cytotoxic and genotoxic effects were assessed. Phagocytosis was dose- and time- dependent and at 24 h 52% of nPS and 58% of mPS were engulfed. Despite the high homeostasis of professional phagocytes, significant ROS increases and DNA damage were observed after exposure to oxidised particles. The results highlight that the environmental aging processes enhances the adverse health effects of micro and nanoplastics.
Topics: Humans; Microplastics; Plastics; Polystyrenes; Reactive Oxygen Species; Phagocytes; Water Pollutants, Chemical
PubMed: 36842547
DOI: 10.1016/j.etap.2023.104086 -
Nature Communications Oct 2021Phase-separated biomolecular condensates must respond agilely to biochemical and environmental cues in performing their wide-ranging cellular functions, but our...
Phase-separated biomolecular condensates must respond agilely to biochemical and environmental cues in performing their wide-ranging cellular functions, but our understanding of condensate dynamics is lagging. Ample evidence now indicates biomolecular condensates as viscoelastic fluids, where shear stress relaxes at a finite rate, not instantaneously as in viscous liquids. Yet the fusion dynamics of condensate droplets has only been modeled based on viscous liquids, with fusion time given by the viscocapillary ratio (viscosity over interfacial tension). Here we used optically trapped polystyrene beads to measure the viscous and elastic moduli and the interfacial tensions of four types of droplets. Our results challenge the viscocapillary model, and reveal that the relaxation of shear stress governs fusion dynamics. These findings likely have implications for other dynamic processes such as multiphase organization, assembly and disassembly, and aging.
Topics: Optical Tweezers; Polystyrenes; Shear Strength; Viscosity
PubMed: 34645832
DOI: 10.1038/s41467-021-26274-z -
Ecotoxicology and Environmental Safety Jun 2022Microplastics are widely distributed, such as oceans, rivers and the atmosphere, with many opportunities for human exposure and potential health risks. Polystyrene...
Microplastics are widely distributed, such as oceans, rivers and the atmosphere, with many opportunities for human exposure and potential health risks. Polystyrene microplastic (PS-MPS) exposure has been found to cause sperm damage to mice; however, the mechanism by which this happens remains unclear. Here, GC-2 cells, a mouse spermatocyte line, were exposed to 5 µm PS-MPS to investigate mitochondrial damage. The results showed that 5 µm PS-MPS decreased ATP content, reduced the mitochondrial membrane potential, damaged the integrity of the mitochondrial genome, and caused an imbalance of homoeostasis between mitochondrial division and fusion. The mitochondrial PINK1/Parkin autophagy pathway was activated. Time-series analysis revealed that PS-MPS damaged the mitochondrial structure through cellular oxidative stress, and mitochondrial function was maintained to some extent after PS-MPS damage. This study revealed the mitochondrial toxicity of polystyrene microplastics, thus providing a basis for understanding the causes of sperm damage by polystyrene microplastics.
Topics: Animals; Male; Mice; Microplastics; Oxidative Stress; Plastics; Polystyrenes; Spermatozoa; Water Pollutants, Chemical
PubMed: 35489138
DOI: 10.1016/j.ecoenv.2022.113520 -
Advanced Science (Weinheim,... Jun 2023A new straight forward approach to create nanoporous polymer membranes with well defined average pore diameters is presented. The method is based on fast mechanical...
A new straight forward approach to create nanoporous polymer membranes with well defined average pore diameters is presented. The method is based on fast mechanical deformation of highly entangled polymer films at high temperatures and a subsequent quench far below the glass transition temperature T . The process is first designed generally by simulation and then verified for the example of polystyrene films. The methodology does not need any chemical processing, supporting substrate, or self assembly process and is solely based on polymer inherent entanglement effects. Pore diameters are of the order of ten polymer reptation tube diameters. The resulting membranes are stable over months at ambient conditions and display remarkable elastic properties.
Topics: Polymers; Nanopores; Polystyrenes; Temperature; Hot Temperature
PubMed: 37096844
DOI: 10.1002/advs.202207472 -
Ecotoxicology and Environmental Safety Dec 2022The digestive enzyme of plant are generally α-amylase. They functions enzyme that breakdown starch into maltose and sugars. This happens in the endosperm of the seed....
The digestive enzyme of plant are generally α-amylase. They functions enzyme that breakdown starch into maltose and sugars. This happens in the endosperm of the seed. Due to pollutants, this process get happened one of emergent xenobiotics are micro and nano plastics. This study involves the interaction 100 nm size of polystyrene nano plastic (PSNPs) on α-amylase. The hyperchromism of α-amylase - PSNPs conjugate's revealed that ground-state complex in a microenvironment. Fluorescence quenching happened when the concentration of PSNPs was increased. The Stern Volmer plot revealed binding constant (K) was 1.904 × 1019 M. S while the quenching constant (K) was 1.036 × 1011 M, the blue shift of the peak showed static quenching. The binding constant was K = 4.2 × 1012, the number of binding site on PSNPs for α-amylase was n = 1.12. The synchronous result showed a gradual reduction in the intensity of Trp residues because when the α-amylase interacts with PSNPs short-range π-π interaction happens around the Trp163 residues. The enzyme activity of α-amylase by 44 % and its IC value was found to be 100 µg/mL. The enzyme kinetics (Vmax) analysis showed the type of inhibition with and without PSNPs Vmax 769 and Vmax 303 µg/mL/min, uncompetitive inhibition respectively. The effect of PSNPs on the enzymatic activity of α-amylase showed structural alterations of the protein. Therefore the in vitro and in silico studies were shown evidence of interaction between α-amylase and PSNPs leads to conformational structural changes in α-amylase.
Topics: alpha-Amylases; Polystyrenes; Amylases; Microplastics; Starch
PubMed: 36306622
DOI: 10.1016/j.ecoenv.2022.114226 -
Ecotoxicology and Environmental Safety Jan 2024Micro(nano)plastics are prevalent in the environment, and prolonged exposure to them represents a threat to human health. The goal of this study is to assess the health...
Micro(nano)plastics are prevalent in the environment, and prolonged exposure to them represents a threat to human health. The goal of this study is to assess the health risk of long-term exposure to nanoplastics (NPs) at environmental concentrations on the intestinal mechanical and immune barrier in mice. In this study, mice were provided drinking water containing polystyrene NPs (PS-NPs; 0.1, 1, and 10 mg·L) for 32 consecutive weeks. The levels of endocytosis proteins caveolin and clathrin and of tight junctional proteins claudin-1, occludin, and ZO-1, and morphological changes, proportion of lymphocytes B in MLNs and lymphocytes T in IELs and LPLs were determined by immunohistochemistry, hematoxylin-eosin, and flow cytometry assays in the intestinal tissues of mice at 28 weeks. The activities or concentrations of ROS, SOD, MDA, and GSH-Px and inflammatory factors (IL-1β, IL-6, and TNF-α) in the intestinal tissues of mice were measured by ELISA at 12, 16, 20, 24, and 32 weeks. Compared with the control group, oral ingested PS-NPs entered the intestinal tissues of mice and upregulated expression levels of the clathrin and caveolin. The intestinal tissue structure of mice in the PS-NPs (1 and 10 mg·L) exposure groups showed significant abnormalities, such as villus erosion, decreased of crypts numbers and large infiltration of inflammatory cells. Exposure to 0.1 mg·L PS-NPs decreased occludin protein levels, but not claudin-1 and ZO-1 levels. The levels of these three tight junction proteins decreased significantly in the 1 and 10 mg·L PS-NPs exposed groups. Exposure to PS-NPs led to a significant time- and dose-dependent increase in ROS and MDA levels, and concurrently decreased GSH-Px and SOD contents. Exposure to PS-NPs increased the proportion of B cells in MLNs, and decreased the proportion of CD8 T cells in IELs and LPLs. The levels of pro-inflammatory cytokines IL-6, TNF-α and IL-1β were markedly elevated after PS-NPs exposure. Long-term PS-NPs exposure impaired intestinal mechanical and immune barrier, and indicate a potentially significant threat to human health.
Topics: Humans; Polystyrenes; Microplastics; CD8-Positive T-Lymphocytes; Interleukin-6; Occludin; Reactive Oxygen Species; Tumor Necrosis Factor-alpha; Caveolins; Clathrin; Superoxide Dismutase; Nanoparticles
PubMed: 38039854
DOI: 10.1016/j.ecoenv.2023.115749 -
Water Research Nov 2022In this study, the aggregation behavior of polystyrene nanoplastics (PS NPs) in the absence or presence of oppositely charged particulate matters is systematically...
In this study, the aggregation behavior of polystyrene nanoplastics (PS NPs) in the absence or presence of oppositely charged particulate matters is systematically investigated for a wide range of electrolyte conditions. Herein, we used isothermal titration calorimetry combined with time-resolved dynamic light scattering to provide kinetic and thermodynamic insights into the NP aggregation. The thermodynamic profiles of homoaggregation and heteroaggregation were fit using an independent site and two independent sites models, respectively, demonstrating different interaction modes of both aggregation processes. We found that the contribution of solvation entropy was significant and variable in most cases, and this thermodynamic parameter was a large determinant of the thermodynamics of NP aggregation. Furthermore, the stability of PS NPs in natural water matrices was found to be correlated with ionic strength and the content of natural colloids (e.g., metal oxides and clay particles). These results point to the importance of considering the role of thermodynamic variables when studying the fate of NPs within various environmental conditions.
Topics: Microplastics; Nanoparticles; Polystyrenes; Osmolar Concentration; Thermodynamics
PubMed: 36323211
DOI: 10.1016/j.watres.2022.119286 -
NanoImpact Oct 2023There is a lack of knowledge about the fate and impact of microplastics (MPs) and nanoplastics (NPs), as well as their potential uptake and impact on plants and...
There is a lack of knowledge about the fate and impact of microplastics (MPs) and nanoplastics (NPs), as well as their potential uptake and impact on plants and microorganisms. The predicted environmental concentrations (PEC) of frequent polymers in soils are low, and therefore, difficult to detect with the available techniques, which explains the knowledge gaps. Therefore, model particles (polystyrene particles (PS-P), 343 nm) and palladium (Pd) nanoparticle-doped polystyrene particles (PS-Pd-PS-P, 442 nm) were synthesized, characterized, and subsequently applied to agricultural soils (Cambisol, Podzol, PS target contents: 25 mg kg, 75 mg kg, 225 mg kg). A combination of different techniques, such as inductively coupled plasma-mass spectrometry (ICP-MS), pyrolysis-gas chromatography-mass spectrometry (Pyr-GC-MS), dynamic light scattering (DLS), and scanning electron microscopy (SEM), were used to characterize the particles in the dispersions, soils and plants. The spiked soils were applied to a chronical plant toxicity test with oat (Avena sativa). The applied particle contents could be recovered from both soils by ICP-MS (Pd, 89% - 99%), and Pyr-GC-MS (PS, 73% - 120%). Moreover, non-aggregated particles in soils and on oat roots were visualized through SEM. The ratio obtained for the Pd contents in oat roots to that in the Cambisol (2.2-2.7) and the Podzol (2.3-2.6) implied that particles accumulated on the root surface or in the roots. No Pd was detected in the oat shoots, which indicated that no translocation occurred from the roots to the shoots. Despite particle accumulation at or in the roots, no clear effects on plant growth were observed. Furthermore, the soil microorganisms (Podzol) and the soil water repellency (Cambisol, Podzol) showed no clear monotone concentration-response relationship after exposure to PS-P and PS-Pd-PS-P. The findings are complex and illustrate the urgent need for further sophisticated experimental studies to elucidate the impacts of NPs on physicochemical soil function, plants, and soil organisms. The model PS-P doped with Pd nanoparticles significantly enhanced the development and validation of methods for investigating MPs and NPs in environmental matrices, highlighting their considerable potential for further studies.
Topics: Soil; Polystyrenes; Microplastics; Plastics; Palladium; Toxicity Tests, Chronic; Oxidation-Reduction
PubMed: 37734654
DOI: 10.1016/j.impact.2023.100484 -
Scientific Reports Oct 2018Microbial electrochemical systems provide an environmentally-friendly means of energy conversion between chemical and electrical forms, with applications in wastewater...
Microbial electrochemical systems provide an environmentally-friendly means of energy conversion between chemical and electrical forms, with applications in wastewater treatment, bioelectronics, and biosensing. However, a major challenge to further development, miniaturization, and deployment of bioelectronics and biosensors is the limited thickness of biofilms, necessitating large anodes to achieve sufficient signal-to-noise ratios. Here we demonstrate a method for embedding an electroactive bacterium, Shewanella oneidensis MR-1, inside a conductive three-dimensional poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) matrix electropolymerized on a carbon felt substrate, which we call a multilayer conductive bacterial-composite film (MCBF). By mixing the bacteria with the PEDOT:PSS precursor in a flow-through method, we maintain over 90% viability of S. oneidensis during encapsulation. Microscopic analysis of the MCBFs reveal a tightly interleaved structure of bacteria and conductive PEDOT:PSS up to 80 µm thick. Electrochemical experiments indicate S. oneidensis in MCBFs can perform both direct and riboflavin-mediated electron transfer to PEDOT:PSS. When used in bioelectrochemical reactors, the MCBFs produce 20 times more steady-state current than native biofilms grown on unmodified carbon felt. This versatile approach to control the thickness of bacterial composite films and increase their current output has immediate applications in microbial electrochemical systems, including field-deployable environmental sensing and direct integration of microorganisms into miniaturized organic electronics.
Topics: Acoustic Impedance Tests; Bacteria; Biosensing Techniques; Bridged Bicyclo Compounds, Heterocyclic; Electric Conductivity; Electronics; Membranes, Artificial; Microscopy, Electron, Scanning; Polymerization; Polymers; Polystyrenes
PubMed: 30327574
DOI: 10.1038/s41598-018-33521-9 -
Ecotoxicology and Environmental Safety Sep 2022Generally, individual microplastics (MPs) or lead (Pb) exposure could initiate ovarian toxicity. However, their combined effects on the ovary and its mechanism in...
Generally, individual microplastics (MPs) or lead (Pb) exposure could initiate ovarian toxicity. However, their combined effects on the ovary and its mechanism in mammals remained unclear. Female C57BL/6 mice were used in this study to investigate the combined ovarian toxicity of polystyrene MPs (PS-MPs, 0.1 mg/d/mouse) and Pb (1 g/L) for 28 days. Results showed that co-exposure to PS-MPs and Pb increased the accumulation of Pb in ovaries, the histopathological damage in ovaries and uterus, the serum malondialdehyde levels and decreased serum superoxide dismutase and sex hormone levels significantly when compared with single PS-MPs and Pb exposure. These observations indicated that co-exposure exerted more severe toxicity to mouse ovaries and uterus. Furthermore, co-exposure to PS-MPs and Pb caused endoplasmic reticulum (ER) stress by activating the PERK/eIF2α signaling pathway in the ovary, which resulted in apoptosis. However, the oxidative and ovarian damage were alleviated, and the mRNA levels of genes related to the PERK/eIF2α signaling pathway were down-regulated to levels of the control mice in the PS-MPs and Pb co-exposed mice administered with ER stress inhibitor (Salubrinal, Sal) or the antioxidant (N-acetyl-cysteine, NAC). In conclusion, our findings suggested that the combination of PS-MPs and Pb aggravated ovarian toxicity in mice by inducing oxidative stress and activating the PERK/eIF2α signaling pathway, thereby providing a basis for future studies into the combined toxic mechanism of PS-MPs and Pb in mammals.
Topics: Animals; Eukaryotic Initiation Factor-2; Female; Lead; Mammals; Mice; Mice, Inbred C57BL; Microplastics; Ovary; Plastics; Polystyrenes; Signal Transduction
PubMed: 35981484
DOI: 10.1016/j.ecoenv.2022.113966