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The article discusses the application of hydrophobic polystyrene nanoparticles as a collector for coal flotation, aiming to demonstrate the possibility of sorting coal fines with nanoparticles. The...

The article describes the analysis of the adsorption properties of commercially available fibers. Negatively charged polystyrene particles were used for the adsorption on the selected fibers at different pH ranges of the used electrolyte. The streaming potential method proved useful in the assessment of the electrokinetic properties of the fibers. As expected, good adsorption was observed for most fibers that were positively charged in the conditions of the experiments due to electrostatic attraction. Interestingly, for some fibres an increase in zeta potential was observed in the conditions in which both the adsorbent and the adsorbate were negatively charged. An explanation was proposed for this phenomenon, but could not be proved. The adsorption in the conditions of the isoelectric points of the fibers resulted in little to no changes in their zeta potential in most cases. Moreover, in some cases, the adsorption study produced scattered and irreproducible results. This behavior may have its origin in the nature of the selected fibers, which were mostly technical fibers for applications in fields other than adsorption.

Conducting emulsion polymerization in continuous flow mode for polymer nanoparticle synthesis has the potential to improve productivity and reliability but has to face the fact that the emulsion is difficult to remain stable without stirring. In this work, a mixed nonionic–anionic emulsifier TX-100/SDBS (4:1) was found to perform much better in stabilizing pre-emulsion than anionic emulsifier SDBS and then was exploited in the microflow system to achieve reliable operation, controllable conversion, and continuous synthesis of nanoparticles with uniform size (PDI < 0.09). The reaction temperature could be elevated to 95 °C, and the emulsifier concentration could be decreased to 8.515 mM. The average size of the nanoparticles was facilely adjusted from 52 to 92 nm by changing the emulsifier concentration.

Plastic pollution has been globally recognized as a critical issue for marine ecosystems and nanoplastics constitute one of the last unexplored areas to understand the magnitude of this threat. However, current difficulties in sampling and identifying nano-sized debris make hard to assess their occurrence in marine environment. Polystyrene nanoparticles (PS NPs) are largely used as nanoplastics in ecotoxicological studies and although acute exposures have been already investigated, long-term toxicity on marine organisms is unknown. Our study aims at evaluating the effects of 40nm PS anionic carboxylated (PS-COOH) and 50nm cationic amino-modified (PS-NH2) NPs in two planktonic species, the green microalga Dunaliella tertiolecta and the brine shrimp Artemia franciscana, respectively prey and predator. PS NP behaviour in exposure media was determined through DLS, while their toxicity to microalgae and brine shrimps evaluated through 72h growth inhibition test and 14 d long-term toxicity test respectively. Moreover, the expression of target genes (i.e. clap and cstb), having a role in brine shrimp larval growth and molting, was measured in 48h brine shrimp larvae. A different behaviour of the two PS NPs in exposure media as well as diverse toxicity to the two planktonic species was observed. PS-COOH formed micro-scale aggregates (Z-Average>1μm) and did not affect the growth of microalgae up to 50μg/ml or that of brine shrimps up to 10μg/ml. However, these negatively charged NPs were adsorbed on microalgae and accumulated (and excreted) in brine shrimps, suggesting a potential trophic transfer from prey to predator. On the opposite, PS-NH2-formed nano-scale aggregates (Z-Average

A modified emulsion polymerisation synthesis route for preparing highly dispersed cationic polystyrene (PS) nanoparticles is reported. The combined use of 2,2′-azobis[2-(2-imidazolin- 2-yl)propane] di-hydrochloride (VA-044) as the initiator and acetone/water as the solvent medium afforded successful synthesis of cationic PS particles as small as 31 nm in diameter. A formation mechanism for the preparation of PS nanoparticles was proposed, whereby the occurrence of rapid acetone diffusion caused spontaneous rupture of emulsion droplets into smaller droplets. Additionally, acetone helped to reduce the surface tension and increase the solubility of styrene, thus inhibiting aggregation and coagulation among the particles. In contrast, VA-044 initiator could effectively regulate the stability of the PS nanoparticles including both the surface charge and size. Other reaction parameters i.e. VA-044 concentration and reaction time were examined to establish the optimum polymerisation conditions.

CD34+ hematopoietic progenitor cells (HPCs) offer great opportunities to develop new treatments for numerous malignant and non-malignant diseases. Nanoparticle (NP)-based strategies can further enhance this potential, and therefore a thorough understanding of the loading behavior of HPCs towards NPs is essential for a successful application. The present study focusses on the interaction kinetics of 40 nm sized carboxylated polystyrene (PS) NPs with HPCs. Interestingly, a transient association of the NPs with HPCs is observed, reaching a maximum within 1 hour and declining afterwards. This behavior is not seen in dendritic cells (CD34-DCs) differentiated from HPCs, which display a monotonic increase in NP load. We demonstrate that this transient interaction requires an energy-dependent cellular process, suggesting active loading and release of NPs by HPCs. This novel observation offers a unique approach to transiently equip HPCs. A simple theoretical approach modeling the kinetics of NP loading and release is presented, contributing to a framework of describing this phenomenon.

Protecting groups are commonly applied in multi-step molecular syntheses to protect one or multiple functional groups from reacting. After the reaction, they are removed from the molecule. In full analogy to this concept, we report the practical and scalable colloidal synthesis of Au semishells using polyphenylsiloxane protecting patches to prevent part of the surface of polystyrene nanoparticles from being covered with Au. After Au deposition, the patches are removed yielding Au semishells. We anticipate that this strategy can be extended to the synthesis of other types of non-centrosymmetric nanoparticles.

Photodynamic inactivation (PDI) is a promising approach for the efficient killing of pathogenic microbes. In this study, the photodynamic effect of sulfonated polystyrene nanoparticles with encapsulated hydrophobic 5,10,15,20-tetraphenylporphyrin (TPP-NP) photosensitizers on Gram-positive (including multi-resistant) and Gram-negative bacterial strains was investigated. The cell viability was determined by the colony forming unit method. The results showed no dark cytotoxicity but high phototoxicity within the tested conditions. Gram-positive bacteria were more sensitive to TPP-NPs than Gram-negative bacteria. Atomic force microscopy was used to detect changes in the morphological properties of bacteria before and after the PDI treatment.

WOS:000533524300107; The impact of nanoplastics (NP) using model polystyrene nanoparticles amine functionalized (PS-NH2) has been investigated on pigment and lipid compositions of the marine diatom Chaetoceros neogracile, at two growth phases using a low (0.05 mu g mL(-1)) and a high (5 mu g mL(-1)) concentrations for 96 h. Results evidenced an impact on pigment composition associated to the light-harvesting function and photo-protection mainly at exponential phase. NP also impacted lipid composition of diatoms with a readjustment of lipid classes and fatty acids noteworthy. Main changes upon NP exposure were observed in galactolipids and triacylglycerol's at both growth phases affecting the thylakoids membrane structure and cellular energy reserve of diatoms. Particularly, exponential cultures exposed to high NP concentration showed an impairment of long chain fatty acids synthesis. Changes in pigment and lipid content of diatom' cells revealed that algae physiology is determinant in the way cells adjust their thylakoid membrane composition to cope with NP contamination stress. Compositions of reserve and membrane lipids are proposed as sensitive markers to assess the impact of NP exposure, including at potential predicted environmental doses, on marine organisms. (C) 2020 Elsevier Ltd. All rights reserved.

The world's oceans are becoming increasingly polluted by plastic waste. In the marine environment, larger plastic pieces may degrade into nanoscale (

Marine diatoms have been identified among the most abundant taxa of microorganisms associated with plastic waste collected at sea. However, the impact of nano-sized plastic fragments (nanoplastics) at single cell and population level is almost unknown. We exposed the marine diatom Skeletonema marinoi to model polystyrene nanoparticles with carboxylic acid groups (PS–COOH NPs, 90 nm) for 15 days (1, 10, 50 μg/mL). Growth, reactive oxygen species (ROS) production, and nano-bio-interactions were investigated. No effect on diatom growth was observed, however Dynamic light scattering (DLS) demonstrated the formation of large PS aggregates which were localized at the diatoms’ fultoportula process (FPP), as shown by TEM images. Increase production of ROS and reduction in chain length were also observed upon PS NPs exposure (p < 0.005). The observed PS-diatom interaction could have serious consequences on diatoms ecological role on the biogeochemical cycle of carbon, by impairing the formation of fast-sinking aggregates responsible for atmospheric carbon fixation and sequestration in the ocean sea floor. S. marinoi exposure to PS NPs caused an increase of intracellular and extracellular oxidative stress, the reduction of diatom's chain length and the adhesion of PS NPs onto the algal surface.

This thesis shows the work done to design, fabricate and characterise the formation of nanostructures built with polystyrene nanospheres (295 nm, 522 nm and 836 nm diameter size) in an attempt to develop all dielectric metamaterials in the optical range. For this purpose, different arrangements were developed to build the nano-devices, using single nanospheres size (295 nm, 522 nm, 836 nm), two nanospheres size (295&522 nm, 295&836 nm, 522&836 nm) and three nanospheres size (295&522&836 nm). The fabrication method uses a electrospray set-up that allows to control de the order of the deposited nanostructures, thus defining and tuning the optical behaviour. Different ordered, semiordered and disordered nanostructures have been successfully fabricated in a very controlled way. Same samples were fabricated by adding isopropyl alcohol in a proportion of 50% polystyrene nanospheres ? 50% isopropyl alcohol. From the different studies, it was proved how the reflectance value is reduced when isopropyl alcohol interacts with polystyrene nanospheres despite the size of the nanospheres. After deposition, optical measurements were performed in order to calculate the percentage of reflectance. Focused Ion Beam (FIB) characterisation verifies the three dimensional distribution of the electrosprayed nanospheres. Simulations were performed in order to compare measured values with theoretical values. The reflectance pattern agrees with the expected results in the cases where total order of the nanostructures (colloidal crystal configuration) is achieved.

Plastics are recognized as a worldwide threat to the environment, possibly affecting human health and wildlife. Small forms of plastics such as micro and nanoplastics can interact with other organic contaminants, potentially acting as chemical carriers and modulating their toxicity. In this study, we investigated the toxicity of polystyrene nanoparticles (Nano-PS) and a real-world environmental PAH mixture (Elizabeth River Sediment Extract – ERSE, comprised of 36 detected PAHs) to zebrafish embryos and larvae. Embryos were exposed to Nano-PS (0.1 – 10 ppm) or ERSE (0.1 – 5% v/v, equivalent to ΣPAH 5.07 – 25.36 ppb), or co-exposed to a combination of both. Larvae exposed to Nano-PS did not exhibit developmental defects, while larvae exposed to ERSE (2 – 5%) showed classic signs of PAH toxicity such as heart malformation and deformities in the jaw, fin, and tail. ERSE (5%) also impaired vascular development in the brain. When co-exposed, Nano-PS decreased the developmental deformities and impaired vascular development caused by ERSE. This was strongly correlated to the lower PAH bioaccumulation detected in the co-exposed animals (whole larvae, as well as the yolk sac, brain, and heart). Our data suggest that PAHs are sorbing to the surface of the Nano-PS, decreasing the concentration, uptake, and toxicity of free PAHs during the exposure. Such sorption of PAHs increases the agglomeration rate of Nano-PS during the exposure time, potentially decreasing the uptake of Nano-PS and associated PAHs. Despite that, similar induction of EROD activity was detected in animals exposed to ERSE in the presence or not of Nano-PS, suggesting that enough PAHs were accumulated in the organisms to induce cellular defense mechanisms. Nano-PS exposure (single or combined with ERSE) decreased the mitochondrial coupling efficiency and increased NADH production, suggesting and impairment on ATP production accompanied by a compensatory mechanism. Our data suggest that nanoplastics can sorb contaminants and potentially decrease their uptake due to particle agglomeration. Nanoplastics also target and disrupt mitochondrial energy production and act as vectors for the mitochondrial uptake of sorbed contaminants during embryonic and larval stages. Such negative effects of nanoplastics on energy metabolism and efficiency could be detrimental under multiple-stressors exposures and energy-demanding scenarios, what remains to be validated.

Micro- (, This work was financed by Generalitat Valenciana (GV-2014/085-Prometeo-II), and talian Antarctic Research Program (PNRA) contract number: PNRA 16_0075 NANOPANTA: Nano-Polymers in the Antarctic marine environment and biota

Several studies have provided information on environmental nanoplastic particles/debris, but the in vitro cyto-genotoxicity is still insufficiently characterized. The aim of this study is to analyze the effects of polystyrene nanoparticles (PNPs) in the Hs27 cell line. The viability of Hs27 cells was determined following exposure at different time windows and PNP concentrations. The genotoxic effects of the PNPs were evaluated by the cytokinesis-block micronucleus (CBMN) assay after exposure to PNPs. We performed ROS analysis on HS27 cells to detect reactive oxygen species at different times and treatments in the presence of PNPs alone and PNPs added to the Crocus sativus L. extract. The different parameters of the CBMN test showed DNA damage, resulting in the increased formation of micronuclei and nuclear buds. We noted a greater increase in ROS production in the short treatment times, in contrast, PNPs added to Crocus sativus showed the ability to extract, thus reducing ROS production. Finally, the SEM-EDX analysis showed a three-dimensional structure of the PNPs with an elemental composition given by C and O. This work defines PNP toxicity resulting in DNA damage and underlines the emerging problem of polystyrene nanoparticles, which extends transversely from the environment to humans, further studies are needed to clarify the internalization process.

Sensitive point-of-care pathogen detection methods are urgently required as pathogens pose a significant threat to food safety and human health. Here, we reported a platform based on a lanthanide-labeled immunochromatographic strip test combined with immunomagnetic separation for the detection of pathogens in food and clinical samples. First, immunomagnetic separation technology was employed as a pre-treatment to eliminate the effect of background in the samples. Then, the lanthanide chelate-loaded carboxyl-modified polystyrene nanoparticles, exhibiting bright luminescence, wide Stokes shift, and excellent stability, were prepared and used to label pathogens with antibody. Finally, an immunochromatographic strip test, based on a sandwich format and supported by our custom-designed portable reader, was used to rapidly quantify the result. Using Salmonella typhimurium as a model pathogen, under optimal conditions, we achieved a detection limit of 103 CFU/mL and a linear range of 104–106 CFU/mL in milk and human serum with good recovery, reproducibility, and specificity. Compared with the existing colloidal gold-based immunochromatographic strip test, our platform showed high sensitivity (100-fold improvement) and provided quantitative determination. Our detection platform was therefore demonstrated to be highly sensitive, rapid (within 1.5 h), and cost-effective, providing a promising platform for point-of-care pathogen detection in food and clinical fields.

Spontaneous assembly of nanoparticles onto a surface is a promising bottom-up concept for the fabrication of new functional materials that can be used for various applications in the nanotechnology. In this paper, we describe a system based on gold/polystyrene (Au/PS) Janus particles arranged onto Au self-assembled monolayer (SAM) of 1-dodecanthiol (NDA). The micro-size Au/PS Janus particles are self-assembled onto Au surface and are dissolved into polystyrene (PS) nanoparticles. The SAM of NDA plays two different roles; it dissolves the original Au/PS Janus particles and organizes the PS nanoparticles onto the Au surface. Overall, our proposed method for the assembly of large-scale area nanoparticles can be extended for further uses in the surface science.

Procalcitonin (PCT) is a potentially specific early marker of bloodstream infection and sepsis. In this work, we report, for the first time, the development of a fluorescence-based immunochromatographic strip test (IST) which employs Eu(DBM)3phen-containing nanoparticles as reporters for the detection of PCT in human serum. Experimental results demonstrate that the developed IST has an excellent ability for rapid (15 min), sensitive (0.05 ng mL−1) and quantitative analysis of PCT, and the assay results are comparable to which of the conventional enzyme-linked immunosorbent assay (ELISA). These results suggest that the developed assay could be utilized for point-of-care detection of PCT.

Two sets of polystyrene nanoparticles (PSNPs) with comparable core sizes but different carboxyl group densities were made and separated using asymmetric flow field flow fractionation (AF4), capillary electrophoresis (CE), and the off-line hyphenation of both methods. Our results revealed the significant potential of two-dimensional off-line AF4-CE hyphenation to improve the separation and demonstrated for the first time, the applicability of CE to determine the functional group density of nanoparticles (NPs). Compared to the result acquired with conductometric titration, the result obtained with synthesized 100 nm sized PSNPs revealed only a slight deviation of 1.7%. Commercial 100 nm sized PSNPs yielded a deviation of 4.6%. For 60 nm sized PSNPs, a larger deviation of 10.6% between both methods was observed, which is attributed to the lower separation resolution.

The evaluation of the role of physicochemical properties in the toxicity of nanoparticles is important for the understanding of toxicity mechanisms and for controlling the behavior of nanoparticles. The surface charge of nanoparticles is suggested as one of the key parameters which decide their biological impact. In this study, we synthesized fluorophore-conjugated polystyrene nanoparticles (F-PLNPs), with seven different types of surface functional groups that were all based on an identical core, to evaluate the role of surface charge in the cellular uptake of nanoparticles. Phagocytic differentiated THP-1 cells or non-phagocytic A549 cells were incubated with F-PLNP for 4 h, and their cellular uptake was quantified by fluorescence intensity and confocal microscopy. The amount of internalized F-PLNPs showed a good positive correlation with the zeta potential of F-PLNPs in both cell lines (Pearson’s r = 0.7021 and 0.7852 for zeta potential vs. cellular uptake in THP-1 cells and nonphagocytic A549 cells, respectively). This result implies that surface charge is the major parameter determining cellular uptake efficiency, although other factors such as aggregation/agglomeration, protein corona formation, and compositional elements can also influence the cellular uptake partly or indirectly.

International audience; While the detection and quantification of nano-sized plastic in the environment remains a challenge, the growing number of polymer applications mean that we can expect an increase in the release of nanoplastics into the environment by indirect outputs. Today, very little is known about the impact of nano-sized plastics on marine organisms. Thus, the objective of this study was to investigate the toxicity of polystyrene nanoplastics (NPs) on oyster (Crassostrea gigas) gametes. Spermatozoa and oocytes were exposed to four NPs concentrations ranging from 0.1 to 100 mg L−1 for 1, 3 and 5 h. NPs coated with carboxylic (PS-COOH) and amine groups (PS-NH2) were used to determine how surface properties influence the effects of nanoplastics. Results demonstrated the adhesion of NPs to oyster spermatozoa and oocytes as suggested by the increase of relative cell size and complexity measured by flow-cytometry and confirmed by microscopy observations. A significant increase of ROS production was observed in sperm cells upon exposure to 100 mg L−1 PS-COOH, but was not observed with PS-NH2, suggesting a differential effect according to the NP-associated functional group. Altogether, these results demonstrate that the effects of NPs occur rapidly, are complex and are possibly associated with the cellular eco-corona, which could modify NPs behaviour and toxicity.

Studying the stability of Pickering emulsion is of great interest for applications including catalysis, oil recovery, and cosmetics. Conventional methods emphasize the overall behavior of bulk emulsions and neglect the influence of particle adsorbing dynamics, leading to discrepancies in predicting the shelf-life of Pickering emulsion-based products. By employing a microfluidic method, the particle adsorption is controlled and the stability of the Pickering emulsions is consequently examined. This approach enables us to elucidate the relationship between the particle adsorption dynamics and the stability of Pickering emulsions on droplet-level quantitatively. Using oil/water emulsions stabilized by polystyrene nanoparticles as an example, the diffusion-limited particle adsorption is demonstrated and investigated the stability criteria with respect to particle size, particle concentration, surface chemistry, and ionic strength. This approach offers important insights for application involving Pickering emulsions and provides guidelines to formulate and quantify the Pickering emulsion-based products.

Trabajo presentado en el Society of Environmental Toxicology and Chemistry (SETAC) Europe 28th Annual Meeting, celebrado en Roma (Italia), del 13 al 17 de mayo de 2018, The accumulation of plastic litter on beaches and open oceans has been identified as one of the major threats in marine ecosystems worldwide. Laboratory experiments have proved that the formation of nano-sized plastics during the polymer degradation may reach marine ecosystem, considered as the most in danger. In present study, the effect of 50 nm cationic amino polystyrene (PS-NH2) was investigated in nauplii of Artemia franciscana, which is commonly used as aquatic model organism in toxicity tests. Acute toxicity tests were performed on nauplii exposed to sub-lethal suspensions of PS-NH2 (0.1, 1 and 10 ¿g/mL) in natural sea water (NSW) for 48 hours. The toxicity was evaluated by measuring growth and several biomarkers as carboxylesterase (CbE), glutathione-S-transferase (GST), cholinesterase (ChE), heat shock protein (HSP70), lipid peroxidation (LP) and catalase (CAT), involved in important physiological processes, such as biotransformation of xenobiotics, neuronal transmission and oxidative stress. The effect of PS-NH2 (at 0.1 and 1 ¿g/mL) on the expression of genes related to metabolism, biosynthesis and embryogenesis during the development of brine shrimp was also investigated. Genes included HSP26, HSP70, mitochondrial uncoupling protein 2 (UCP2), chaperonin-containing TCP (TCP) and late embryogenesis abundant (LEA). Acute exposure to sub-lethal suspensions PS-NH2 caused a significant decrease in growth in A. franciscana nauplii, as well as significant changes in all biomarkers studied, except for LP. A significant up-regulation of HSP26 and HSP70 was observed in nauplii exposed to 1 ¿g/mL of PS-NH2 as well as the modulation of TCP, the latter not significant. This supports the results obtained from biomarkers, suggesting a stress response and potential apoptotic pathway following PS-NH2 exposure. On the contrary, no significant effect on gene expression related to the brine shrimp¿s metabolism (UCP2) was observed, and LEA was significantly modulated only at the lowest concentration tested. These findings indicate that stress-related responses are taking place in exposed nauplii after acute exposure to sub-lethal suspensions of PS-NH2, and confirm the general concern about PS-NH2 and their ability to represent an ecological treat for marine organisms. Given the increasing levels of plastic pollution in the oceans, additional studies should be done considering long-term exposure to analyze the potential risk of nano-sized plastics in marine environments.

The development of novel oral drug delivery systems is an expanding area of research and both new approaches for improving their efficacy and the investigation of their potential toxicological effect are crucial and should be performed in parallel. Polystyrene nanoparticles (NPs) have been used for the production of diagnostic and therapeutic nanosystems, are widely used in food packaging, and have also served as models for investigating NPs interactions with biological systems. The mucous gel layer that covers the epithelium of the gastrointestinal system is a complex barrier-exchange system that it is mainly constituted by mucin and it constitutes the first physical barrier encountered after ingestion. In this study, we aimed to investigate the effect of polystyrene NPs on mucin and its potential role during NP–cell interactions. For this purpose, we evaluated the interaction of polystyrene NPs with mucin in dispersion by dynamic light scattering and with a deposited layer of mucin using a quartz crystal microbalance with dissipation technology. Next, we measured cell viability and the apoptotic state of three enterocyte-like cell lines that differ in their ability to produce mucin, after their exposure to the NPs. Positive charged NPs showed the ability to strongly interact and aggregate mucin in our model. Positive NPs affected cell viability and induced apoptosis in all cell lines independently of their ability of produce mucin.

We report a novel multi-step method for the preparation of ordered mesoporous titania scaffolds and show an illustrative example of their application to solar cells. The method is based on (monolayer) colloidal nanosphere lithography that makes use of polystyrene nanoparticles organised at a water–air interface and subsequently transferred onto a solid substrate. A titania precursor solution (titanium(IV) isopropoxide in ethanol) is then drop-cast onto the monolayer and left to “incubate” overnight. Surprisingly, instead of the expected inverse monolayer-structure, a subsequent calcination step of the precursor yields an ordered monolayer of hollow titania nanospheres with a wall thickness of ∼30–50 nm, and a slightly larger diameter than that of the starting spheres. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) characterization of such scaffolds confirm that they consist of nanocrystalline anatase titania, and that any polystyrene/carbon residues in the scaffolds are below the XPS detection level. As an illustrative application we prepared perovskite solar cells incorporating the templated-nanoparticle scaffolds displaying a respectable power conversion efficiency of ∼9%, twice as large as that of our unoptimized “reference” cells (i.e. incorporating conventional mesoporous or compact titania scaffolds), thereby also demonstrating that the process is relatively robust with respect to optimization of the process parameters.