Paper-supported polystyrene membranes for micro-solid phase extraction of date-rape drugs from urine: A sustainable analytical approach.

BACKGROUND: The rapid development of micro-solid phase extraction (µ-SPE) procedures with new sorption materials, in particular, based on using natural materials, is currently reported. The production of these sorbents and the entire extraction procedure should support the implementation of Green Analytical Chemistry (GAC) principles. Promising materials are sorbents based on paper, which can be relatively easily modified, among others: by covering it with a polymer membrane. In this work, the practical application of paper-supported polystyrene used in the analysis of urine samples containing selected date-rape drugs (DRD) substances, and evaluation of the entire procedure using GAC metrics is presented. RESULTS: The paper-supported polystyrene membranes were successfully fabricated and characterized. The successful polystyrene coating on the paper was confirmed through ATR-FTIR measurements, ensuring even coverage. The µ-SPE procedure using this material facilitated extraction with a throughput of approximately 120 samples per hour in just a few steps. Throughout the research, a mixture of 100 mM acetic acid:methanol:acetonitrile (70:15:15, v/v/v) was selected as an optimal background electrolyte for capillary electrophoresis - mass spectrometry analysis. Validation results of this method demonstrated its suitability, exhibiting good linearity (R2 > 0.95), low limits of detection (3.1-15 ng mL-1), acceptable precision (<15 %), and recovery for all tested analytes. Furthermore, the greenness evaluation conducted with six different metrics: AGREEprep, AGREE, ComplexGAPI, SPMS, hexagonal metric, and WAC indicated the overall eco-friendliness and sustainability of the method, with minor concerns regarding energy consumption. SIGNIFICANCE: The use of cellulose paper with polystyrene membranes for µ-SPE provides a versatile and eco-friendly extraction method for detecting DRDs in urine samples. The presented work is an example of the use of GAC metrics in the evaluation of the analytical procedure. The optimized PT-µ-SPE/CE-MS method allows for minimized reagent usage and waste production. Moreover, the method proves to be sustainable and efficient for forensic toxicology analysis.

Effects of triclosan adsorption on intestinal toxicity and resistance gene expression in Xenopus tropicalis with different particle sizes of polystyrene.

Microplastics (MPs) are commonly found with hydrophobic contaminants in the water column and pose a serious threat to aquatic organisms. The effects of polystyrene microplastics of different particle sizes on the accumulation of triclosan in the gut of Xenopus tropicalis, its toxic effects, and the transmission of resistance genes were evaluated. The results showed that co-exposure to polystyrene (PS-MPs) adsorbed with triclosan (TCS) caused the accumulation of triclosan in the intestine with the following accumulation capacity: TCS + 5 µm PS group > TCS group > TCS + 20 µm PS group > TCS + 0.1 µm PS group. All experimental groups showed increased intestinal inflammation and antioxidant enzyme activity after 28 days of exposure to PS-MPs and TCS of different particle sizes. The TCS + 20 µm PS group exhibited the highest upregulated expression of pro-inflammatory factors (IL-10, IL-1ß). The TCS + 20 µm group showed the highest increase in enzyme activity compared to the control group. PS-MPs and TCS, either alone or together, altered the composition of the intestinal microbial community. In addition, the presence of more antibiotic resistance genes than triclosan resistance genes significantly increased the expression of tetracycline resistance and sulfonamide resistance genes, which may be associated with the development of intestinal inflammation and oxidative stress. This study refines the aquatic ecotoxicity assessment of TCS adsorbed by MPs and provides informative information for the management and control of microplastics and non-antibiotic bacterial inhibitors.

The Effecting Mechanisms of 100 nm Sized Polystyrene Nanoplastics on the Typical Coastal Alexandrium tamarense.

Due to the increase in nanoplastics (NPs) abundance in aquatic environments, their effects on phytoplankton have aroused large research attention. In this study, 100 nm sized polystyrene NPs were chosen to investigate their effecting performance and mechanisms on a typical dinoflagellates Alexandrium tamarense. The results indicated the population growth and photosynthetic efficiencies of A. tamarense were significantly inhibited by NPs exposure, as well as the increase in cellular total carotenoids and paralytic shellfish toxins (PSTs). Meanwhile, the cellar ROS levels increased, corresponding to the increased activities or contents of multiple antioxidant components, including SOD, CAT, GPX, GR, GSH and GSSG. The transcriptional results support the physiological-biochemical results and further revealed the down-regulation of genes encoding the light reaction centers (PSI and PSII) and up-regulation of genes encoding the antioxidant components. Up-regulation of genes encoding key enzymes of the Calvin cycle and glycolytic pathway together with the TCA cycle could accelerate organic carbon and ATP production for A. tamarense cells resistant to NPs stress. Finally, more Glu and acetyl-CoA produced by the enhanced GSH cycle and the glycolytic pathway, respectively, accompanied by the up-regulation of Glu and Arg biosynthesis genes supported the increase in the PST contents under NPs exposure. This study established a data set involving physiological-biochemical changes and gene information about marine dinoflagellates responding to NPs, providing a data basis for further evaluating the ecological risk of NPs in marine environments.

In Situ Preparation of Chlorine-Regenerable Antimicrobial Polymer Molecular Sieve Membranes.

Microbial contamination has profoundly impacted human health, and the effective eradication of widespread microbial issues is essential for addressing serious hygiene concerns. Taking polystyrene (PS) membrane as an example, we herein developed report a robust strategy for the in situ preparation of chlorine-regenerable antimicrobial polymer molecular sieve membranes through combining post-crosslinking and nucleophilic substitution reaction. The cross-linking PS membranes underwent a reaction with 5,5-dimethylhydantoin (DMH), leading to the formation of polymeric N-halamine precursors (PS-DMH). These hydantoinyl groups within PS-DMH were then efficiently converted into biocidal N-halamine structures (PS-DMH-Cl) via a simple chlorination process. ATR-FTIR and XPS spectra were recorded to confirm the chemical composition of the as-prepared PS-DMH-Cl membranes. SEM analyses revealed that the chlorinated PS-DMH-Cl membranes displayed a rough surface with a multitude of humps. The effect of chlorination temperature and time on the oxidative chlorine content in the PS-DMH-Cl membranes was systematically studied. The antimicrobial assays demonstrated that the PS-DMH-Cl membranes could achieve a 6-log inactivation of E. coli and S. aureus within just 4 min of contact time. Additionally, the resulting PS-DMH-Cl membranes exhibited excellent stability and regenerability of the oxidative chlorine content.

Reversibly-bonded microfluidic devices for stable cell culture and rapid, gentle cell extraction.

Microfluidic chips have emerged as significant tools in cell culture due to their capacity for supporting cells to adopt more physiologically relevant morphologies in 3D compared with traditional cell culture in 2D. Currently, irreversible bonding methods, where chips cannot be detached from their substrates without destroying the structure, are commonly used in fabrication, making it challenging to conduct further analysis on cells that have been cultured on-chip. Although some reversible bonding techniques have been developed, they are either restricted to certain materials such as glass, or require complex processing procedures. Here, we demonstrate a simple and reversible polydimethylsiloxane (PDMS)-polystyrene (PS) bonding technique that allows devices to withstand extended operations while pressurized, and supports long-term stable cell cultures. More importantly, it allows rapid and gentle live cell extraction for downstream manipulation and characterization after long-term on-chip culturing, and even further subculturing. Our new approach could greatly facilitate microfluidic chip-based cell and tissue cultures, overcoming current analytical limitations and opening up new avenues for downstream uses of on-chip cultures, including 3D-engineered tissue structures for biomedical applications.

Tailored Physicochemical Cues Direct Human Mesenchymal Stem Cell Differentiation through Epigenetic Regulation Using Colloidal Self-Assembled Patterns.

The extracellular matrix (ECM) shapes the stem cell fate during differentiation by exerting relevant biophysical cues. However, the mechanism of stem cell fate decisions in response to ECM-backed complex biophysical cues has not been fully understood due to the lack of versatile ECMs. Here, we designed two versatile ECMs using colloidal self-assembly technology to probe the mechanisms of their effects on mechanotransduction and stem cell fate regulation. Binary colloidal crystals (BCC) with a hexagonally close-packed structure, composed of silica (5 µm) and polystyrene (0.4 µm) particles as well as a polydimethylsiloxane-embedded BCC (BCCP), were fabricated. They have defined surface chemistry, roughness, stiffness, ion release, and protein adsorption properties, which can modulate the cell adhesion, proliferation, and differentiation of human adipose-derived stem cells (hASCs). On the BCC, hASCs preferred osteogenesis at an early stage but showed a higher tendency toward adipogenesis at later stages. In contrast, the results of BCCP diverged from those of BCC, suggesting a unique regulation of ECM-dependent mechanotransduction. The BCC-mediated cell adhesion reduced the size of the focal adhesion complex, accompanying an ordered spatial organization and cytoskeletal rearrangement. This morphological restriction led to the modulation of mechanosensitive transcription factors, such as c-FOS, the enrichment of transcripts in specific signaling pathways such as PI3K/AKT, and the activation of the Hippo signaling pathway. Epigenetic analyses showed changes in histone modifications across different substrates, suggesting that chromatin remodeling participated in BCC-mediated mechanotransduction. This study demonstrates that BCCs are versatile artificial ECMs that can regulate human stem cells' fate through unique biological signaling, which is beneficial in biomaterial design and stem cell engineering.

Polystyrene nanoplastics of different particle sizes regulate the polarization of pro-inflammatory macrophages.

Microplastics (MPs) are defined as plastic particles smaller than 5 mm in size, and nanoplastics (NPs) are those MPs with a particle size of less than 1000 nm or 100 nm. The prevalence of MPs in the environment and human tissues has raised concerns about their potential negative effects on human health. Macrophages are the major defence against foreign substances in the intestine, and can be polarized into two types: the M1 phenotype and the M2 phenotype. However, the effect of NPs on the polarization of macrophages remains unclear. Herein, we selected polystyrene, one of the most plastics in the environment and controlled the particle sizes at 50 nm and 500 nm respectively to study the effects on the polarization of macrophages. We used mouse RAW264.7 cell line models in this macrophage-associated study. Experiments on cell absorption showed that macrophages could quickly ingest polystyrene nanoplastics of both diameters with time-dependent uptake. Compared to the untreated group and 10 µg/mL treatment group, macrophages exposed to 50 µg/mL groups (50 nm and 500 nm) had considerably higher levels of CD86, iNOS, and TNF-α, but decreased levels of aCD206, IL-10, and Arg-1. According to these findings, macrophage M1 and M2 polarization can both be induced and inhibited by 50 µg/mL 50 nm and 500 nm polystyrene nanoplastics. This work provided the first evidence of a possible MPs mode of action with appropriate concentration and size through the production of polarized M1, providing dietary and environmental recommendations for people, particularly those with autoimmune and autoinflammatory illnesses.

A nanofluidic spiking synapse.

Currently, the nanofluidic synapse can only perform basic neuromorphic pulse patterns. One immediate problem that needs to be addressed to further its capability of brain-like computing is the realization of a nanofluidic spiking device. Here, we report the use of a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate membrane to achieve bionic ionic current-induced spiking. In addition to the simulation of various electrical pulse patterns, our synapse could produce transmembrane ionic current-induced spiking, which is highly analogous to biological action potentials with similar phases and excitability. Moreover, the spiking properties could be modulated by ions and neurochemicals. We expect that this work could contribute to biomimetic spiking computing in solution.

Comparative study of polystyrene microplastic transport behavior in three different filter media: Quartz sand, zeolite, and anthracite.

Microplastics (MPs) are emerging contaminants that are attracting increasing interest from researchers, and the safety of drinking water is greatly affected by their transportation during filtration. Polystyrene (PS) was selected as a representative MPs, and three filter media (quartz sand, zeolite, and anthracite) commonly found in water plants were used. The retention patterns of PS-MPs by various filter media under various background water quality conditions were methodically investigated with the aid of DLVO theory and colloidal filtration theory. The results show that the different structures and elemental compositions of the three filter media cause them to exhibit different surface roughnesses and surface potentials. A greater surface roughness of the filter media can provide more deposition sites for PS-MPs, and the greater surface roughness of zeolite and anthracite significantly enhances their ability to inhibit the migration of PS-MPs compared with that of quartz sand. However, surface roughness is not the only factor affecting the migration of MPs. The lower absolute value of the surface potential of anthracite causes the DLVO energy between it and PS-MPs to be significantly lower than that between zeolite and PS-MPs, which results in stronger retention of PS-MPs by anthracite, which has a lower surface roughness, than zeolite, which has a higher surface roughness. The transport of PS-MPs in the medium is affected by the combination of the surface roughness of the filter media and the DLVO energy. Under the same operating conditions, the retention efficiencies of the three filter materials for PS-MPs followed the order of quartz sand < zeolite < anthracite. Additionally, the conditions of the solution markedly influenced the transport ability of PS-MPs within the simulated filter column. The transport PS-MPs in the simulated filter column decreased with increasing solution ionic strength and cation valence. Naturally, dissolved organic matter promoted the transfer of PS-MPs in the filter layer, and humic acid had a much stronger facilitating impact than fulvic acid. The study findings might offer helpful insight for improving the ability of filter units ability to retain MPs.

Selective recovery of pyrolyzates of biodegradable (PLA, PHBH) and common plastics (HDPE, PP, PS) during co-pyrolysis under slow heating.

Pyrolytic synergistic interactions, in which the production of pyrolyzates is enhanced or inhibited, commonly occur during the co-pyrolysis of different polymeric materials, such as plastics and biomass. Although these interactions can increase the yield of desired pyrolysis products under controlled degradation conditions, the desired compounds must be separated from complex pyrolyzates and further purified. To balance these dual effects, this study was aimed at examining pyrolytic synergistic interactions during slow heating co-pyrolysis of biodegradable plastics including polylactic acid (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexaoate) (PHBH) and petroleum-based plastics including high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS). Comprehensive investigations based on thermogravimetric analysis, pyrolysis-gas chromatography/mass spectrometry, and evolved gas analysis-mass spectrometry revealed that PLA and PHBH decompose at lower temperatures (273-378 °C) than HDPE, PP, and PS (386-499 °C), with each polymer undergoing independent decomposition without any pyrolytic interactions. Thus, the independent pyrolysis of biodegradable plastics, such as PLA and PHBH, with common plastics, such as HDPE, PP, and PS, can theoretically be realized through temperature control, enabling the selective recovery of their pyrolyzates in different temperature ranges. Thus, pyrolytic approaches can facilitate the treatment of mixed biodegradable and common plastics.

Bio-based microplastic polylactic acid exerts the similar toxic effects to traditional petroleum-based microplastic polystyrene in mussels.

Microplastics (MPs) have accumulated in the oceans, causing adverse effects on marine organisms and the environment. Biodegradable polylactic acid (PLA) is considered as an excellent substitute for traditional petroleum-based plastics, but it is difficult to degrade completely and easily become MPs in the marine environment. To test the ecological risk of bio-based PLA, we exposed thick-shelled mussels (Mytilus coruscus) to bio-based PLA and petroleum-based polystyrene (PS) (at 102, 104, and 106 particles/L) for 14 days. The significant increase in enzyme activities related to oxidative stress and immune response showed that mussels were under physiological stress after MP ingestion. While enzyme activities of nerve conduction and energy metabolism were significantly disturbed after exposure. Meanwhile, normal physiological activities in respiration, ingestion and assimilation were also suppressed in association with enzyme changes. The negative effects of PS and PLA in mussels were not differentiated, and further integration analysis of integrated biomarker response (IBR) and principal component analysis (PCA) also showed that PLA would induce adverse effects in mussels and ecological risks as PS, especially at environmental concentrations. Therefore, it is necessary to pay more attention to the environmental and ecological risk of bio-based MP PLA accumulating in the marine environment.

3D printable and biocompatible PEDOT:PSS-ionic liquid colloids with high conductivity for rapid on-demand fabrication of 3D bioelectronics.

3D printing has been widely used for on-demand prototyping of complex three-dimensional structures. In biomedical applications, PEDOT:PSS has emerged as a promising material in versatile bioelectronics due to its tissue-like mechanical properties and suitable electrical properties. However, previously developed PEDOT:PSS inks have not been able to fully utilize the advantages of commercial 3D printing due to its long post treatment times, difficulty in high aspect ratio printing, and low conductivity. We propose a one-shot strategy for the fabrication of PEDOT:PSS ink that is able to simultaneously achieve on-demand biocompatibility (no post treatment), structural integrity during 3D printing for tall three-dimensional structures, and high conductivity for rapid-prototyping. By using ionic liquid-facilitated PEDOT:PSS colloidal stacking induced by a centrifugal protocol, a viscoplastic PEDOT:PSS-ionic liquid colloidal (PILC) ink was developed. PILC inks exhibit high-aspect ratio vertical stacking, omnidirectional printability for generating suspended architectures, high conductivity (~286 S/cm), and high-resolution printing (~50 µm). We demonstrate the on-demand and versatile applicability of PILC inks through the fabrication of 3D circuit boards, on-skin physiological signal monitoring e-tattoos, and implantable bioelectronics (opto-electrocorticography recording, low voltage sciatic nerve stimulation and recording from deeper brain layers via 3D vertical spike arrays).

Characterizing Dissipative Elastic Metamaterials Produced by Additive Manufacturing.

Viscoelastic behavior can be beneficial in enhancing the unprecedented dynamics of polymer metamaterials or, in contrast, negatively impacting their wave control mechanisms. It is, therefore, crucial to properly characterize the viscoelastic properties of a polymer metamaterial at its working frequencies to understand viscoelastic effects. However, the viscoelasticity of polymers is a complex phenomenon, and the data on storage and loss moduli at ultrasonic frequencies are extremely limited, especially for additively manufactured polymers. This work presents a protocol to experimentally characterize the viscoelastic properties of additively manufactured polymers and to use them in the numerical analysis of polymer metamaterials. Specifically, the protocol includes the description of the manufacturing process, experimental procedures to measure the thermal, viscoelastic, and mechanical properties of additively manufactured polymers, and an approach to use these properties in finite-element simulations of the metamaterial dynamics. The numerical results are validated in ultrasonic transmission tests. To exemplify the protocol, the analysis is focused on acrylonitrile butadiene styrene (ABS) and aims at characterizing the dynamic behavior of a simple metamaterial made from it by using fused deposition modeling (FDM) three-dimensional (3D) printing. The proposed protocol will be helpful for many researchers to estimate viscous losses in 3D-printed polymer elastic metamaterials that will improve the understanding of material-property relations for viscoelastic metamaterials and eventually stimulate the use of 3D-printed polymer metamaterial parts in various applications.

Oral exposure to polystyrene nanoplastics altered the hypothalamic-pituitary-testicular axis role in hormonal regulation, inducing reproductive toxicity in albino rats.

BACKGROUND: Nanoplastics can be considered a novel contaminant for the environment because of their extensive applications in modern society, which represents a possible threat to humans. Nevertheless, the negative effect of polystyrene nanoplastics (PS-NPs) on male reproduction, fertility, and progeny outcomes is not well known. Thus, the aim of the present work was to calculate the median lethal dose (LD50) and investigate the consequences of exposure to PS-NPs (25 nm) on male reproductive toxicity. METHODS: This investigation first determined the LD50 of PS-NPs in male Wistar rats, and then in a formal study, 24 rats were distributed into three groups (n = 8): the control group; the low-dose group (3 mg/kg bw); and the high-dose group (10 mg/kg bw) of PS-NPs administered orally for 60 days. On the 50th day of administration, the fertility test was conducted. RESULTS: The LD50 was determined to be 2500 mg/kg. PS-NP administration induced significant alternations, mainly indicating mortality in the high-dose group, a significant elevation in body weight gain, declined sperm quality parameters, altered reproductive hormonal levels, thyroid endocrine disruption, an alternation of the normal histo-architecture and the histo-morphometric analysis of the testes, and impaired male fertility. CONCLUSION: Altogether, the current findings provide novel perspectives on PS-NP general toxicity with specific reference to male reproductive toxicity.

Comparison of polystyrene and hydrogel microcarriers for optical imaging of adherent cells.

Significance: The ability to observe and monitor cell density and morphology has been imperative for assessing the health of a cell culture and for producing high quality, high yield cell cultures for decades. Microcarrier-based cultures, used for large-scale cellular expansion processes, are not compatible with traditional visualization-based methods, such as widefield microscopy, due to their thickness and material composition. Aim: Here, we assess the optical imaging compatibilities of commercial polystyrene microcarriers versus custom-fabricated gelatin methacryloyl (gelMA) microcarriers for non-destructive and non-invasive visualization of the entire microcarrier surface, direct cell enumeration, and sub-cellular visualization of mesenchymal stem/stromal cells. Approach: Mie scattering and wavefront error simulations of the polystyrene and gelMA microcarriers were performed to assess the potential for elastic scattering-based imaging of adherent cells. A Zeiss Z.1 light-sheet microscope was adapted to perform light-sheet tomography using label-free elastic scattering contrast from planar side illumination to achieve optical sectioning and permit non-invasive and non-destructive, in toto, three-dimensional, high-resolution visualization of cells cultured on microcarriers. Results: The polystyrene microcarrier prevents visualization of cells on the distal half of the microcarrier using either fluorescence or elastic scattering contrast, whereas the gelMA microcarrier allows for high fidelity visualization of cell morphology and quantification of cell density using light-sheet fluorescence microscopy and tomography. Conclusions: The combination of optical-quality gelMA microcarriers and label-free light-sheet tomography will facilitate enhanced control of bioreactor-microcarrier cell culture processes.

Physiological and genetic responses of the benthic dinoflagellate Prorocentrum lima to polystyrene microplastics.

Microplastics are well known as contaminants in marine environments. With the development of biofilms, most microplastics will eventually sink and deposit in benthic environment. However, little research has been done on benthic toxic dinoflagellates, and the effects of microplastics on benthic dinoflagellates are unknown. Prorocentrum lima is a cosmopolitan toxic benthic dinoflagellate, which can produce a range of polyether metabolites, such as diarrhetic shellfish poisoning (DSP) toxins. In order to explore the impact of microplastics on marine benthic dinoflagellates, in this paper, we studied the effects of polystyrene (PS) on the growth and toxin production of P. lima. The molecular response of P. lima to microplastic stress was analyzed by transcriptomics. We selected 100 nm, 10 µm and 100 µm PS, and set three concentrations of 1 mg L-1, 10 mg L-1 and 100 mg L-1. The results showed that PS exposure had limited effects on cell growth, but increased the OA and extracellular polysaccharide content at high concentrations. After exposure to PS MPs, genes associated with DSP toxins synthesis, carbohydrate synthesis and energy metabolism, such as glycolysis, TCA cycle and pyruvate metabolism, were significantly up-regulated. We speculated that after exposure to microplastics, P. lima may increase the synthesis of DSP toxins and extracellular polysaccharides, improve the level of energy metabolism and gene expression of ABC transporter, thereby protecting algal cells from damage. Our findings provide new insights into the effects of microplastics on toxic benthic dinoflagellates.

Laccase-Treated Polystyrene Surfaces with Caffeic Acid, Dopamine, and L-3,4-Dihydroxyphenylalanine Substrates Facilitate the Proliferation of Melanocytes and Embryonal Carcinoma Cells NTERA-2.

This study presents the effects of treating polystyrene (PS) cell culture plastic with oxidoreductase enzyme laccase and the catechol substrates caffeic acid (CA), L-DOPA, and dopamine on the culturing of normal human epidermal melanocytes (NHEMs) and human embryonal carcinoma cells (NTERA-2). The laccase-substrate treatment improved PS hydrophilicity and roughness, increasing NHEM and NTERA-2 adherence, proliferation, and NHEM melanogenesis to a level comparable with conventional plasma treatment. Cell adherence dynamics and proliferation were evaluated. The NHEM endpoint function was quantified by measuring melanin content. PS surfaces treated with laccase and its substrates demonstrated the forming of polymer-like structures. The surface texture roughness gradient and the peak curvature were higher on PS treated with a combination of laccase and substrates than laccase alone. The number of adherent NHEM and NTERA-2 was significantly higher than on the untreated surface. The proliferation of NHEM and NTERA-2 correspondingly increased on treated surfaces. NHEM melanin content was enhanced 6-10-fold on treated surfaces. In summary, laccase- and laccase-substrate-modified PS possess improved PS surface chemistry/hydrophilicity and altered roughness compared to untreated and plasma-treated surfaces, facilitating cellular adherence, subsequent proliferation, and exertion of the melanotic phenotype. The presented technology is easy to apply and creates a promising custom-made, substrate-based, cell-type-specific platform for both 2D and 3D cell culture.

Realistic Nanoplastics Induced Pulmonary Damage via the Crosstalk of Ferritinophagy and Mitochondrial Dysfunction.

The smaller size fraction of plastics may be more substantially existing and detrimental than larger-sized particles. However, reports on nanoplastics (NPs), especially their airborne occurrences and potential health hazards to the respiratory system, are scarce. Previous studies limit the understanding of their real respiratory effects, since sphere-type polystyrene (PS) nanoparticles differ from NPs occurring in nature with respect to their physicochemical properties. Here, we employ a mechanical breakdown method, producing NPs directly from bulk plastic, preserving NP properties in nature. We report that among four relatively high abundance NP materials PS, polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polyethylene (PE) with a size of 100 nm, PVC induced slightly more severe lung toxicity profiles compared to the other plastics. The lung cytotoxicity of NPs is higher than that of commercial PS NPs and comparable to natural particles silicon dioxide (SiO2) and anatase titanium dioxide (TiO2). Mechanistically, BH3-interacting domain death agonist (Bid) transactivation-mediated mitochondrial dysfunction and nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy or ferroptosis are likely common mechanisms of NPs regardless of their chemical composition. This study provides relatively comprehensive data for evaluating the risk of atmospheric NPs to lung health.

Persistent Luminescence Nanoplatform for Autofluorescence-Free Tracking of Submicrometer Plastic Particles in Plant.

The uptake of plastic particles by plants and their transport through the food chain make great risks to biota and human health. Therefore, it is important to trace plastic particles in the plant. Traditional fluorescence imaging in plants usually suffers significant autofluorescence background. Here, we report a persistent luminescence nanoplatform for autofluorescence-free imaging and quantitation of submicrometer plastic particles in plant. The nanoplatform was fabricated by doping persistent luminescence nanoparticles (PLNPs) onto polystyrene (PS) nanoparticles. Cr3+-doped zinc gallate PLNP was employed as the dopant for autofluorescence-free imaging due to its persistent luminescence nature. In addition, the Ga element in PLNP was used as a proxy to quantify the PS in the plant by inductively coupled plasma mass spectrometry (ICP-MS). Thus, the developed nanoplatform allows not only dual-mode autofluorescence-free imaging (persistent luminescence and laser-ablation ICP-MS) but also ICP-MS quantitation for tracking PS in plant. Application of this nanoplatform in a typical plant model Arabidopsis thaliana revealed that PS mainly distributed in the root (>99.45%) and translocated very limited (<0.55%) to the shoot. The developed nanoplatform has great potential for quantitative tracing of submicrometer plastic particles to investigate the environmental process and impact of plastic particles.

Array-wide uniform PEDOT:PSS electroplating from potentiostatic deposition.

Electroplating of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) is important in many neuroelectronic applications but is challenging to achieve uniformity on large-scale microelectrode arrays (MEA) using conventional galvanostatic methods. In this study, we address this challenge through a potentiostatic method and demonstrate highly uniform electroplating of PEDOT:PSS on MEA with more than one hundred electrodes, all at cellular sizes. The validation of this approach involves comparisons with galvanostatic deposition methods, showcasing unparalleled deposition yield and uniformity. Systematic electrochemical characterizations reveal similarities in structure and stability from potentiostatic deposited coatings. The advances developed here establish the potentiostatic method and detailed process to achieve a uniform coating of PEDOT:PSS on large-scale MEA, with broad utility in neuroelectronics.