Anionic nanoplastic contaminants promote Parkinson's disease-associated α-synuclein aggregation.

Recent studies have identified increasing levels of nanoplastic pollution in the environment. Here, we find that anionic nanoplastic contaminants potently precipitate the formation and propagation of α-synuclein protein fibrils through a high-affinity interaction with the amphipathic and non-amyloid component (NAC) domains in α-synuclein. Nanoplastics can internalize in neurons through clathrin-dependent endocytosis, causing a mild lysosomal impairment that slows the degradation of aggregated α-synuclein. In mice, nanoplastics combine with α-synuclein fibrils to exacerbate the spread of α-synuclein pathology across interconnected vulnerable brain regions, including the strong induction of α-synuclein inclusions in dopaminergic neurons in the substantia nigra. These results highlight a potential link for further exploration between nanoplastic pollution and α-synuclein aggregation associated with Parkinson's disease and related dementias.

Anionic Nanoplastic Contaminants Promote Parkinson's Disease-Associated α-Synuclein Aggregation.

Recent studies have identified increasing levels of nanoplastic pollution in the environment. Here we find that anionic nanoplastic contaminants potently precipitate the formation and propagation of α-synuclein protein fibrils through a high-affinity interaction with the amphipathic and non-amyloid component (NAC) domains in α-synuclein. Nanoplastics can internalize in neurons through clathrin-dependent endocytosis, causing a mild lysosomal impairment that slows the degradation of aggregated α-synuclein. In mice, nanoplastics combine with α-synuclein fibrils to exacerbate the spread of α-synuclein pathology across interconnected vulnerable brain regions, including the strong induction of α-synuclein inclusions in dopaminergic neurons in the substantia nigra. These results highlight a potential link for further exploration between nanoplastic pollution and α-synuclein aggregation associated with Parkinson's disease and related dementias.

Bringing sex toys out of the dark: exploring unmitigated risks.

A majority of American adults report having used sex toys, which, by design, interact with intimate and permeable body parts yet have not been subject to sufficient risk assessment or management. Physical and chemical data are presented examining potential risks associated with four types of currently available sex toys: anal toy, beads, dual vibrator, and external vibrator. A standardized abrasion machine made real-time breakdown of products into microplastics and nanoplastics. The microplastics from the sex toys were then solvent extracted and analyzed using GC-MS. Rates of microplastics and nanoplastics released during abrasion testing from most microplastic release to least was the anal toy, beads, dual vibrator, external vibrator. Both micro- and nanoplastics particles were generated following the abrasion test, with the 50 percentile diameters (D50) ranging from the anal beads at 658.5 µm, dual vibrator at 887.83 µm, anal toy at 950 µm, and external vibrator at 1673.33 µm. The material matrix of each product was analyzed using ATR-FTIR, with results identifying the anal toy as polyethylene terephthalate (PET), the anal beads as polyvinyl chloride (PVC), the external vibrator as a silicone blend (polydimethylsiloxane [PDMS]), and the dual vibrator as a rubber mixture (polyisoprene). After extraction, phthalates known to be endocrine disruptors were present in all tested sex toys at levels exceeding hazard warnings. Analogous findings have been reported for similar materials that, when incorporated into other product categories, are subject to regulatory scrutiny in both the US and EU. This data set is not intended to be representative of sex toys as an entire class of products, nor are the abrasion experiments claiming to simulate exact use conditions. However, these exploratory data frame potential concerns, highlighting research questions and the need for prompt prioritization of protective action. Therefore, future studies and multi-stakeholder action are needed to understand and reduce risk for this class of products. Supplementary Information: The online version contains supplementary material available at 10.1186/s43591-023-00054-6.

From bottle to microplastics: Can we estimate how our plastic products are breaking down?

Microplastics (MPs) have become an emerging new pollutant of rising concern due to the exponential growth of plastics in consumer products. Most MP and nanoplastic pollution comes from the fragmentation of plastics through mechanical stress, chemical reactions and biological degradation that occurs during use and after disposal. Models predicting the generation and behavior of MP in the environment are developing, however there is lack of data to predict the rates of MP generation as a function of the abrasive forces. A method to deliver scalable, quantitative release rates of MPs during mechanical stress throughout a plastic's life cycle (e.g., sanding, chewing, river and ocean disposal) is described. A custom abrasion machine was built with features to provide data to calculate power input. The generation rate of MPs through abrasion was tested for the following 3D printed polymers: polylactic acid (PLA), polycarbonate (PC), thermoplastic polyurethane 85A (TPU), polyethylene glycol terephthalate (PETG), high-impact polystyrene (HIPS), and nylon. Each material underwent tensile strength material tests to identify which mechanical properties drive their abrasion rate. Abrasion rate was not observed to correlate to macroscopic mechanic properties. Results indicate that the order of abrasion from most to least were HIPS, nylon, PC, PLA, PETG, and then TPU. This study will help comprehend and provide data to understand generation rates of MPs from consumer plastic products and macro-plastic debris. This will be instrumental in helping to better understand the release of MPs and nanoplastics into the environment and to provide data for fate and transport models, especially in order to predict the amount of plastic entering water systems. MP generation rates and power inputs can be correlated with each plastic's use to inform which release the most MPs and how to better change these products in order to reduce pollution in water sources.

Quantifying Mechanical Abrasion of MWCNT Nanocomposites Used in 3D Printing: Influence of CNT Content on Abrasion Products and Rate of Microplastic Production.

Manufactured nanomaterials (MNMs) are incorporated as "nanofillers" into consumer products to enhance properties of interest. Multiwalled carbon nanotubes (MWCNTs) are known for their unique properties and have many applications in polymers. However, the release of MWCNTs during the nanoenabled product life cycle is concerning. During the use phase, mechanical stresses can produce fragmented materials containing MNMs. The degree of MNM release, the resulting exposure to these materials, and the potential impacts of their release are active research topics. In this study, we describe methodological improvements to study the abrasion of plastics containing MNMs (nanocomposites) and report on characteristics of abrasion products produced and rates of microplastic production. The abrasion device developed for this work allows for the measurement of power inputs to determine scaled release rates. Abrasion rates for plastics used in 3D printing were found to be 0.27 g/m2/s for the PETG polymer and 0.3 g/m2/s for the 2% MWCNT-PETG nanocomposite. Embedded and protuberant MWCNTs appeared to impact the particle size, shape, hydrophobicity, and surface charge of the microplastics, while the inclusion of MWCNTs had a small effect on microplastic production. Measurements of power input to the abrasion process provided a basis for estimating microplastic production rates for these nanocomposites.