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Biology Letters Apr 2020Microplastics (plastics < 5 mm) are a potential threat to marine biodiversity. However, the effects of microplastic pollution on animal behaviour and cognition are...
Microplastics (plastics < 5 mm) are a potential threat to marine biodiversity. However, the effects of microplastic pollution on animal behaviour and cognition are poorly understood. We used shell selection in common European hermit crabs () as a model to test whether microplastic exposure impacts the essential survival behaviours of contacting, investigating and entering an optimal shell. We kept 64 female hermit crabs in tanks containing either polyethylene spheres ( = 35) or no plastic ( = 29) for 5 days. We then transferred subjects into suboptimal shells and placed them in an observation tank with an optimal alternative shell. Plastic-exposed hermit crabs showed impaired shell selection: they were less likely than controls to contact optimal shells or enter them. They also took longer to contact and enter the optimal shell. Plastic exposure did not affect time spent investigating the optimal shell. These results indicate that microplastics impair cognition (information-gathering and processing), disrupting an essential survival behaviour in hermit crabs.
Topics: Animals; Anomura; Behavior, Animal; Microplastics; Plastics
PubMed: 32343937
DOI: 10.1098/rsbl.2020.0030 -
Environmental Pollution (Barking, Essex... Jan 2022In response to the growing worldwide plastic pollution problem, the field of nanoplastics research is attempting to determine the risk of exposure to nanoparticles... (Review)
Review
In response to the growing worldwide plastic pollution problem, the field of nanoplastics research is attempting to determine the risk of exposure to nanoparticles amidst their ever-increasing presence in the environment. Since little is known about the attributes of environmental nanoplastics (concentration, composition, morphology, and size) due to fundamental limitations in detection and quantification of smaller plastic particles, researchers often improvise by engineering nanoplastic particles with various surface modifications as models for laboratory toxicological testing. Polystyrene and other commercially available or easily synthesized polymer materials functionalized with surfactants or fluorophores are typically used for these studies. How surfactants, additives, fluorophores, the addition of surface functional groups for conjugation, or other changes to surface attributes alter toxicological profiles remains unclear. Additionally, the limited polymers used in laboratory models do not mimic the vast range of polymer types comprising environmental pollutants. Nanomaterials are tricky materials to investigate due to their high surface area, high surface energies, and their propensity to interact with molecules, proteins, and biological probes. These unique properties can often invalidate common laboratory assays. Extreme care must be taken to ensure that results are not artefactual. We have gathered zeta potential values for various polystyrene nanoparticles with different functionalization, in different solvents, from the reported literature. We also discuss the effects of surface engineering and solvent properties on interparticle interactions, agglomeration, particle-protein interactions, corona formation, nano-bio interfaces, and contemplate how these parameters might confound results. Various toxicological exemplars are critically reviewed, and the relevance and shortfalls of the most popular models used in nanoplastics toxicity studies published in the current literature are considered.
Topics: Microplastics; Nanoparticles; Nanostructures; Plastics; Polystyrenes; Water Pollutants, Chemical
PubMed: 34748888
DOI: 10.1016/j.envpol.2021.118442 -
ACS Omega Apr 2022Structural variations (oligolactide segments, functionalized end groups, and different plasticizer cores) were utilized to tailor the performances of biobased...
Structural variations (oligolactide segments, functionalized end groups, and different plasticizer cores) were utilized to tailor the performances of biobased plasticizers for polylactide (PLA). Six plasticizers were developed starting from 1,4-butanediol and isosorbide as cores: two monomeric (1,4-butanediol levulinate and isosorbide levulinate) and four oligomeric plasticizers with hydroxyl or levulinate ester end groups (1,4-butanediol-based oligolactide, isosorbide-based oligolactide, 1,4-butanediol-based oligomeric levulinate, and isosorbide-based oligomeric levulinate). Structural variations in plasticizer design were reflected in the thermal stability, plasticizing efficiency, and migration resistance. The monomeric plasticizer 1,4-butanediol levulinate decreased the glass-transition temperature of PLA from 59 to 16 °C and increased the strain at break substantially from 6 to 227% with 20 wt % addition. 1,4-Butanediol-based oligomeric levulinate exhibited better thermal stability and migration resistance, though the plasticizing efficiency was slightly lower (glass-transition temperature = 28 °C; strain at break = 202%). Compared to PLA films plasticized by plasticizers with flexible butanediol cores, those plasticized by plasticizers with rigid isosorbide cores exhibited higher Young's modulus and thermal stability and lower plasticizing efficiency. Furthermore, plasticizers with levulinate ester end groups had improved thermal stability, plasticizing efficiency, and migration resistance compared to the corresponding plasticizers with hydroxyl end groups. Hence, a set of controlled structural variations in plasticizer design were successfully demonstrated as a potent route to tailor the plasticizer performances.
PubMed: 35573211
DOI: 10.1021/acsomega.2c01160 -
Environmental Pollution (Barking, Essex... Aug 2023Human membrane drug transporters are recognized as major actors of pharmacokinetics; they also handle endogenous compounds, including hormones and metabolites. Chemical... (Review)
Review
Human membrane drug transporters are recognized as major actors of pharmacokinetics; they also handle endogenous compounds, including hormones and metabolites. Chemical additives present in plastics interact with human drug transporters, which may have consequences for the toxicokinetics and toxicity of these widely-distributed environmental and/or dietary pollutants, to which humans are highly exposed. The present review summarizes key findings about this topic. In vitro assays have demonstrated that various plastic additives, including bisphenols, phthalates, brominated flame retardants, poly-alkyl phenols and per- and poly-fluoroalkyl substances, can inhibit the activities of solute carrier uptake transporters and/or ATP-binding cassette efflux pumps. Some are substrates for transporters or can regulate their expression. The relatively low human concentration of plastic additives from environmental or dietary exposure is a key parameter to consider to appreciate the in vivo relevance of plasticizer-transporter interactions and their consequences for human toxicokinetics and toxicity of plastic additives, although even low concentrations of pollutants (in the nM range) may have clinical effects. Existing data about interactions of plastic additives with drug transporters remain somewhat sparse and incomplete. A more systematic characterization of plasticizer-transporter relationships is needed. The potential effects of chemical additive mixtures towards transporter activities and the identification of transporter substrates among plasticizers, as well as their interactions with transporters of emerging relevance deserve particular attention. A better understanding of the human toxicokinetics of plastic additives may help to fully integrate the possible contribution of transporters to the absorption, distribution, metabolism and excretion of plastics-related chemicals, as well as to their deleterious effects towards human health.
Topics: Humans; Plastics; Toxicokinetics; Plasticizers; Membrane Transport Proteins; Environmental Pollutants; Drug Interactions
PubMed: 37236587
DOI: 10.1016/j.envpol.2023.121882 -
The Science of the Total Environment May 2023Several chemicals with widespread consumer uses have been identified as endocrine-disrupting chemicals (EDCs), with a potential risk to humans. The occurrence in indoor... (Review)
Review
Several chemicals with widespread consumer uses have been identified as endocrine-disrupting chemicals (EDCs), with a potential risk to humans. The occurrence in indoor dust and resulting human exposure have been reviewed for six groups of known and suspected EDCs, including phthalates and non-phthalate plasticizers, flame retardants, bisphenols, per- and polyfluoroalkyl substances (PFAS), biocides and personal care product additives (PCPs). Some banned or restricted EDCs, such as polybrominated diphenyl ethers (PBDEs), di-(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), are still widely detected in indoor dust in most countries, even as the predominating compounds of their group, but generally with decreasing trends. Meanwhile, alternatives that are also potential EDCs, such as bisphenol S (BPS), bisphenol F (BPF), decabromodiphenyl ethane (DBDPE) and organophosphate flame retardants (OPFRs), and PFAS precursors, such as fluorotelomer alcohols, have been detected in indoor dust with increasing frequencies and concentrations. Associations between some known and suspected EDCs, such as phthalate and non-phthalate plasticizers, FRs and BPs, in indoor dust and paired human samples indicate indoor dust as an important human exposure pathway. Although the estimated daily intake (EDI) of most of the investigated compounds was mostly below reference values, the co-exposure to a multitude of known or suspected EDCs requires a better understanding of mixture effects.
Topics: Humans; Environmental Exposure; Environmental Monitoring; Endocrine Disruptors; Plasticizers; Dust; Flame Retardants; Air Pollution, Indoor; Halogenated Diphenyl Ethers
PubMed: 36828075
DOI: 10.1016/j.scitotenv.2023.162374 -
International Journal of Molecular... Apr 2023Bisphenol A (BPA) is a plasticizer that is widely used in the manufacturing of polycarbonate plastics (PC) and epoxy resins for use in a broad range of consumer...
Bisphenol A (BPA) is a plasticizer that is widely used in the manufacturing of polycarbonate plastics (PC) and epoxy resins for use in a broad range of consumer products, including materials in contact with food and beverages, as well as medical devices, toys and dental sealants [...].
Topics: Phenols; Benzhydryl Compounds; Plasticizers; Food
PubMed: 37175739
DOI: 10.3390/ijms24098028 -
European Journal of Pharmaceutical... Jan 2022The oral bioavailability and efficacy of baicalein is dramatically limited by its low solubility and effect of efflux. In our study, we chose PVP-VA64 as a carrier and...
The oral bioavailability and efficacy of baicalein is dramatically limited by its low solubility and effect of efflux. In our study, we chose PVP-VA64 as a carrier and TPGS as a plasticizer and efflux inhibitor to prepare a solid dispersion of baicalein using hot-melt extrusion technology to improve its solubility and bioavailability. The hot-melt process and formulation were optimized, and a BAC-PVP VA64-TPGS solid dispersion (BPT-SD) was prepared. BAC exists in an amorphous or molecular state in BPT-SD. BPT-SD comprised irregular lumps and small particles without BAC or carrier characteristics. The dissolution efficiency of BPT-SD improved under sink conditions. FTIR showed a strong hydrogen bond between BAC and PVP-VA64 in BPT-SD. BPT-SD maintained good physical stability for 6 months. The apparent permeability coefficient of BAC in the Caco-2 cell model confirmed that BPT-SD had higher gastrointestinal membrane permeability. A rat pharmacokinetic study showed that BPT-SD had higher C and AUC24h, shorter T, and 2.88-fold higher bioavailability than BAC. A behavioral experiment in chronic unpredictable mild stress (CUMS) mice confirmed the antidepressant efficacy of BAC. BPT-SD reversed depression-like behavior in CUMS mice and improved BAC bioavailability. BAC preparation into a solid dispersion significantly enhanced dissolution performance and bioavailability.
Topics: Animals; Biological Availability; Caco-2 Cells; Drug Compounding; Flavanones; Humans; Mice; Plasticizers; Rats; Solubility; Vitamin E
PubMed: 34774716
DOI: 10.1016/j.ejps.2021.106071 -
World Journal of Microbiology &... Mar 2023Polyurethane (PU) is a plastic polymer which, due to its various desirable characteristics, has been applied extensively in domestic, industrial and medical fields for... (Review)
Review
Polyurethane (PU) is a plastic polymer which, due to its various desirable characteristics, has been applied extensively in domestic, industrial and medical fields for the past 50 years. Subsequently, an increasing amount of PU waste is generated annually. PU, like many other plastics, is highly resistant to degradation and is a substantial threat to our environment. Currently PU wastes are handled through conventional disposal techniques such as landfill, incineration and recycling. Due to the many drawbacks of these techniques, a 'greener' alternative is necessary, and biodegradation appears to be the most promising option. Biodegradation has the potential to completely mineralise plastic waste or recover the input materials and better enable recycling. There are hurdles to overcome however, primarily the efficiency of the process and the presence of waste plastics with inherently different chemical structures. This review will focus on polyurethanes and their biodegradation, outlining the difficulty of degrading different versions of the same material and strategies for achieving more efficient biodegradation.
Topics: Plastics; Polyurethanes; Waste Disposal Facilities; Bacteria; Biodegradation, Environmental
PubMed: 36929307
DOI: 10.1007/s11274-023-03558-8 -
Bioresource Technology Apr 2023Versatility and desirable attributes of synthetic plastics have greatly contributed towards their wide applications. However, vast accumulation of plastic wastes in... (Review)
Review
Versatility and desirable attributes of synthetic plastics have greatly contributed towards their wide applications. However, vast accumulation of plastic wastes in environment as a result of their highly recalcitrant nature has given rise to plastic pollution. Existing strategies in alleviating plastic wastes accumulation are inadequate, and there is a pressing need for alternative sustainable approaches in tackling plastic pollution. In this context, plastic biodegradation has emerged as a sustainable and environmental-friendly approach in handling plastic wastes accumulation, due to its milder and less energy-intensive conditions. In recent years, extensive research effort has focused on the identification of microorganisms and enzymes with plastic-degrading abilities. This review aims to provide a timely and holistic view on the current status of plastic biodegradation, focusing on recent breakthroughs and discoveries in this field. Furthermore, current challenges associated to plastic biodegradation are discussed, and the future perspectives for continuous advancement of plastic biodegradation are highlighted.
Topics: Plastics; Biodegradation, Environmental; Waste Management
PubMed: 36828218
DOI: 10.1016/j.biortech.2023.128772 -
Environmental Science & Technology Aug 2021Microplastic (MP) pollution-an emerging environmental challenge of the 21st century-refers to accumulation of environmentally weathered polymer-based particles with...
Microplastic (MP) pollution-an emerging environmental challenge of the 21st century-refers to accumulation of environmentally weathered polymer-based particles with potential environmental and health risks. Because of technical and practical challenges when using environmental MPs for risk assessment, most available data are generated using plastic models of limited environmental relevancy (i.e., with physicochemical characteristics inherently different from those of environmental MPs). In this study, we assess the effect of dominant weathering conditions-including thermal, photo-, and mechanical degradation-on surface and bulk characteristics of polystyrene (PS)-based single-use products. Further, we augment the environmental relevance of model-enabled risk assessment through the design of engineered MPs. A set of optimized laboratory-based weathering conditions demonstrated a synergetic effect on the PS-based plastic, which was fragmented into millions of 1-3 μm MP particles in under 16 h. The physicochemical properties of these engineered MPs were compared to those of their environmental counterpart and PS microbeads often used as MP models. The engineered MPs exhibit high environmental relevance with rough and oxidized surfaces and a heterogeneous fragmented morphology. Our results suggest that this top-down synthesis protocol combining major weathering mechanisms can fabricate improved, realistic, and reproducible PS-based plastic models with high levels of control over the particles' properties. Through increased environmental relevancy, our plastic model bolsters the field of risk assessment, enabling more reliable estimations of risk associated with an emerging pollutant of global concern.
Topics: Environmental Monitoring; Environmental Pollution; Microplastics; Plastics; Polystyrenes; Water Pollutants, Chemical
PubMed: 34291927
DOI: 10.1021/acs.est.1c02196