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Polyethylene terephthalate microplastics (PET-MPs) have emerged as significant environmental pollutants with potential health risks. This study investigates the cytotoxic effects of PET-MPs on BEAS-2B lung epithelial cells through integrated transcriptomic and metabolomic analyses. The results of the CCK8 assay showed a reduction in the viability of BEAS-2B cells following continuous exposure to PET-MPs. Transcriptomic analysis identified 1412 differentially expressed genes (DEGs) mainly enriched in apoptosis and extracellular matrix organization processes. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that these DEGs are predominantly involved in the PI3K-Akt, TNF, and MAPK signaling pathways. Metabolomic analysis identified 2869 differentially expressed metabolites (DEMs), mainly associated with pyrimidine, arginine, proline, and β-alanine metabolism pathways. Multi-omics analysis indicated that PET-MPs primarily disrupt lipid metabolism, which may lead to an increased risk of apoptosis. We hypothesize that PET-MPs affect lipid metabolism by up-regulating the ANGPTL4 gene, thereby promoting cellular apoptosis. This study reveals the mechanisms of PET-MPs toxicity, emphasizing the potential risks they pose to human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Bivalve hemocytes, particularly granulocytes and hyalinocytes, play a crucial role in cell-mediated immunity. However, their interactions with aged plastic particles, exhibiting altered properties that more closely resemble those in natural environments, remain largely underexplored. This study assesses the differential responses of hemocyte subpopulations (Mytilus edulis) to chemically aged polyethylene terephthalate (PET) microplastic (MPs) and nanoplastic (NPs) particles across multiple cellular effect endpoints. Particle characteristics were analyzed using Single Particle Extinction and Scattering, Raman Spectroscopy, Scanning Electron Microscopy, and Dynamic Light Scattering. In vitro experiments with aged PET MPs (1.9 µm) and NPs (0.68 µm) were conducted at three internally relevant concentrations: 10 (C1), 10³ (C2), and 10⁵ particles/mL (C3). Cellular responses were assessed by measuring lysosomal content stability, reactive oxygen species (ROS) production, cellular mortality, and morphological parameters using flow cytometry at 6, 12, 24, and 48 hours. Our findings provide mechanistic insights into the differential sensitivities of granulocytes and hyalinocytes to aged PET, influenced by particle size and concentration. Specifically, aged PET MPs and NPs induce distinct size and concentration-dependent patterns of lysosomal destabilization, coinciding with the loss of functional integrity. Elevated ROS levels were observed only in granulocytes and hyalinocytes exposed to high concentrations of aged PET NPs, underscoring the effects on oxidative stress. Both aged PET MPs and NPs induce significant increases in cellular mortality, particularly after 24 h of exposure at high concentrations. These findings reveal the complex cellular mechanisms underlying hemocyte functional impairment following exposure to aged PET particles under environmentally and biologically relevant conditions., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Raewyn M. Town reports a relationship with Ecotoxicology and Environmental Safety that includes: board membership. Co-author is a member of the International Editorial Board of Ecotoxicology and Environmental Safety - R.M.T. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The interaction between particles and proteins is a key factor determining the toxicity responses of particles. Therefore, this study aimed to examine the interaction between the emerging pollutant polyethylene terephthalate micro/nanoplastics from water bottles with bovine serum albumin. The physicochemical characteristics of micro/nanoplastics were investigated using nuclear magnetic resonance, x-ray diffraction, Fourier transform infrared, dynamic light scattering, and x-ray energy dispersive spectroscopy after exposure to various concentrations and durations of protein. Furthermore, the impact of protein-treated micro/nanoplastics on biological activities was examined using the mitochondrial activity and membrane integrity of A549 cells and the activity and biofilm production of Staphylococcus aureus. The structural characteristics of micro/nanoplastics revealed an interaction with protein. For instance, the assignment of protein-related new proton signals (e.g., CH 2 , methylene protons of CH 2 O), changes in available protons s (e.g., CH and CH 3 ), crystallinity, functional groups, elemental ratios, zeta potentials (-11.3 ± 1.3 to -12.4 ± 1.7 to 25.5 ± 2.3 mV), and particle size (395 ± 76 to 496 ± 60 to 866 ± 82 nm) of micro/nanoplastics were significantly observed after protein treatment. In addition, the loading (0.012-0.027 mM) and releasing (0.008-0.013 mM) of protein also showed similar responses with structural characteristics. Moreover, the cell-based responses were changed regarding the structural and surface characteristics of micro/nanoplastics and the loading efficiencies of protein. For example, insignificant mitochondrial activity (2%-10%) and significant membrane integrity (12%-28%) of A549 cells increased compared with control, and reductions in bacterial activity (5%-40%) in many cases and biofilm production specifically at low dose of all treatment stages (13%-46% reduction) were observed., (© 2024 The Author(s). Environmental Toxicology published by Wiley Periodicals LLC.)

Polyethylene terephthalate (PET) fibers are contaminated in wastewater from various primary sources, such as washing textile waters. PET fibers in the environment can be degraded into microfibers because of weathering processes such as sunlight, physical wear, and heat. Although recent studies reported adverse effects of PET microfibers on aquatic organisms, the lack of information on their toxicity and mode of action hampers the risk assessment of PET microfibers. Therefore, this study aimed to investigate the biological effects of PET microfibers and their underlying mechanisms in early-staged sheepshead minnows (Cyprinodon variegatus). PET microfibers (about 13 μm diameter × 106 μm length) were prepared by cutting PET threads and treated to sheepshead minnow larvae at 10 and 100 mg/L for 10 days. No acute toxicity was found in the minnow, but PET microfibers significantly produced reactive oxygen species and reduced behavioral responses of traveled distance and maximum velocity. The transcriptomic data suggested that Merkel cells (flow sensors) and corpuscles of Stannius (calcium regulator) are putative targets, which were derived from oxidative stress, sensory neuropathy, cognitive impairment, and movement disorders. These findings underscore that although PET microfibers are not directly lethal to sheepshead minnows, they could impact their survival by damaging swimming-related key genes. This study provides new insights into how PET microfibers are toxic to aquatic organisms and disrupt ecosystems beyond survival and pathological changes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Glitter is a type of microplastic, and thus there is a need to assess its potential impacts on the environment and to assess the potential for non-plastic cellulose nanocrystal structurally colored glitters as safe and sustainable replacements. The ecotoxicity of glitter has been mostly ignored in the research literature, with only a few published studies focusing on aquatic organisms. Therefore, an exposure experiment was conducted to examine the impact of conventional polyethylene terephthalate (PET) glitter as well as untreated and heat-treated cellulose nanocrystal (CNC) based glitter on the survival, reproduction, and length of Folsomia candida (springtail). Folsomia candida reproduction was reduced by 61% (P = 0.013) after exposure to PET glitter at 1000 mg/kg, while no significant effects were observed on F. candida survival and length. In contrast, there were no significant impacts on F. candida survival, length, or reproduction when exposed to untreated or heat-treated CNC glitter. These results indicate that exposure to PET glitter may impact soil invertebrates at the population level, and that CNC glitter has potential as a biodegradable non-plastic alternative to PET glitter to decrease detrimental effects on soil ecosystems., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Benjamin Droguet reports financial support was provided by UK Research and Innovation - Engineering and Physical Sciences Research Council. Silvia Vignolini reports financial support was provided by UK Research and Innovation - Engineering and Physical Sciences Research Council. Benjamin Droguet reports a relationship with Sparxell UK Limited that includes: employment and equity or stocks. Silvia Vignolini reports a relationship with Sparxell UK Limited that includes: equity or stocks and funding grants. Benjamin Droguet has patent #WO2023025863A1/GB2610186B pending to Sparxell UK Limited. Silvia Vignolini has patent #WO2023025863A1/GB2610186B pending to Sparxell UK Limited. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

To investigate whether environmental concentrations of fragmented polyethylene terephthalate (PET) microplastics (MPs) have additional or combined effects on endocrine-disrupting activity, Java medaka (Oryzias javanicus) were exposed to 17β-estradiol (E2; 5, 10, 50, and 100 ng L -1 ), bisphenol A (BPA; 5, 10, 50, and 100 µg L -1 ), and E2 and BPA combined with PET MPs (1 and 100 particles L -1 ) for 200 days. The growth parameters, such as body length and weight, were significantly decreased by the highest concentrations of E2 and BPA. A significant reduction in egg production was observed in female fish exposed to BPA, with an additive toxic effect of PET MPs. A female-biased sex ratio was observed in fish exposed to both chemicals. Exposure to E2 significantly increased the hepatosomatic index (HSI) in both sexes, while no significant effect was observed in the gonadosomatic index (GSI). Exposure to BPA significantly increased the HSI in female fish and decreased the GSI in both sexes of fish. An additive effect of PET MPs was observed on the GSI value of female exposed to BPA. Significant elevations in vitellogenin (VTG) levels were observed in both sexes due to exposure to E2 and BPA. Additive effects of PET MPs were observed on VTG levels in males exposed to E2 and BPA. Taken together, even long-term treatment with PET MPs induced only a negligible additive effect on the endocrine-disrupting activity in Java medaka at environmentally relevant concentrations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Microplastics (MPs) are a major concern in marine ecosystem because MPs are persistent and ubiquitous in oceans and are easily consumed by marine biota. Although many studies have reported the toxicity of MPs to marine biota, the toxicity of environmentally relevant types of MPs is little understood. We investigated the toxic effects of fragmented polyethylene terephthalate (PET) MP, one of the most abundant MPs in the ocean, on the marine rotifer Brachionus koreanus at the individual and molecular level. No significant rotifer mortality was observed after exposure to PET MPs for 24 and 48 h. The ingestion and egestion assays showed that rotifers readily ingested PET MPs in the absence of food but not when food was supplied; thus, there were also no chronic effects of PET MPs. In contrast, intracellular reactive oxygen species levels and glutathione S-transferase activity in rotifers were significantly increased by PET MPs. Transcriptomic and metabolomic analyses revealed that genes and metabolites related to energy metabolism and immune processes were significantly affected by PET MPs in a concentration-dependent manner. Although acute toxicity of PET MPs was not observed, PET MPs are potentially toxic to the antioxidant system, immune system, and energy metabolism in rotifers., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Plastic pollution has become a major environmental concern, and various plastic polymers are used daily. A study was conducted to examine the toxic effects of polyethylene terephthalate (PET) nanoplastics (NPLs) on Drosophila melanogaster. We have successfully synthesized PET NPLs and characterized using DLS, Zeta potential, TEM, HRTEM, SAED, XRD, FTIR, and Raman spectroscopy to gain crucial insights into the structure and properties. We fed PET NPLs to Drosophila to assess toxicity. ROS was quantified using DCFH-DA and NBT, and the nuclear degradation was checked by DAPI staining. Quantification of protein and activity of antioxidant enzymes like SOD, catalase depicted the adverse consequences of PET NPLs exposure. The dorsal side of the abdomens, eyes, and wings were also defective when phenotypically analyzed. These results substantiate the genotoxic and cytotoxic impact of nanoplastics. Notably, behavioral observations encompassing larval crawling and climbing of adults exhibit normal patterns, excluding the presence of neurotoxicity. Adult Drosophila showed decreased survivability, and fat accumulation enhanced body weight. These findings contribute to unraveling the intricate mechanisms underlying nanoplastic toxicity and emphasize its potential repercussions for organismal health and ecological equilibrium.

The environmental presence of nano- and micro-plastic particles (NMPs) is suspected to have a negative impact on human health. Environmental NMPs are difficult to sample and use in life science research, while commercially available plastic particles are too morphologically uniform. Additionally, this NMPs exposure exhibited biological effects, including cell internalization, oxidative stress, inflammation, cellular adaptation, and genotoxicity. Therefore, developing new methods for producing heterogenous NMPs as observed in the environment is important as reference materials for research. Thus, we aimed to generate and characterize NMPs suspensions using a modified ultrasonic protocol and to investigate their biological effects after exposure to different human cell lines. To this end, we produced polyethylene terephthalate (PET) NMPs suspensions and characterized the particles by dynamic light scattering and scanning electron microscopy. Ultrasound treatment induced polymer degradation into smaller and heterogeneous PET NMPs shape fragments with similar surface chemistry before and after treatment. A polydisperse suspension of PET NMPs with 781 nm in average size and negative surface charge was generated. Then, the PET NMPs were cultured with two human cell lines, A549 (lung) and HaCaT (skin), addressing inhalation and topical exposure routes. Both cell lines interacted with and have taken up PET NMPs as quantified via cellular granularity assay. A549 but not HaCaT cell metabolism, viability, and cell death were affected by PET NMPs. In HaCaT keratinocytes, large PET NMPs provoked genotoxic effects. In both cell lines, PET NMPs exposure affected oxidative stress, cytokine release, and cell morphology, independently of concentration, which we could relate mechanistically to Nrf2 and autophagy activation. Collectively, we present a new PET NMP generation model suitable for studying the environmental and biological consequences of exposure to this polymer., Competing Interests: Declaration of competing interest The authors declare no conflict of interest with regard to the publication of this article., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Polyethylene terephthalate (PET) is a common plastic widely used in food and beverage packaging that poses a serious risk to human health and the environment due to the continual rise in its production and usage. After being produced and used, PET accumulates in the environment and breaks down into nanoplastics (NPs), which are then consumed by humans through water and food sources. The threats to human health and the environment posed by PET-NPs are of great concern worldwide, yet little is known about their biological impacts. Herein, the smallest sized PET-NPs so far (56 nm) with an unperturbed PET structure were produced by a modified dilution-precipitation method and their potential cytotoxicity was evaluated in Saccharomyces cerevisiae. Exposure to PET-NPs decreased cell viability due to oxidative stress induction revealed by the increased expression levels of stress response related-genes as well as increased lipid peroxidation. Cell death induced by PET-NP exposure was mainly through apoptosis, while autophagy had a protective role.

The ubiquitous pollution of plastic particles in most environmental matrices leads to concern about any potential adverse effects on human health. Most studies on the toxicological effect of nanoplastics has focused on standard particles of polystyrene. In reality humans are exposed to a large variety of different types and sizes of plastic material via oral intake and inhalation. In this study, we investigated the effect of polyethylene terephthalate (PET) nanoplastic particles from ground food containers from a supermarket. The aim was to investigate a possible link between exposure to PET nanoplastics and genotoxic response in a cell model of the human airway epithelial (A549) cells. Further, we investigated the combined effect of PET and chemicals known to alter the cellular redox state, as a model of partially compromised antioxidant defense system. DNA damage was assessed by the alkaline comet assay. The ground PET nanoplastics have a mean hydrodynamic diameter of 136 nm in water. The results showed that PET exposure led to increased reactive oxygen species production (approximately 30 % increase compared to unexposed cells). In addition, exposure to PET nanoplastic increased the level of DNA strand breaks (net increase = 0.10 lesions/10 6 base pair, 95 % confidence interval: 0.01, 0.18 lesions/10 6 base pair). Pre- or post-exposure to hydrogen peroxide or buthionine sulfoximine did not lead to a higher level of DNA damage. Overall, the study shows that exposure to PET nanoplastics increases both intracellular reactive oxygen production and DNA damage in A549 cells., Competing Interests: Declaration of Competing Interest The authors report no declarations of interest., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: The presence of polyethylene terephthalate (PET) oligomers in food contact materials (FCMs) is well-documented. Consumers are exposed through their migration into foods and beverages; however, there is no specific guidance for their safety evaluation., Objectives: This systematic evidence map (SEM) aims to identify and organize existing knowledge and associated gaps in hazard and exposure information on 34 PET oligomers to support regulatory decision-making., Methods: The methodology for this SEM was recently registered. A systematic search in bibliographic and gray literature sources was conducted and studies evaluated for inclusion according to the Populations, Exposures, Comparators, Outcomes, and Study type (PECOS) framework. Inclusion criteria were designed to record hazard and exposure information for all 34 PET oligomers and coded into the following evidence streams: human, animal, organism (non-animal), ex vivo, in vitro, in silico, migration, hydrolysis, and absorption, distribution, metabolism, excretion/toxicokinetics/pharmacokinetics (ADME/TK/PK) studies. Relevant information was extracted from eligible studies and synthesized according to the protocol., Results: Literature searches yielded 7445 unique records, of which 96 were included. Data comprised migration (560 entries), ADME/TK/PK-related (253 entries), health/bioactivity (98 entries) and very few hydrolysis studies (7 entries). Cyclic oligomers were studied more frequently than linear PET oligomers. In vitro results indicated that hydrolysis of cyclic oligomers generated a mixture of linear oligomers, but not monomers, potentially allowing their absorption in the gastrointestinal tract. Cyclic dimers, linear trimers and the respective smaller oligomers exhibit physico-chemical properties making oral absorption more likely. Information on health/bioactivity effects of oligomers was almost non-existent, except for limited data on mutagenicity., Conclusions: This SEM revealed substantial deficiencies in the available evidence on ADME/TK/PK, hydrolysis, and health/bioactivity effects of PET oligomers, currently preventing appropriate risk assessment. It is essential to develop more systematic and tiered approaches to address the identified research needs and assess the risks of PET oligomers., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Alex Odermatt reports financial support was provided by Federal Food Safety and Veterinary Office FSVO. Alex Odermatt reports administrative support was provided by Swiss Centre for Applied Human Toxicology (SCAHT). This involves handling of reporting to the FSVO and the transfer of funds from the FSVO. Martin Wilks reports a relationship with SCAHT that includes: director. Nicolas Roth reports a relationship with SCHAT that includes: employment. Jane Muncke and Birgit Geueke report a relationship with Food Packaging Forum that includes: employment. Jane Muncke and Birgit Geueke were not restricted in any way by the FPF in planning and conducting this work. Beat J. Brueschweiler reports a relationship with Swiss Federal Food Safety and Veterinary Office (FSVO) that includes: employment. Beat J. Brueschweiler acted in a personal expert capacity and not as a sponsor representative. Benoit Schilter reports a relationship with Nestlé R&D Centre that includes: previous employment. Benoit Schilter was not restricted in any way by Nestlé R&D Centre in planning and conduction this work., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Polyethylene terephthalate (PET) oligomers are ubiquitous in PET used in food contact applications. Consumer exposure by migration of PET oligomers into food and beverages is documented. However, no specific risk assessment framework or guidance for the safety evaluating of PET oligomers exist to date., Aim: The aim of this systematic evidence map (SEM) is to identify and organize existing knowledge clusters and associated gaps in hazard and exposure information of PET oligomers. Research needs will be identified as an input for chemical risk assessment, and to support future toxicity testing strategies of PET oligomers and regulatory decision-making., Search Strategy and Eligibility Criteria: Multiple bibliographic databases (incl. Embase, Medline, Scopus, and Web of Science Core Collection), chemistry databases (SciFinder-n, Reaxys), and gray literature sources will be searched, and the search results will be supplemented by backward and forward citation tracking on eligible records. The search will be based on a single-concept PET oligomer-focused strategy to ensure sensitive and unbiased coverage of all evidence related to hazard and exposure in a data-poor environment. A scoping exercise conducted during planning identified 34 relevant PET oligomers. Eligible work of any study type must include primary research data on at least one relevant PET oligomer with regard to exposure, health, or toxicological outcomes., Study Selection: For indexed scientific literature, title and abstract screening will be performed by one reviewer. Selected studies will be screened in full-text by two independent reviewers. Gray literature will be screened by two independent reviewers for inclusion and exclusion., Study Quality Assessment: Risk of bias analysis will not be conducted as part of this SEM., Data Extraction and Coding: Will be performed by one reviewer and peer-checked by a second reviewer for indexed scientific literature or by two independent reviewers for gray literature., Synthesis and Visualization: The extracted and coded information will be synthesized in different formats, including narrative synthesis, tables, and heat maps., Systematic Map Protocol Registry and Registration Number: Zenodo: https://doi.org/10.5281/zenodo.6224302., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Nanoplastics are more likely to be suspended in air and pose a risk of respiratory exposure. However, the early health effects of low-dose nanoplastics on the respiratory system, which are expected to reflect the risk of atmospheric nanoplastics, need to be further evaluated. In this study, nanoparticles of polyethylene terephthalate, a representative plastic polymer in air, were prepared by a precipitation method. The toxicity impacts of nano-PET at environmental concentrations on the human lung carcinoma cell A549 cells were evaluated. Although the nano-PET was identified to enter the cells by confocal microscope observation and alkali-assisted thermal depolymerization coupled with LC-MS/MS analysis, the nano-PET exhibited low toxicity on mitochondrial membrane potential levels and cell apoptosis. At low concentrations of 0.10 and 0.98 μg/mL, the nano-PET had a slight promotion effect on cell viability, while an inhibitory effect on cell viability presented at higher nano-PET concentrations of 98.40 and 196.79 μg/mL. The cell survival rate at 98.4 and 196.79 μg/mL of nano-PET are lower than that of the control, and significant oxidative stress in cells caused by the nano-PET exposure at 49.2 μg/mL was observed. A decrease tendency of mitochondrial membrane potential with the increasing nano-PET exposure presents, which is consistent with the change of reactive oxygen species. Furthermore, nano-PET at ≦ 98.4 μg/mL could not increase the sum of apoptotic in the cells, but the late apoptotic cells increased with the increase of the exposure dose. The major mechanism of the toxic effect of nano-PET on cells may be the increase of reactive oxygen species caused by oxidative stress, which in turn induces a decrease in the mitochondrial membrane potential. This study provides information on the toxicity of nano-PET at environmental concentrations in human lung cells, which helps to enrich the risk cognition of nanoplastics in the respiratory system., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The PET hydrolase from Ideonella sakaiensis (IsPETase) is efficient for PET degradation, which provides a promising solution for environmental contamination by plastics. This study focuses on improving the excretion of IsPETase from E. coli by signal peptide (SP) engineering. A SP enhancer B1 (MERACVAV) was fused to the N-terminal of commonly-used SP (PelB, MalE, LamB, and OmpA) to mediate excretion of IsPETase. Strikingly, the modified SP B1OmpA, B1PelB, and B1MalE significantly increased the excretion of IsPETase, while IsPETase was basically expressed in periplasmic space without enhancer B1. The excretion efficiency of IsPETase mediated by B1PelB was improved by 62 folds compared to that of PelB. The hydrolysis of PET by crude IsPETase in culture solution was also enhanced. Furthermore, the amount of released MHET/TPA from PET by IsPETase was increased by 2.7 folds with pre-incubation of hydrophobin HFBII. Taken together, this work may provide a feasible strategy for the excretion and application of the IsPETase., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Polyethylene terephthalate (PET) is widely used material and as such became highly enriched in nature. It is generally considered inert and safe plastic, but due to the recent increased efforts to break-down PET using biotechnological approaches, we realized the scarcity of information about structural analysis of possible degradation products and their ecotoxicological assessment. Therefore, in this study, 11 compounds belonging to the group of PET precursors and possible degradation products have been comprehensively characterized. Seven of these compounds including 1-(2-hydroxyethyl)-4-methylterephthalate, ethylene glycol bis(methyl terephthalate), methyl bis(2-hydroxyethyl terephtahalate), 1,4-benzenedicarboxylic acid, 1,4-bis[2-[[4-(methoxycarbonyl)benzoyl]oxy]ethyl] ester and methyl tris(2-hydroxyethyl terephthalate) corresponding to mono-, 1.5-, di-, 2,5- and trimer of PET were synthetized and structurally characterized for the first time. In-silico druglikeness and physico-chemical properties of these compounds were predicted using variety of platforms. No antimicrobial properties were detected even at 1000 μg/mL. Ecotoxicological impact of the compounds against marine bacteria Allivibrio fischeri proved that the 6 out of 11 tested PET-associated compounds may be classified as harmful to aquatic microorganisms, with PET trimer being one of the most toxic. In comparison, most of the compounds were not toxic on human lung fibroblasts (MRC-5) at 200 μg/mL with inhibiting concentration (IC50) values of 30 μg/mL and 50 μg/mL determined for PET dimer and trimer. Only three of these compounds including PET monomer were toxic to nematode Caenorhabditis elegans at high concentration of 500 μg/mL. In terms of the applicative potential, PET dimer can be used as suitable substrate for the screening, identification and characterization of novel PET-depolymerizing enzymes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Microfibers (MFs) have recently become an increasingly prevalent pollutant in ecosystems and pose a direct threat to organisms and an indirect threat via adsorption of other pollutants. Here, we used Caenorhabditis elegans to study multigenerational effects of polyethylene terephthalate (PET) MFs (diameter 17.4 μm) by observing the maternal generation (P0) to the seventh offspring generation (F7) with continuous MF exposure. Exposure to 250-μm PET MFs decreased locomotion behavior and induced intestinal reactive oxygen species (ROS) in the P0 generation compared with other PET MF sizes. Moreover, no notably negative effects on survival were observed in any generation during continuous exposure to 250-μm PET MFs. However, the reproduction rate clearly decreased in the F2 and F3 generations but gradually recovered in the F4-F7 generations. Developmental abnormalities showed a close relationship with body length. Although some recovery was confirmed, there were significant decreases in body length in the F2-F5 generations. Interestingly, growth inhibition was also observed in the F6 generation without MF exposure. ROS production and dermal damage in the P0-F5 generations might have resulted in the toxicological responses. To the best of our knowledge, this is the first study to provide evidence of multigenerational toxicity of MFs in C. elegans., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Plastics enter in terrestrial natural system primarily by agricultural purposes, while acid rain is the result of anthropogenic activities. The synergistic effects of microplastics and acid rain on plant growth are not known. In this study, different sizes of polyethylene terephthalate (PET) and acid rain are tested on Lepidium sativum, in two separate experimental sets. In the first one we treated plants only with PET, in the second one we used PET and acid rain together. In both experimentations we analyzed: i) plant biometrical parameters (shoot height, leaf number, percentage inhibition of seed germination, fresh biomass), and ii) oxidative stress responses (hydrogen peroxide; ascorbic acid and glutathione). Results carried out from our experiments highlighted that different sizes of polyethylene terephthalate are able to affect plant growth and physiological responses, with or without acid rain supplied during acute toxicity (6 days). SHORT DESCRIPTION: This study showed that different sizes of PET microplastics affect physiological and biometrical responses of Lepidum sativum seedlings, with or without acid rain; roots and leaves responded differently., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Determination of polyethylene terephthalate (PET) dimer up to heptamer 1st series cyclic oligomers, applying an LC-qTOF-MS method, has been developed and validated. Recoveries ranged between 80 and 112% with RSDs lower than 15%. An innovative semi-quantitative approach has been applied for 2nd and 3rd series cyclic oligomers, using the closest structural-similar 1st series cyclic oligomer standard as analytical reference. Oligomers from the three series were quantified in PET teabags after migration experiments with water and food simulants C (20% v/v ethanol in water) and D1 (50% v/v ethanol in water). No legal migration limits exist currently for these substances. In silico genotoxicity assessment of all identified oligomers has been performed and showed no genotoxicity alert for linear or cyclic molecules. Exposure assessment was performed using EFSA's approach on the total sum of migrating oligomers and on toxicological threshold-of-concern. Amounts found in water were in some cases significantly higher than the respective limits, especially in the worst-case scenario of multiple consumption., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Microplastic (MP) contamination represents a serious threat for marine organisms. Several lab studies demonstrated adverse effects induced by exposure to different MP polymers toward diverse marine species. However, the information regarding toxicity of polyethylene terephthalate (PET) MPs is largely unknown. The present study was aimed at investigating the adverse effects induced by 7-day exposure to two concentrations (0.125 or 12.5 µg/ml) micronized, irregular shaped and variable size PET microparticles (PET-MPs) toward Manila clam ( Ruditapes philippinarum) . Histological analyses were performed to assess tissue damage on digestive glands, gonads, gut and gills, whereas oxidative stress-related effects, including the concentration of pro-oxidant molecules, activity of antioxidant (superoxide dismutase - SOD, catalase - CAT and glutathione peroxidase - GPx) and detoxifying (glutathione S-transferase - GST) enzymes, as well as levels of lipid peroxidation, were determined in gills and digestive gland. Our results showed that clams ingest and egest micronized PET-MPs, but no marked histological alterations to bivalve tissues occurred. Although PET-MPs did not produce oxidative stress in the digestive gland, these materials significantly altered oxidative status of gills, leading to lipid peroxidation. No apparent clear indication of a weakness of bivalve health status was obtained in this study.

A great deal of attention has been paid lately to release of phthalate esters (PAEs) from polyethylene terephthalate (PET) bottles into PET bottled drinking water due to their potential endocrine-disrupting effects. Three kinds of PAEs, including diethyl phthalate (DEP), dimethyl phthalate (DMP) and dibutyl phthalate (DBP), were detected in 10 popular brands of PET bottles in Beijing, ranging from 101.97 μg/kg to 709.87 μg/kg. Meanwhile, six kinds of PAEs, including DEP, DMP, DBP, n-butyl benzyl phthalate (BBP), di-n-octyl phthalate (DOP) and di(2-ethylhexyl) phthalate (DEHP), were detected in PET bottled water, ranging from 0.19 μg/L to 0.98 μg/L, under an outdoor storage condition, while their concentrations ranged from 0.18 μg/L to 0.71 μg/L under an indoor storage condition. Furthermore, the concentrations of PAEs in brand D and E bottles were slightly increased when the storage time was prolonged. In addition, the concentrations of PAEs in commercial water contained in brand B and H bottles and pure water contained in brand E and G bottles were also slightly increased with the increase of storage temperature. Interestingly, DBP mainly contributed to the increased PAEs levels in simulation water. These results suggest that a part of the PAEs in PET bottled water originated from plastic bottles, which was related to the storage time and temperature. However, the PAEs in PET bottled water only pose a negligible risk to consumers if they follow the recommendations, such as storage at a common place (24 °C), away from sun and in a short period of time.

Management of infected wounds is one of the most costly procedures in the health care sector. Burn wounds are of significant importance due to the high infection risk that can possibly lead to severe consequences such as sepsis. Because antibiotic wound treatments have caused increasing antibiotic resistance in bacteria, there is currently a strong need for alternative strategies. Therefore, we developed new antimicrobial wound dressings consisting of pH-responsive human serum albumin/silk fibroin nanocapsules immobilized onto cotton/polyethylene terephthalate (PET) blends loaded with eugenol, which is an antimicrobial phenylpropanoid. Ultrasound-assisted production of eugenol-loaded nanocapsules resulted in particle sizes (hydrodynamic radii) between 319.73 ± 17.50 and 574.00 ± 92.76 nm and zeta potentials ranging from -10.39 ± 1.99 mV to -12.11 ± 0.59 mV. Because recent discoveries have indicated that the sweat glands contribute to wound reepithelialisation, release studies of eugenol were conducted in different artificial sweat formulas that varied in pH. Formulations containing 10% silk fibroin with lower degradation degree exhibited the highest release of 41% at pH 6.0. After immobilization, the functionalized cotton/PET blends were able to inhibit 81% of Staphylococcus aureus and 33% of Escherichia coli growth. Particle uniformity, silk fibroin concentration, and high surface-area-to-volume ratio of the produced nanocapsules were identified as the contributing factors leading to high antimicrobial activities against both strains. Therefore, the production of antimicrobial textiles using nanocapsules loaded with an active natural compound that will not contribute to antibiotic resistance is seen as a potential future alternative to commercially available antiseptic wound dressings.

Sustainable alternatives to landfill disposal for municipal mixed wastes represents a major challenge to governments and waste management industries. In the state of New South Wales (NSW) Australia, mechanical biological treatment (MBT) is being used to reduce the volume and pathogen content of organic matter isolated from municipal waste. The product of this treatment, a compost-like output (CLO) referred to as mixed waste organic output (MWOO), is being recycled and applied as a soil amendment. However, the presence of contaminants in MWOO including trace organics, trace metals and physical contaminants such as microplastic fragments has raised concerns about potential negative effects on soil health and agriculture following land application. Here, we used multiple lines of evidence to examine the effects of land application of MWOO containing microplastics in three soils to a variety of terrestrial biota. Treatments included unamended soil, MWOO-amended soil and MWOO-amended soil into which additional high-density polyethylene (HDPE), polyethylene terephthalate (PET), or polyvinyl chloride (PVC) microplastics were added. Tests were conducted in soil media that had been incubated for 0, 3 or 9 months. Addition of microplastics had no significant negative effect on wheat seedling emergence, wheat biomass production, earthworm growth, mortality or avoidance behaviour and nematode mortality or reproduction compared to controls. There was also little evidence the microplastics affected microbial community diversity, although measurements of microbial community structure were highly variable with no clear trends., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Recent studies have demonstrated the occurrence of microplastic fibers (MFs) in soil environments. To determine whether MFs are harmful for soil biota, we evaluated toxic effects on terrestrial snails (Achatina fulica) after 28 d exposure to polyethylene terephthalate MFs at concentrations of 0.01-0.71 g kg -1 (dry soil weight). Digestion kinetics experiments on 24 snails showed that MFs can be ingested and excreted within 48 h. We found the appearance of cracks and deterioration on the surface of MFs after depuration by the digestive system. Prolonged exposure to 40 snails showed that 0.14-0.71 g kg -1 MFs caused an average reduction of 24.7-34.9% food intake and 46.6-69.7% excretion. 0.71 g kg -1 MFs induced significant villi damage in the gastrointestinal walls of 40% snails, but did not influence the histology of the liver and kidney. Moreover, 0.71 g kg -1 MFs exposure reduced glutathione peroxidase (59.3 ± 13.8%) and total antioxidant capacity (36.7 ± 8.5%), but elevated malondialdehyde level (58.0 ± 6.4%) in the liver, which indicates oxidative stress is involved in the toxic mechanism. Our results suggest that MFs have adverse impacts on the fitness of soil organisms, and highlight the ecological risks of microplastic pollution in terrestrial ecosystems., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Poor haemocompatibility of material surfaces is a serious limitation that can lead to failure of blood-contacting devices and implants. In this work, we have improved the haemocompatibility of polyethylene terephthalate (PET) surfaces by immobilizing apyrase/ecto-nucleoside triphosphate diphosphohydrolase (NTPDase) on to the carboxylated PET. NTPDase immobilized PET surfaces scavenge the ADP released by activated platelets, which prevents further platelet activation and aggregation. The surface properties of the modified PET were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDAX), and contact angle measurement. The enzyme attachment and stability on the modified PET surfaces were evaluated. The kinetics of free enzyme and immobilized enzyme were studied and fitted using the Michaelis-Menten kinetic model. Both free and immobilized NTPDase followed Michaelis-Menten kinetics with similar Michaelis-Menten constants (K m ). This suggests that the activity of NTPDase was unchanged upon immobilization. Protein adsorption and %hemolysis was significantly reduced for carboxylated PET and NTPDase immobilized PET surfaces compared to unmodified PET. Lactate dehydrogenase assay showed that the number of adhered platelets reduced by more than an order of magnitude for the NTPDase immobilized PET surface compared to unmodified PET. These results clearly indicate that NTPDase immobilization significantly enhances the haemocompatibility of PET surfaces.

Herein, we designed and constructed a dual functional surface with antimicrobial and antifouling abilities to prevent protein and bacterial attachment that are significant challenges in biomedical devices. Primary amino-group-capped sulfobetaine of DMMSA was synthesized and then grafted onto polydopamine pretreated PET sheets via click chemistry. The sheets were subsequently immersed into silver ion solution, in which the absorbed silver ions were reduced to silver nanoparticles (AgNPs) in situ by a polydopamine layer. The antifouling assays demonstrated that the resultant PET/DMMSA/AgNPs sheets exhibited great antifouling performances against bovine serum albumin (BSA), bovine fibrinogen (BFG), platelets, and bacteria, the critical proteins/microorganisms leading to implant failure. The antibacterial data suggested that the sheets had dual functions as inhibitors of bacterial growth and bactericide and could efficiently delay the biofilm formation. This repelling and killing approach is green and simple, with potential biomedical applications.

In spite of advances have been made during the past decades, the problems associated with small-diameter vascular grafts, including low patency and compliance mismatch and in consequence of that thrombosis, aneurysm and intimal hyperplasia are still challenges. To address these problems, net polyurethane (PU) and poly (ethylene terephthalate) (PET) polymers and hybrid PU/PET were electrospun to create three different types of small-diameter vascular scaffolds due to their unique physicochemical characteristics: PU, PET, and novel hybrid PU/PET scaffolds. The results show that the PU and PET composite can improve the mechanical properties of the tissue-engineered vascular scaffolds in the range of the native vessels where the non-cytotoxicity characteristic of these well-known polymers is still immutable. The compliance and stiffness factor of the fabricated hybrid scaffolds were 4.468 ± 0.177 and 22.718 ± 0.896%/0.01 mmHg, respectively, which were significantly different with that of the net PU and PET electrospun scaffolds. Other properties such as ultimate tensile stress (UTS) (3.56 ± 1.21 MPa) were also in good accordance with the native vessels. Furthermore, FT-IR analysis testified the presence of both PU and PET in the hybrid scaffolds. Overall, we were able to fabricate a hybrid scaffold as a small-diameter vascular graft that mechanically matched the gold standard of blood vessel substitution.

Over the past decade, microscopic plastic debris, known as microplastics, emerged as a contaminant of concern in marine and freshwater ecosystems. Although regularly detected in aquatic environments, the toxicity of those synthetic particles is not well understood. To address this, we investigated whether the exposure to microplastics adversely affects the amphipod Gammarus pulex, a key freshwater invertebrate. Juvenile (6-9 mm) and adult (12-17 mm) individuals were exposed to irregular, fluorescent polyethylene terephthalate fragments (PET, 10-150 μm; 0.8-4,000 particles mL -1 ) for 24 h. Results show that body burden after 24 h depends on the dose and age of G. pulex with juveniles ingesting more microplastics than adults. After chronic exposure over 48 d, microplastics did not significantly affect survival, development (molting), metabolism (glycogen, lipid storage) and feeding activity of G. pulex. This demonstrates that even high concentrations of PET particles did not negatively interfere with the analyzed endpoints. These results contradict previous research on marine crustaceans. Differences may result from variations in the exposure regimes (e.g., duration, particle concentrations), plastic characteristics (e.g., type, size, shape, additives) as well as the species-specific morphological, physiological and behavioral traits. As a detritivorous shredder G. pulex is adapted to feed on non-digestible materials and might, therefore, be less sensitive towards exposure to synthetic particles. Accordingly, we argue that the autecology needs to be taken into account and that research should focus on identifying traits that render species susceptible to microplastic exposure., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Large amounts of plastic end up in the oceans every year where they fragment into microplastics over time. During this process, microplastics and their associated plasticizers become available for ingestion by different organisms. This study assessed the effects of microplastics (Polyethylene terephthalate; PET) and one plasticizer (Di(2-ethylhexyl)phthalate; DEHP) on mortality, productivity, population sizes and gene expression of the calanoid copepod Parvocalanus crassirostris. Copepods were exposed to DEHP for 48h to assess toxicity. Adults were very healthy following chemical exposure (up to 5120µg L -1 ), whereas nauplii were severely affected at very low concentrations (48h LC 50 value of 1.04 ng L -1 ). Adults exposed to sub-lethal concentrations of DEHP (0.1-0.3µg L -1 ) or microplastics (10,000-80,000 particles mL -1 ) exhibited substantial reductions in egg production. Populations were exposed to either microplastics or DEHP for 6 days with 18 days of recovery or for 24 days. Populations exposed to microplastics for 24 days significantly depleted in population size (60±4.1%, p<0.001) relative to controls, whilst populations exposed for only 6 days (with 18 days of recovery) experienced less severe depletions (75±6.0% of control, p<0.05). Populations exposed to DEHP, however, exhibited no recovery and both treatments (6 and 24 days) yielded the same average population size at the termination of the experiment (59±4.9% and 59±3.4% compared to control; p<0.001). These results suggest that DEHP may induce reproductive disorders that can be inherited by subsequent generations. Histone 3 (H3) was significantly (p<0.05) upregulated in both plastic and DEHP treatments after 6 days of exposure, but not after 18 days of recovery. Hsp70-like expression showed to be unresponsive to either DEHP or microplastic exposure. Clearly, microplastics and plasticizers pose a serious threat to zooplankton and potentially to higher trophic levels., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The development of a scheme for the safety evaluation of mechanical recycling processes for polyethylene terephthalate (PET) is described. The starting point is the adoption of a threshold of toxicological concern such that migration from the recycled PET should not give rise to a dietary exposure exceeding 0.0025 μg kg(-1) bw day(-1), the exposure threshold value for chemicals with structural alerts raising concern for potential genotoxicity, below which the risk to human health would be negligible. It is practically impossible to test every batch of incoming recovered PET and every production batch of recycled PET for all the different chemical contaminants that could theoretically arise. Consequently, the principle of the safety evaluation is to measure the cleaning efficiency of a recycling process by using a challenge test with surrogate contaminants. This cleaning efficiency is then applied to reduce a reference contamination level for post-consumer PET, conservatively set at 3 mg kg(-1) PET for a contaminant resulting from possible misuse by consumers. The resulting residual concentration of each contaminant in recycled PET is used in conservative migration models to calculate migration levels, which are then used along with food consumption data to give estimates of potential dietary exposure. The default scenario, when the recycled PET is intended for general use, is that of an infant weighing 5 kg and consuming every day powdered infant formula reconstituted with 0.75 L of water coming from water bottles manufactured with 100% recycled PET. According to this scenario, it can be derived that the highest concentration of a substance in water that would ensure that the dietary exposure of 0.0025 µg kg(-1) bw day(-1) is not exceeded, is 0.017 μg kg(-1) food. The maximum residual content that would comply with this migration limit depends on molecular weight and is in the range 0.09-0.32 mg kg(-1) PET for the typical surrogate contaminants.

The purpose of this study was to investigate the impact of temperature on the release of PET-bottle constituents into water and to assess the potential health hazard using in vitro bioassays with bacteria and human cell lines. Aldehydes, trace metals and other compounds found in plastic packaging were analysed in PET-bottled water stored at different temperatures: 40, 50, and 60°C. In this study, temperature and the presence of CO2 increased the release of formaldehyde, acetaldehyde and antimony (Sb). In parallel, genotoxicity assays (Ames and micronucleus assays) and transcriptional-reporter gene assays for estrogenic and anti-androgenic activity were performed on bottled water extracts at relevant consumer exposure levels. As expected, and in accordance with the chemical formulations specified for PET bottles, neither phthalates nor UV stabilisers were present in the water extracts. However, 2,4-di-tert-butylphenol, a degradation compound of phenolic antioxidants, was detected. In addition, an intermediary monomer, bis(2-hydroxyethyl)terephthalate, was found but only in PET-bottled waters. None of the compounds are on the positive list of EU Regulation No. 10/2011. However, the PET-bottled water extracts did not induce any cytotoxic, genotoxic or endocrine-disruption activity in the bioassays after exposure., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Plasticizers or plastic materials such as phthalates, bisphenol-A (BPA), and styrene are widely used in the plastic industry and are suspected endocrine-disrupting chemicals (EDC). Although plastic materials such as polypropylene (PP) and polyethylene terephthalate (PET) are not EDC and are considered to be safe, their potential properties as EDC have not been fully investigated. In this study, plastic samples eluted from plastic food containers (PP or PET) were investigated in Sprague-Dawley rats using Hershberger and uterotrophic assays. In the Hershberger assay, 6-wk-old castrated male rats were orally treated for 10 consecutive days with plastic effluent at 3 different doses (5 ml/kg) or vehicle control (corn oil, 1 ml/100 g) to determine the presence of both anti-androgenic and androgenic effects. Testosterone (0.4 mg/ml/kg) was subcutaneously administered for androgenic evaluation as a positive control, whereas testosterone (0.4 mg/ml/kg) and flutamide (3 mg/kg/day) were administered to a positive control group for anti-androgenic evaluation. The presence of any anti-androgenic or androgenic activities of plastic effluent was not detected. Sex accessory tissues such as ventral prostate or seminal vesicle showed no significant differences in weight between treated and control groups. For the uterotrophic assay, immature female rats were treated with plastic effluent at three different doses (5 ml/kg), with vehicle control (corn oil, 1 ml/100 g), or with ethinyl estradiol (3 μg/kg/d) for 3 d. There were no significant differences between test and control groups in vagina or uterine weight. Data suggest that effluents from plastic food containers do not appear to produce significant adverse effects according to Hershberger and uterotrophic assays.

Whereas the nature of healing reaction in skeletal muscle following implantation of biomaterial has been extensively studied, the extent of variation in cell phenotypes is poorly known. Here, we studied the phenotypic alteration of cell types following injury in skeletal muscle of rabbits implanted with a commonly used biomaterial, polyethylene terephthalate (PET) fabric. Following implantation, histomorphological features were studied after 1, 4, and 12 weeks. Routine objective histomorphological evaluation was supplemented with histochemistry for collagen and immunohistochemistry for proliferating cell nuclear antigen (PCNA), CD34, vimentin, and alpha smooth muscle actin (α-SMA). The extent of reaction was quantified. The foreign body giant cells were found to comprise subpopulations, based on the variation in vimentin detectability or the presence of differentially capable proliferating nuclei (PCNA positive). Many rhabdomyocytes adjacent to the implant were PCNA-positive and some of them showed CD34 positivity. Often, the rhabdomyocytes very near to implanted PET fabric assumed a myofibroblast phenotype as evidenced by vimentin and/or α-SMA positivity at immunohistochemistry. Overall, the results suggested a phenotypic alteration of native cell types following implantation of PET fabric in rabbit skeletal muscle. Quantification of such cell types at the tissue-material interphase in relation to the deposition of collagen may be desirable during safety evaluation of biomaterials by histomorphology.

Non-woven polyethylene terephthalate (PET) fibers produced via melt blowing and compounded into a 6 mm diameter 3D tubular scaffold were developed with artery matching mechanical properties. This work compares the effects of ethylene oxide (EtO) and low temperature plasma (LTP) sterilization on PET surface chemistry and biocompatibility. As seen through X-ray photoelectron spectroscopy (XPS) analysis, LTP sterilization led to an increase in overall oxygen content and the creation of new hydroxyl groups. EtO sterilization induced alkylation of the PET polymer. The in vitro cytotoxicity showed similar fibroblastic viability on LTP- and EtO-treated PET fibers. However, TNF-α release levels, indicative of macrophage activation, were significantly higher when macrophages were incubated on EtO-treated PET fibers. Subcutaneous mice implantation revealed an inflammatory response with foreign body reaction to PET grafts independent of the sterilization procedure., (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Though microbially safe, concerns have been raised about the genotoxic/mutagenic quality of solar-disinfected drinking water, which might be compromised as a result of photodegradation of polyethylene terephthalate (PET) bottles used as SODIS reactors. This study assessed genotoxic risk associated with the possible release of genotoxic compounds into water from PET bottles during SODIS, using the Ames fluctuation test. Negative genotoxicity results were obtained for water samples that had been in PET bottles and exposed to normal SODIS conditions (strong natural sunlight) over 6 months. Under SODIS conditions, bottles were exposed to 6 h of sunlight, followed by overnight room temperature storage. They were then emptied and refilled the following day and exposed to sunlight again. Genotoxicity was detected after 2 months in water stored in PET bottles and exposed continuously (without refilling) to sunlight for a period ranging from 1 to 6 months. However, similar genotoxicity results were also observed for the dark control (without refill) samples at the same time-point and in no other samples after that time; therefore it is unlikely that this genotoxicity event is related to solar exposure.

Background: Recent reports suggest that endocrine disruptors may leach into the contents of bottles made from polyethylene terephthalate (PET). PET is the main ingredient in most clear plastic containers used for beverages and condiments worldwide and has previously been generally assumed not to be a source of endocrine disruptors., Objective: I begin by considering evidence that bottles made from PET may leach various phthalates that have been putatively identified as endocrine disruptors. I also consider evidence that leaching of antimony from PET containers may lead to endocrine-disrupting effects., Discussion: The contents of the PET bottle, and the temperature at which it is stored, both appear to influence the rate and magnitude of leaching. Endocrine disruptors other than phthalates, specifically antimony, may also contribute to the endocrine-disrupting effect of water from PET containers., Conclusions: More research is needed in order to clarify the mechanisms whereby beverages and condiments in PET containers may be contaminated by endocrine-disrupting chemicals.

Spunbond, nonwoven fabrics consisting of polyethylene and polyethylene terephthalate, which meet food contact requirements, may be used as pouch materials for products containing food and/or flavor ingredients that are held in the mouth. In these situations ingestion may occur, resulting in exposure to the fabric and potentially antimony, a catalyst used in polyethylene terephthalate. To assess potential adverse effects when such a material is ingested, a 13 week dietary study in Sprague-Dawley CD rats and a Salmonella reverse mutation assay were conducted. Ground fabric was dosed at target concentrations of 0.5%, 2.5%, and 5% in the dietary study. Antimony trioxide in the polyethylene terephthalate was used to determine the test material concentration in the diet and was also assessed for bioavailability. Detectable levels of antimony were found in 2/20 blood samples of control rats, and in 20/20 high-dose group rats. No toxicologically relevant treatment related effects were observed in any of end points evaluated in the feeding study. In the mutagenicity assay, ground fabric was extracted in phosphate buffered saline or dimethysulfoxide and tested in Salmonella strains TA98, TA100, TA102, TA1535, and TA1537 with and without S9 activation. No mutagenic response was observed at any dose level tested. These results demonstrate that repeated daily ingestion of a spunbond, nonwoven polymer fabric consisting of polyethylene and polyethylene terephthalate for up to 13 weeks is well tolerated in rats, with no apparent target-organ toxicity at dietary levels up to 5%, and that fabric extracts are not mutagenic in a bacterial reverse mutation assay.

A comparative high-pressure liquid chromatography (HPLC) analysis of monomers, terephthalic acid (TPA), isophthalic acid (IPA), and dimethyl terephthalate (DMT) from polyethylene terephthalate (PET) food containers was conducted. Monomer linearities and sensitivities were calibrated between established and novel HPLC analyses. Safety of PET containers was evaluated with newly established detection methods for TPA, IPA, and DMT. Migration of the 3 monomers into food simulants (water, 4% acetic acid, 20% alcohol, and n-heptane) from 56 PET containers collected from open markets was monitored. Migrated monomers were not detected over 0.1 ppm of detection limit. The corresponding estimated daily intake was measured to confirm the safety of these publicly available PET containers and to permit comparison to the specific migration limit of the European Union. The estimated daily intake of 3 monomers migrating from PET was 0.0384 mg/kg each. This represented only 0.6% of the European Union's specific migration limit, confirming the safety of the examined containers.

The aim of the study was to evaluate the toxic and mutagenic effects of bottled purified and natural spring waters for drinking. The study presents the genotoxicologic results of drinking water samples packaged in polyethylene terephthalate (PET) bottles. Genotoxic agents have the potential to interact with DNA and may cause DNA damage. Endpoints analyzed included mitotic index (MI), replication index (RI), and sister chromatid exchange (SCE). An analysis of variance test (ANOVA) was performed to evaluate the results. A significant decrease in MI and RI was observed compared with negative control cultures, respectively, (p<0.05, p<0.01). It is found that SCE frequency increases compared with negative control. There is no significant difference between negative control and drinking water samples and among drinking water samples for sister chromatid exchange induction (p>0.05).

Host responses to biomaterials control the biological performance of implanted medical devices. Upon implantation, synthetic materials adsorb biomolecules, which trigger an inflammatory cascade comprising coagulation, leukocyte recruitment/adhesion, and foreign body reaction. The foreign body reaction and ensuing fibrous encapsulation severely limit the in vivo performance of numerous biomedical devices. While it is well established that plasma fibrinogen and secreted cytokines modulate leukocyte recruitment and maturation into foreign body giant cells, mediators of chronic inflammation and fibrous encapsulation of implanted biomaterials remain poorly understood. Using plasma fibronectin (pFN) conditional knock-out mice, we demonstrate that pFN modulates the foreign body response to polyethylene terephthalate disks implanted subcutaneously. Fibrous collagenous capsules were two-fold thicker in mice depleted of pFN compared to controls. In contrast, deletion of pFN did not alter acute leukocyte recruitment to the biomaterial, indicating that pFN modulates chronic fibrotic responses. The number of foreign body giant cells associated with the implant was three times higher in the absence of pFN while macrophage numbers were not different, suggesting that pFN regulates the formation of biomaterial-associated foreign body giant cells. Interestingly, cellular FN (cFN) was present in the capsules of both normal and pFN-depleted mice, suggesting that cFN could not compensate for the loss of pFN. These results implicate pFN in the host response to implanted materials and identify a potential target for therapeutic intervention to enhance the biological performance of biomedical devices.

The aim of this study was to ascertain the possible toxicological effects of chemicals released into mineral water packaged in polyethylene terephthalate (PET) bottles. Two commercial mineral waters, bottled both in PET and glass and stored under different conditions, were examined using the Allium cepa test. The influence of the water samples on macroscopic (root length, colour and form) and microscopic (root tip mitotic index, chromosome aberrations) parameters was examined. The water samples were analysed after: (A) controlled-condition storage (no direct light exposure and 18 +/- 2 degrees C), (B) storage at 40 degrees C for 10 days, in the dark (migration test in accordance with 82/711/EEC), and (C) exposure to sunlight and varying temperatures (18-38 degrees C, mean temperature 25 +/- 3 degrees C). The two water samples bottled in PET induced cytogenetic aberrations regardless of the storage conditions. These signs of toxicity were evident even only 8 weeks after bottling, which is well within the recommended expiry date. Storage conditions were very important, as is suggested by the finding that chromosomal aberrations were particularly apparent after exposure to direct sunlight. However, as plant systems are not considered as primary screening tools by current international guidelines for mammalian systems, extrapolation of the results from this test system to other systems and, eventually, to human beings should be based on results from a battery of assays covering various metabolic pathways.

Failures of small internal diameter vascular grafts have been caused by the lack of a stable endothelial lining to form on their artificial surfaces. Polymer surfaces can be optimized by means of proper treatment to allow a homogeneous and uniform coverage in artificial prosthesis applications. Several solutions were studied to improve cell attachment and growth on artificial materials. In the present study, polyethyleneterephthalate (PET) surfaces were treated by plasma processes with oxygen and ammonia and also in the presence of a gas mixture to verify the effect of functional groups grafting onto the endothelial cell growth. Related surface chemical modifications were investigated by X-ray photoelectron spectroscopy (XPS). Then using cytotoxicity and cytocompatibility tests, the biocompatibility of the modified PET surfaces was assessed by studying the behavior of human umbilical vein endothelial cells (HUVEC). The results showed that plasma-treated PET samples have no toxic effect on HUVEC. The cytocompatibility tests revealed an increase in cell growth with incubation time and the presence of well-spread and flattened cells (SEM analyses). Thus it is reported that plasma treatments can improve PET biocompatibility to HUVEC., (Copyright 2000 John Wiley & Sons, Inc.)

The influence of polyethylene terephthalate (PET) on the release of platelet derived growth factor AB (PDGF-AB) and basic fibroblast growth factor (bFGF) by in vitro cultured human endothelial cells was assessed by enzyme immunoassay. No significant differences were observed in the production of PDGF-AB with respect to the negative control cultures. A significant increase was observed in the production of bFGF after 48 and 72 h with respect to the negative control cultures. It can be concluded that PET may induce an increase in the production of basic FGF in endothelial cells.

This study proposed a new strategy assessing the health risks of mineral water packaging and compared the chemical analytical techniques and some in vitro cytotoxicological assays for the study of PVC and PET materials at the main stages of the manufacturing process of bottles. These evaluations were carried out with food simulant (deionized-endotoxin-tested water) and with natural mineral water in real conditions of packaging and storage (from 0 to 24 months). The complementarity of these two approaches is discussed. Some analytical and cytotoxic abnormalities were detected in the food simulant after contact with the batches of powdered PVC compound, PET resin and their intermediate steps of transformation (PVC-'paraison', PET-'perform'). But these results did not reflect the actual behaviour of the finished PVC and PET bottles, for which no major abnormality was detected in the natural mineral water.

Poly(ethylene terephthalate) film was modified with argon or perfluorohexane plasma to obtain hydrophilic or hydrophobic surfaces, respectively. Various biological experiments in vitro and in vivo were chosen in order to evaluate the influence of such treatment on biocompatibility. Plasma modification does not cause toxic effects and does not influence disadvantageously the tested polyester biocompatibility. The huge changes in surface energy cause only minor changes in the biological behaviour of the samples.

A long-term for possible carcinogenicity was conducted by subcutaneous implantation of 1 cm 2 pieces of polyethylenetherophthalate vascular grafts (PET-VG) to 150 BDF1 mice and 120 Syrian golden hamsters of either sex. A false operation was carried out in the same number of animals of control groups. Implantation was performed in nine-week-old animals. The observation period was 73 weeks for mice and 82 weeks for hamsters. A total of 161 tumors (81 in the experimental group) with 15 localizations were observed in mice and 43 tumors (20 in the experimental group) with 13 localizations--in hamsters. No pathological or statistical evidence of induction of tumors by PET-VG was found. It is concluded that under the conditions of this study PET-VG is not carcinogenic for BDF1 mice and Syrian golden hamsters of either sex.