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1.
Ecotoxicol Environ Saf ; 187: 109788, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31648073

RESUMO

The potential threats of microplastics to global health are a new problem. However, little is known about the influence of microplastics on soil organisms. Here, we investigated the effects of low-density polyethylene (LDPE, < 400 µm) on earthworms (Eisenia fetida) under different concentrations (0.1, 0.25, 0.5, 1.0, 1.5 g/kg dry) with three replicates in artificial soil. Results showed that surface damage of earthworms was observed at the concentration of 1.5 g/kg LDPE after exposure 28 days. The microplastics were ingested in a dose-response manner. Smaller sizes of LDPE microplastics were found in the casts of E. fetida, and approximately 30% of the microplastics egested (size < 100 µm) were increased compared with initial microplastics in the soil. The catalase activity and malondialdehyde content increased significantly at the concentration of 1.0 g/kg LDPE after exposure 28 days, and acetylcholine esterase was significantly stimulated at concentrations of 1.5 and 1.0 g/kg LDPE on days 21 and 28, respectively. The results of this study demonstrate the potential risk of LDPE microplastics to E. fetida and may provide a reference for the impact of microplastics on terrestrial creatures.


Assuntos
/toxicidade , Oligoquetos/efeitos dos fármacos , Polietileno/toxicidade , Poluentes do Solo/toxicidade , Solo/química , Animais , Relação Dose-Resposta a Droga , Malondialdeído/metabolismo , Oligoquetos/metabolismo , Tamanho da Partícula , Polietileno/química , Poluentes do Solo/química
2.
Sci Total Environ ; 700: 134867, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31706091

RESUMO

Different studies have reported the ecotoxicological effects of polyethylene microplastics (PE MPs) on aquatic organisms; however, little is known about their toxicity in the early life stages of aquatic vertebrates living in freshwater ecosystems. Thus, the aim of the current study is to evaluate the toxicity of PE MPs throughout the development of Danio rerio after their static and semi-static exposure to different concentrations of these pollutants (6.2, 12.5, 25, 50 and 100 mg/L) - models were monitored at different time-periods, namely: 24, 48, 72, 96, 120 and 144 h. Based on the collected data, small PE MP concentrations have harmful effects on D. rerio embryos and larvae; the magnitude and characteristics of these effects depend on the adopted exposure system, which can be static or semi-static. PE MPs had negative effect on embryos' hatching rate in both exposure systems. However, the early hatching observed during the exposure through the static system could explain the lower larval survival rate after egg hatching. Nevertheless, PE MPs induced significant changes in various morphometric parameters. The present study is the first to assess the addressed topic; therefore, it is recommended to carry out future investigations to broaden the knowledge about PE MP toxicity.


Assuntos
/toxicidade , Polietileno/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos , Embrião não Mamífero , Peixe-Zebra/embriologia
3.
Chemosphere ; 240: 124855, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31542579

RESUMO

Plastic wastes are widespread pollutants in marine environments and several studies have focused on their impacts on different ecosystems. Microplastics (MPs, < 5 mm) have been the focus of a particularly extensive investigation because of their ubiquity, large surface area, interactions with organisms, and the challenges they present in terms of disposal and management. However, studies regarding their fates and life cycle in ecosystems are still limited. This study examined the effects of presence of food (the green microalga Dunaliella salina) on egestion rate of polyethylene MPs in the mussel Mytilus galloprovincialis. Ingestion and egestion rates were calculated after 6, 12, 18, and 24 h of depuration. The results suggest that MPs exposed to algal food persisted in the mussels. A single exposure of MPs without food induced relatively rapid excretion by the mussels compared to MPs exposure with food. This could be attributed to the ability of mussels to distinguish between nutritive foods and unusable suspended particles. Thus, environmental factors, such as food abundance, can affect the cycle or fate of MPs in marine environments.


Assuntos
Exposição Dietética/efeitos adversos , Mytilus/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Clorofíceas , Ecossistema , Ecotoxicologia , Mytilus/fisiologia , Polietileno/toxicidade
4.
Mar Pollut Bull ; 143: 140-143, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31789149

RESUMO

In this study, the acute toxicity of microplastics (MPs) on unicellular organisms as marine decomposers and microalgae was assessed, by evaluating standards endpoints included in International Standard Organization (ISO) protocols. The bacteria Vibrio fischeri and the diatom Phaeodactylum tricornutum were exposed to different sizes (1-500 µm) of polyethylene MPs in order to evaluate bioluminescence inhibition and microalgal growth. No acute toxicity was found on bacteria or microalgae in an order of magnitude above environmentally relevant concentrations, suggesting that tested MPs did not affect the investigated biological processes. In conclusion, standard ecotoxicological endpoints are not sufficiently sensitive to assess the potential effects of MPs on decomposers and primary producers, conversely to nanoplastics. These findings highlight that the current approach for MP risk assessment in unicellular species should be revised, by providing alternative endpoints to be included in standardized protocols, able to monitor the fate and biological effects of MPs.


Assuntos
Aliivibrio fischeri/efeitos dos fármacos , Diatomáceas/efeitos dos fármacos , Ecotoxicologia/métodos , Poluentes Químicos da Água/toxicidade , Microalgas/efeitos dos fármacos , Polietileno/toxicidade , Testes de Toxicidade Aguda
5.
Aquat Toxicol ; 216: 105296, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31541944

RESUMO

There is increasing concern about how microplastics (MPs) are impacting marine ecosystems. In particular, studies on how MPs impact microalgae are required because of the abundance of MPs and importance of green microalgae as primary producers. This study investigated how MPs that are larger (200 µm) than algal cells impact them, using the marine microalga Dunaliella salina as the test species. The microalga was exposed to polyethylene MPs for 6 days. Of interest, the growth and photosynthetic activity of D. salina was enhanced with exposure to MPs, while cell morphology (size and granularity) was not impacted. This phenomenon might be explained by trace concentrations of additive chemicals (endocrine disruptors, phthalates, stabilizers) that possibly leached from MPs promoting the growth and photosynthetic activity of D. salina. We also confirmed that MP size contributes towards determining how plastics affect microalgae. Specifically, as MP size shrinks compared to algal cell size, MPs have increasingly adverse effects. MPs of very small size (like nanoplastics) induce particularly adverse effects on algae. Further studies are required to establish the relationship between algal cell size and MP size.


Assuntos
Microalgas/efeitos dos fármacos , Microesferas , Tamanho da Partícula , Plásticos/toxicidade , Polietileno/toxicidade , Forma Celular/efeitos dos fármacos , Clorofila/metabolismo , Microalgas/citologia , Microalgas/crescimento & desenvolvimento , Fotossíntese/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade
6.
Environ Pollut ; 254(Pt B): 113094, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31479815

RESUMO

Research using various species of wild and cultured fish has identified negative effects of short-term exposure to microbeads. Although wild animals might be contaminated with microbeads and/or other pharmaceuticals, data regarding the long-term effects remain limited. To clearly elucidate the effects of microbeads, studies of long-term exposure using animal models are necessary. Our aim was to elucidate the effects of microbeads alone on the growth and fecundity of medaka following long-term exposure (12 weeks). In experiment 1, fish groups (except controls) were temporarily exposed to polyethylene microbeads (10-63 µm diameter) a low dose of 0.065 microbeads-mg/L and high dose of 0.65 microbeads-mg/L. In experiment 2, see-through medaka and fluorescent polyethylene microbeads (10-45 µm diameter) were used to estimate the retention time of ingested microbeads in the digestive tract, which was 4-9 days. The low dose of microbeads did not affect growth but did decrease the number of eggs and the hatching rate. The high dose decreased growth, the number of eggs, and hatching rate. Growth differences were recognized for the first time at 7 weeks, and differences in the number of eggs at 12 weeks. Thus, long-term tests using medaka indicated that microbeads per se exhibit growth inhibition and reproductive toxicity. These effects could be associated with nutritional factors resulting from the long retention time of microbeads in the digestive tract. We also determined the dose that affects only fecundity. This suggests that normal growth of medaka in the wild does not mean the environment is free from microbead contamination. We are thus attempting to identify new biological indexes for monitoring the status of microbead contamination using our system.


Assuntos
Microesferas , Oryzias/fisiologia , Polietileno/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Feminino , Intestinos/patologia , Masculino , Oryzias/crescimento & desenvolvimento , Reprodução/efeitos dos fármacos , Testes de Toxicidade
7.
Chemosphere ; 237: 124482, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31398608

RESUMO

The increase in the proportion of microplastics in the environment has intensified the interest in phthalate and microplastic contamination in recent years. In this study, we investigated the response of photosynthetic parameters and the antioxidant system of lettuce to di-n-butyl phthalate (DBP) stress and exposure to various concentrations of microplastic polyethylene (MP) for different durations (14 d and 28 d). Lettuce growth, photosynthetic parameters, and chlorophyll content were reduced significantly after MP- and DBP-only treatments and after the combined (MP + DBP) treatments with both pollutants (P < 0.05), when compared with the control. Our findings indicated that the exposure to MP can inhibit growth, hinder photosynthesis, and interfere with the antioxidant defense system in lettuce. Specifically, compared with the DBP-only treatment group, in all MP + DBP treatment groups, the lettuce growth parameters (dry and fresh weights of the leaves and roots and the number of leaves) decreased (P < 0.05). Moreover, the photosynthetic rate, stomatal conductance, transient transpiration rate, fluorescence parameters, chlorophyll content of leaves, and activity of Rubisco decreased, but the intercellular CO2 concentration increased in all MP + DBP treatment groups. The reduction in photosynthesis was attributed to the limitation of non-porosity and inhibition of the photoelectron flow, and the increase in exogenous MP content aggravated the effect of DBP on photosynthesis in lettuce. Compared with the DBP-only group, in all MP + DBP treatment groups, the content of superoxide radicals and hydrogen peroxide in lettuce leaves and roots increased. Antioxidant levels increased with the increase in MP content, except in the 1.0 mg mL-1 MP treatment after 14 d. Although the antioxidant system exhibited certain protective effects in the latter treatment, the cell membranes were still damaged. The degree of damage to cells decreased with the growth of lettuce, but the damage to root tissue always remained higher than that of the leaves. In conclusion, exposure to exogenous MP exacerbated the damage to lettuce by DBP.


Assuntos
Dibutilftalato/toxicidade , Alface/efeitos dos fármacos , Polietileno/toxicidade , Antioxidantes/metabolismo , Clorofila/metabolismo , Peróxido de Hidrogênio/metabolismo , Alface/fisiologia , Fotossíntese/efeitos dos fármacos , Ácidos Ftálicos , Folhas de Planta/metabolismo , Plásticos/metabolismo , Polietileno/metabolismo , Plântula/efeitos dos fármacos
8.
Ecotoxicol Environ Saf ; 182: 109442, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31352214

RESUMO

To identify the physical effects, behavioral changes, and gene expression profiles of the phase 1 detoxification-related gene (cyp 1a) and oogenesis-related gene (vtg 1) induced by microplastics, high-density polyethylene microplastics of various sizes were used because of their dominance in coastal areas and effluent samples in Hong Kong. Adult zebrafish were used as the model organism to identify the upper and lower boundaries of microplastics ingestion and were exposed to individual polyethylene microplastics in five size ranges (10-22 µm, 45-53 µm, 90-106 µm, 212-250 µm, and 500-600 µm) at a concentration of 2 mg/L for 96 h. To study behavioral changes and targeted gene expression profiles via real-time PCR (qPCR), a mixture of microplastics in three size ranges at effluent-related (11 particles/L), moderate (110 particles/L), and high concentrations (1,100 particles/L) were applied for 96 h. The zebrafish behavior was recorded by a video camera and by two observers (interrater reliability, >85%). The results implied that the upper and lower size boundaries for microplastic ingestion were 558.4 ±â€¯26.2 µm (yellow) and 19.7 ±â€¯3.1 µm (red), respectively. In addition, 61 ±â€¯10% of fish in medium concentration treatments and 61 ±â€¯10% of fish in high concentration treatments were found with the microplastic ingestion and remaining in their intestine. In addition, 28 ±â€¯10% of fish in high concentration treatments were found with microplastic retaining in their gills (No. of fishes = 18 in each treatment). The presence of microplastics, which occupied 89 ±â€¯6% of intestine area, reduced the voids inside the intestine for feed. The expression of cyp1a in the intestine (medium concentration) and vtg1 in the liver (medium and high concentration) showed significant up-regulation, and abnormal behavior (i.e., seizures and tail bent downward) was observed (medium and high concentration). In summary, the effects on the aryl hydrocarbon receptor (AHR) pathway, disruption of the oogenesis process, and neurotoxicity could be caused by acute exposure of adult zebrafish to microplastics.


Assuntos
Plásticos/toxicidade , Polietileno/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Brânquias/efeitos dos fármacos , Hong Kong , Reprodutibilidade dos Testes , Testes de Toxicidade Aguda , Peixe-Zebra/metabolismo
9.
Mar Pollut Bull ; 142: 54-57, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31232336

RESUMO

Plastic debris in the oceans is a major and growing problem in global environmental pollution. There are increasing concerns that plastic debris is a source of contaminant, either added during manufacturing or adsorbed from the environment. However, there is little information about the acute toxicity of leachates from plastic debris on marine organisms. In this study, we conducted experiments to evaluate the toxicity of leachates from two single-use polyethylene plastic bags (PB1 and PB2) with the embryo and larvae of the commercial clam Meretrix meretrix. Results showed that fertilization of the embryos was not affected by plastic leachates, but the developments of D-veliger larvae, including survival, deformity, and shell height, were significantly affected by plastic leachates from both PB1 and PB2 compared to the controls of filtered seawater. We speculate that compounds leaching from plastic bags are responsible for the observed toxicity. Therefore, leaching toxicity from plastic debris should be considered when assessing the risks of plastic pollution in the oceans.


Assuntos
Bivalves/efeitos dos fármacos , Polietileno/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Bivalves/crescimento & desenvolvimento , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Alimentos Marinhos , Água do Mar
10.
Environ Pollut ; 252(Pt A): 522-531, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31167160

RESUMO

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.


Assuntos
Biota/efeitos dos fármacos , Polietilenotereftalatos/toxicidade , Polietileno/toxicidade , Cloreto de Polivinila/toxicidade , Poluentes do Solo/toxicidade , Agricultura , Animais , Austrália , Biomassa , Nematoides/crescimento & desenvolvimento , New South Wales , Oligoquetos/crescimento & desenvolvimento , Reciclagem , Solo/química , Poluentes do Solo/análise , Triticum/crescimento & desenvolvimento , Gerenciamento de Resíduos
11.
Sci Total Environ ; 672: 862-868, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30978548

RESUMO

Microplastics (MPs) are emerging contaminants of freshwater ecosystems. Once in aquatic systems, most of these plastic particles undergo processes of fragmentation, biofouling, and sedimentation, resulting in increased concentrations of smaller sized and irregularly-shaped particles in the sediment. High levels of MPs in freshwater sediments can denote a potential threat to benthic and sediment-dwelling organisms such as dipteran larvae. This study evaluates the ecotoxicological effect of three pools of irregularly-shaped polyethylene (PE) microplastics (pools containing 90% of the particles within 32-63 µm (size-class A), 63-250 µm (size-class B) and 125-500 µm (size-class C)), with concentrations ranging from 1.25 to 20 g Kg-1 sediment, on the dipteran Chironomus riparius life-history traits. After ten days of exposure, larvae ingested PE particles typically in the 32-63 µm range, even when 90% of the particles possessed higher size (i.e., in size-classes B and C) and the larvae mandible allowed the ingestion of such bigger-sized particles. Thus, the number of ingested particles was higher in size-class A, followed by B and C, and led to a significant reduction with similar magnitude on larval growth (Lowest Observed Effect Concentrations (LOEC) = 2.5 g Kg-1 sediment DW) and a significant delay on imagoes emergence (e.g., LOEC = 1.5 g Kg-1 sediment DW for females). The results from this study show that the ingestion and persistence of small-sized polyethylene microplastics caused significant impairments on life-history traits of C. riparius. Considering their role on freshwater food-webs and the potential persistence of small-sized PE particles in their larval gut, these results also point for the potential adverse effects of small-sized microplastics at the community and ecosystem level.


Assuntos
Chironomidae/fisiologia , Exposição Dietética/estatística & dados numéricos , Plásticos/análise , Polietileno/análise , Poluentes Químicos da Água/análise , Animais , Monitoramento Ambiental , Cadeia Alimentar , Sedimentos Geológicos , Traços de História de Vida , Tamanho da Partícula , Plásticos/toxicidade , Polietileno/toxicidade , Poluentes Químicos da Água/toxicidade
12.
Environ Pollut ; 247: 890-897, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30735918

RESUMO

Microplastics (MPs) are an emerging contaminant and are confirmed to be ubiquitous in the environment. Adverse effects of MPs on aquatic organisms have been widely studied, whereas little research has focused on soil invertebrates. We exposed the soil springtail Folsomia candida to artificial soils contaminated with polyethylene MPs (<500 µm) for 28 d to explore the effects of MPs on avoidance, reproduction, and gut microbiota. Springtails exhibited avoidance behaviors at 0.5% and 1% MPs (w/w in dry soil), and the avoidance rate was 59% and 69%, respectively. Reproduction was inhibited when the concentration of MPs reached 0.1% and was reduced by 70.2% at the highest concentration of 1% MPs compared to control. The half-maximal effective concentration (EC50) value based on reproduction for F. candida was 0.29% MPs. At concentrations of 0.5% dry weight in the soil, MPs significantly altered the microbial community and decreased bacterial diversity in the springtail gut. Specifically, the relative abundance of Wolbachia significantly decreased while the relative abundance of Bradyrhizobiaceae, Ensifer and Stenotrophomonas significantly increased. Our results demonstrated that MPs exerted a significant toxic effect on springtails and can change their gut microbial community. This can provide useful information for risk assessment of MPs in terrestrial ecosystems.


Assuntos
Artrópodes/fisiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Polietileno/toxicidade , Poluentes do Solo/toxicidade , Animais , Artrópodes/efeitos dos fármacos , Aprendizagem da Esquiva , Bactérias , Microbiota , Plásticos/toxicidade , Reprodução/efeitos dos fármacos , Solo
13.
Mar Pollut Bull ; 138: 58-62, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30660309

RESUMO

Planktonic sea-urchin larvae actively ingest polyethylene microplastics (MP) that accumulate in the larval stomach and can be distinguished from natural food using polarized light microscopy. MP filtering rates were similar to those of natural particles (microalgae) of the same size range; 0.30 to 0.35 mL min-1. However, the ingestion of MP did not increase the toxicity of a hydrophobic organic chemical, the 4­n­nonylphenol (NP), either in microalgae-fed or starved larvae. The 48 h EC50 of NP was more than two fold higher in fed (158.8 to 190.9 µg L-1) compared to starved larvae (64.3 to 83.7 µg L-1), disregarding the presence and amount of MP, which did not significantly affect larval growth. Therefore, MP did not act as vectors of a hydrophobic chemical such as NP to these planktonic organisms. These results challenge the hypothetical role of MP as vectors of organic contaminants to marine food webs.


Assuntos
Exposição Dietética/efeitos adversos , Fenóis/toxicidade , Polietileno/toxicidade , Ouriços-do-Mar/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Zooplâncton/efeitos dos fármacos , Animais , Conteúdo Gastrointestinal , Larva/efeitos dos fármacos , Microalgas , Plásticos
14.
Environ Pollut ; 246: 509-517, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30583159

RESUMO

Toxicity of single microplastics on organisms has been reported widely, however, their joint toxicity with other contaminants on phytoplankton is rarely investigated. Here, we studied the toxicity of triclosan (TCS) with four kinds of microplastics namely polyethylene (PE, 74 µm), polystyrene (PS, 74 µm), polyvinyl chloride (PVC, 74 µm), and PVC800 (1 µm) on microalgae Skeletonema costatum. Both growth inhibition and oxidative stress including superoxide dismutase (SOD) and malondialdehyde (MDA) were determined. We found that TCS had obvious inhibition effect on microalgae growth within the test concentrations, and single microplastics also had significant inhibition effect which followed the order of PVC800 > PVC > PS > PE. However, the joint toxicity of PVC and PVC800 in combination with TCS decreased more than that of PE and PS. The higher adsorption capacity of TCS on PVC and PVC800 was one possible reason for the greater reduction of their toxicity. The joint toxicity of PVC800 was still most significant (PE < PVC < PS < PVC800) because of the minimum particle size. According to the independent action model, the joint toxicity systems were all antagonism. Moreover, the reduction of SOD was higher than MDA which revealed that the physical damage was more serious than intracellular damage. SEM images revealed that the aggregation of microplastics and physical damage on algae was obvious. Collectively, the present research provides evidences that the existence of organic pollutants is capable of influencing the effects of microplastics, and the further research on the joint toxicity of microplastics with different pollutants is urgent.


Assuntos
Diatomáceas/efeitos dos fármacos , Microalgas/crescimento & desenvolvimento , Fitoplâncton/efeitos dos fármacos , Plásticos/toxicidade , Polietileno/toxicidade , Poliestirenos/toxicidade , Cloreto de Polivinila/toxicidade , Triclosan/toxicidade , Poluentes Químicos da Água/toxicidade , Adsorção , Malondialdeído/análise , Microalgas/efeitos dos fármacos , Estresse Oxidativo , Tamanho da Partícula , Superóxido Dismutase/análise , Poluentes Químicos da Água/análise
15.
Environ Pollut ; 246: 423-434, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30579211

RESUMO

The contamination of marine ecosystems with microplastics, such as the polymer polyethylene, a commonly used component of single-use packaging, is of global concern. Although it has been suggested that biodegradable polymers, such as polylactic acid, may be used to replace some polyethylene packaging, little is known about their effects on marine organisms. Blue mussels, Mytilus edulis, have become a "model organism" for investigating the effects of microplastics in marine ecosystems. We show here that repeated exposure, over a period of 52 days in an outdoor mesocosm setting, of M. edulis to polyethylene microplastics reduced the number of byssal threads produced and the attachment strength (tenacity) by ∼50%. Exposure to either type of microplastic altered the haemolymph proteome and, although a conserved response to microplastic exposure was observed, overall polyethylene resulted in more changes to protein abundances than polylactic acid. Many of the proteins affected are involved in vital biological processes, such as immune regulation, detoxification, metabolism and structural development. Our study highlights the utility of mass spectrometry-based proteomics to assess the health of key marine organisms and identifies the potential mechanisms by which microplastics, both conventional and biodegradable, could affect their ability to form and maintain reefs.


Assuntos
Mytilus edulis/fisiologia , Plásticos/toxicidade , Proteoma/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Exposição Ambiental , Hemolinfa/química , Mytilus edulis/química , Poliésteres/toxicidade , Polietileno/toxicidade
16.
J Orthop Surg Res ; 13(1): 311, 2018 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-30522505

RESUMO

BACKGROUND: Commonly used contemporary orthopaedic sutures have been identified as a potential causative factor in the development of post-arthroscopic glenohumeral chondrolysis. Currently, little is known about the body's immune response to these materials. The aim of this study was to examine the biological response of synovial tissue to three commonly used orthopaedic sutures, using a murine airpouch model. METHODS: Fifty rats were used in this study (ten per group). An airpouch was created in each rat, and test materials were implanted. Test materials consisted of an intact polyethylene terephthalate suture with a polybutilate coating (suture A), an intact polyethylene suture braided around a central polydiaxannone core (suture B), an intact polyethylene/polyester cobraid suture with a silicone coating (suture C), and particles of suture C (particles C). Rats were sacrificed at 1 or 4 weeks following implantation. Histological (multinucleated giant cell count) and immunohistochemical (expression of matrix metalloproteinases MMP-1,-2,-3,-9,-13) markers of inflammation were examined. RESULTS: Multinucleated giant cells were present in all specimens containing suture material but not in the control specimens. No significant differences were found in the number of giant cells between the intact suture groups at either time point. Significantly higher numbers of giant cells were noted in the particles C group compared to the intact suture C group at both time points (p = 0.021 at 1 week, p = 0.003 at 4 weeks). Quantitative analysis of immunohistochemical staining expression at 4 weeks showed that significantly more MMP (-1,-2,-9,-13) was expressed in the particles C group than the intact suture C group (p = 0.024, p = 0.009, p = 0.002, and p = 0.007 for MMP-1, MMP-2, MMP-9, and MMP-13, respectively). No significant difference was seen in the expression of MMP-3 (p = 0.058). CONCLUSIONS: There were no differences observed between the biological reactivity of commonly used intact orthopaedic sutures A, B, and C. However, wear particles of suture C elicited a significantly greater inflammatory response than intact suture alone. This was confirmed by increased numbers of multinucleated giant cells as well as MMP ( -1,-2,-9,-13) expression. Further studies are needed to determine whether this inflammatory response may play a role in the development of post-arthroscopic glenohumeral chondrolysis or interfere with biological healing. These findings have important clinical implications relating to surgical technique and surgical implant design.


Assuntos
Mediadores da Inflamação/metabolismo , Teste de Materiais/métodos , Suturas/efeitos adversos , Membrana Sinovial/metabolismo , Animais , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Ácidos Ftálicos/administração & dosagem , Ácidos Ftálicos/toxicidade , Polietileno/administração & dosagem , Polietileno/toxicidade , Distribuição Aleatória , Ratos , Ratos Wistar , Técnicas de Sutura/efeitos adversos , Membrana Sinovial/efeitos dos fármacos , Membrana Sinovial/patologia
17.
Environ Sci Pollut Res Int ; 25(33): 33599-33610, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30276680

RESUMO

Soils are both a sink and a pathway of plastic wastes, but there is a great lack of knowledge regarding their impacts on soil biota. To tackle the mechanisms of toxicity of these contaminants to soil invertebrates, earthworms (Eisenia fetida Savigny, 1826) were exposed during 28 days to different concentrations of low-density polyethylene microplastics (62, 125, 250, 500 and 1000 mg MPs kg-1 soildw) with sizes ranging between 250 and 1000 µm, in an artificial soil. The ecotoxicological responses were evaluated by analysing various oxidative stress biomarkers (catalase, glutathione S-transferase and thiobarbituric acid reactive substances), a biomarker of energy metabolism (lactate dehydrogenase) and overall organism molecular changes by Fourier transform infrared spectrometry (FTIR) and nuclear magnetic resonance (NMR) analyses. Significant effects resulting from an unbalanced oxidative stress system, expressed in terms of thiobarbituric acid reactive substances levels were recorded on earthworms exposed at the three highest concentrations tested. Despite that, no significant changes were recorded on the molecular profiles of earthworms by FTIR-ATR. NMR analysis pointed out for differences from the control, only for earthworms exposed to the lowest concentration of MPs. Considering that stress responses are complex, and involve multiple mechanisms, a cluster analysis taking into account all the parameters assessed, clearly identified two groups of earthworms separated by the concentration of 250 mg MPs kg-1 soildw, above each meaningful effects were recorded.


Assuntos
Metabolismo Energético/efeitos dos fármacos , Oligoquetos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Polietileno/toxicidade , Poluentes do Solo/toxicidade , Animais , Biomarcadores/metabolismo , Catalase/metabolismo , Glutationa Transferase/metabolismo , Oligoquetos/metabolismo , Solo/química
18.
Cell Physiol Biochem ; 50(3): 1100-1112, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30355954

RESUMO

BACKGROUND/AIMS: Aseptic loosening is a common reason for failed artificial hip replacement after total hip arthroplasty. Aseptic loosening is mostly the result of wear debris that causes osteolysis and weakens the structures that support the prosthesis. Wear debris plays a crucial role in osteolysis during the loosening process, and polyethylene (PE) particles are found as wear debris more frequently than any other type of particle. In the absence of effective therapeutic agents, osteolysis has been hard to treat. Previous studies have demonstrated that curcumin influences signalosome-associated kinases and the proteasome-ubiquitin system during osteoclastogenesis. The aims of this study were to explore the anti-osteolysis effect of curcumin and if possible to identify the signaling pathway involved in a model of PE-induced osteolysis. METHODS: Differentiation of osteoclasts was induced in vitro by PE particles in RAW264.7 (monocyte/macrophage) cells and in vivo by calvarial and air pouch models of osteolysis established by PE stimulation in mice. We performed a set of TRAP staining, realtime polymerase chain reaction (PCR), and Western blot experiments to evaluate the anti-osteolytic effect of curcumin by comparing specimens that were exposed and not exposed to curcumin. RESULTS: Curcumin had a promising inhibitory effect on osteolysis induced by wear debris and suppressed the RANK/c-Fos/NFATc1 signaling pathway. CONCLUSION: Curcumin can prevent PE-induced osteolysis and bone loss. An inhibitory effect on the RANK/c-Fos/NFATc1 signaling pathway may explain the anti-osteolysis activity of curcumin.


Assuntos
Curcumina/farmacologia , Polietileno/toxicidade , Transdução de Sinais/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Curcumina/uso terapêutico , Quinase I-kappa B/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , NF-kappa B/metabolismo , Fatores de Transcrição NFATC/genética , Fatores de Transcrição NFATC/metabolismo , Osteoclastos/citologia , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Osteólise/patologia , Osteólise/prevenção & controle , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ligante RANK/metabolismo , Células RAW 264.7 , Crânio/diagnóstico por imagem , Crânio/patologia , Microtomografia por Raio-X
19.
Int J Nanomedicine ; 13: 4913-4926, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30214197

RESUMO

Introduction: The physiologic safety of devices and materials intended for clinical implantation should be evaluated. This study, a logical extension of our previous work, aimed to investigate the safety of a novel contraceptive device, the copper/low-density polyethylene nanocomposite intrauterine device (nano-Cu/LDPE IUD), through studies of its potential toxicity after acute and subchronic administration in mice and rats. Methods: For the acute toxicity study, single 50 mL/kg doses of nano-Cu/LDPE IUD extracts were administered to mice via intravenous or intraperitoneal injection. General behavioral adverse effects, mortality, and body weights were evaluated for up to 72 hours. In the 13-week subchronic toxicity study, the nano-Cu/LDPE composite with 10-fold higher than the standard clinical dose was implanted subcutaneously into the dorsal skin of Wistar rats. The control group underwent a sham procedure without material insertion. Results: During all acute study observation times, the biologic reactions of the mice in the nano-Cu/LDPE group did not differ from those observed in the control group. The groups did not differ statistically in terms of body weight gain, and no macroscopic changes were observed in any organs. In the subchronic study, no clinical signs of toxicity or mortality were observed in either the nano-Cu/LDPE or control group during the 13-week period. The nano-Cu/LDPE composite did not cause any alterations in body weight, food consumption, hematologic and biochemical parameters, or organ weight relative to the control for any observed sample group. Histopathologic examinations of the organs revealed normal architecture, indicating that the inserted material did not cause morphologic disturbances in the rats. Conclusion: Overall, the results indicate that the nano-Cu/LDPE IUD did not induce systemic toxicity under experimental conditions of the recommended standard practices, suggesting that the novel material IUD is safe and feasible for future contraceptive applications.


Assuntos
Cobre/toxicidade , Dispositivos Intrauterinos de Cobre/efeitos adversos , Nanocompostos/toxicidade , Polietileno/toxicidade , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Humanos , Masculino , Camundongos , Nanotecnologia , Tamanho do Órgão/efeitos dos fármacos , Especificidade de Órgãos/efeitos dos fármacos , Próteses e Implantes , Ratos Wistar
20.
BMC Res Notes ; 11(1): 567, 2018 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-30089517

RESUMO

OBJECTIVE: It is well established that polyethylene (PE) wear particles induce macrophage production of cytokines and mediators associated with the pathogenesis of inflammatory osteolysis. The objective of this study was to examine the potential of three Lactobacillus strains to attenuate the TNF-α cytokine response of macrophages exposed to Ceridust 3615 PE particles. An in vitro experimental model using the RAW 246.7 macrophage cell line and PE particles was utilized. RESULTS: Lactobacillus strains were found to modulate the cytokines in a strain and dose specific manner. Only the Lactobacillus acidophilus strain that was tested was able to attenuate PE particle-induced TNF-α production by RAW 246.7 macrophages. This effect was independent of IL-10 cytokine levels since all three strains of lactobacilli yielded comparable levels of IL-10. It was concluded that some, but not all, Lactobacillus strains may be useful in reducing the risk of inflammatory osteolysis and that further studies in appropriate in vivo models are warranted. Furthermore, this in vitro model can be used to evaluate the inflammatory potential of new materials being tested for use as joint implants.


Assuntos
Inflamação , Lactobacillus , Macrófagos/efeitos dos fármacos , Animais , Citocinas , Camundongos , Osteólise , Polietileno/toxicidade , Fator de Necrose Tumoral alfa
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