RESUMO
Classically, particle-induced periprosthetic osteolysis at the implant-bone interface has explained the aseptic loosening of joint replacement. This response is preceded by triggering both the innate and acquired immune response with subsequent activation of osteoclasts, the bone-resorbing cells. Although particle-induced periprosthetic osteolysis has been considered a foreign body chronic inflammation mediated by myelomonocytic-derived cells, current reports describe wide heterogeneous inflammatory cells infiltrating the periprosthetic tissues. This review aims to discuss the role of those non-myelomonocytic cells in periprosthetic tissues exposed to wear particles by showing original data. Specifically, we discuss the role of T cells (CD3+, CD4+, and CD8+) and B cells (CD20+) coexisting with CD68+/TRAP- multinucleated giant cells associated with both polyethylene and metallic particles infiltrating retrieved periprosthetic membranes. This review contributes valuable insight to support the complex cell and molecular mechanisms behind the aseptic loosening theories of orthopedic implants.
Assuntos
Prótese Articular , Osteólise , Humanos , Osteólise/metabolismo , Prótese Articular/efeitos adversos , Osteoclastos/metabolismo , Inflamação/metabolismo , Polietileno/efeitos adversos , Polietileno/metabolismoRESUMO
Low-density polyethylene (LDPE), biaxially oriented polypropylene (BOPP), and expanded polystyrene (EXPS) are the most common plastics found in every home of the world, but only ~ 10% enter the recycling chains. Consequently, the study of plastic biodegradation by microorganisms and insects, such as the wax moths, has gained special interest. Galleria mellonella (L.) has been shown to consume single-layered polyethylene and polystyrene, though biological impacts of this consumption have been rarely reported. We evaluated the consumption of different plastics by G. mellonella larvae (L7, mean size: 25-30 mm) and its effect on larval duration, survival, and development. For this, we offered the larvae five diets: single-layered LDPE, EXPS, BOPP, triple-layered polyethylene (SB, for silo-bags), and a control with beeswax. We recorded the state and weight of the materials and the state of larvae until they reached the adult stage. Larvae consumed more PE (both LDPE and SB) and EXPS than BOPP; still, they were able to emerge as adults in all treatments. Larvae that consumed plastics turned into pupal stage faster than those that consumed beeswax, regardless of the type and amount of plastic consumed. This is the first report of wild G. mellonella larvae in Argentina consuming biaxially polypropylene and silo-bags.
Assuntos
Mariposas , Animais , Larva/metabolismo , Plásticos/metabolismo , Polietileno/metabolismo , Polipropilenos , Poliestirenos/metabolismoRESUMO
Despite the toxicity of microplastics (MPs) in freshwater fish has been demonstrated in previous studies, their effects when mixed with other pollutants (organic and inorganic) are poorly understood. Thus, we aimed to test the hypothesis that the association of polyethylene MPs (PE-MPs) to a mix of emerging pollutants induces more adverse genotoxic, mutagenic, and redox unbalance effects in adult zebrafish (Danio rerio), after 15 days of exposure. Although the accumulation of MPs in animals was greater in animals exposed to PE-MPs alone, erythrocyte DNA damage (comet assay) and the frequency of erythrocytic nuclear abnormalities (ENAs) evidenced in zebrafish exposed to PE-MPs alone were as pronounced as those observed in animals exposed to the mix of pollutant (alone or in combination with MPs), which constitutes the big picture of the current study. Moreover, we noticed that such effects were associated with an imbalance between pro-and antioxidant metabolism in animals, whose activity of superoxide dismutase (SOD) and catalase (CAT) was assessed in different organs which were not sufficient to counterbalance the production of reactive oxygen species [hydrogen peroxide (H2O2)] and nitrogen [nitric oxide (NO)] evaluated. The principal component analysis (PCA) also revealed that while the antioxidant activity was more pronounced in the brain and liver of animals, the highest production of H2O2 was perceived in the gills and muscles, suggesting that the biochemical response of the animals was organ-dependent. Thus, the present study did not demonstrate antagonistic, synergistic, or additive effects on animals exposed to the combination between PE-MPs and a mix of pollutants in the zebrafish, which reinforces the theory that interactions between pollutants in aquatic ecosystems may be as complex as their effects on freshwater ichthyofauna.
Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Animais , Antioxidantes/metabolismo , Dano ao DNA , Ecossistema , Poluentes Ambientais/análise , Peróxido de Hidrogênio/metabolismo , Microplásticos/toxicidade , Mutagênicos , Oxirredução , Plásticos/toxicidade , Polietileno/metabolismo , Polietileno/toxicidade , Poluentes Químicos da Água/análise , Peixe-Zebra/metabolismoRESUMO
Polyethylene-degrading bacteria have been emerging as a rational and safe alternative in bioremediation strategies. In this context, some Paenibacillus species produce enzymes involved in the biodegradation of pollutants. Among the enzymes involved in the biodegradation of polyethylene, the alkane hydroxylases, encoded by alkB homologous genes, play a key role in this process. Therefore, this study aimed to identify and perform a genomic investigation of the first polyethylene-degrading Paenibacillus sp. strain, named DK1. The whole-genome sequence-based analysis revealed that the DK1 strain belonged to the species Paenibacillus aquistagni and shared a total of 4327 CDSs with P. aquistagni strain 11. On the other hand, a comparison of the gene clusters showed that DK1 strain harbored a genetic context surrounding the alkB-like gene similar to that found in Pseudomonas sp. strains. The percentage of similarity ranged from 47.88 to 99.76% among all complete amino acid sequences of AlkB-like proteins analyzed. Nevertheless, the predicted amino acid sequences of AlkB-like contained typical structural motifs of alkane hydroxylases, such as His boxes and the HYG motif. These findings associated with the previously reported phenotypic results highlighted the potential of P. aquistagni strain DK1 to biodegrade polyethylene. Therefore, further studies focusing on the biochemical and structural properties of the AlkB-like protein from Paenibacillus may also contribute to the development of sustainable bioremediation strategies.
Assuntos
Citocromo P-450 CYP4A/genética , Paenibacillus/genética , Paenibacillus/metabolismo , Polietileno/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Citocromo P-450 CYP4A/metabolismo , DNA Bacteriano , Microbiologia Industrial , Paenibacillus/isolamento & purificação , Filogenia , Análise de Sequência de DNA , Instalações de Eliminação de Resíduos , Sequenciamento Completo do GenomaRESUMO
Plastic waste disposal in the environment is a major issue worldwide, whose effects on different biotas are the object of several investigations. The toxicity caused by microplastics (MPs) in organisms living in freshwater environments remains little explored. Little is known about the consequences of the exposure to these pollutants on the health of amphibians. Thus, we tested the hypothesis that the exposure of Physalaemus cuvieri tadpoles to microplastic polyethylene (PE MP) causes histopathological damage to their liver. Data collected after seven days of exposure to MPs (60â¯mg/L) have shown that pollutant bioaccumulation in tadpoles' liver was correlated to different histopathological changes (blood vessel dilation, infiltration, congestion, hydropic degeneration, hypertrophy and hyperplasia), which showed the histopathotoxicity of MPs. Furthermore, we observed changes in hepatocyte nuclei size (area and diameter), volume and shape induced by the exposure to PE MPs, a fact that evidenced the cytotoxic effect of these pollutants. To the best of our knowledge, the current study is the first to report the histopathotoxicity of PE MPs in representatives of the amphibian group, and it contributes to improving knowledge about these pollutants and how they may affect the health of these animals.
Assuntos
Larva/efeitos dos fármacos , Fígado/efeitos dos fármacos , Microplásticos/toxicidade , Polietileno/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Anuros , Bioacumulação , Brasil , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Fígado/metabolismo , Fígado/patologia , Microplásticos/metabolismo , Polietileno/metabolismo , Poluentes Químicos da Água/metabolismoRESUMO
The annual production of plastics has doubled over the past 15 years and, consequently, a large amount of plastic has accumulated in the environment generating ecological problems. In this study, a Paenibacillus sp. isolate was obtained from a landfill from Brazil and it presented the alkane hydroxylase gene (alkB). Weight loss of low-density polyethylene (LDPE) was measured and a significant difference in final weight compared to initial weight was assessed. Some chemical characteristics, such as bond scissions and formation of new functional groups [carboxylic acids (3300-2500 cm-1), esters (1210-1163 cm-1), and ethers (1075-1020 cm-1)], were detected by Fourier-transform infrared spectroscopy. Bacterial colonization on the plastic surface and physical changes, as formation of cracks and pits, was visualized by scanning electron microscopy. This isolate was susceptible to all the antimicrobials tested. Therefore, this isolate possesses great potential to degrade polyethylene and become an option for LDPE bioremediation.
Assuntos
Biodegradação Ambiental , Citocromo P-450 CYP4A/genética , Paenibacillus/metabolismo , Polietileno/metabolismo , Brasil , Microscopia Eletrônica de Varredura , Oxirredução , Paenibacillus/genética , Paenibacillus/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier , Instalações de Eliminação de ResíduosRESUMO
This study investigated occurrence of microplastic particles in digestive tracts of fishes from the Amazon River estuary. A total of 189 fish specimens representing 46 species from 22 families was sampled from bycatch of the shrimp fishery. Microplastic particles removed from fish gastrointestinal tracts were identified using Attenuated Total Reflectance - Fourier Transform Infrared (ATR-FTIR). In total, 228 microplastic particles were removed from gastrointestinal tracts of 26 specimens representing 14 species (30% of those examined). Microplastic particles were categorized as pellets (97.4%), sheets (1.3%), fragments (0.4%) and threads (0.9%), with size ranging from 0.38 to 4.16â¯mm. There was a positive correlation between fish standard length and number of particles found in gastrointestinal tracts. The main polymers identified by ATR-FTIR were polyamide, rayon and polyethylene. These findings provide the first evidence of microplastic contamination of biota from the Amazon estuary and northern coast of Brazil.
Assuntos
Peixes/metabolismo , Plásticos/metabolismo , Animais , Brasil , Celulose/análise , Celulose/metabolismo , Ingestão de Alimentos , Monitoramento Ambiental , Estuários , Peixes/classificação , Trato Gastrointestinal/química , Trato Gastrointestinal/metabolismo , Pandalidae/química , Pandalidae/classificação , Pandalidae/metabolismo , Plásticos/análise , Polietileno/análise , Polietileno/metabolismo , Rios/química , Alimentos Marinhos/análise , Poluentes Químicos da Água/análiseRESUMO
Discarded PE-based products pose a social and environmental threat because of their recalcitrance to degradation, a consequence of the unique set of PE's physicochemical properties. In this study we isolated nine novel PE-degrading bacteria from plastic debris found in soil of the savanna-like Brazilian Cerrado. These bacterial strains from the genera Comamonas, Delftia, and Stenotrophomonas showed metabolic activity and cellular viability after a 90-day incubation with PE as the sole carbon source. ATR/FTIR indicated that biodegraded PE undergone oxidation, vinylene formation, chain scission, among other chemical changes. Considerable nanoroughness shifts and vast damages to the micrometric surface were confirmed by AFM and SEM. Further, phase imaging revealed a 46.7% decrease in the viscous area of biodegraded PE whereas Raman spectroscopy confirmed a loss in its crystalline content, suggesting the assimilation of smaller fragments. Intriguingly, biodegraded PE chemical fingerprint suggests that these strains use novel biochemical strategies in the biodegradation process. Our results indicate that these microbes are capable of degrading unpretreated PE of very high molecular weight (191,000gmol-1) and survive for long periods under this condition, suggesting not only practical applications in waste management and environmental decontamination, but also future directions to understand the unraveled metabolism of synthetic polymers.
Assuntos
Comamonas/metabolismo , Delftia/metabolismo , Polietileno/análise , Poluentes do Solo/análise , Stenotrophomonas/metabolismo , Aderência Bacteriana , Brasil , Comamonas/isolamento & purificação , Delftia/isolamento & purificação , Viabilidade Microbiana , Óleo Mineral/análise , Óleo Mineral/metabolismo , Modelos Teóricos , Polietileno/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Stenotrophomonas/isolamento & purificaçãoRESUMO
We studied the biodegradation of green polyethylene (GP) by Pleurotus ostreatus. The GP was developed from renewable raw materials to help to reduce the emissions of greenhouse gases. However, little information regarding the biodegradation of GP discarded in the environment is available. P. ostreatus is a lignocellulolytic fungus that has been used in bioremediation processes for agroindustrial residues, pollutants, and recalcitrant compounds. Recently, we showed the potential of this fungus to degrade oxo-biodegradable polyethylene. GP plastic bags were exposed to sunlight for up to 120 days to induce the initial photodegradation of the polymers. After this period, no cracks, pits, or new functional groups in the structure of GP were observed. Fragments of these bags were used as the substrate for the growth of P. ostreatus. After 30 d of incubation, physical and chemical alterations in the structure of GP were observed. We conclude that the exposure of GP to sunlight and its subsequent incubation in the presence of P. ostreatus can decrease the half-life of GP and facilitate the mineralization of these polymers.
Assuntos
Biodegradação Ambiental , Pleurotus/metabolismo , Polietileno/metabolismoRESUMO
This study evaluated the influence of a high organic loading rate (OLR) on thermophilic hydrogen production at an up-flow anaerobic packed-bed reactor (APBR) treating a residual liquid stream of a Brazilian biorefinery. The APBR, filled with low-density polyethylene, was operated at an OLR of 84.2 kg-COD m(-3) d(-1). This value was determined in a previous study. The maximum values of hydrogen production and yield were 5,252.6 mL-H2 d(-1) and 3.7 mol-H2 mol(-1)(total carbohydrates), respectively. However, whereas the OLR remained constant, the specific organic load rate (sOLR) decreased throughout operation from 1.38 to 0.72 g-Total carbohydratesg-VS(-1) h(-1), this decrease negatively affected hydrogen production. A sOLR of 0.98 g-Total carbohydratesg-VS(-1) h(-1) was optimal for hydrogen production. The microbial community was studied using 454-pyrosequencing analysis. Organisms belonging to the genera Caloramator, Clostridium, Megasphaera, Oxobacter, Thermoanaerobacterium, and Thermohydrogenium were detected in samples taken from the reactor at operation days 30 and 60, suggesting that these organisms contribute to hydrogen production.