Uso de biomarcadores de contaminação ambiental na avaliação do impacto do vazamento de óleo derivado de petróleo em ecossistemas de água doce /

Orientador : Ciro Alberto de Oliveira RibeiroDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Ecologia e Conservaçao. Defesa: Curitiba, 2006Inclui bibliografiaÁrea de concentração : Ecotoxicologi

Polystyrene nanoplastics and microplastics can act as Trojan horse carriers of benzo(a)pyrene to mussel hemocytes in vitro

[EN]In this work we studied the ability of polystyrene (PS) nanoplastics (NPs) and microplastics (MPs) to transfer benzo(a)pyrene (BaP) to mussel hemocytes and to produce toxic effects in vitro. For this, intracellular fate and toxicity of PS NPs (0.05 μm) and MPs (0.5 and 4.5 μm) alone or with BaP and of BaP alone were assessed. Particles of 0.05 and 0.5 µm largely aggregated in the exposure medium whereas presence of BaP reduced particle aggregation. Cells internalized PS NPs and MPs alone or with BaP and these were found inside and outside lysosomes, depending on their size. PS particles alone or with BaP were cytotoxic to hemocytes only at the highest concentrations tested. The same was true for most sublethal endpoints except for increased phagocytic activity provoked by NPs and 0.5 μm MPs at lower concentrations. Plastic particles appeared to be the main drivers for reduced plasma membrane integrity and increased phagocytic and lysosomal activities whereas BaP appeared to contribute more to reduced cell viability and phagocytosis and increased ROS production and genotoxicity. Overall, PS NPs and MPs can act as carriers of BaP to mussel hemocytes, rising concerns about risks plastics associated to pollutants may pose to aquatic organisms.This work was carried out within the EU Project PLASTOX (JPI Oceans 005/2015) and was funded by the Spanish MINECO (NACE Project, CTM2016-81130-R) and Basque Government (Consolidated Research Groups Grant IT1302-19)

Functionalized Fluorescent Silica Nanoparticles for Bioimaging of Cancer Cells

Functionalized fluorescent silica nanoparticles were designed and synthesized to selectively target cancer cells for bioimaging analysis. The synthesis method and characterization of functionalized fluorescent silica nanoparticles (50–60 nm), as well as internalization and subcellular localization in HeLa cells is reported here. The dye, rhodamine 101 (R101) was physically embedded during the sol–gel synthesis. The dye loading was optimized by varying the synthesis conditions (temperature and dye concentration added to the gel) and by the use of different organotriethoxysilanes as a second silica precursor. Additionally, R101, was also covalently bound to the functionalized external surface of the silica nanoparticles. The quantum yields of the dye-doped silica nanoparticles range from 0.25 to 0.50 and demonstrated an enhanced brightness of 230–260 fold respect to the free dye in solution. The shell of the nanoparticles was further decorated with PEG of 2000 Da and folic acid (FA) to ensure good stability in water and to enhance selectivity to cancer cells, respectively. In vitro assays with HeLa cells showed that fluorescent nanoparticles were internalized by cells accumulating exclusively into lysosomes. Quantitative analysis showed a significantly higher accumulation of FA functionalized fluorescent silica nanoparticles compared to nanoparticles without FA, proving that the former may represent good candidates for targeting cancer cells.This research was funded by the Basque Government, grant numbers IT912-16 and IT-1302-19; Ministry of Economy and Competitiveness (MINECO), grant numbers MAT2017-83856-C3-3-P and CTM2016-81130-R; and the University of the Basque Country (UPV/EHU), grant number COLAB19/01

Cell and tissue level responses in mussels Mytilus galloprovincialis dietarily exposed to PVP/PEI coated Ag nanoparticles at two seasons

Silver nanoparticles (Ag NPs) are present in numerous consumer products due to their antimicrobial and other unique properties, thus concerns about their potential input into aquatic ecosystems are increasing. Toxicity of Ag NPs in waterborne exposed aquatic organisms has been widely investigated, but studies assessing the potential toxic effects caused after ingestion through the food web, especially at low realistic concentrations, remain scarce. Moreover, it is not well known whether season may influence toxic effects of Ag NPs. The main objective of this study was to determine cell and tissue level responses in mussels Mytilus galloprovincialis dietarily exposed to poly-N-vinyl-2-pirrolidone/polyethyleneimine (PVP/PEI) coated 5 nm Ag NPs for 1, 7 and 21 days both in autumn and spring. Mussels were fed every day with microalgae Isochrysis galbana exposed for 24 h to a low dose (1 mu g Ag/L Ag NPs) in spring and to a higher dose (10 mu g Ag/L Ag NPs) in spring and autumn. Mussels fed with microalgae exposed to the high dose accumulated Ag significantly after 21 days in both seasons, higher levels being measured in autumn compared to spring. Intralysosomal metal accumulation measured in mussel digestive gland and time- and dose-dependent reduction of mussels health status was similar in both seasons. DNA strand breaks increased significantly in hemocytes at both exposure doses along the 21 days in spring and micronuclei frequency showed an increasing trend after 1 and 7 days of exposure to 1 mu g Ag/L Ag NPs in spring and to 10 mu g Ag/L in both seasons. Values decreased after 21 days of exposure in all the cases. In conclusion, PVP/PEI coated 5 nm Ag NPs ingested through the food web were significantly accumulated in mussel tissues and caused adverse cell and tissue level effects both in autumn and in spring.This work has been funded by the Spanish Ministry of Economy and Competitiveness (Nano Silver Omics project MAT2012-39372), Basque Government (SAIOTEK project S-PE13UN142 and Consolidated Research Group GIC IT810-13 and IT1302-19), the University of the Basque Country UPV/EHU (UFI 11/37 and PhD fellowship to N.D.) and French Ministry of Higher Education and Research (PhD fellowship to M.M.)

Red haloBODIPYs as theragnostic agents: The role of the substitution at meso position

Three different molecular designs based on BODIPY dye have been proposed as photosensitizers (PSs) for photodynamic therapy (PDT) by the inclusion of halogen atoms (Iodine) at 2,6-positions and with extended conjugation at 3, 5-positions and varying the substitution at meso position. The synthesis is described and their main photophysical features including singlet oxygen production and triplet states were characterized by absorption and fluorescence spectroscopy (steady-state and time-correlated) and nanosecond transient absorption spectroscopy. The results were compared with the commercial Chlorin e6. The three new red-halogen-BODIPYs showed a great balance between singlet oxygen generation (Phi(Delta)>= 0.40) and fluorescence (Phi(fl)>= 0.22) for potential application on PDT, and particularly in theragnosis. In vitro experiments in HeLa cells were done to study their performance and to elucidate the best potential candidate for PDT.This research was funded by the Basque Government, grant numbers IT912-16, IT-1302-19 and IT1639-22. This work is supported by Min-isterio de Ciencia, Innovacion y Universidades-Agencia Estatal de Investigacion (MCI/AEI) , grant numbers MAT2017-83856-C3-2-P and 3-P, PID2020-114347RB-C32, PID2020-114755 GB-C32 and the Uni-versity of the Basque Country (UPV/EHU) , grant number COLAB19/01. R.P.M. thanks UPV/EHU for postdoctoral felowship (DOCREC 20/55) . Open Access funding is provided by University of Basque Country

Uso de biomarcadores de contaminação ambiental na avaliação do impacto do vazamento de óleo derivado de petróleo em ecossistemas de água doce /

Orientador : Ciro Alberto de Oliveira RibeiroDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Ecologia e Conservaçao. Defesa: Curitiba, 2006Inclui bibliografiaÁrea de concentração : Ecotoxicologi

Impacts of dietary exposure to different sized polystyrene microplastics alone and with sorbed benzo[a]pyrene on biomarkers and whole organism responses in mussels Mytilus galloprovincialis

Due to their hydrophobicity and relatively large surface area, microplastics (MPs) can act as carriers of hydrophobic pollutants in the ocean and may facilitate their transfer to organisms. This study examined effects of dietary exposure to polystyrene MPs of 0.5 and 45 mu m alone and with sorbed benzo[a]pyrene (BaP) on mussels Mytilus galloprovincialis in order to elucidate the effects of MP size and the presence of sorbed BaP on the organism. MPs were provided daily, mixed with algae, during 26 days at equivalent mass (0.058 mg/L), corresponding to 1000 particles/mL for 4.5 mu m MPs and to 7.44 x 10(5) particles/mL for 0.5 mu m MPs. Effects were determined on early cellular biomarkers in hemocytes, structure and cell type composition of digestive tubules (DTs), histopathology and whole organism responses (condition index (CI), clearance rate (CR), food absorption efficiency (AE), respiration rate (RR) and scope for growth (SFG)). BaP concentrations in mussels increased with time, in particular when sorbed to smaller MPs. Large MPs were abundant in the lumen of stomach and DTs, but were also occasionally found within epithelial cells. Effects in all treatments increased with exposure time. MPs with sorbed BaP were more toxic than MPs alone according to hemocyte viability and catalase activity and to the quantitative structure of DT epithelium. Higher toxicity of small MPs compared to larger ones was recorded for DNA damage and cell composition of DTs. At tissue level a slight increase in prevalence of inflammatory responses occurred in all exposed groups. At whole organism level a compensatory effect was observed on absorption efficiency across MP treatments at day 26, resulting in increased SFG in mussels exposed to small MPs with sorbed BaP. This could be related to an increased energy need to deal with stress observed in biomarkers. Further work is required to understand the Trojan horse effect of a variety of plastic type, size, shape combinations together with a wide variety of pollutants. (C) 2019 The Authors. Published by Elsevier B.V.This work was funded by Spanish MINECO (NACE project CTM2016-81130-R), Basque Government (consolidated group IT810-13) and predoctoral fellowship to NGS and UPV/EHU (UFI 11/37, VRI grant PLASTOX). Work carried out within EU project PLASTOX (JPI Oceans 005/2015)