Percorrer por autor "Rocha, Thiago Lopes"
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- Assessing cadmium-based quantum dots effect on the gonads of the marine mussel Mytilus galloprovincialisPublication . Gonçalves, Joanna M.; Rocha, Thiago Lopes; Nélia Mestre, N. C. Mestre, N. Mestre; Fonseca, T. G.; Bebianno, M.This study assesses the sex-specific effects induced by CdTe QDs, on the marine mussel Mytilus galloprovincialis in comparison to its dissolved counterpart. A 14 days exposure to CdTe QDs and dissolved Cd was conducted (10 mu g Cd L-1), analysing Cd accumulation, oxidative stress, biotransformation, metallothionein and oxidative damage in the gonads. Both Cd forms caused significant antioxidant alterations, whereby QDs were more pro-oxidant, leading to oxidative damage, being females more affected. Overall, biochemical impairments on gonads of M. galloprovincialis demonstrate that the reproductive toxicity induced by CdTe QDs in mussels are sex-dependent and mediated by oxidative stress and lipid peroxidation. It is crucial to acknowledge how gametes are affected by metal-based nanoparticles, such as Cd-based QDs. As well as understanding the potential changes they may undergo at the cellular level during gametogenesis, embryogenesis and larval development potentially leading to serious impacts on population sustainability and ecosystem health.
- Environmental behaviour and ecotoxicity of quantum dots at various trophic levels: A reviewPublication . Rocha, Thiago Lopes; Mestre, Nélia; Teixeira Saboia-Morais, Simone Maria; Bebianno, Maria JoãoDespite the wide application of quantum dots (QDs) in electronics, pharmacy and nanomedicine, limited data is available on their environmental health risk. To advance our current understanding of the environmental impact of these engineered nanomaterials, the aimof this review is to give a detailed insight on the existing information concerning the behaviour, transformation and fate of QDs in the aquatic environment, as well as on its mode of action (MoA), ecotoxicity, trophic transfer and biomagnification at various trophic levels (micro-organisms, aquatic invertebrates and vertebrates). Data show that several types of Cd-based QDs, even at low concentrations (bmg Cd L-1), induce different toxic effects compared to their dissolved counterpart, indicating nano-specific ecotoxicity. QD ecotoxicity at different trophic levels is highly dependent on its physico-chemical properties, environmental conditions, concentration and exposure time, as well as, species, while UV irradiation increases its toxicity. The state of the art regarding the MoA of QDs according to taxonomic groups is summarised and illustrated. Accumulation and trophic transfer of QDs was observed in freshwater and seawater species, while limited biomagnification and detoxification processes were detected. Finally, current knowledge gaps are discussed and recommendations for future research identified. Overall, the knowledge available indicates that in order to develop sustainable nanotechnologies there is an urgent need to develop Cd-free QDs and new "core-shell-conjugate" QD structures. (C) 2016 Elsevier Ltd. All rights reserved.
- Histopathological assessment and inflammatory response in the digestive gland of marine mussel Mytilus galloprovincialis exposed to cadmium-based quantum dotsPublication . Rocha, Thiago Lopes; Saboia-Morais, Simone Maria Teixeira; Bebianno, MariaAlthough tissue-level biomarkers have been widely applied in environmental toxicology studies, the knowledge using this approach in marine invertebrates exposed to engineered nanomaterials (ENMs) remains limited. This study investigated histopathological alterations and inflammatory responses induced by Cd-based quantum dots (QDs), in comparison with their dissolved counterparts, in the marine mussel Mytilus galloprovincialis. Mussels were exposed to CdTe QDs and dissolved Cd at the same concentration (10 mu g Cd L-1) for 14 days and a total of 15 histopathological alterations and 17 histomorphometric parameters were analysed in the digestive gland along with the determination of histopathological condition indices (I-h). A multivariate analysis showed that the mussel response to QDs was more related to exposure time, inflammatory conditions (frequency of haemocytic infiltration and granulocytomas) and changes of cell-type composition (especially the rate between basophilic and digestive cells) when compared to dissolved Cd, while the response to dissolved Cd was associated with histomorphometric parameters of the epithelium and lumen of digestive tubules and increase of the atrophic tubule frequency. Both Cd forms induced higher I-h compared to unexposed mussels indicating a significant decrease in the health status of digestive gland in a Cd form and time-dependent pattern. Results indicate that the multiparametric tissue-level biomarkers in the digestive gland provide a suitable approach to assess the ecotoxicity and mode of action of metal-based ENMs in marine bivalves. (C) 2016 Elsevier B.V. All rights reserved.
- Multibiomarker assessment of cadmium-based quantum dots effects in the marine mussel Mytilus galloprovincialisPublication . Rocha, Thiago Lopes; Bebianno, Maria JoãoNanotechnology and use of engineered nanomaterials (ENMs) may improve life quality, economic growth and environmental quality, but their environmental risk in the marine environment is scarce. Properties of quantum dots (QDs), namely small size, unique optical and biofunctional properties, allow their use in nanomedicine, biology and electronics, but also confer different toxicity compared to its dissolved counterparts. Accordingly, this thesis assessed the toxicokinetics (TK), mode of action (MoA) and toxicity of CdTe QDs (10 μg Cd L-1) in the marine mussel Mytilus galloprovincialis, compared to dissolved Cd for 21 days followed by 50 days depuration. For this purpose, Cd distribution in different mussel tissues, subcellular fractions and biodeposits were analysed, TK parameters estimated (accumulation and elimination rates, bioconcentration factor and half-life time) and multibiomarkers assessed: immunotoxicity (density, viability and differential cell count of hemocytes), cytotoxicity (lysosomal membrane stability - LMS), genotoxicity (DNA damage and nuclear anomalies), oxidative stress (superoxide dismutase - SOD, catalase - CAT, glutathione peroxidase - GPx and glutatione-S-Transferase - GST), metal exposure (metallothionein - MT), oxidative damage (lipid peroxidation - LPO), tissue-level biomarkers (17 histomorphometric parameters of digestive tubules, inflammatory and histopathological conditions indices) and proteomic responses. Results showed that the digestive gland plays an important role in storage, metabolism and detoxification of QDs, while gills have similar functions for dissolved Cd and the hemolymph in transport, distribution and regulation of QDs. Tissue specific metabolism patterns and nano-specific effects were identified, wherein the MoA and toxicity of QDs in mussels is time dependent and involve oxidative stress, immune response, DNA damage and differential protein expression. Mussels were unable to completely eliminate the QDs (t1/2 > 50 days), highlighting their potential source of toxicity for human health and environment. M. galloprovincialis is a significant target of QDs ecotoxicity and represent a suitable biomonitor for assess their environment risk.
- Plant-based silver nanoparticles ecotoxicity: perspectives about green technologies in the one health contextPublication . Silva Brito, Rafaella; Bebianno, Maria; Rocha, Thiago LopesSilver nanoparticles (AgNPs) have extensive applications in nanomedicine and parasitology, particularly as antifungal, bactericidal, antiviral, larvicidal, mosquitocidal, and tick-killing agents. Plant-based AgNPs (PB-AgNPs) have been studied as a safer and biocompatible strategy to collaborate in disease control. However, knowledge concerning the toxicity of PB-AgNPs in non-target organisms is still limited. A scientometric and systematic review was conducted to comprehensively understand the potential toxicity associated with these nanoparticles. In brief, the assessment of PB-AgNPs toxicological and ecotoxicity aspects needs to be aligned with their development for target organisms. Our review demonstrates that different PB-AgNPs can cause lethal and sublethal effects like increased oxidative stress, cardiotoxicity, neurotoxicity, hepatotoxicity, hematotoxicity, and, DNA damage, alongside others, particularly in aquatic organisms. Besides, the toxicity of PB-AgNPs for terrestrial and some aquatic organisms remains poorly understood. Additionally, the similar LC50 range between non-target aquatic organisms and target organisms highlights the potential ecological impact of PB-AgNPs. Comprehensive toxicological assessments and further research are crucial to ensure the safe and sustainable use of PB-AgNPs in a One Health context.
- Subcellular partitioning kinetics, metallothionein response and oxidative damage in the marine mussel Mytilus galloprovincialis exposed to cadmium-based quantum dotsPublication . Rocha, Thiago Lopes; Gomes, Tânia; Durigon, Emerson Giuliani; Bebianno, Maria JoãoThe environmental health impact of metal-based nanomaterials is of emerging concern, but their metabolism and detoxification pathways in marine bioindicator species remain unclear. This study investigated the role of subcellular partitioning kinetics, metallothioneins (MTs) response and oxidative damage (lipid peroxidation LPO) in the marine mussel Mytilus galloprovincialis exposed to CdTe quantum dots (QDs) in comparison with its dissolved counterpart. Mussels were exposed to QDs and dissolved Cd for 21 days at 10 mu g Cd L-1 followed by a 50 days depuration. Higher Cd concentrations were detected in fractions containing mitochondria, nucleus and lysosomes, suggesting potential subcellular targets of QDs toxicity inmussel tissues. Tissue specific metabolism patterns were observed in mussels exposed to both Cd forms. Although MT levels were directly associated with Cd in both forms, QDs subcellular partitioning is linked to biologically active metal (BAM), but no increase in LPO occurred, while in the case of dissolved Cd levels are in the biologically detoxified metal (BDM) form, indicating nano-specific effects. Mussel gills showed lower detoxification capability of QDs, while the digestive gland is the major tissue for storage and detoxification of both Cd forms. Both mussel tissues were unable to completely eliminate the Cd accumulated in the QDs form (estimated half-life time > 50 days), highlighting the potential source of Cd and QDs toxicity for human and environmental health. Results indicate tissue specific metabolism patterns and nano-specific effects in marine mussel exposed to QDs. (C) 2016 Elsevier B.V. All rights reserved.
- Toxic effects of cisplatin cytostatic drug in mussel Mytilus galloprovincialisPublication . Trombini, Chiara; da Fonseca, Taina Garcia; Morais, Matilde; Rocha, Thiago Lopes; Blasco, Julian; Bebianno, Maria JoãoAntineoplastic drugs used in chemotherapy were detected in aquatic environment: despite the very low concentrations (ng L-1 to ug L-1), due to their potent mechanism of action they could have adverse effects on non-target aquatic organisms particularly under chronic exposure. Cisplatin (CDDP) is one of the most effective anticancer drug currently in use but information on its ecotoxicological effects is very limited. In this study, Mytilus galloprovincialis was used to investigate the toxic effects related to CDDP exposure. Mussels were exposed to cisplatin (100 ng L-1) for 14 days: antioxidant (superoxide dismutase, catalase, total and selebium-dependent glutathione peroxidase) and phase II (glutathione-S-transferase) enzymes activities, oxidative damage (lipid peroxidation), genotoxicity (DNA damage) and neurotoxicity (acetylcholinesterase) was evaluated. Results indicate that CDDP at tested concentration induce changes in the antioxidant capacity, oxidative stress in target organs (digestive gland and gills) as well as DNA damage in mussel hemocytes and neurotoxicity representing a risk for non-target organisms. (C) 2016 Elsevier Ltd. All rights reserved.