Histopathological assessment and inflammatory response in the digestive gland of marine mussel Mytilus galloprovincialis exposed to cadmium-based quantum dots

Tissue specific responses to cadmium-based quantum dots in the marine mussel Mytilus galloprovincialis

Toxic effects of copper oxide nanoparticles in midgut and fat body of Galleria mellonella (Lepidoptera: Pyralidae)

Toxicokinetics and tissue distribution of cadmium-based Quantum Dots in the marine mussel Mytilus galloprovincialis

Development of histopathological indices in a commercial marine bivalve (Ruditapes decussatus) to determine environmental quality

Effects of dietary Pb and Cd and their combination on lysosomal and tissue-level biomarkers and histopathology in digestive gland of the land snail, Cantareus apertus (Born, 1778)

Caffeine (Caff) is one of the most widely used substances in the human diet and a well-recognized drug. Its input into surface waters is remarkable, but biological effects on aquatic organisms are unclear, particularly in combination with pollutants of suspected modulatory activity, like microplastics (MP). The aim of this study was to reveal the impact on the marine mussel Mytilus galloprovincialis (Lamark, 1819) of Caff (20.0 μg L−1) in the environmentally relevant combination (Mix) with MP 1 mg L−1 (size 35–50 μm) after the exposure for 14 days. Untreated and exposed to Caff and MP separately groups were also examined. Cell viability and cell volume regulation in hemocytes and digestive cells, as well as the indexes of oxidative stress, glutathione (GSH/GSSG) and metallothioneins levels, and caspase-3 activity in digestive gland were assessed. MP and Mix reduced Mn-superoxide dismutase, catalase, and glutathione S-transferase activities and level of lipid peroxidation, but increased the digestive gland cell viability, GSH/GSSG ratio (by 1.4–1.5-fold), metallothioneins level and their Zn content, while Caff did not affect oxidative stress indexes and metallothionein-related Zn chelation. Protein carbonyls were not targeted in all exposures. The distinguishing feature of the Caff group was the decline (2-fold) in caspase-3 activity and low cell viability. The multi-stress effect of Mix was shown by the worsening of the volume regulation of digestive cells and confirmed by discriminant analysis of biochemical indexes. The special capabilities of M. galloprovincialis as a sentinel organism make it an excellent bio-indicator reflecting the multi-stress effects in sub-chronic exposures to potentially harmful substances. The identification of the modulation of individual effects in combined exposure increases the need to base monitoring programs on studies of multi-stress effects in sub-chronic exposures.

In October 2010 the National Organic Standards Board recommended that engineered nanomaterials (ENMs) be prohibited from food products bearing the U.S. Department of Agriculture’s coveted Organic label.1 If the department adopts the recommendation, ENMs will find themselves in the same officially taboo category as genetically modified organisms when it comes to organic foods—nanotechnology-enabled innovations like flavor- and texture- enhancing ingredients and shelf life– extending packaging will be off the menu. Prior to issuing its recommendation, the board received thousands of public comments and petition signatures supporting the ban and virtually none opposing it. Although an official decision could take years, supporters are confident the recommendation will be adopted, and it will go down as one of the first lines drawn in the sand when it comes to the reach of this relatively new and potentially transformative technology in the American marketplace. Nanotechnology-enabled products are quietly proliferating on U.S. store shelves, despite nagging questions about the safety of synthetic nanoparticles and the products that contain them. “[I]n our regulation of food and most consumer products, we don’t implement the precautionary principle. Things go to market before we know whether or not they’re really safe for human beings over the long term,” says Alexis Baden-Mayer, a lawyer with the Organic Consumers Association, an advocacy group, who attended the meeting and campaigned for the ban. Baden-Mayer and other observers perceive a distinct lack of public awareness about how common ENMs are becoming in the market-place, and she hopes discussion among consumers of organic products will help change that. “Consumers don’t know much about nanotechnology, and the first time they may hear about it is now when they learn that the organic regulations are going to prohibit [it],” she says. The International Organization for Standardization defines a nanomaterial as a material with any external dimension between 1 and 100 nm.2 (By comparison, a double strand of DNA is about 2 nm thick.) Nanoparticles, which have been the focus of most nanotoxicology studies to date,3 are one subset of nanomaterials. Nanoparticles include structures of various shapes, such as nanotubes, nanowires, quantum dots, and fullerenes. They also occur naturally in substances like air, smoke, and sea spray, and “incidental” nanoparticles are created during processes such as combustion and food milling, churning, freezing, and homogenization. (Naturally occurring and incidental nanoparticles were not included in the National Organic Standards Board’s recommendation to ban ENMs.) Nanotechnology—the deliberate synthesis and manipulation of nanomaterials—began in the 1980s. Today thousands of ENMs are manufactured in a kaleidoscope of substances, shapes, and sizes for use in a wide range of products and industrial processes that take advantage of their novel physical, thermal, optical, and biological properties. These properties may be determined by the ENM’s chemical composition, size or shape, crystal structure, solubility, adhesion (the force that holds the nanoparticle components together), or surface chemistry, charge, or area.3 Industry analysts have been forecasting “game-changing” advances as a result of nanotechnology in renewable energy, computers, communications, pollution cleanup, agriculture, medicine, and more.4 Clothing, sunscreens, cosmetics, sporting equipment, batteries, food packaging, dietary supplements, and electronics are just a few of the types of nanotechnology-enabled goods in use by U.S. consumers. But safety questions arise around the nanoparticles in some of these products. The novel biological and physical properties of some ENMs pose unique challenges to comprehensive safety research, and investigators are working to figure out just how hazardous they might be to people, wildlife, and the environment. Compared with larger particles, nanoparticles’ tiny size means tissues may take them up more readily. It also can give them an unusual ability to travel throughout the body, including into cells and cell nuclei, and across the placenta and the blood–brain barrier, as demonstrated in rodent studies.5,6 No cases of human illness or death have been definitively attributed to ENMs. However, a number of researchers and consumer and environmental advocates have warned that the abundant unknowns make it necessary to proceed with caution lest we repeat the history of asbestos, polychlorinated biphenyls, the insecticide DDT, and other innovations that seemed valuable when they were introduced, proceeded with little oversight, and ultimately caused major health or environmental problems.

Quantum dots (QDs), as one of the emerging nanomaterials, have been widely studied by scientists due to their advantages and potential in bioimaging, especially cell imaging. Cadmium (Cd)-based QDs, which have the best photoluminescence property, have received widespread attention. However, due to the obvious toxicity problem of these QDs, their cell imaging application is hindered. Recently, the emergence of Cd-free-metal and metal-free QDs with lower toxicity makes people consider that Cd-based QDs may be substituted by these QDs. However, problems of these QDs in cytotoxicity also cannot be ignored. Some reports claimed that their prepared emerging QDs for cell imaging were low toxicity, but there still exist up-regulation of oxidative stress, inflammation, and apoptosis from other reports. And, up to now, few reports have separately summarized and discussed the issues of cell imaging and cytotoxicity of different types of QDs. Therefore, in this review, we classify QDs as following three types, Cd-based, Cd-free-metal and metal-free QDs, focus on the cell, the essential unit of life, discuss cell imaging application and cytotoxicity of QDs, and finally elucidate main mechanisms of cytotoxicity respectively. This review provides reference for the toxicity evaluation of QDs and highlights the potential cytotoxicity of Cd-free QDs.

Assessment of the effects of Cu and Ag in oysters Crassostrea gigas (Thunberg, 1793) using a battery of cell and tissue level biomarkers

As a consequence of their unique characteristics, the use of Engineered Nanomaterials (ENMs) is rapidly increasing in industrial, agricultural products, as well as in environmental technology. However, this fast expansion and use make likely their release into the environment with particular concerns for the aquatic ecosystems, which tend to be the ultimate sink for this type of contaminants. Considering the settling behaviour of particulates, benthic organisms are more likely to be exposed to these compounds. In this way, the present review aims to summarise the most recent data available from the literature on ENMs behaviour and fate in aquatic ecosystems, focusing on their ecotoxicological impacts towards marine and estuarine bivalves. The selection of ENMs presented here was based on the OECD's Working Party on Manufactured Nanomaterials (WPMN), which involves the safety testing and risk assessment of ENMs. Physical-chemical characteristics and properties, applications, environmental relevant concentrations and behaviour in aquatic environment, as well as their toxic impacts towards marine bivalves are discussed. Moreover, it is also identified the impacts derived from the simultaneous exposure of marine organisms to ENMs and climate changes as an ecologically relevant scenario.

The queen conch, Strombus gigas (Linnaeus, 1758), is a marine mollusc of ecological and economic importance in the Caribbean. Its populations are declining due to overexploitation. We describe ontogenesis of the digestive gland in S. gigas during the larval stages. Larvae were studied over a period of 42 d in laboratory culture, from eggs to crawling stage. Experiments were conducted at 28 ± 1°C. Veligers were reared at a density of 100 larvae l−1 in 10-l containers. Larvae were fed with the microalgae Nannochloropsis oculata at a concentration of 1,000 cells l−1. In this study, we analysed ultrastructural ontogenesis of the digestive gland in strombid larvae using light and electron microscopy. Examination for Coccidia (Apicomplexa) symbionts in the digestive gland was done by viewing sections with light and scanning electron microscopes at different larval development stages during a 42-d period. In early veligers (9 d after hatching), only digestive cells were observed in the digestive gland. By the late veliger stages (17 d old), both digestive and crypt cells were apparent in the digestive gland. Within crypt cells, spherocrystals were detected and the presence of Ca, Cl, Cu, P and Zn was identified by energy-dispersive X-ray spectroscopy. In late pediveligers (35 d old), the digestive gland still exhibited only digestive and crypt cells. Vacuolated cells (i.e. harbour the coccidian symbionts in adults) were only observed in newly settled juveniles (42 d old) and were devoid of apicomplexan structures. While coccidian symbionts were found in the digestive gland of adult S. gigas, they were not observed in the digestive gland of S. gigas larvae from hatching to settlement under laboratory conditions. This suggests that this symbiont is not vertically transmitted to new host generations in this marine gastropod species.

The digestive glands of four groups of mussels (Mytilus galloprovincialis) were examined under light and electron microscopes. Individuals of the first group were fixed immediately after their extraction from seawater; those of the second, after having been kept out of water for 2 h; while those of the third and fourth groups, after maintenance in the aquarium for 1 day and 1 week, respectively. The digestive gland cells of the mussels kept out of the water for 2 h presented, in many cases, extensive morphological disorganization, expressed mainly by cytoplasmic extrusions into the tubule lumen. In contrast, the mussels kept in the aquarium for 1 day showed no disintegration phenomena in their digestive cells, but presented a decrease in the height of the tubule epithelium and increased size of the tubule lumen. Similarly, the mussels kept in the aquarium for 1 week presented cells characterized by increased height compared to those of the mussels of the previous group, as well as a quite inactive epithelium, with no extrusion of cytoplasmic materials into the lumen. The values of the "lysosomal membrane stability" test (LMS), a bioindicator of general stress, were also evaluated. The mussels kept in the aquarium for 1 day showed decreased LMS values compared to the values for other mussel groups, which indicated that general stress had increased. Results of the present study show that care should be taken in sampling and handling of mussels for use in biomonitoring studies.

ADVERTISEMENT RETURN TO ISSUEPREVReviewChemical Basis of Interactions Between Engineered Nanoparticles and Biological SystemsQingxin Mu†, Guibin Jiang§, Lingxin Chen∥, Hongyu Zhou†⊥, Denis Fourches, Alexander Tropsha#, and Bing Yan*†View Author Information† School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China§ State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China∥ Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China⊥ Department of Surgery, Emory University School of Medicine, Atlanta, Georgia 30322, United States# Laboratory for Molecular Modeling, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States*Phone: +86-531-88380019. Fax: +86-531-88380029. E-mail: [email protected]Cite this: Chem. Rev. 2014, 114, 15, 7740–7781Publication Date (Web):June 13, 2014Publication History Received29 May 2013Published online13 June 2014Published inissue 13 August 2014https://pubs.acs.org/doi/10.1021/cr400295ahttps://doi.org/10.1021/cr400295areview-articleACS PublicationsCopyright © 2014 American Chemical SocietyRequest reuse permissionsArticle Views12613Altmetric-Citations466LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Carbon nanotubes,Genetics,Metal oxide nanoparticles,Molecules,Nanoparticles Get e-Alerts

Reversible alterations in epithelial cell turnover in digestive gland of winkles ( Littorina littorea) exposed to cadmium and their implications for biomarker measurements

BackgroundWith the rapid development of nanotechnology, more and more nanoproducts are being released into the environment where they may both pose ecological risks and be toxic to living organisms. The ecotoxicological impact of quantum dots (QDs), a class of nanoparticles (NPs), on aquatic organisms is becoming an emerging issue, this due to their nano-specific properties, to the physico-chemical transformation in the environment and to the possible release of toxic metals from their structure such as Cd.MethodsIn this work, (i) spectroscopic measurements of commercially available Cd-based QDs (CdSe/ZnS-COOH) were made at various pH values (5.0 and 7.0) to study their interactions (at a concentration of 4 nm) with various strains of Gram-positive and Gram-negative gut bacteria after short-term exposure and (ii) the antibacterial efficacy of QDs and Cd2+ (at a concentration 0.09–3.56 mM) against gut bacteria isolated from wild freshwater Salmo trutta fry was studied at different temperatures (15 °C and 25 °C) and pH values (5.0 and 7.0) by applying a well-established disc diffusion assay.ResultsTwenty-six gut bacterial isolates from wild Salmo trutta fry were identified as Aeromonas spp., A. popoffii, A. salmonicida, A. sobria, Carnobacterium maltaromaticum, Buttiauxella sp., Listeria sp., Microbacterium sp., Shewanella putrefaciens and Serratia sp. Cd-based (CdSe/ZnS-COOH) QDs at a concentration of 4 nm were found to be stable in aqueous media (with pH 7.0) or starting to form aggregates (at pH 5.0), thus, apparently, did not release heavy metals (HMs) into the media over 48 h in conditions of light or dark and did not show antibacterial efficacy on the gut bacteria isolated from wild Salmo trutta fry after short-term (9 h and 48 h) incubations. Cd2+ was found to produce significant dose-dependent toxic effects on bacterial growth, and the size of the inhibition zones on some of the tested strains significantly correlated with temperature. The most sensitive and the most resistant to Cd2+ were the Gram-positive bacteria, for which the minimum inhibitory concentration (MIC) values of Cd2+ were 0.09–0.27 mM and 3.11–3.29 mM respectively and varied significantly between the tested temperatures (15 °C and 25 °C). The MIC values of Cd2+ for the Gram-negative bacteria (18 out of 22 strains) ranged from 0.44 to 0.71 mM and did not differ significantly between the tested temperatures. Among the selected Gram-positive and Gram-negative strains, those with the higher sensitivity towards Cd2+ also revealed relatively stronger signals of QDs photoluminescence (PL) when transferred after incubation into fresh medium without QDs. In addition, the formation of endogenous metalloporphyrins observed spectroscopically in some bacterial strains indicates certain differences in metabolic activity that may play a protective role against potential oxidative damage.