Multidisciplinary screening of toxicity induced by silica nanoparticles during sea urchin development

High concentrations of phthalates affect the early development of the sea urchin Paracentrotus lividus

The toxicity of three phthalates (PAEs) - butylbenzyl phthalate (BBP), diethyl phthalate (DEP), and di-(2-ethylhexyl) phthalate (DEHP) - was tested on the Mediterranean sea urchin Paracentrotus lividus. Fertilized eggs were exposed to environmental and high PAE concentrations for 72 h. The potential toxic effects on larval development and any morphological anomalies were then assessed to estimate PAEs impact. Environmental concentrations never affected development, while high concentrations induced toxic effects in larvae exposed to BBP (EC50: 2.9 ×103 µg/L) and DEHP (EC50: 3.72 ×103 µg/L). High concentrations caused skeletal anomalies, with a slight to moderate impact for DEP/DEHP and BBP, respectively. PAE toxicity was: BBP>DEHP>DEP. In conclusion, the three PAEs at environmental concentrations do not pose a risk to sea urchins. However, PAE concentrations should be further monitored in order not to constitute a concern to marine species, especially at their early developmental stages.

Prospects and hazards of silica nanoparticles: Biological impacts and implicated mechanisms

With the thrive of nanotechnology, silica nanoparticles (SiNPs) have been extensively adopted in the agriculture, food, cosmetic, and even biomedical industries. Due to the mass production and use, SiNPs inevitably entered the environment, resulting in ecological toxicity and even posing a threat to human health. Although considerable investigations have been conducted to assess the toxicity of SiNPs, the correlation between SiNPs exposure and consequent health risks remains ambiguous. Since the biological impacts of SiNPs can differ from their design and application, the toxicity assessment for SiNPs may be extremely difficult. This review discussed the application of SiNPs in different fields, especially their biomedical use, and documented their potential release pathways into the environment. Meanwhile, the current process of assessing SiNPs-related toxicity on various model organisms and cell lines was also detailed, thus estimating the health threats posed by SiNPs exposure. Finally, the potential toxic mechanisms of SiNPs were also elaborated based on results obtained from both in vivo and in vitro trials. This review generally summarizes the biological effects of SiNPs, which will build up a comprehensive perspective of the application and toxicity of SiNPs.

Assessing the toxicity of aegerolysin-based bioinsecticidal complexes using the sea urchin Paracentrotus lividus as model organism

The use of alternative solutions for pest management to replace pesticides in agriculture is of great interest. Proteinaceous complexes deriving from edible oyster mushrooms were recently proposed as environmentally friendly bioinsecticides. Such complexes, composed of ostreolysin A6 (OlyA6) and pleurotolysin B (PlyB), target invertebrate-specific membrane sphingolipids in insect's midgut, causing death through the formation of transmembrane pores. In this work, the potential impact of OlyA6/PlyB complexes was tested in the Mediterranean sea urchin Paracentrotus lividus, as an indicator of environmental quality. The ability of the fluorescently tagged OlyA6 to bind sea urchin gametes (sperm, eggs), the lipidome of sea urchin gametes, and the potential toxic effects and developmental anomalies caused by OlyA6/PlyB complexes on P. lividus early development (embryo, larvae) were investigated. The binding of the fluorescently tagged OlyA6 could be observed only in sea urchin eggs, which harbor OlyA6 sphingolipid membrane receptors, conversely to sperm. High protein concentrations affected sea urchin fertilization (>750 µg/L) and early development (> 375 µg/L in embryos; >100 µg/L in larvae), by causing toxicity and morphological anomalies in embryos and larvae. The main anomalies consisted in delayed embryos and incorrect migration of the primary mesenchyme cells that caused larval skeletal anomalies. The classification of these anomalies indicated a slight environmental impact of OlyA6/PlyB complexes at concentrations higher than 750 µg/L. Such impact should not persist in the marine environment, due to the reversible anomalies observed in sea urchin embryos and larvae that may promote defense strategies. However, before promoting the use of OlyA6/PlyB complexes as bio-pesticides at low concentrations, further studies on other marine coastal species are needed.

Human and environmental impacts of nanoparticles: a scoping review of the current literature

Use of nanoparticles have established benefits in a wide range of applications, however, the effects of exposure to nanoparticles on health and the environmental risks associated with the production and use of nanoparticles are less well-established. The present study addresses this gap in knowledge by examining, through a scoping review of the current literature, the effects of nanoparticles on human health and the environment. We searched relevant databases including Medline, Web of Science, ScienceDirect, Scopus, CINAHL, Embase, and SAGE journals, as well as Google, Google Scholar, and grey literature from June 2021 to July 2021. After removing duplicate articles, the title and abstracts of 1495 articles were first screened followed by the full-texts of 249 studies, and this resulted in the inclusion of 117 studies in the presented review.In this contribution we conclude that while nanoparticles offer distinct benefits in a range of applications, they pose significant threats to humans and the environment. Using several biological models and biomarkers, the included studies revealed the toxic effects of nanoparticles (mainly zinc oxide, silicon dioxide, titanium dioxide, silver, and carbon nanotubes) to include cell death, production of oxidative stress, DNA damage, apoptosis, and induction of inflammatory responses. Most of the included studies (65.81%) investigated inorganic-based nanoparticles. In terms of biomarkers, most studies (76.9%) used immortalised cell lines, whiles 18.8% used primary cells as the biomarker for assessing human health effect of nanoparticles. Biomarkers that were used for assessing environmental impact of nanoparticles included soil samples and soybean seeds, zebrafish larvae, fish, and Daphnia magna neonates.From the studies included in this work the United States recorded the highest number of publications (n = 30, 25.64%), followed by China, India, and Saudi Arabia recording the same number of publications (n = 8 each), with 95.75% of the studies published from the year 2009. The majority of the included studies (93.16%) assessed impact of nanoparticles on human health, and 95.7% used experimental study design. This shows a clear gap exists in examining the impact of nanoparticles on the environment.

Characterization and Behaviour of Silica Engineered Nanocontainers in Low and High Ionic Strength Media

Mesoporous silica engineered nanomaterials are of interest to the industry due to their drug-carrier ability. Advances in coating technology include using mesoporous silica nanocontainers (SiNC) loaded with organic molecules as additives in protective coatings. The SiNC loaded with the biocide 4,5-dichloro-2-octyl-4-isothiazolin-3-one (DCOIT), i.e., SiNC-DCOIT, is proposed as an additive for antifouling marine paints. As the instability of nanomaterials in ionic-rich media has been reported and related to shifting key properties and its environmental fate, this study aims at understanding the behaviour of SiNC and SiNC-DCOIT in aqueous media with distinct ionic strengths. Both nanomaterials were dispersed in (i) low- (ultrapure water-UP) and (ii) high- ionic strength media-artificial seawater (ASW) and f/2 medium enriched in ASW (f/2 medium). The morphology, size and zeta potential (ζP) of both engineering nanomaterials were evaluated at different timepoints and concentrations. Results showed that both nanomaterials were unstable in aqueous suspensions, with the initial ζP values in UP below -30 mV and the particle size varying from 148 to 235 nm and 153 to 173 nm for SiNC and SiNC-DCOIT, respectively. In UP, aggregation occurs over time, regardless of the concentration. Additionally, the formation of larger complexes was associated with modifications in the ζP values towards the threshold of stable nanoparticles. In ASW, SiNC and SiNC-DCOIT formed aggregates (<300 nm) independently of the time or concentration, while larger and heterogeneous nanostructures (>300 nm) were detected in the f/2 medium. The pattern of aggregation detected may increase engineering nanomaterial sedimentation rates and enhance the risks towards dwelling organisms.

Amino-functionalized mesoporous silica nanoparticles (NH2-MSiNPs) impair the embryonic development of the sea urchin Paracentrotus lividus

Nanoparticles have found use in a wide range of applications, mainly as carriers of active biomolecules. It is thus necessary to assess their toxicity for human health, as well as for the environment, on which there is still a gap of knowledge. In this work, sea urchin Paracentrotus lividus, a widely used model for embryotoxicity and spermiotoxicity, has been used to assess potential detrimental effects of amino-functionalized mesoporous silica nanoparticles (NH₂-MSiNPs) on embryonic development. Specifically, gametes quality, embryogenesis morphological and timing alterations, and cellular stress markers, such as mitochondrial functionality, were assessed in presence of different concentrations of NH₂-MSiNPs in filtered seawater (FSW). Furthermore, dorsal-ventral axis development and skeletogenesis were characterized by microscopy imaging and gene expression analysis. NH₂-MSiNPs determined a strong reduction in the egg fertilization rate. Consequently, the presence of NH₂-MSiNPs resulted detrimental in P. lividus embryonic development, with severe morphological alterations correlated with an increased embryos mortality. Finally, NH₂-MSiNPs treatment was responsible for other toxic effects, such as reduced mitochondrial function and skeletogenesis alterations, according to the reduced mineralization sites in the endoskeleton formation and the related genes altered expression. Taken together, these results suggest the potential toxic effects of NH₂-MSiNPs on the marine ecosystem, with consequences for the development and reproduction of its organisms. Despite their promising potential as carriers of biomolecules, it is pivotal to consider that their uncontrolled use may result harmful to the environment and, consequently, to living organisms.

Zinc Oxide Nanoparticles Induce DNA Damage in Sand Dollar Scaphechinus mirabilis Sperm

Products containing nanomaterials are becoming more and more common in everyday life. Zinc oxide nanoparticles (ZnO NPs), meanwhile, are among the most widely used NPs. However, their genotoxic effect on the germ products of marine organisms is poorly understood. Therefore, the effects of ZnO NPs and zinc ions (20, 50, 100, 200 µg/L) on the sperm of sand dollar Scaphechinus mirabilis were compared. Comet assay showed that both tested pollutants caused an increase in DNA damage to 6.57 ± 2.41 and 7.42 ± 0.88% DNA in the comet tail, for zinc ions and ZnO NPs, respectively. Additionally, a different pattern was shown by the increase in DNA damage, with increasing concentration of pollutants, in different experimental groups.

Exposure of adult sand dollars (Scaphechinus mirabilis) (Agassiz, 1864) to copper oxide nanoparticles induces gamete DNA damage

The increase in the number of products containing nanoparticles (NPs) poses a real threat to the environment. Recently, more evidence has been added to predictive models about the presence of NPs in various natural and anthropogenic systems. The acute toxicity of most aquatic NPs has now been well documented. However, data such as the ecotoxicological significance of the long-lasting effects of NPs on the reproductive system and gamete quality of aquatic organisms are still relatively scarce. Therefore, a 10-day experiment was carried out on the sand dollar Scaphechinus mirabilis (Agassiz, 1864) exposed to low (20 and 40 μg/L) concentrations of copper oxide nanoparticles (CuO NPs). An accumulation of copper in tissues and a significant increase in lipid peroxidation product concentrations after exposure to NP were observed. A significant decrease in the fertilization rate was shown at 40 μg/L. No significant changes in embryonic or larval development were found. However, comet analysis results showed a significant increase in DNA damage in spermatozoa exposed to CuO NPs, which may further manifest as negative effects at later developmental stages or in subsequent generations.

Oxidative Stress in Far Eastern Mussel Mytilus trossulus (Gould, 1850) Exposed to Combined Polystyrene Microspheres (µPSs) and CuO-Nanoparticles (CuO-NPs)

The ingress of nanoparticles of metal oxides and microfragments of synthetic polymers (microplastics) into a marine environment causes unpredictable consequences. The effects of such particles cannot be predicted due to a lack of ecotoxicological information. In this research, a series of laboratory experiments were conducted on the combined effects of CuO-nanoparticles (CuO-NPs) and polystyrene microspheres (µPSs) on the development of oxidative stress processes in the marine filter-feeder mollusk Mytilus trossulus. Biomarkers of oxidative stress, including the lysosome membrane stability of hematocytes (LMS), the index of antioxidant activity (IAA), the levels of malonaldehyde (MDA) and protein carbonyls (PCs), and DNA damage in digestive gland cells, were measured after 5 days of exposure. Based on a battery of biochemical markers, it was shown that oxidative stress was induced at varying degrees in the experimental mollusks when exposed to CuO-NPs and µPSs both separately and in combination. In contrast, the single-treatment effect on the lysosomal membrane was enhanced by the combined CuO-NPs and µPSs (from 77.14 ± 8.56 to 42 ± 4.26 min). In addition, exposure to both the compounds alone and in combination decreased the IAA (from 22.87 ± 1.25, to 19.55 ± 0.21, 10.73 ± 0.53, and 12.06 ± 1.62 nM/mg protein, respectively). The PC level significantly increased only after CuO-NP exposure (from 0.496 ± 0.02 to 0.838 ± 0.03 μM/mg protein). Furthermore, the results showed that the investigated particles, both alone and in combination, promoted DNA damage in digestive gland cells (from 2.02 ± 0.52 to 5.15 ± 0.37, 18.29 ± 2.14, and 10.72 ± 2.53%, respectively), indicating that these compounds are genotoxic. Overall, the results obtained suggest that oxidative stress is the leading factor in the negative effects of CuO-NPs and µPSs. Considering the exceptional role of genome integrity in the functioning of biological systems, the revealed damages in the DNA molecule structure should be attributed to the most important manifestations of the toxicity of these two forms of marine pollution.

Fabrication and In Vitro/Vivo Evaluation of Drug Nanocrystals Self-Stabilized Pickering Emulsion for Oral Delivery of Quercetin

The aim of this study was to develop a new drug nanocrystals self-stabilized Pickering emulsion (NSSPE) for improving oral bioavailability of quercetin (QT). Quercetin nanocrystal (QT–NC) was fabricated by high pressure homogenization method, and QT–NSSPE was then prepared by ultrasound method with QT–NC as solid particle stabilizer and optimized by Box-Behnken design. The optimized QT–NSSPE was characterized by fluorescence microscope (FM), scanning electron micrograph (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The stability, in vitro release, and in vivo oral bioavailability of QT–NSSPE were also investigated. Results showed that the droplets of QT–NSSPE with the size of 10.29 ± 0.44 μm exhibited a core-shell structure consisting of a core of oil and a shell of QT–NC. QT–NSSPE has shown a great stability in droplets shape, size, creaming index, zeta potential, and QT content during 30 days storage at 4, 25, and 40 °C. In vitro release studies showed that QT–NSSPE performed a better dissolution behavior (65.88% within 24 h) as compared to QT–NC (50.71%) and QT coarse powder (20.15%). After oral administration, the AUC_0–t of QT–NSSPE was increased by 2.76-times and 1.38 times compared with QT coarse powder and QT–NC. It could be concluded that NSSPE is a promising oral delivery system for improving the oral bioavailability of QT.

Aquatic ecotoxicity of manufactured silica nanoparticles: A systematic review and meta-analysis

Manufactured silica nanoparticles are used worldwide in large volumes for a variety of applications. An exposure of environmental organisms is therefore likely, and several data on the ecotoxicology of silica nanoparticles to different organisms have been published in recent years. This systematic review compiles and assesses these studies, in order to analyse the sensitivity distribution across different organisms. On this basis, maximum acceptable environmental concentrations are suggested and potential environmental risks are discussed. 1429 papers were retrieved from the scientific literature (Scopus), the U.S. ECOTOX knowledge database. 63 studies were finally included in the review and appraised according to the nanoCRED criteria. A total of 219 ecotoxicological endpoints recorded in 38 species (7 taxonomic groups) were condensed into a species sensitivity distribution. The resulting concentration that is hazardous for a maximum of 5% of exposed species (HC05) is 130 μg/L, from which a PNEC of 30 μg/L is estimated by applying an assessment factor of 5. These concentrations are 1-3 orders of magnitudes above the concentrations modelled to occur in European aquatic ecosystems. Algae and bacteria have a comparatively low sensitivity to MSNP exposure, likely because their cell wall forms a protective barrier against nanoparticle exposure. Similarly, embryonic stages of fish also show a comparatively low sensitivity due to the protection from their chorion. However, the fish species Labeo rohita and Oncorhynchus mykiss are among the most sensitive species. The ecotoxicity of silica nanoparticles is linked to the number of hydroxyl groups on their surface, corresponding to findings from human toxicological studies. It is recommended that future ecotoxicological studies use explicit concentration-response designs, use proven biocide-free testing material, comparatively apply mass and surface area as exposure metrics, and provide important metainformation in the study report.

Simultaneous Influence of Gradients in Natural Organic Matter and Abiotic Parameters on the Behavior of Silver Nanoparticles in the Transition Zone from Freshwater to Saltwater Environments

As nanoparticles have been found to cause a range of harmful impacts in biota, understanding processes and transformations which may stabilize and increase their persistence time in the environment are of great importance. As nanoparticles carried in riverine or wastewaters will eventually reach estuaries, understanding their behavior and transport potential in this transition zone from fresh to marine waters is essential, particularly as estuaries are sensitive ecological zones, oftentimes encompassing ornithologically important areas. In this direction, we report on the influence of combined gradients of riverine and marine natural organic matter (NOM) on the temporal stability of biocorona-encapsulated silver nanoparticles in terms of ion release kinetics. In parallel, salinity, pH and oxygen saturation were simultaneously varied to create a model to mimic the complex estuarine environment. While humic acid (HA) and alginate (Alg) disrupted the stabilizing ability of the nanoparticle protein corona to a greater and lesser degree, respectively, they slowed the rate of ion release in freshwater at pH 6.6 and in saltwater at pH 8, respectively, while oxygen saturation was also found to be an important factor. Thus, as the type of NOM changes with pH along a salinity gradient in an estuary, conditions required to increase the persistence time of nanoparticles are serendipitously met, with greater colloidal stability achieved in cases where there is more rapid replacement of HA with Alg. Despite the strong gradients in ionic strength, pH and oxygen saturation, the protein corona was not sufficiently disrupted at the nanoparticle surface to be substituted by NOM indicating the greater adsorption energy of the protein's hydrophobic domains. Ultimately, it is the specific NOM profile of individual estuaries that may provide the best indicator for predicting the stability and persistence of silver nanoparticles as they transition from fresh to salt water environments.

Individual and Binary Mixture Toxicity of Five Nanoparticles in Marine Microalga Heterosigma akashiwo

The investigation of the combined toxic action of different types of nanoparticles (NPs) and their interaction between each other and with aquatic organisms is an important problem of modern ecotoxicology. In this study, we assessed the individual and mixture toxicities of cadmium and zinc sulfides (CdS and ZnS), titanium dioxide (TiO₂), and two types of mesoporous silicon dioxide (with no inclusions (SMB3) and with metal inclusions (SMB24)) by a microalga growth inhibition bioassay. The counting and size measurement of microalga cells and NPs were performed by flow cytometry. The biochemical endpoints were measured by a UV-VIS microplate spectrophotometer. The highest toxicity was observed for SMB24 (EC50, 3.6 mg/L) and CdS (EC50, 21.3 mg/L). A combined toxicity bioassay demonstrated that TiO₂ and the SMB3 NPs had a synergistic toxic effect in combinations with all the tested samples except SMB24, probably caused by a “Trojan horse effect”. Sample SMB24 had antagonistic toxic action with CdS and ZnS, which was probably caused by metal ion scavenging.

Ecotoxicity of silica nanoparticles in aquatic organisms: An updated review

This review aims to (i) provide a current overview of the main characteristics of SiNP (physical and chemical properties, applications, and emissions), (ii) evaluate the scientific production up to date concerning SiNP, with focus on their toxic effects, through a bibliometric analysis, (iii) describe the main toxic mechanisms of SiNP, (iv) assess the current knowledge about ecotoxicity of SiNP on aquatic organisms (marine and freshwater), and (v) identify the main gaps in the knowledge of SiNP toxicity from an environmentally point of view. The scientific production of SiNP concerning their chemical and physical characteristics has increased exponentially. However, little information is available regarding their ecotoxicity. Particle functionalization is a key factor that reduces SiNP toxicity. Most of the studies employed standard species as test organisms, being the local/native ones poorly represented. Further studies employing long-term exposures and environmentally relevant concentrations are needed to deepen the knowledge about this emergent pollutant.

Toxicity of Carbon, Silicon, and Metal-Based Nanoparticles to Sea Urchin Strongylocentrotus Intermedius

With the increasing annual production of nanoparticles (NPs), the risks of their harmful influence on the environment and human health are rising. However, our knowledge about the mechanisms of interaction between NPs and living organisms is limited. Prior studies have shown that echinoderms, and especially sea urchins, represent one of the most suitable models for risk assessment in environmental nanotoxicology. To the best of the authors’ knowledge, the sea urchin Strongylocentrotus intermedius has not been used for testing the toxicity of NPs. The present study was designed to determine the effect of 10 types of common NPs on spermatozoa activity, egg fertilization, and early stage of embryo development of the sea urchin S. intermedius. In this research, we used two types of multiwalled carbon nanotubes (CNT-1 and CNT-2), two types of carbon nanofibers (CNF-1 and CNF-2), two types of silicon nanotubes (SNT-1 and SNT-2), nanocrystals of cadmium and zinc sulfides (CdS and ZnS), gold NPs (Au), and titanium dioxide NPs (TiO₂). The results of the embryotoxicity test showed the following trend in the toxicity level of used NPs: Au > SNT-2 > SNT-1 > CdS > ZnS > CNF-2 > CNF-1 > TiO₂ > CNT-1 > CNT-2. This research confirmed that the sea urchin S. intermedius can be considered as a sensitive and stable test model in marine nanotoxicology.

Toxicity of Carbon, Silicon, and Metal-Based Nanoparticles to the Hemocytes of Three Marine Bivalves

Simple Summary

The growing nanotechnology industry disposes of a variety of nanoparticles with different physiochemical properties in everyday life. However, the dependence of the safety and toxicity of nanoparticles on their physicochemical properties remains unclear. Bivalve molluscs represent an efficient model for the investigation of nanoparticle toxicity owing to their filtrating ability and feeding on particles suspended in the water. Moreover, the blood cells of bivalve molluscs, the hemocytes, have been suggested as a good analog test-object to mammalian immune cells, phagocytes. In this study, we used hemocytes of three marine bivalve species, namely, Crenomytilus grayanus, Modiolus modiolus, and Arca boucardi, to evaluate and compare the toxic effects of 10 different types of nanoparticles. We gave short-term exposure of the nanoparticles to the hemocytes and registered viability and changes in their cell membrane polarization by employing flow cytometry. Metal-based nanoparticles were the most toxic to the cells of all three tested bivalve mollusc species. However, the sensitivity to different nanoparticle types varied between species. Moreover, the registered cell membrane depolarization indicated an early toxic response and raised concern that chronic long-term exposure of nanoparticles (even if they were previously declared as safe) is a serious threat for aquatic organisms.

Abstract

Nanoparticles (NPs) have broad applications in medicine, cosmetics, optics, catalysis, environmental purification, and other areas nowadays. With increasing annual production of NPs, the risks of their harmful influence on the environment and human health are also increasing. Currently, our knowledge about the mechanisms of the interaction between NPs and living organisms is limited. The marine species and their habitat environment are under continuous stress owing to the anthropogenic activities, which result in the release of NPs in the aquatic environment. We used a bioassay model with hemocytes of three bivalve mollusc species, namely, Crenomytilus grayanus, Modiolus modiolus, and Arca boucardi, to evaluate the toxicity of 10 different types of NPs. Specifically, we compared the cytotoxic effects and cell-membrane polarization changes in the hemocytes exposed to carbon nanotubes, carbon nanofibers, silicon nanotubes, cadmium and zinc sulfides, Au-NPs, and TiO₂ NPs. Viability and the changes in hemocyte membrane polarization were measured by the flow cytometry method. The highest aquatic toxicity was registered for metal-based NPs, which caused cytotoxicity to the hemocytes of all the studied bivalve species. Our results also highlighted different sensitivities of the used tested mollusc species to specific NPs.

Metal-containing nanoparticles derived from concealed metal deposits: An important source of toxic nanoparticles in aquatic environments

The potential environmental risks of engineered nanoparticles in aquatic environment have attracted considerable attention, but naturally produced nanoparticles have relatively been ignored, such as ore-related nanoparticles. To obtain more information about the natural ore-related nanoparticles, deep groundwater and well water samples were respectively collected in or around four major metal deposits in Inner Mongolia, China. These water samples were tested with high resolution transmission electron microscopy (TEM) and abundant metal-containing nanoparticles were found. Major ore-forming elements of corresponding metal deposits, such as Fe, Pb, Zn and Cu, and even associated elements, such as As, Sb, Sn and Cr, significantly contributed to the chemical compositions of these detected nanoparticles. Through comparison analyses, these metal-containing nanoparticles were shown to be originally from deep concealed metal deposits. They were the products of faulting and oxidation of ore minerals, and were transported long distances by water flow. Notably, these ore-related nanoparticles happened to have similar components with those nanoparticles of high environmental risks. Coupled with the analytical results of Atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectrometry (ICP-MS), it is recommended that the concentration limits of metal-containing nanoparticles should be considered in the safety assessment of drinking water. This is the first time, so far as we know, that naturally produced ore-related nanoparticles in the aquatic environment were listed as a kind of material with environmental risks. Considering the wide distribution of concealed metal deposits, more attention on related studies was urgently required for establishing specialized risk assessment and monitoring system.

A Survey on Tubulin and Arginine Methyltransferase Families Sheds Light on P. lividus Embryo as Model System for Antiproliferative Drug Development

Tubulins and microtubules (MTs) represent targets for taxane-based chemotherapy. To date, several lines of evidence suggest that effectiveness of compounds binding tubulin often relies on different post-translational modifications on tubulins. Among them, methylation was recently associated to drug resistance mechanisms impairing taxanes binding. The sea urchin is recognized as a research model in several fields including fertilization, embryo development and toxicology. To date, some α- and β-tubulin genes have been identified in P. lividus, while no data are available in echinoderms for arginine methyl transferases (PRMT). To evaluate the exploiting of the sea urchin embryo in the field of antiproliferative drug development, we carried out a survey of the expressed α- and β-tubulin gene sets, together with a comprehensive analysis of the PRMT gene family and of the methylable arginine residues in P. lividus tubulins. Because of their specificities, the sea urchin embryo may represent an interesting tool for dissecting mechanisms of tubulin targeting drug action. Therefore, results herein reported provide evidences supporting the P. lividus embryo as animal system for testing antiproliferative drugs.

DNA damages and offspring quality in sea urchin Paracentrotus lividus sperms exposed to ZnO nanoparticles

The recent advances in nanotechnology lead to a potential increase of the release of nanoparticles (NPs) into marine environment through different routes, with possible toxic effects upon the living part of this ecosystem. One of the ways of NPs marine contamination gaining today increasing concern stems from the widespread use cosmetics containing ZnO NPs as UV-filter. Although the possible adverse effects on marine organisms have been already ascertained, the information about the possible genotoxicity of ZnO NPs is still scant. In this work the spermiotoxicity of ZnO particles of different sizes (ZnO Bulk > 200 nm, ZnO NPs 100 nm and ZnO NPs 14 nm) was assessed, using Paracentrotus lividus spermatozoa, by evaluating the DNA damage of the exposed sperm, fertilization capability and DNA damage transmission to progeny. Our results showed that ZnO NPs induced DNA damages in spermatozoa after 30 min of exposure. While the sperm fertilization capability was not affected, morphological alterations (skeletal alterations) in offspring were observed and a positive correlation between sperm DNA damage and offspring quality was reported. This study underlines that a possible spermiotoxic action of ZnO NPs at concentration close to those reported in marine coastal water could occur.

Silica nanoparticles induce abnormal mitosis and apoptosis via PKC-δ mediated negative signaling pathway in GC-2 cells of mice

The potential health hazards of silica nanoparticles (SiNPs) have attracted more and more attentions. Researches had shown that SiNPs could damage seminiferous epithelium and reduce the quantity and quality of sperms, however the specific mechanism of male reproductive toxicity induced by SiNPs still unclear. So we designed to investigate the mechanism of SiNPs on male mice using spermatocyte lines (GC-2spd cells) after exposure to SiNPs (6.25, 12.5, 25 and 50 μg/mL) for 24 h. The present study showed that SiNPs entered GC-2 cells and mainly localized in the cytoplasm and lysosome. And internalized SiNPs damaged mitochondria structures. As a result, SiNPs not only induced a dose-dependent reduction in cell viability, but also increased the LDH release and apoptosis rate in GC-2 cells. Furthermore, SiNPs induced DNA strand breaks and abnormal mitosis, and arrested GC-2 cells at the G0/G1 phase. Besides, SiNPs could simultaneously activate both PKC-mediated negative signaling pathway (PKC-δ/p53/p21cip1) and positive signaling pathway (PKC-α/MAPK). However, the lower expressions of cyclin E and cyclin-dependent kinases 2 (CDK2) indicated that PKC-δ signaling pathway played a major role in cell cycle process. These results suggested internalized SiNPs in GC-2 cells induced DNA strand breaks and activated PKC-mediated signaling pathway. While the activation of PKC-δ signaling pathway led to cell cycle arrest and apoptosis, thereby resulting in abnormal mitosis. The present study may provide a new evidence to elucidate the toxic mechanisms of male reproductive system, and will be beneficial for safety assessment of SiNPs products.

Parental exposure to heavy fuel oil induces developmental toxicity in offspring of the sea urchin Strongylocentrotus intermedius

The present study investigated the toxic effects of parental (maternal/paternal) exposure to heavy fuel oil (HFO) on the adult reproductive state, gamete quality and development of the offspring of the sea urchin Strongylocentrotus intermedius. Adult sea urchins were exposed to effluents from HFO-oiled gravel columns for 7 days to simulate an oil-contaminated gravel shore, and then gametes of adult sea urchins were used to produce embryos to determine developmental toxicity. For adult sea urchins, no significant difference in the somatic size and weight was found between the various oil loadings tested, while the gonad weight and gonad index were significantly decreased at higher oil loadings. The spawning ability of adults and fecundity of females significantly decreased. For gametes, no effect was observed on the egg size and fertilization success in any of the groups. However, a significant increase in the percentage of anomalies in the offspring was observed and then quantified by an integrative toxicity index (ITI) at 24 and 48 h post fertilization. The offspring from exposed parents showed higher ITI values with more malformed embryos. The results confirmed that parental exposure to HFO can cause adverse effects on the offspring and consequently affect the recruitment and population maintenance of sea urchins.

In situ embryo toxicity test with sea urchin: Development of exposure chamber for test execution

In situ toxicity tests represent a technique rarely performed owing to the lack of standard methodologies or to technical or economic problems. Nevertheless, its application would allow for a more realistic interpretation of pollution effects than those obtained by standard laboratory tests. The goal of this study is to develop and validate a specific exposure chamber for in situ exposition of Paracentrotus lividus embryos to obtain a defined methodology to perform the sea urchin embryo toxicity test in field conditions. After a first part of the study to verify the feasibility of the test chamber and the methodology, this approach was used as a tool to investigate whether the cruise ship "Costa Concordia" shipwrecked on Giglio Island (Tuscany, Italy), could have acted as a source of pollution. The results obtained for in situ tests showed, on average, percentages of normal embryos lower than those obtained in laboratory conditions and a greater sensitivity than for those obtained in the laboratory owing to the time-integration of results. Thus the exposure chamber and the in situ methodology so far developed would appear to be suitable tools for future application in the environmental quality evaluation of marine waters.

Effects of polystyrene microbeads in marine planktonic crustaceans

Plastic debris accumulates in the marine environment, fragmenting into microplastics (MP), causing concern about their potential toxic effects when ingested by marine organisms. The aim of this study was to verify whether 0.1µm polystyrene beads are likely to trigger lethal and sub-lethal responses in marine planktonic crustaceans. MP build-up, mortality, swimming speed alteration and enzyme activity (cholinesterases, catalase) were investigated in the larval stages of Amphibalanus amphitrite barnacle and of Artemia franciscana brine shrimp exposed to a wide range of MP concentrations (from 0.001 to 10mgL^-1) for 24 and 48h. The results show that MP were accumulated in crustaceans, without affecting mortality. Swimming activity was significantly altered in crustaceans exposed to high MP concentrations (> 1mgL^-1) after 48h. Enzyme activities were significantly affected in all organisms exposed to all the above MP concentrations, indicating that neurotoxic effects and oxidative stress were induced after MP treatment. These findings provide new insight into sub-lethal MP effects on marine crustaceans.

Impact of cationic polystyrene nanoparticles (PS-NH2) on early embryo development of Mytilus galloprovincialis: Effects on shell formation

The potential release of nanoparticles (NPs) into aquatic environments represents a growing concern for their possible impact on aquatic organisms. In this light, exposure studies during early life stages, which can be highly sensitive to environmental perturbations, would greatly help identifying potential adverse effects of NPs. Although in the marine bivalve Mytilus spp. the effects of different types of NPs have been widely investigated, little is known on the effects of NPs on the developing embryo. In M. galloprovincialis, emerging contaminants were shown to affect gene expression profiles during early embryo development (from trocophorae-24 hpf to D-veligers-48 hpf). In this work, the effects of amino-modified polystyrene NPs (PS-NH₂) on mussel embryos were investigated. PS-NH₂ affected the development of normal D-shaped larvae at 48 hpf (EC₅₀ = 0.142 mg/L). Higher concentrations (5-20 mg/L) resulted in high embryotoxicity/developmental arrest. At concentrations ≅ EC₅₀, PS-NH₂ affected shell formation, as shown by optical and polarized light microscopy. In these conditions, transcription of 12 genes involved in different biological processes were evaluated. PS-NH₂ induced dysregulation of transcription of genes involved in early shell formation (Chitin synthase, Carbonic anhydrase, Extrapallial Protein) at both 24 and 48 hpf. Decreased mRNA levels for ABC transporter p-glycoprotein-ABCB and Lysozyme were also observed at 48 hpf. SEM observations confirmed developmental toxicity at higher concentrations (5 mg/L). These data underline the sensitivity of Mytilus early embryos to PS-NH₂ and support the hypothesis that calcifying larvae of marine species are particularly vulnerable to abiotic stressors, including exposure to selected types of NPs.

Sunscreen products impair the early developmental stages of the sea urchin Paracentrotus lividus

Marine ecosystems are increasingly threatened by the release of personal care products. Among them, sunscreens are causing concern either for the effects on skin protection from UV radiation and for the potential impacts on marine life. Here, we assessed the UVA protective efficacy of three sunscreens on human dermal fibroblasts, including two common products in Europe and USA, and an eco-friendly product. The sunscreens' effects were also tested on Paracentrotus lividus, a marine species possibly threatened by these contaminants. We found that all tested sunscreens had similar efficacy in protecting human fibroblasts from UVA radiation. Conversely, the sunscreens' effects on embryo-larval development of P. lividus were dependent on the product tested. In particular, the USA sunscreen, containing benzophenone-3, homosalate and preservatives, caused the strongest impact on the sea urchin development, whereas the eco-friendly sunscreen determined the weakest effects. These results suggest that although the tested products protected human skin cells from UVA-induced damage, they might severely affect the success of recruitment and survival of the sea urchin. Our findings underline the importance of developing eco-friendly sunscreens for minimising or avoiding the impact on marine life while protecting human skin from UV damage.

Effects of monocrotophos pesticide on cholinergic and dopaminergic neurotransmitter systems during early development in the sea urchin Hemicentrotus pulcherrimus

During early development in sea urchins, classical neurotransmitters, including acetylcholine (ACh), dopamine (DA), and serotonin (5-HT), play important roles in the regulation of morphogenesis and swimming behavior. However, the underlying mechanisms of how organophosphate pesticides cause developmental neurotoxicity by interfering with different neurotransmitter systems are unclear. In this study, we investigated the effects of 0.01, 0.10, and 1.00mg/L monocrotophos (MCP) pesticide on the activity of acetyltransferase (ChAT), acetylcholinesterase (AChE), monoamine oxidase, the concentration of DA, dopamine transporter, and the transcription activity of DA receptor D₁ and tyrosine hydroxylase, during critical periods in cholinergic and dopaminergic nervous system development in sea urchin (Hemicentrotus pulcherrimus) embryos and larvae. At the blastula stages, MCP disrupted DA metabolism but not 5-HT metabolism, resulting in abnormal development. High ChAT and AChE activity were observed at the gastrulation-completed stage and the two-armed pluteus stage, respectively, MCP inhibited ChAT activity and AChE activity/distribution and resulted in developmental defects of the plutei. From the gastrula stage to the two-armed pluteus stage, we found ubiquitous disrupting effects of MCP on ACh, DA, and 5-HT metabolism, particularly at critical periods during the development of these neurotransmitter systems. Therefore, we propose that this disruption is one of the main mechanisms of MCP-related developmental neurotoxicity, which would contribute better understanding insight into the mechanism of MCP pesticide's toxic effects.

Overview of the molecular defense systems used by sea urchin embryos to cope with UV radiation

The sea urchin embryo is a well-recognized developmental biology model and its use in toxicological studies has been widely appreciated. Many studies have focused on the evaluation of the effects of chemical stressors and their mixture in marine ecosystems using sea urchin embryos. These are well equipped with defense genes used to cope with chemical stressors. Recently, ultraviolet radiation (UVR), particularly UVB (280-315 nm), received more attention as a physical stressor. Mainly in the Polar Regions, but also at temperate latitudes, the penetration of UVB into the oceans increases as a consequence of the reduction of the Earth's ozone layer. In general, UVR induces oxidative stress in marine organisms affecting molecular targets such as DNA, proteins, and lipids. Depending on the UVR dose, developing sea urchin embryos show morphological perturbations affecting mainly the skeleton formation and patterning. Nevertheless, embryos are able to protect themselves against excessive UVR, using mechanisms acting at different levels: transcriptional, translational and post-translational. In this review, we recommend the sea urchin embryo as a suitable model for testing physical stressors such as UVR and summarize the mechanisms adopted to deal with UVR. Moreover, we review UV-induced apoptotic events and the combined effects of UVR and other stressors.

Influence of Nanotoxicity on Human Health and Environment: The Alternative Strategies

Currently, nanotechnology revolutionizing both scientific and industrial community due to their applications in the fields of medicine, environmental protection, energy, and space exploration. Despite of the evident benefits of nanoparticles, there are still open questions about the influence of these nanoparticles on human health and environment. This is one of the critical issues that have to be addressed in the near future, before massive production of nanomaterials. Manufactured nanoparticles, which are finding ever-increasing applications in industry and consumer products fall into the category of emerging contaminants with ecological and toxicological effects on populations, communities and ecosystems. The existing experimental knowledge gave evidence that inhaled nanoparticles are less efficiently separated than larger particles by the macrophage clearance mechanisms and these nanoparticles are known to translocate through the lymphatic, circulatory and nervous systems to many tissues and organs, including the brain. In this review we highlight adverse impacts of nanoparticles on human and the environment with special emphasis on green nanoscience as a sustainable alternative.

Nanotoxicity of graphene oxide: Assessing the influence of oxidation debris in the presence of humic acid

This study sought to evaluate the toxicological effects of graphene oxide (GO) through tests with Danio rerio (zebrafish) embryos, considering the influence of the base washing treatment and the interaction with natural organic matter (i.e., humic acid, HA). A commercial sample of GO was refluxed with NaOH to remove oxidation debris (OD) byproducts, which resulted in a base washed GO sample (bw-GO). This process decreased the total oxygenated groups in bw-GO and its stability in water compared to GO. When tested in the presence of HA, both GO and bw-GO stabilities were enhanced in water. Although the embryo exposure showed no acute toxicity or malformation, the larvae exposed to GO showed a reduction in their overall length and acetylcholinesterase activity. In the presence of HA, GO also inhibited acid phosphatase activity. Our findings indicate a mitigation of material toxicity after OD removal. The difference in the biological effects may be related to the materials' bioavailability and biophysicochemical interactions. This study reports for the first time the critical influence of OD on the GO material biological reactivity and HA interaction, providing new data for nanomaterial environmental risk assessment and sustainable nanotechnology.

Amino-modified polystyrene nanoparticles affect signalling pathways of the sea urchin (Paracentrotus lividus) embryos

Polystyrene nanoparticles have been shown to pose serious risk to marine organisms including sea urchin embryos based on their surface properties and consequently behaviour in natural sea water. The aim of this study is to investigate the toxicity pathways of amino polystyrene nanoparticles (PS-NH₂, 50 nm) in Paracentrotus lividus embryos in terms of development and signalling at both protein and gene levels. Two sub-lethal concentrations of 3 and 4 μg/mL of PS-NH₂ were used to expose sea urchin embryos in natural sea water (PS-NH₂ as aggregates of 143 ± 5 nm). At 24 and 48 h post-fertilisation (hpf) embryonic development was monitored and variations in the levels of key proteins involved in stress response and development (Hsp70, Hsp60, MnSOD, Phospho-p38 Mapk) as well as the modulation of target genes (Pl-Hsp70, Pl-Hsp60, Pl-Cytochrome b, Pl-p38 Mapk, Pl-Caspase 8, Pl-Univin) were measured. At 48 hpf various striking teratogenic effects were observed such as the occurrence of cells/masses randomly distributed, severe skeletal defects and delayed development. At 24 hpf a significant up-regulation of Pl-Hsp70, Pl-p38 Mapk, Pl-Univin and Pl-Cas8 genes was found, while at 48 hpf only for Pl-Univin was observed. Protein profile showed different patterns as a significant increase of Hsp70 and Hsp60 only after 48 hpf compared to controls. Conversely, P-p38 Mapk protein significantly increased at 24 hpf and decreased at 48 hpf. Our findings highlight that PS-NH₂ are able to disrupt sea urchin embryos development by modulating protein and gene profile providing new understandings into the signalling pathways involved.

The Effect of Photobiomodulation on the Sea Urchin Paracentrotus lividus (Echinodermata) Using Higher-Fluence on Fertilization, Embryogenesis, and Larval Development: An In Vitro Study

OBJECTIVE

The aim of this study was to investigate the photobiomodulation (PBM) effect of the 808 nm diode laser irradiation on spermatozoa, eggs, fertilized eggs, embryos, and larvae of Paracentrotus lividus, using two different power settings.

BACKGROUND DATA

Studies have shown the possible use of PBM in artificial insemination. These have shown the potential effect of low-power laser irradiation on spermatozoa, while there are few studies on the effect of laser photonic energy on oocytes and almost no reports on the influence of lasers in embryogenesis.

METHODS

P. lividus gametes, zygotes, embryos, and larvae were irradiated using the 808 nm diode laser (fluence 64 J/cm² using 1 W or 192 J/cm² with 3 W) with a flat-top hand-piece delivery, compared to a control without laser irradiation (0 J/cm²-0 W). The fertilization rate and the early developmental stages were investigated.

RESULTS

The fertilization ability was not affected by the sperm/egg irradiation. At the gastrula stage, no significant differences were observed compared with the control samples. In the late pluteus stage, there were no differences in the developmental percentage observed between the control and the treated samples (1 W), with the exception of larvae from gastrulae and larvae, which were irradiated at 3 W.

CONCLUSIONS

This study has demonstrated that both the 64 J/cm²-1 W and the 192 J/cm²-3 W do not induce morphological damage on the irradiated P. lividus gametes whose zygotes generate normal embryos and larvae. Our data therefore support the assumption to use higher fluence in preliminary studies on in vitro fertilization.

Effects of nanomaterials on marine invertebrates

The development of nanotechnology will inevitably lead to the release of consistent amounts of nanomaterials (NMs) and nanoparticles (NPs) into marine ecosystems. Ecotoxicological studies have been carried out to identify potential biological targets of NPs, and suitable models for predicting their impact on the health of the marine environment. Recent studies in invertebrates mainly focused on NP accumulation and sub-lethal effects, rather than acute toxicity. Among marine invertebrates, bivalves represent by large the most studied group, with polychaetes and echinoderms also emerging as significant targets of NPs. However, major scientific gaps still need to be filled. In this work, factors affecting the fate of NPs in the marine environment, and their consequent uptake/accumulation/toxicity in marine invertebrates will be summarized. The results show that in different model species, NP accumulation mainly occurs in digestive tract and gills. Data on sub-lethal effects and modes of action of different types of NPs (mainly metal oxides and metal based NPs) in marine invertebrates will be reviewed, in particular on immune function, oxidative stress and embryo development. Moreover, the possibility that such effects may be influenced by NP interactions with biomolecules in both external and internal environment will be introduced. In natural environmental media, NP interactions with polysaccharides, proteins and colloids may affect their agglomeration/aggregation and consequent bioavailability. Moreover, once within the organism, NPs are known to interact with plasma proteins, forming a protein corona that can affect particle uptake and toxicity in target cells in a physiological environment. These interactions, leading to the formation of eco-bio-coronas, may be crucial in determining particle behavior and effects also in marine biota. In order to classify NPs into groups and predict the implications of their release into the marine environment, information on their intrinsic properties is clearly insufficient, and a deeper understanding of NP eco/bio-interactions is required.

A new drug nanocrystal self-stabilized Pickering emulsion for oral delivery of silybin

A new silybin nanocrystal self-stabilized Pickering emulsion (SN-SSPE) has been developed using a high pressure homogenization method to improve the oral bioavailability of silybin. Influences of homogenization pressure and drug content on the formation of SN-SSPE were studied. The morphology, structure and size of Pickering emulsion droplets were characterized using a scanning electron micrograph, confocal laser scanning microscopy and atomic force microscopy. The stability, in vitro release and in vivo oral bioavailability of SN-SSPE were investigated. Results indicated that the particle size of silybin nanocrystals (SN-NC) decreased when homogenization pressure increased until 100MPa. When the content of silybin reached 300mg or above, a stable Pickering emulsion of silybin could be formed by sufficient SN-NC covering surfaces of oil droplets completely and thus self-stabilizing the Pickering emulsion. The emulsion droplet of SN-SSPE with the size of 27.3±3.1μm showed a core-shell structure consisting of a core of oil and a shell of SN-NC. SN-SSPE has shown high stability over 40days. The in vitro release rate of SN-SSPE was faster than silybin coarse powder and similar to silybin nanocrystalline suspension (SN-NCS). The peak concentration of silybin of SN-SSPE following intragastric administration in rats was increased by 2.5-fold and 3.6-fold compared with SN-NCS and silybin coarse powder, respectively. The AUC of SN-SSPE was increased by 1.6-fold and 4.0-fold compared with SN-NCS and silybin coarse powder, respectively. All these results showed that the Pickering emulsion of silybin could be stabilized by nanocrystals of silybin itself and increased the oral bioavailability of silybin. The drug nanocrystalline self-stabilized Pickering emulsion was a promising oral drug delivery system for poorly soluble drugs.

Mesoporous silica nanoparticles enhance seedling growth and photosynthesis in wheat and lupin

The application of mesoporous silica nanoparticles (MSNs) as a smart delivery system to agricultural crops is gaining attention but the release of nanoparticles into the environment may pose a potential threat to biological systems. We investigated the effects of MSNs on the growth and development of wheat and lupin plants grown under controlled conditions. We report a dramatic increase in the growth of wheat and lupin plants exposed to MSNs. We also found that, in leaves, MSNs localised to chloroplasts and that photosynthetic activity was significantly increased. In addition, absorption and cellular distribution of MSNs by the two plant species following root uptake were observed using scanning electron microscopy equipped with energy dispersive spectroscopy (SEM-EDS). Following uptake of MSNs at 500 and 1000 mg L(-1), there was enhancement of seed germination, increased plant biomass, total protein and chlorophyll content. Treatment of both species with MSNs at the highest concentration (2000 mg L(-1)) did not result in oxidative stress or cell membrane damage. These findings show that MSNs can be used as novel delivery systems in plants and that over the range of concentrations tested, MSNs do not have any negative impacts on plant growth or development.

Swimming speed alteration in the early developmental stages of Paracentrotus lividus sea urchin as ecotoxicological endpoint

Behavioral endpoints have been used for decades to assess chemical impacts at concentrations unlikely to cause mortality. With recently developed techniques, it is possible to investigate the swimming behavior of several organisms under laboratory conditions. The aims of this study were: i) assessing for the first time the feasibility of swimming speed analysis of the early developmental stage sea urchin Paracentrotus lividus by an automatic recording system ii) investigating any Swimming Speed Alteration (SSA) on P. lividus early stages exposed to a chemical reference; iii) identifying the most suitable stage for SSA test. Results show that the swimming speed of all the developmental stages was easily recorded. The swimming speed was inhibited as a function of toxicant concentration. Pluteus were the most appropriate stage for evaluating SSA in P. lividus as ecotoxicological endpoint. Finally, swimming of sea urchin early stages represents a sensitive endpoint to be considered in ecotoxicological investigations.