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Neutron activation of engineered nanoparticles as a tool for tracing their environmental fate and uptake in organisms
Abstract
Studies regarding the environmental impact of engineered nanoparticles (ENPs) are hampered by the lack of tools to localize and quantify ENPs in water, sediments, soils, and organisms. Neutron activation of mineral ENPs offers the possibility of labeling ENPs in a way that avoids surface modification and permits both localization and quantification within a matrix or an organism. Time-course experiments in vivo also may be conducted with small organisms to study metabolism and exposure, two aspects currently lacking in ecotoxicological knowledge about ENPs. The present report explains some of the prerequisites and advantages of neutron activation as a tool for studying ENPs in environmental samples and ecologically relevant organisms, and it demonstrates the suitability of neutron activation for Ag, Co/Co3O4, and CeO2 nanoparticles. In a preliminary experiment with the earthworm Eisenia fetida, the dietary uptake and excretion of a Co nanopowder (average particle size, 4 nm; surface area, 59 m2/g) were studied. Cobalt ENPs were taken up to a high extent during 7 d of exposure (concentration ratios of 0.16-0.20 relative to the ENP concentration in horse manure) and were largely retained within the worms for a period of eight weeks, with less than 20% of absorbed ENPs being excreted. Following dissection of the worms, 60Co was detected in spermatogenic cells, cocoons, and blood using scintillation counting and autoradiography. The experimental opportunities that neutron activation of ENPs offer are discussed.
... Several studies are reported to explain the bioaccumulation, depuration, and excretion of NPs in body of earthworms. Various techniques are being utilized to study the bioaccumulation of various NPs including inductively coupled plasma (Coleman et al. 2010;Hu et al. 2010;Schlich et al. 2013;Shoults-Wilson et al. 2011a, b, c;Stewart et al. 2013;Unrine et al. 2010a, b), gamma spectrometry (Coutris et al. 2012;Oughton et al. 2008), X-ray micro-spectroscopy (Unrine et al. 2010a), micro X-ray fluorescence spectrometry (Lapied et al. 2011), liquid scintillation counting (Lapied et al. 2010;Petersen et al. 2008Petersen et al. , 2009Petersen et al. , 2011, flame atomic absorption spectrophotometry (Heggelund et al. 2014;Li et al. 2011), and microwave . It observed that dermal uptake of metal ions of NMs occurs in soft-bodied invertebrate species like earthworms. ...
... Unrine et al. 2010b), Au-NPs(Coutris et al. 2012;Oughton et al. 2008) ZnO-NPs(Hu et al. 2010), Al-NPs(Coleman et al. 2010), carbon-based NPsPetersen et al. 2011), Co-NPs(Coutris et al. 2012;Oughton et al. 2008), Ti-NPs(Hu et al. 2010;Lapied et al. 2011) has been studied. Usually, some of the metal-based NPs partly dissolve to form aggregates and agglomerates and accumulate in the environment. ...
... Unrine et al. 2010b), Au-NPs(Coutris et al. 2012;Oughton et al. 2008) ZnO-NPs(Hu et al. 2010), Al-NPs(Coleman et al. 2010), carbon-based NPsPetersen et al. 2011), Co-NPs(Coutris et al. 2012;Oughton et al. 2008), Ti-NPs(Hu et al. 2010;Lapied et al. 2011) has been studied. Usually, some of the metal-based NPs partly dissolve to form aggregates and agglomerates and accumulate in the environment. ...
The environmental basin is continuously getting exposed to the nanomaterials (NMs) with the advancement of the nanotechnological world. Though the ecotoxicological effect of nanoparticles (NPs) is currently widely investigated, we have only a handful of knowledge regarding their effects on the biology of naturally available scavenger like an earthworm. Moreover, our current understanding in the context of the possible influence of nanomaterial on earthworm and their effectiveness in performing the remediation process and nullification of toxic forms is scarce. Again, as the earthworms represent soil invertebrates, they are always focussed on and occupy a crucial trophic level. Many nanotoxicologists and ecotoxicologists have focussed their study on earthworms to find out how and why nanoparticles exert their toxic effects and how to remediate nanotoxicity. Studies showed that nanomaterials exert a minor effect on the survival and growth pattern of adult earthworms, but NPs exposure reduces the reproductive activity of earthworms. However, it is interesting to mention that earthworm has the unique ability to biodegrade or bioaccumulate or biotransform NPs and released them as a component of soil.
... Theoretically; the shorter the half-life of a radionuclide -the lesser amount is needed to achieve a given "signal" (count rate). For, e.g, [ 18 F] with 120minutes half-life a normal diagnostic dose for an adult is around 300MBq (megabequerel) this corresponds to 85 pikogram of fluorine. The radioactive decay law is N = N 0 e -λt , where N is the amount of radioactivity at a given time "t" and N 0 is the starting amount of activity (t=0) and λ is the decay constant; λ= ln2/ t ½ ; t ½ is the half-life (in seconds). ...
... Labelled particles were used to assess the biodistribution pattern after intravenous administration in rodents up to 1 hour. In another work, the same group reported the activation of 18Oenriched aluminium oxide NPs [16] and 18 O-enriched TiO 2 NPs [17] using in both cases the 18 O(p,n) 18 F nuclear reaction. For TiO 2 NPs, the simultaneous formation of other radioisotopes by activation of the titanium atom, i.e., 48 V, 47 V, 44g Sc, could be detected. ...
... First, NPs can be activated in solution; second, NPs with thermally-sensitive functionalities can be activated. Unfortunately, the number of nuclear reactions with appropriate cross section values is very limited, and in practice this strategy has been only applied to a very limited range of NPs [18][19][20]. ...
Cancer remains as one of the major causes of death worldwide. The emergence of nanotechnology has opened new avenues for the development of nanoparticle (NP)- based diagnostic and therapeutic tools. NPs of different chemical composition, size, shape and surface decoration can be prepared using a wide variety of synthetic strategies. Subsequent radiolabelling with positron or gamma emitters results in potential diagnostic agents which may offer improved selectivity and/or specificity for the target organ or tissue, enabling the acquisition of images with higher signal-to-contrast ratio. Incorporation of alpha or beta emitters leads to therapeutic agents with application in the field of radiotherapy. Here, we first describe the different labeling strategies reported so far for the incorporation of radionuclides into NPs. Recent advances in the use of nanoparticulate constructs both in the diagnostic and therapeutic arenas are then discussed and examples of their application are briefly discussed.
... Apoptotic cells remained in the organism's cuticle and intestinal epithelium and were immediately exposed to AgNPs, which altered nutrient absorption and the immune protection provided by the chloragogenous tissue (Lapied et al., 2010). Oughton et al. (2008) exposed E. fetida to CoNPs (4 nm) for seven days, which demonstrated the retention of these NPs in cocoons, blood, and spermatogenic cells after eight weeks, and only 20% of the ingested NPs were excreted out (Oughton et al., 2008). ...
... Apoptotic cells remained in the organism's cuticle and intestinal epithelium and were immediately exposed to AgNPs, which altered nutrient absorption and the immune protection provided by the chloragogenous tissue (Lapied et al., 2010). Oughton et al. (2008) exposed E. fetida to CoNPs (4 nm) for seven days, which demonstrated the retention of these NPs in cocoons, blood, and spermatogenic cells after eight weeks, and only 20% of the ingested NPs were excreted out (Oughton et al., 2008). ...
Nanomaterials (NMs) are progressively employed in many sectors because of their novel properties; however, their introduction into the environment is of great interest to agriculture, food security, and health. Specifically, the NMs accumulation in soils could disrupt the soil and plant systems, probably posing a threat to crop yield. In this chapter, we have comprehensively discussed the toxic impacts of NMs on the soil ecosystem. It emphasizes how the potential widespread application of NPs in various fields may have negative effects on the soil ecosystem, such as changes in soil constituents and microflora (bacteria, nematodes, and earthworms), which eventually affect plant growth and development. It also emphasizes the genotoxic and cytotoxic impacts, influence on reactive oxygen species (ROS), and anti-oxidative activities in plants caused by NMs.
... 34 The radiolabelling of nanoparticles has the potential of providing an analysis technique for laboratory research that allows sensitive detection with unprecedented experimental ease [35][36][37] and has already proven to be a valuable tool for fate analysis of nanomaterials in organisms. [38][39][40][41][42] Employing smart radiolabelling strategies even has the potential of providing both, mechanistic insight at sub-acute toxicity concentrations. 10 Based on previous efforts we developed an isotopic dualradiolabelling strategy to shed light on uptake pathways of anthropogenic cerium in organisms. ...
... They were irradiated with thermal neutrons at a neutron flux of 1 × 10 13 for 63 h. 40 After a decay time of 29 d the ampule was broken and the [Ce-141]CeO 2 NPs taken up in DI water. ...
Manufactured nanoparticles, such as CeO2, give rise to novel risks when released into the environment. To assess these risks it is important to quantify the nanoparticle mass flows, as well as their speciation and the mechanisms of their transformation. We developed an innovative dual-radiolabelling strategy for CeO2nanoparticles using neutron activation and in-diffusion labelling to radiolabel CeO2nanoparticles with both Ce-141 and Ce-139. The different distribution of the radiolabels in the particles does not only allow easy dose determination in uptake studies but also enables us to track the uptake pathways of the anthropogenic cerium. By measuring the activity as well as the isotope ratio we tracked the uptake, transformation and excretion of CeO2nanoparticles in freshwater shrimp. We found that 99.99% of the uptaken particles are excreted, leaving the gut with excrement. The remaining 0.01% were internalizedviaa dissolution-based pathway and accumulated in the hepatopancreas of the shrimp at a dose range of pg CeO2per shrimp. Most importantly, our results show that dissolution is not only coincidental but instrumental in the uptake of the cerium into the internal organs of the shrimp.
... Schleh et al. 2013;Kreyling et al. 2017a, b, c;Xie et al. 2010;Zhang et al. 2009) and environmental studies (e.g. Kleiven et al. 2018;Chekli et al. 2016;Vitorge et al. 2014;Coutris et al. 2012;Oughton et al. 2008) where they demonstrated the advantage of very high detection sensitivity and easy quantification, usually without special specimen preparation procedures (Bello and Warheit 2017;Llop et al. 2013;Weiss and Diabate 2011). However, since the properties and behaviour of nanoparticles depend on a large variety of physicochemical parameters, utmost care is required not to change any of these during the labelling procedure. ...
... Various purely physical radiolabelling techniques have been described that avoid chemical processing or surface functionalization, which entails the risk of altering the behaviour of the nanoparticles in the envisaged experimental environment. Probably most frequently applied are neutron activation techniques Oughton et al. 2008;Häfeli et al. 2001). Also, techniques where activation is achieved by exposure of nanoparticles to light ion beams have been developed Holzwarth et al. 2014). ...
In realistic exposure scenarios, the detection and quantification of engineered nanoparticles in complex environmental or biological matrixes is a challenge since nanoparticle concentrations are frequently low and have to be discerned from a background that may contain the same elements in various chemical forms in much higher concentrations. The use of radiolabelled nanoparticles may overcome these difficulties offering high detection sensitivity without the necessity of complex sample preparation procedures. However, the labelling procedure must not alter the physicochemical and biological properties of the nanoparticles. In the present work, the radiolabelling of three different types of TiO2 nanoparticles with primary particle sizes between 5 nm and 26 nm with commercially available 44Ti has been investigated applying a simple diffusion heat treatment at 180 °C for 2.5 h on nanoparticles impregnated with a solution containing the 44Ti radiolabel. The same treatment has been investigated to radiolabel amorphous SiO2 nanoparticles with 44Ti. The radiolabels are stably integrated in the nanoparticle matrix, and the release is less than 0.1% in aqueous suspension at neutral pH for at least 4 weeks. The method appears to be fast and reliable. By transmission electron microscopy, dynamic light scattering and ζ-potential measurements, only minor alterations of the nanoparticle size could be detected in the range of 1 to 2 nm.
... While evidence on toxic effects is abundant, and numerous adverse biological effects have been reported in much detail 12,13 , information on the internal distribution of nanoparticles taken up by exposed organisms is scarce. Particularly, data on the mobility and interaction of NPs with critical organs and tissues within complete intact organisms are lacking. ...
... However, only a few studies have investigated their potential effects on exposed organisms. Previous investigations of physical, chemical and toxicological properties of commercially available Co NPs have shown that such particles were readily ingested by important soil species and that their uptake induced adverse effects 12,13 . Therefore, the study of the internal distribution and effects of the exposure of living organisms to Co (NPs) is highly relevant. ...
Synchrotron radiation phase-contrast computed nanotomography (nano-CT) and two- and three-dimensional (2D and 3D) nanoscopic X-ray fluorescence (nano-XRF) were used to investigate the internal distribution of engineered cobalt nanoparticles (Co NPs) in exposed individuals of the nematode Caenorhabiditis elegans. Whole nematodes and selected tissues and organs were 3D-rendered: anatomical 3D renderings with 50 nm voxel size enabled the visualization of spherical nanoparticle aggregates with size up to 200 nm within intact C. elegans. A 20 × 37 nm2 high-brilliance beam was employed to obtain XRF elemental distribution maps of entire nematodes or anatomical details such as embryos, which could be compared with the CT data. These maps showed Co NPs to be predominantly present within the intestine and the epithelium, and they were not colocalized with Zn granules found in the lysosome-containing vesicles or Fe agglomerates in the intestine. Iterated XRF scanning of a specimen at 0° and 90° angles suggested that NP aggregates were translocated into tissues outside of the intestinal lumen. Virtual slicing by means of 2D XRF tomography, combined with holotomography, indicated presumable presence of individual NP aggregates inside the uterus and within embryos.
... However, it has been shown that a high proportion of the Co core/Co 3 O 4 shell (Co@Co 3 O 4 ) NPs added to feed is uptaken and retained in the earthworm Eisenia fetida. 91 Furthermore, the clearance of gut contents during excretion was relatively slow, and at 8 weeks of depuration, less than 20% of the absorbed Co had been excreted. ...
... After dietary exposure of Co@Co 3 O 4 NPs, 60 Co was detected in spermatogenic cells and cocoons in earthworms, indicating the presence of MENPs in reproductive organs. 91 The accumulation of Ag NPs in rat fetuses and infant rats consuming their mother's breast milk after administration to pregnant or lactating female rats was also observed by use of a low-background semiconductor γ-ray spectrometer. 92 The accumulation of Ag NPs in fetuses was seen to be 0.085−0.147% of the administered dose, which exceeded the penetration of NPs across the hematoencephalic barrier into the brain of females and was comparable to the accumulation in liver, blood, and muscle carcass of adult animals. ...
The rapidly growing applicability of metal-containing engineered nanoparticles (MENPs) has made their environmental fate, biouptake, and transformation important research topics. However, considering the relatively low concentration of MENPs and the high concentration of background metals in the environment and in organisms, tracking the fate of MENPs in environment-related scenarios remains a challenge. Intrinsic labeling of MENPs with radioactive or stable isotopes is a useful tool for the highly sensitive and selective detection of MENPs in the environment and organisms, thus enabling tracing of their transformation, uptake, distribution, and clearance. In this review, we focus on radioactive/stable isotope labeling of MENPs for their environmental and biological tracing. We summarize the advantages of intrinsic radioactive/stable isotopes for MENP labeling and discuss the considerations in labeling isotope selection and preparation of labeled MENPs, as well as exposure routes and detection of labeled MENPs. In addition, current practice in the use of radioactive/stable isotope labeling of MENPs to study their environmental fate and bioaccumulation is reviewed. Future perspectives and potential applications are also discussed, including imaging techniques for radioactive- and stable-isotope-labeled MENPs, hyphenated multistable isotope tracers with speciation analysis, and isotope fractionation as a MENP tracer. It is expected that this critical review could provide the necessary background information to further advance the applications of isotope tracers to study the environmental fate and bioaccumulation of MENPs.
... Labelling ENMs with radioisotopes using neutron activation is technique that permits quantification and tracing in soil and soil organisms. The neutron activation process results in minimal modification of particle surfaces or changes in chemical properties of metal or metal oxide ENMs (Oughton et al., 2008). Subsequent quantification by gamma spectrometry is a very sensitive and nondestructive method, an important advantage in kinetic studies that involves living organisms and repeated measurements of ENM accumulation during time course experiments. ...
... Salt solutions of Ce (Agilent ICP-MS standard in nitric acid) and SnCl 2 were added to polyethylene vials and evaporated at 90 C over night. All vials were sealed and submitted to neutron activation (NA) at a flux of 9,11 e 9,30 Â 10 12 neutrons cm À2 s À1 for 14 h at the reactor of the Institute of Energy Technology (Kjeller, Norway) (See Oughton et al., 2008 for further details). The specific activity of irradiated NPs and ions at the start of the experiment was determined by gamma spectrometry using a Ge-detector (Canberra, Meriden, CT, USA) targeting their respective specific gamma energies ( 141 Ce, 145.4 keV; 113 Sn, 255.1 and 391.7 keV). ...
The growing number of nanotechnology products on the market will inevitably lead to the release of engineered nanomaterials with potential risk to humans and environment. This study set out to investigate the exposure of soil biota to engineered nanoparticles (NPs). Cerium dioxide (CeO2 NPs) and tin dioxide nanoparticles (SnO2 NPs) were radiolabelled using neutron activation, and employed to assess the uptake and excretion kinetics in the earthworm Eisenia fetida. Through sequential extraction, NPs bioavailability in two contrasting soils and in earthworm feed was also investigated. Neither CeO2 NPs nor SnO2 NPs bioaccumulated in earthworms, and both were rapidly excreted when worms were transferred to clean soil. Low bioavailability was also indicated by low amounts of NPs recovered during extraction with non-stringent extractants. CeO2 NPs showed increasing mobility in organic soil over time (28 days), indicating that organic matter has a strong influence on the fate of CeO2 NPs in soil.
... Neutron activation has been also used so as to study the effects of Co-NPs in the earthworm Eisenia fetida. Using scintillation counting and autoradiography, 4 nm Co-NPs constituting a nanopowder (59 m 2 /g) were detected in spermatogenic cells, cocoons, and blood [10]. ...
... Eisenia fetida exposed during seven days to 4 nm Co-NPs retained the NPs during eight weeks during which only about 20% of ingested NPs were excreted. These NPs were found in blood and cocoons and spermatogenic cells [10]. ...
Since several years nanoparticles (NPs) are produced by industries and used in several fields of activities. They are finally found in aquatic and terrestrial environments, where they are ingested by living organisms in which they accumulate, before being eliminated. In organisms, NPs represent foreign elements with their own physicochemical properties due to their small size. So NPs may interfere with the normal physiological mechanisms of the embryos, growing animals, and adults, and it is indispensable to understand their potentially direct or indirect harmful effects on living organisms. It has been already shown that NPs could be toxic to bacteria, algae, invertebrates, and vertebrates. In this review, several examples of recent studies are given. We will examine successively the effects of NPs on terrestrial and semiaquatic and aquatic vertebrate and invertebrate animals.
... (Hu et al. 2010;Lapied et al. 2011), and carbon-based NPs (Li et al. 2010;Li et al. 2013;Petersen et al. 2011) has also been studied. Oughton et al. (2008) and Coutris et al. (2012) used neutron-activated CoNPs and AgNPs to trace the environmental fate, bioavailability (bioaccumulation), and excretion of the NPs. CoNPs exhibited greater retention within the earthworm and higher bioaccumulation factors than AgNPs. ...
... Bioaccumulation of NPs has been evaluated by micro X-ray fluorescence spectrometry (Lapied et al. 2011), inductively coupled plasma (Coleman et al. 2010; Hu et al. 2010; Schlich et al. 2013; Shoults-Wilson et al. 2011a,b,c; Stewart et al. 2013; Unrine et al. 2010a; 2010b), flame atomic absorption spectrophotometry (Heggelund et al. 2014; Li et al. 2011), X-ray microspectroscopy (Unrine et al. 2010b), gamma spectrometry (Coutris et al. 2012; Oughton et al. 2008), liquid scintillation counting (Li et al. 2010; Petersen et al. 2008; 2009; 2011), and microwave (Li et al. 2013). Bioaccumulation of AuNPs (Coutris et al. 2012; Oughton et al. 2008; Shoults-Wilson et al. 2011b; Unrine et al. 2010b), CuNPs (Unrine et al. 2010a), Al 2 O 3 NPs(Coleman et al. 2010), CoNPs(Coutris et al. 2012;Oughton et al. 2008),(Hu et al. 2010), TiO 2 NPs ...
The concern regarding the ecotoxicological effects of nanomaterials in the terrestrial environment is increasing. Against this background, several studies have investigated the effects of different nanomaterials on various earthworm species. Since the earthworm is a representative invertebrate present in soil and occupies an important trophic level, many studies have focussed on earthworms. Understanding how and why nanoparticles are toxic to organisms is important to nanotoxicologists and ecotoxicologists. We have collated information from studies on the toxicity of metal- and carbon-based nanomaterials to earthworms in the soil matrix, and trends in the adverse effects of nanomaterials on earthworms were analyzed. Most studies showed that the survival and growth of adult earthworms are negligibly affected by nanomaterials in the soil. However, many studies reported that nanomaterials may result in a reduction in the reproductive activity. This study presents an intensive overall view of the ecotoxicological impact of nanomaterials on earthworms at the organism, cellular, and molecular levels.
... cyclic voltammetry was reported as a rapid alternative method for the assessment of Ag 0 and dissolved Ag + ions concentration [78]. Neutron activation used in the analysis of the concentration of the released silver nanoparticles showed the mechanism of transport of silver nanoparticles across different trophic levels of the aquatic ecosystem [79]. Mathematical models earlier used for assessing the fate of the silver nanoparticles released into the environment were mostly represented incorrectly due to the simplified aspects of chemistry and transport of nanoparticles assumed. ...
The current scenario of water resources shows the dominance of pollution caused by the draining of industrial effluents. The polluted waters have resulted in severe health and environmental hazards urging for a suitable alternative to resolve the implications. Various physical and chemical treatment steps currently in use for dye effluent treatment are more time consuming, cost-intensive, and less effective. Alternatively, nanoparticles due to their excellent surface properties and chemical reactivity have emerged as a better solution for dye removal and degradation. In this regard, the potential of silver nanoparticles in dye effluent treatment was greatly explored. Efforts were taken to unravel the kinetics and statistical optimization of the treatment conditions for the efficient removal of dyes. In addition, the role of silver nanocomposites has also experimented with colossal success. On the contrary, studies have also recognized the mechanisms of silver nanoparticle-mediated toxicity even at deficient concentrations and their deleterious biological effects when present in treated water. Hence, the fate of the silver nanoparticles released into the treated water and sludge, contaminating the soil, aquatic environment, and underground water is of significant concern. This review summarizes the current state of knowledge regarding the use of silver nanoparticles and silver-based nanocomposites in effluent treatment and comprehends the recent research on mitigation of silver nanoparticle-induced toxicity.
... Neutron activation of mineral ENPs offers the possibility of labeling ENPs in a way that avoids surface modification and permits both localization and quantification within a matrix or an organism. Oughton et al. 35 demonstrates the suitability of neutron activation for Ag, Co/Co 3 O 4 , and CeO 2 nanoparticles. They studied the dietary uptake and excretion of a Co nanopowder (average particle size, 4 nm; surface area, 59 m 2 g À1 ) in the earthworm Eisenia fetida. ...
The main object of this chapter is to extend the research field of metallomic to a fast developing research area as nanoscience and technology. This chapter is divided into 6 sections. The systematic study of metallic nanomaterials, nanometallomics, is first proposed in section 1. Then the definition and research area of nanometallomics is discussed in section 2. The application of nuclear techniques in characterization, oxidation state analysis and electronic configuration of metallic nanomaterials is introduced in section 3 while the application of nuclear techniques like neutron activation analysis, ICP-MS, X-ray fluorescence analysis, and isotopic tracing techniques in the quantification and biodistribution of metallic nanomaterials is reported in section 4. In section 5, the structural analysis for bio-nano interaction is reviewed which shows X-ray absorption spectroscopy is a powerful tool in this area. Finally in section 6, the outlook of nanometallomics as an emerging research field is demonstrated. The integrated techniques provide a useful platform for the quantification, biodistribution and structural analysis of metallic nanomaterials.
... The primary particle size of the C-Ag NPs were 4 nm (main size population), and for the uncoated nanoparticles U-Ag NPs it has previously been measured to be 20 nm (Coutris et al. 2012;Oughton et al. 2008). However, it was clear that the uncoated particles (U-Ag NPs) was mainly found in larger aggregates (see supplementary information). ...
The potential impact of Ag nanoparticles on aquatic organisms is to a large extent determined by their bioavailability through different routes of exposure. In the present study juvenile Atlantic salmon (Salmo salar) were exposed to different sources of radiolabeled Ag (radiolabeled 110mAg nanoparticles and 110mAgNO3). After 48 h waterborne exposure to 3 µg/L citrate stabilized 110mAg nanoparticles or 110mAgNO3, or a dietary exposure to 0.6 mg Ag/kg fish (given as citrate stabilized or uncoated 110mAg nanoparticles, or 110mAgNO3), Ag had been taken up in fish regardless of route of exposures and source of Ag (Ag nanoparticles or AgNO3). Waterborne exposure led to high Ag concentrations on the gills, and dietary exposure to high concentrations in the gastrointestinal tract. Silver distribution to the target organs was similar for both dietary and waterborne exposure, with liver as the main target organ. The accumulation level of Ag was 2‐3 times higher for AgNO3 than for Ag nanoparticles when exposed through water, whereas dietary exposure led to no significant differences. The transfer (Bq/g liver/g food or water) from exposure through water was four orders of magnitude higher than from feed using the smallest, citrate stabilized Agnanoparticles (4 nm). The smallest nanoparticles had a five times higher bioavailability in food compared to the larger and uncoated Ag nanoparticles (20 nm). Despite the relatively low transfer of Ag from diet to fish, the short lifetime of Ag nanoparticles in water and transfer to sediment, feed or sediment dwelling food sources such as larvae and worms, could make diet a significant long‐term exposure route. This article is protected by copyright. All rights reserved
... Nanoecotoxicology is a sub-discipline of ecotoxicology and particularly aims to identify and predict effects drawn by nano sized materials on ecosystems. To attain this objective, nanoecotoxicology needs to take into consideration the entry routes and fate of nanomaterials in the abiotic and biotic environment to define exposure (Oughton et al. 2008;Kahru and Ivask 2013). Furthermore needs to recognize those interactions of nanomaterials with biota that alter the proper function of cells comprising an organism, thus impacting populations, which in turn can lead to changes in community structure and function. ...
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.
... The highest accumulation was found in the blood and the intestinal tract and the least in the reproductive organs. Still, at high concentrations (87 mg kg À1 food), Co from Co NPs have been found in reproductive organs and cocoons produced after the worms had been transferred to a non contaminated environment [13]. ...
... This approach can make the ENP of interest easily detectable, even in complex matrices containing relevant concentrations of environmental nanoparticles (Z€ anker and Schierz, 2012). Possible labelling methods for ENP tracking include fluorescence labelling (where a dye is attached to the surface of the ENPs (Kirchner et al., 2005)), radiolabeling with g or b emitters (Ferguson et al., 2008;Oughton et al., 2008;Petersen et al., 2008;Abbas et al., 2010;Gibson et al., 2011;Hildebrand and Franke, 2012), and isotope labelling with stable isotopes (Gulson and Wong, 2006;Croteau et al., 2011;Dybowska et al., 2011). The labelling process can either be performed directly during the nanoparticle synthesis by using a labelled precursor or via post-synthesis manipulation (Z€ anker and Schierz, 2012), but labelling during synthesis is preferable. ...
... The ENMs were purchased from a commercial source and labeled via isotope exchange. Oughten et al. (2008) employed neutron activation to label Co-ENMs. Both approaches eliminate the logistical challenges of working with radioactive materials during synthesis, but other logistical challenges remain. ...
Bioavailability of Me-ENMs to aquatic organisms links their release into the environment to ecological implications. Close examination shows some important differences in the conceptual models that define bioavailability for metals and Me-ENMs. Metals are delivered to aquatic animals from Me-ENMs via water, ingestion, and incidental surface exposure. Both metal released from the Me-ENM and uptake of the nanoparticle itself contribute to bioaccumulation. Some mechanisms of toxicity and some of the metrics describing exposure may differ from metals alone. Bioavailability is driven by complex interaction of particle attributes, environmental transformations, and biological traits. Characterization of Me-ENMs is an essential part of understanding bioavailability and requires novel methodologies. The relative importance of the array of processes that could affect Me-ENM bioavailability remains poorly known, but new approaches and models are developing rapidly. Enough is known, however, to conclude that traditional approaches to exposure assessment for metals would not be adequate to assess risks from Me-ENMs.
... Findings regarding NPs ecotoxicity for soil species had highlighted the varied nature of responses to different NP types. For example, it has been shown that earthworms do not readily absorb carbon NPs from soil (Petersen et al, 2008a(Petersen et al, , 2008b, whereas metal NPs like TiO 2 , ZnO, Ag, CeO 2 , Au, and CuO can be taken up (Hu et al, 2010;Oughton et al, 2008;Pang et al, 2012). In freshwater and marine invertebrate organisms, many studies demonstrated the potential impact of these nanomaterials to activate the detoxication system, genotoxic and oxidative responses, as well as causing harsh impact on organisms' behavior (including burrowing and locomotion) Buffet et al, 2012b;Jackson et al, 2012). ...
The aim of this thesis was to determine the impact of two types of metal nanoparticles (cadmium sulphide - CdS - and gold - Au) on two aquatic models (tubifex worms and zebrafish Danio rerio). The approach has been to dope the Garonne sediment with the two types of nanoparticles and characterize the effect of this contamination on the two animals using multiple markers at different levels of biological organization (biochemical responses, neurotransmission activity, genotoxicity, gene expression and bioturbation activity). The effects were evaluated after exposure to contaminated sediment in experimental microcosms systems for twenty days. In a number of cases this work revealed an effect of the nanoparticles that was not due to metal but to the nanoparticulate properties. Indeed, in the case of CdS nanoparticles, we observed alterations in the genome as well as the modification of the bioturbation activity of worms tubifex in response to the contamination of nanoparticles but not to that of the ionic form. In this work we observed the release of gold nanoparticles from the sediment into the water column, and its potential bioavailability to fish. These nanoparticles were causing DNA damage in both organisms, modifying the expression of certain genes and increased acetylcholinesterase activity in zebrafish. Bioturbation results showed no effects of gold nanoparticles on the movement of worms.
... As an excellent tool for tracing the environmental fate of NPs and their uptake and accumulation in organisms (Oughton et al. 2008;Bystrzejewska-Piotrowska et al. 2012), gamma spectrometry following neutron activation of platinum was used for Pt-NP analysis in plant tissues. Details of the procedure are described elsewhere (Bystrzejewska-Piotrowska et al. 2012). ...
Nanoparticles (NPs) are commonly used, and concerns about their possible adverse effects are being voiced as well. However, little is known about the fates of NPs released to the environment. The aim of the study was to (i) evaluate the ability of Sinapis alba and Lepidium sativum plants to take up platinum nanoparticles (Pt-NPs) and translocate them to aboveground organs, (ii) compare the accumulation efficiency of different forms of platinum and (iii) identify the forms in which platinum is stored in plant tissues. Plants were cultivated on medium supplemented with different concentrations of Pt-NPs and [Pt(NH3)4](NO3)2. Platinum content in plants was determined using inductively coupled plasma mass spectrometry. For the identification of the presence of Pt-NPs in plant tissues, gamma spectrometry following iron irradiation was applied. It was found that L. sativum and S. alba are tolerant to applied concentrations of Pt-NPs and have an ability to take up platinum from the medium and translocate it to aboveground organs. The highest concentration of platinum was observed in plant roots (reaching 8.7 g kg−1 for S. alba). We tentatively conclude that platinum is accumulated as nanoparticles. The obtained results suggest future application of plants for phytoremediation and recovery of noble metal nanoparticles.
... When the same nanopowder material was new, Oughton et al. showed that the Co NP were characterized by a Co metal core with a Co 3 O 4 -CoO shell [2]. These observations are interesting because the absence of Co metal signals for both XANES and XRD in the present work shows that speciation has significantly altered during ~8 years of storage in the original plastic container. ...
... When the same nanopowder material was new, Oughton et al. showed that the Co NP were characterized by a Co metal core with a Co 3 O 4 -CoO shell [2]. These observations are interesting because the absence of Co metal signals for both XANES and XRD in the present work shows that speciation has significantly altered during ~8 years of storage in the original plastic container. ...
... This information is usually missing when determining the total amount of an element using common analytical methods, such as ICP, MS, and ASA. Neutron activation is a powerful method for tracing the environmental fate of NPs and their accumulation in organisms [17] and has previously been applied for the analysis of Fe 3 O 4 -NPs accumulation by plants [18]. ...
Water environments are noted as being some of the most exposed to the influence of toxic nanoparticles (NPs). Therefore, there is a growing need for the investigation of the accumulation and toxicity of NPs to aquatic organisms. In our studies neutron activation followed by gamma spectrometry and liquid scintillation counting were used for studying the accumulation of silver nanoparticles (AgNPs) by freshwater larvae of Chironomus and fish Danio rerio. The influence of exposition time, concentration and the source of nanoparticles on the efficiency of AgNP accumulation were studied. It was found that AgNPs are efficiently accumulated by Chironomid larvae for the first 30 hours of exposition; then, the amount of silver nanoparticles decreases. The silver content in larvae increases together with the NP concentration in water. Larvae which have accumulated AgNPs can be a source of nanoparticles for fish and certainly higher levels of Ag in the trophic chain. In comparison with water contamination, silver nanoparticles are more efficiently accumulated if fish are fed with AgNP-contaminated food. Finally, it was concluded that the applied study strategy, including neutron activation of nanoparticles, is very useful technique for tracing the uptake and accumulation of NPs in organisms.
... It is capable of impressive sensitivity with a minimum of sample preparation. Using NA for detecting nanoparticles in organisms is not unprecedented.[185] It does require access to a facility capable of performing the neutron bombardment and the associated instrumentation. ...
... On the other hand, toxicity studies with such materials require reliable methods for detecting, tracing and quantifying nanoparticles (NPs), which is usually a major problem for non-labelled nanomaterials (Weiss and Diabate 2011). Radiolabelling represents one of the most sensitive and quantitative techniques for this purpose with the potential to properly quantify NPs in various biological systems (Pérez-Campaña et al. 2013;Llop et al. 2013;Pérez-Campaña et al. 2012;Weiss and Diabate 2011;Abbas et al. 2010;Ponti et al. 2009;Oughton et al. 2008;Kreyling et al. 2004). However, since radiotracers can usually not be incorporated into large-scale industrial manufacturing processes, post-synthesis radiolabelling procedures must be applied. ...
Radiolabelling of industrially manufactured nanoparticles is useful for nanoparticle dosimetry in biodistribution or cellular uptake studies for hazard and risk assessment. Ideally for such purposes, any chemical processing post production should be avoided as it may change the physico-chemical characteristics of the industrially manufactured species. In many cases, proton irradiation of nanoparticles allows radiolabelling by transmutation of a tiny fraction of their constituent atoms into radionuclides. However, not all types of nanoparticles offer nuclear reactions leading to radionuclides with adequate radiotracer properties. We describe here a process whereby in such cases nanoparticles can be labelled with (7)Be, which exhibits a physical half-life of 53.29 days and emits γ-rays of 478 keV energy, and is suitable for most radiotracer studies. (7)Be is produced via the proton-induced nuclear reaction (7)Li(p,n)(7)Be in a fine-grained lithium compound with which the nanoparticles are mixed. The high recoil energy of (7)Be atoms gives them a range that allows the (7)Be-recoils to be transferred from the lithium compound into the nanoparticles by recoil implantation. The nanoparticles can be recovered from the mixture by dissolving the lithium compound and subsequent filtration or centrifugation. The method has been applied to radiolabel industrially manufactured SiO2 nanoparticles. The process can be controlled in such a way that no alterations of the (7)Be-labelled nanoparticles are detectable by dynamic light scattering, X-ray diffraction and electron microscopy. Moreover, cyclotrons with maximum proton energies of 17-18 MeV that are available in most medical research centres could be used for this purpose.
... In the case of titanium dioxide, studying the uptake and translocation via stable isotope tracing could be a possibility (Gulson and Wong, 2006). For silver and cerium dioxide neutron activation and detection by gamma spectroscopy or autoradiography, could be a promising approach (Oughton et al., 2008). Verification through transmission electron microscopy might be difficult with the particles used in this study due to a low contrast and presumably low concentrations in the observed slides. ...
... This last result, if compared to those found in algae and plant agar tests, is surprising and, to explain it, a different aggregation of NPs or lower protection against oxidative stress in water has been postulated. Similarly, although no evident toxicity was recorded after NP administration with food to the earthworm Eisenia foetida (Oughton et al., 2008) and to the terrestrial crustacean Porcellio scaber (Drobne, Jemec and Pipan Tkalec, 2009;Jemec et al., 2008), the soil nematode Caenorhabditis elegans poorly tolerated the exposure to metallic NPs when the experiments were conducted in water (Roh et al., 2009;Wang, Wick and Xing, 2009b). ...
Biological barriers represent a stumbling block to the pharmacological treatment of lesions occurring in central nervous system or retina. The advent of nanodrugs was welcomed as a means to tide over and cross the barriers. Expectations, however, have not been completely fulfilled, as nanocarriers often accumulated at the endothelial frontier, rather than cross it over. The super-paramagnetism of iron oxide nanoparticles improved the diagnostic power of the magnetic resonance imaging and opened new perspectives. These nanoparticles, which can be addressed to the target organ by an external magnetic field, provide local imaging of the lesion, on-demand release of therapeutic agent, and subsequent imaging of the repair. Nanogels that present a sol–gel phase transition at body temperature are easy to inject and remain immobilized near the site of injection. There they promote prolonged and sustained release of drugs, or frame a shell for cell precursors to fully develop into mature neurons or glia.
... It was shown that, under well-established irradiation conditions, Fe 3 O 4 nanoparticles do not undergo significant structural modifications; so the results are in accordance with studies carried out with the same non-radioactive nanomaterials and the radiolabelling method can be fruitfully applied to uptake studies because of the low-level exposure where higher sensitivity is required. Suitability of neutron activation for 60 Co/Co 3 O 4 (and also Ag and CeO 2 ) nanoparticles as a method for labeling and to demonstrate the traceability of radioactive nanoparticles in soil and soil organisms was studied [90]. Neutron activation of Ag, CeO 2 , and Co nanoparticles resulted in sufficient formation of the isotopes 110m Ag, 141 Ce, and 60 Co (half-lives of 250 d, 32.5 d, and 5.27 years, respectively). ...
Selected nanoparticles and nanocomposites on the basis of radioactive elements are reviewed. Isotopes of metallic gold, iodine and technetium salts, CeO2 and other lanthanide and actinide compounds, as well as several p- (P, C, F, Te) and d- (Fe, Co, Cu, Cd, Zn) elements form most common radioactive nanoparticles. Methods for their fabrication, including dopation with radionuclides and neutron/proton/deuteron activation, are discussed. These nanocomposites possess a series of useful applications, in particular in biology and medicine, including cancer therapeutics, drug delivery systems and radiotracers, as well as in the studies of several catalytic processes and materials structure.
The toxicity of nanoparticles (NPs) is a critical research topic in nanotechnology, as it is essential to understand thehazards posed by the wide spectrum of NPs that vary in shape, size, and composition. Previous reviews have yet to thoroughlyexplore the Biological Effective Doses of NPs, which drive toxicity and are influenced by factors such as solubility, charge, shape,contaminants, and the ability of NPs to translocate from the deposition site in the lungs. This review aims to fill the gap in theliterature by providing an overview of the possible toxicity of nanoparticles in zebrafish during growth stages, with a focus onoxidative stress, and exploring the available modes of toxicity that are relevant to conventional pathogenic particles. This reviewalso discusses the effects of nanomaterials on the reproductive system in animal models, providing insight into the potential toxicityof nanoparticles in humans. This review aims to provide a comprehensive overview of the toxicity of nanoparticles and to criticallyexplore the challenges associated with implementing nanotechnology, particularly in the pharmaceutical development of noveltherapeutic products and regulatory issues. The review also considers recent uses and projected nanotechnology advancements,providing a basis for future research in this field. In conclusion, this review rectifies the lacunae in previously published reviews byproviding a comprehensive overview of the toxicity of nanoparticles and exploring the challenges associated with implementingnanotechnology. The aim and objective of this review are to provide a comprehensive understanding of the toxicity of nanoparticlesand to guide future research in this field.
Nanotoxicology involves the study disclosing the toxicity of nanoparticles. An adverse effect caused by the manufacture either during processing or as the final product with nano materials may affect the human society either in vitro or in vivo. Determining the association of nanoparticles with cell mechanism, cell uptake, and subcellular confinement is necessary, as the novel physicochemical properties of nanomaterials may raise new toxicological concerns. It is mandatory to modify and organize the in vitro tests created to reflect the in vivo learning and make them suitable for all applications. Numerous assays are available for in vitro nanotoxicity assessment. This review summarizes the major techniques used in characterization and quantification of nanotoxicology studies. Various in vitro assays like cell viability assay, oxidative stress assay and inflammatory assay etc., characterization and imaging techniques like optical imaging methods (optical microscopes), high – content screening method (electron microscopes) were discussed to reveal the impact of nanoparticles towards environment, human health and involves in examining the risk assessment of nanomaterials among the surrounding environment. This article will be beneficial for beginners and researchers in the field of nanotoxicology studies/research.
Radiolabeled metal‐based nanoparticles (MNPs) have drawn considerable attention in the fields of nuclear medicine and molecular imaging, drug delivery, and radiation therapy, given the fact that they can be potentially used as diagnostic imaging and/or therapeutic agents, or even as theranostic combinations. Here, we present a systematic review on recent advances in the design and synthesis of MNPs with major focuses on their radiolabeling strategies and the determinants of their in vivo pharmacokinetics, and together how their intended applications would be impacted. For clarification, we categorize all reported radiolabeling strategies for MNPs into indirect and direct approaches. While indirect labeling simply refers to the use of bifunctional chelators or prosthetic groups conjugated to MNPs for post‐synthesis labeling with radionuclides, we found that many practical direct labeling methodologies have been developed to incorporate radionuclides into the MNP core without using extra reagents, including chemisorption, radiochemical doping, hadronic bombardment, encapsulation, and isotope or cation exchange. From the perspective of practical use, a few relevant examples are presented and discussed in terms of their pros and cons. We further reviewed the determinants of in vivo pharmacokinetic parameters of MNPs, including factors influencing their in vivo absorption, distribution, metabolism, and elimination, and discussed the challenges and opportunities in the development of radiolabeled MNPs for in vivo biomedical applications. Taken together, we believe the cumulative advancement summarized in this review would provide a general guidance in the field for design and synthesis of radiolabeled MNPs towards practical realization of their much desired theranostic capabilities.
This article is categorized under:
• Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
• Diagnostic Tools > Diagnostic Nanodevices
• Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease
Abstract
One example of radiolabeled metal‐based nanoparticles (MNPs) along with their noninvasive imaging evaluation is shown here to represent the potential use of MNPs as nanotheranostics of cancer. Hollow gold nanoparticles were radiolabeled with ¹⁰³Pd through an electroless deposited copper layer followed by ¹⁰³Pd galvanic replacement of copper. The in vivo distribution evaluation of the radiolabeled nanoparticles was performed by single‐photon emission computed tomography imaging fused with computed tomography in a prostate cancer xenograft mouse model of PC3‐tumor over 7 weeks (Moeendarbari et al., 2016).
Studies of radioactive isotopes at the liquid-solid or gas-solid interface are enabling a detailed mechanistic understanding the effects of radioactive decay on physical, biological, and chemical systems. In recent years, there has been a burgeoning interest in using radioactive isotopes for both imaging and therapeutic purposes by attaching them to the surface of colloidal nanoparticles. By merging the field of nanomedicine with the more mature field of internal radiation therapy, researchers are discovering new ways to diagnose and treat cancer. In this perspective, we discuss state-of-the-art radioactive thin films as applied to both well-defined surfaces and more complex nanoparticles. We highlight the design considerations that are unique to radioactive films, which originate from the damaging and potentially self-destructive emissions produced during radioactive decay and highlight future opportunities in the largely underexplored area between radioisotope chemistry and nanoscience.
Nano-scale zero-valent iron (nZVI) is highly-attractive material that is widely studied and used for pollution abatement, and thus it is one of the most abundant types of engineered nanoparticles introduced into the environment. Nevertheless, there is still a lack of information about the extent of nZVI migration and fate in real groundwater conditions and associated environmental impact and risks related to its introduction into the groundwater/soil. The present paper proposes a new analytical approach based on a multi-elemental signatures (ICP-MS analyses of trace elements in particular nZVI type and soil/groundwater samples) enabling easy tracing of nZVI and their transformation products, as well as their distinguishing from background colloids. A multi-elemental signatures approach was verified under laboratory conditions (in a large-scale sand-filled tank) and subsequently verified at three contaminated sites remediated with nZVI. Multivariate data analysis on 39 elements, such as principle component analysis (PCA), demonstrates that the method can be used to observe changes in signatures over time and it enabled us to confirm the presence of nZVI in monitoring wells. PCA analysis indicated that lanthanides are particularly suitable for tracing nZVI particles.
Remediation using nanoparticles depends on proper documentation of safety aspects, one of which is their ecotoxicology. Ecotoxicology of nanoparticles has some special features; while traditional ecotoxicology aims at measuring possible negative effects of more or less soluble chemicals or dissolved elements, nanoecotoxicology aims at measuring the toxicity of particles, and its main focus is on effects that are unique to nano-sized particles, as compared to larger particles or solutes. One of the main challenges when testing the ecotoxicity of nanoparticles lies in maintaining stable and reproducible exposure conditions, and adapting these to selected test organisms and endpoints. Another challenge is to use test media that are relevant to the matrices to be treated. Testing of nanoparticles used for remediation, particularly redox-active Fe-based nanoparticles, should also make sure to exclude confounding effects of altered redox potential that are not nanoparticle-specific. Yet another unique aspect of nanoparticles used for remediation is considerations of ageing of nanoparticles in soil or water, leading to reduced toxicity over field-relevant time scales. This review discusses these and other aspects of how to design and interpret appropriate tests and use these in hazard descriptions for subsequent risk assessments.
The analysis of the environmental behavior and toxicity of metal oxide nanoparticles (MONPs) is complicated by high metal concentrations in natural matrices. To better detect and quantify MONPs in complex samples, a variety of traceable labels can be incorporated. There are four primary categories of MONP labels: fluorescent dyes, radioisotopes, stable isotopes, and dopant/core-shell labels. This review describes each MONP labeling technique, along with its advantages and drawbacks, and provides strategies for choosing the most appropriate labeling method for a given study design.
Metallomics, focusing on the global and systematic understanding of the metal uptake, trafficking, role, and excretion in biological systems, has attracted more and more attention. Metal-related nanomaterials, including metallic and metal-containing nanomaterials, have unique properties compared to their macroscale counterparts and therefore require special attention. The absorption, distribution, metabolism, excretion (ADME) behavior of metal-related nanomaterials in the biological systems is influenced by their physicochemical properties, the exposure route, and the microenvironment of the deposition site. Nanomaterials not only may interact directly or indirectly with genes, proteins, and other molecules to bring genotoxicity, immunotoxicity, DNA damage, and cytotoxicity but may also stimulate the immune responses, circumvent tumor resistance, and inhibit tumor metastasis. Because of their advantages of absolute quantification, high sensitivity, excellent accuracy and precision, low matrix effects, and nondestructiveness, nuclear and related analytical techniques have been playing important roles in the study of metallomics and nanometallomics. In this chapter, we present a comprehensive overview of nuclear and related analytical techniques applied to the quantification of metallome and nanometallome, the biodistribution, bioaccumulation, and transformation of metallome and nanometallome in vivo, and the structural analysis. Besides, metallomics and nanometallomics need to cooperate with other -omics, like genomics, proteomics, and metabolomics, to obtain the knowledge of underlying mechanisms and therefore to improve the application performance and to reduce the potential risk of metallome and nanometallome.
Titanium dioxide nanoparticles (TiO2 NPs) are increasingly entering natural systems due to their widespread production and use. It is critical that TiO2 NP behavior is studied in real-world systems, but experimental work is complicated by the high levels of background titanium present in every environmental compartment. To assist in distinguishing between engineered NPs and background titanium, labeled particles with gold nanoparticle cores and TiO2 shells (Au@TiO2 NPs) were developed and the properties and behavior compared to unlabeled TiO2 NPs. Both particle types had primary particle diameters of approximately 200 nm and were stable in solutions at ionic strengths up to 500 mM due to a polyvinylpyrrolidone surface coating. To demonstrate utility, the Au@TiO2 NPs were used in several spike-and-recovery experiments in complex matrices such as activated sludge and a river water-sunscreen mixture. Au@TiO2 NPs were accurately quantified at using instrumental neutron activation analysis and inductively coupled plasma optical emission spectrometry.
The interactions of nanoparticles (NPs) with biochar (BC) and soil components may substantially influence NP availability and toxicity to biota. In the present study, earthworms (Eisenia fetida) were exposed for 28 d to a residential or agricultural soil amended with 0-2000 mg CeO2 NP/kg and with biochar (produced by the pyrolysis of pecan shells at 350°C and 600 °C) at various application rates (0-5% [w/w]). After 28 d, earthworms were depurated and analyzed for Ce content, moisture content and lipid peroxidation. The results showed minimal toxicity to the worms; however, biochar (350°C or 600 °C) was the dominant factor, accounting for 94% and 84% of the variance for moisture content and lipid peroxidation, respectively, in the exposed earthworms. For both soils with 1000 mg CeO2/kg, 600 °C, biochar significantly decreased the accumulation of Ce in the worm tissues. Amendment with 350 °C biochar had mixed responses on Ce uptake. Analysis by µ-XRF and µ-XANES was used to evaluate Ce localization, speciation and persistence in CeO2- and biochar (BC)-exposed earthworms after depuration for 12, 48 and 72 h. Earthworms from the 500 mg CeO2/kg and 0% BC treatments eliminated most Ce after a 48 h depuration period. However, in the same treatment and with 5% BC-600 (biochar pyrolysis temperature of 600°C), ingested biochar fragments (~ 50 µm) with Ce adsorbed to the surfaces were retained in the gut after 72 h. Additionally, Ce remained in earthworms from the 2000 mg CeO2/kg and 5% BC treatments after depuration for 48 h. Analysis by µ-XANES showed that within the earthworm tissues, Ce remained predominantly as Ce+4O2, with only few regions (2-3µm2) where it was found in the reduced form (Ce+3). The present findings highlight that soil and biochar properties have a significant influence in the internalization of CeO2 NPs in earthworms; such interactions need to be considered when estimating NP fate and effects in the environment.
A major challenge in following the fate of engineered nanoparticles (NPs) is their detection in environmental media, and in particular their isolation from background metal and natural colloidal material. This represents a particular hurdle for the use of, for example, Fe-based NPs in remediation, owing to high levels of naturally occurring iron. As part of the EU NANOREM project, the WP6 overall goal is the development and application of analytical methods and protocols for in-situ measurement and detection of nanoparticles. Inductively coupled plasma mass spectrometry (ICP-MS) applied to tracking nanoparticles requires an analysis of the particles and comparison with background measurements from environmental samples such as water, sediment or soil. This can allow a set of elements to be selected such as lanthanides whose ratios are typical for nanoparticles but present at very different ratios in environmental samples. Our hypothesis of work proposes that iron nanoparticles used in NANOREM field injection experiments have a distinctive lanthanides signature that, after an injection event, modify the background lanthanide signature of water/sediment samples towards profiles similar to that of the nanoparticles. Results obtained from iron-based nanoparticles such as CARBOIRON®, NANOFER 25S, NANOGOETHITE and milled nZVI indeed demonstrated a distinctive lanthanide signature. These signatures allowed also to differentiate from background sedimentary profiles obtained in diverse injection fields sites used along the NANOREM initiative such as Israel, Switzerland, Germany and Czech Republic. Finally, results from selected monitoring wells from Fe NPs injection at field site Spolchemie II in Ústi nad Labem II, Czech Republic indicated that the lanthanides signature strategy could be used as complementary tool of ionic Fe field measurement for long term monitoring of trace amounts of NPs.
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.
This chapter reviews the available literature on radiolabeling methods and their applications of a series of nanomaterials-carbon nanomaterials, metal-based nanomaterials, polymeric nanomaterials, and so on. Radiolabeling of nanoparticles can be achieved by either direct labeling, including synthesis of nanoparticles from radioactive precursors, neutron or ion-beam activation, cation exchange or isotopic exchange, physical absorption, and covalent attachment, or indirect labeling, including bifunctional chelators, prosthetic groups. Quantitative determination of engineered nanomaterials in biological and environmental matrices is the main difficulty of these studies and is of paramount importance to understand the behavior of nanoparticles in the environment and organisms. It is well known that most nanomaterials are chemically reactive and may undergo various transformations in biological and environmental conditions. To fully understand the biological and environmental impacts of engineered nanomaterials (ENM), speciation analysis of nanoparticles in samples using X-ray absorption spectroscopy (XAS), scanning transmission X-ray microscopy (STXM), and so on, is generally required.
To assess the environmental impact of radioactive contamination of different ecosystems, information on source terms, mobility, biological uptake, and associated effects is needed. However, naturally occurring and artificially produced radionuclides can be present in different physicochemical forms (ions, colloids, nanoparticles, pseudocolloids, particles) influencing the mobility and biological uptake. Following severe nuclear events associated with the nuclear weapon or fuel cycles, a major fraction of refractory radionuclides will be present as radioactive particles; radionuclides are also present as colloids or low molecular mass (LMM) ionic species in effluents from nuclear installations. Thus, the distribution of radionuclide species depends on the source and release scenarios. LMM radionuclide species are believed to be mobile and potentially bioavailable, while high molecular mass (HMM) species such as nanoparticles, colloids, polymers, and pseudocolloids are mobile in water. Radioactive particles are considered biologically inert, but can be retained in filtering organisms as well as in soils and sediments. If mobile species are present, ecosystem transfer is relatively fast, whereas the ecosystem transfer is delayed if particles are present. Owing to time-dependent transformation processes such as interactions of mobile and reactive radionuclide species with components in soils and sediments or particle weathering and subsequent remobilization of associated radionuclide species, the original distribution of radionuclides deposited in ecosystems will change over time. Therefore, information on radionuclide species released and deposited, as well as on time-dependent transformation processes influencing the distribution of radionuclide species, is essential for the assessment of the environmental impact and risk associated with radionuclide contamination. This article summarizes available speciation techniques that should be utilized within radioecology, including fractionation and solid-state speciation, to characterize radionuclide species in waters, soils, and sediments.
To assess the environmental impact of radioactive contamination of different ecosystems, information on source terms, mobility, biological uptake, and associated effects is needed. However, naturally occurring and artificially produced radionuclides can be present in different physicochemical forms (ions, colloids, nanoparticles, pseudocolloids, particles) influencing the mobility and biological uptake. Following severe nuclear events associated with the nuclear weapon or fuel cycles, a major fraction of refractory radionuclides will be present as radioactive particles; radionuclides are also present as colloids or low molecular mass (LMM) ionic species in effluents from nuclear installations. Thus, the distribution of radionuclide species depends on the source and release scenarios. LMM radionuclide species are believed to be mobile and potentially bioavailable, while high molecular mass (HMM) species such as nanoparticles, colloids, polymers, and pseudocolloids are mobile in water. Radioactive particles are considered biologically inert, but can be retained in filtering organisms as well as in soils and sediments. If mobile species are present, ecosystem transfer is relatively fast, whereas the ecosystem transfer is delayed if particles are present. Owing to time-dependent transformation processes such as interactions of mobile and reactive radionuclide species with components in soils and sediments or particle weathering and subsequent remobilization of associated radionuclide species, the original distribution of radionuclides deposited in ecosystems will change over time. Therefore, information on radionuclide species released and deposited, as well as on time-dependent transformation processes influencing the distribution of radionuclide species, is essential for the assessment of the environmental impact and risk associated with radionuclide contamination. This article summarizes available speciation techniques that should be utilized within radioecology, including fractionation and solid-state speciation, to characterize radionuclide species in waters, soils, and sediments.
With the rapid development of nanotechnology, studies on biological effects of nanomaterials have becoming hotspots. However, the fully understanding of fate and toxicological behavior of nanomaterials as a result of interactions with complex biosystem are highly dependent on the reliable analytical techniques. Synchrotron radiation is an advanced light source with notable quality such as high brightness, high level of polarization, high collimation, high brilliance, high intensity and wide tunability in energy/wavelength. It provides particular advantages in elemental mapping and structure characterization of nanomaterials. In this paper, the applications of synchrotron radiation and related nuclear analytical techniques in the studies on the toxicological or biological behaviors of nanomaterials in biological systems are critically reviewed, along with their advantages and limitations. Mentioned techniques include synchrotron radiation X ray fluorescence (SRXRF), X-ray absorption fine structure (XAFS, XANES and EXAFS), synchrotron radiation circular dichroism spectroscopy (SRCD), inductively coupled plasma mass spectrometry (ICP-MS), neutron activation analysis (NAA), and isotopic tracing. High throughput quantification of nanomaterials can be achieved by ICP-MS and NAA. The distribution mappings of nanomaterials can be performed by SRXRF and isotopic tracing. Structural characterization can be acquired by XAFS and SRCD. All together, these novel techniques will help to lead a better understanding of the biological effects of nanomaterials.
With the rapid development of nanotechnology and its applications, the potential interactions of nanomaterials with living systems and environment have attracted increasing attention from the public, manufacturers of nanomaterial-based products, academic researchers and policymakers. Nanotoxicology is emerging as an important subdiscipline of nanotechnology as well as toxicology. Nanotoxicology studies rely on many analytical methods for the characterization of nanomaterials and detection of nanomaterials in living systems. In this case, radioanalytical methods play an important role due to their intrinsic merits such as high sensitivity, good accuracy, ability to distinguish the endogenous or exogenous sources of materials, and ability of in situ and in vivo analysis. This article reviews recent progress of applications of radioanalytical methods in nanotoxicology studies, with emphasis on radiolabeling methods of nanomaterials.
When nanomaterials meet the biological world, the cellular interaction of nanoparticles is routinely assessed in in vitro systems. Establishing dose–response relationships requires that the dose of nanoparticles delivered to the cell is accurate and precise. Nanoparticles as such or coated with high molecular-weight compounds are rarely uniform and the influence of heterogeneity, including polydispersity both in size and mass density, on the delivered dose is never studied before. Furthermore, a probabilistic term describing particle adherence to cells is introduced and the importance is discussed. By tracing the movement of discrete particles via modeling, it is found that the influence of heterogeneity cannot be neglected when the average particle size promotes settling over diffusion. However, the influence of polydispersity on the delivered cellular dose is less critical for particulate systems whose mean size promotes diffusion. The influence of a non-instantaneous particle association to the cell is negligible for particles whose motion is dominated by settling, but it is relevant for small particles whose motion is governed by diffusion.
Distinguishing nanomaterials of interest from background nanosized matter already present in the sampling environment is a challenging task. In this study, we propose the use of rare earth elements (REEs) as high-sensitivity labels to identify and to monitor their fate following manipulation. The REE labels were added during the synthesis of TiO2 nanoparticles with hydrodynamic sizes of 15 nm. The REE-labelled nanomaterials allow the monitoring of nanoparticle aerosols formed during handling of nanoparticulate materials in a glove box. The deposition of the labelled TiO2 nanoparticles on working surfaces could be verified by electron microscopy and surface analysis, using the presence of lanthanide elements as an identification label. The total amount of TiO2 nanoparticles in the deposited material could be quantified by a procedure based on wiping the deposition area followed by digestion of the collected matter and analysis by flame emission spectrometry.
The effect of adding cobalt, as 60Co, to the food source of the earthworm Eisenia foetida was studied. Cobalt was retained with a half-life of 387 ± 43 (SD) days in the worm. After 172 days more cobalt was concentrated in the gut than the body wall. 60Co was not transmitted from adults to cocoons. Prolonged studies involving the addition of CoCl2 (0, 8.2, 16.5 and 82.5 μg Co g−1) to a food source low in Co indicated that total Co concentrations of 17.6 and 25.9 μg g−1 resulted in significantly increased maximum weights compared to the control worms which were exposed to 9.4 μg Co g−1. The highest Co addition (82.5 μg g−1, total 91.9 μg g−1) caused no increase in maximum weight over controls, but resulted in a statistically significant lag in early growth compared to that of all other groups. Significantly more cocoons were produced by worms fed 17.6 or 25.9 μg Co g−1 compared with those fed 9.4 or 91.9 μg Co−1 Co.
In laboratory experiments, earthworms (Eisenia foetida) exhibited no assimilation of radioactive 60Co from mineral soil, but did assimilate small quantities (about 7% of ingestion) of 60Co from manure. This study supports earlier work suggesting that earthworms assimilate only small amounts of inorganic elements from mineral soil, and that any assimilation of metals must be from the organic fraction of soils. Thus, assimilation rates are a function of substrate quality. When fed to earthworms, gamma-emitting radioactive elements can provide measurement of assimilation efficiency, gut passage time and feeding rate.
The working principle of nuclear analytical methods (NAMs) is not influenced by the chemical bond. Consequently, they are independent counterparts to the well-known chemical procedures. NAMs obey fundamental laws or can be described and understood thoroughly. This qualifies them as candidates for reference methods. Although following similar nuclear reaction schemes, they comprise bulk analyzing capability (neutron and photon activation analysis) as well as detection power in surface near regions of solids (ion beam techniques). Prominent features of NAMs are sensitivity, selectivity, multielement determination and linearity of the calibration function covering a concentration range of several orders of magnitude. Moreover, ion beam techniques allow depth profiling with nm-resolution in several cases while the ion microprobe additionally offers a lateral resolution in the micron-scale. As NAMs require expensive apparatus (nuclear reactor, accelerator in radioactive control areas) their availability is restricted to a small number of suitably equipped institutes. However, they are able to solve complex analytical tasks, take part in key comparisons and play an essential role in the certification of reference materials.
Although progress has recently been made toward understanding the health and environmental consequences of these materials, challenges remain for future research.
This study investigates the aqueous stability of multi-walled carbon nanotubes (MWNTs) in the presence of natural organic matter (NOM). MWNTs were readily dispersed as an aqueous suspension in both model NOM (Suwannee River NOM (SR-NOM)) solutions and natural surface water (actual Suwannee River water with unaltered NOM background), which remained stable for over 1 month. Microscopic analyses suggested that the suspension consisted primarily of individually dispersed MWNTs. Concentrations of MWNTs suspended in the aqueous phase, quantified using thermal optical transmittance analysis (TOT), ranged from 0.6 to 6.9 mg/L as initial concentrations of MWNT and SR-NOM were varied from 50 to 500 mg/L and 10 to 100 mg/L, respectively. Suwannee River water showed a similar MWNT stabilizing capacity as compared to the model SR-NOM solutions. For the same initial MWNT concentrations, the concentrations of suspended MWNT in SR-NOM solutions and Suwannee River water were considerably higher than that in a solution of 1% sodium dodecyl sulfate, a commonly used surfactant to stabilize CNTs in the aqueous phase. These findings suggest that dispersal of carbon-based nanomaterials in the natural, aqueous environment might occur to an unexpected extent following a mechanism that has not been previously considered in environmental fate and transport studies.
The increasing use of engineered nanoparticles (NP) in industrial and household applications will very likely lead to the release of such materials into the environment. Assessing the risks of these NP in the environment requires an understanding of their mobility, reactivity, ecotoxicity and persistency. This review presents an overview of the classes of NP relevant to the environment and summarizes their formation, emission, occurrence and fate in the environment. The engineered NP are thereby compared to natural products such as soot and organic colloids. To date only few quantitative analytical techniques for measuring NP in natural systems are available, which results in a serious lack of information about their occurrence in the environment. Results from ecotoxicological studies show that certain NP have effects on organisms under environmental conditions, though mostly at elevated concentrations. The next step towards an assessment of the risks of NP in the environment should therefore be to estimate the exposure to the different NP. It is also important to notice that most NP in technical applications are functionalized and therefore studies using pristine NP may not be relevant for assessing the behavior of the NP actually used.
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