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ABSTRACT: Commercially available carbon nanotubes (CNT) often contain some quantities of metallic and carbonaceous impurities. These impurities influence their physicochemical properties and performance, and accordingly a number of potential applications. The lack of information of metal impurities may also preclude accurate environmental and health risk assessments for specific CNT materials. To address these needs, a quantitative analysis of the metal contents has been made in a number of commercial carbon nanotubes produced by different manufacturers. More than 20 metals or metalloids were determined by neutron activation analysis. The results indicate arranging from 0.44 to 3 wt% of catalyst residues remained although the producers claim to provide a catalyst-free product. Most of the impurity elements are transition metals, such as Fe, Ni, Mo, Y, Co and Cr. In addition to the expected catalyst residues, other unexpected impurity elements were detected including As, Gd, W, Yb, Sm and so on. Metallic impurities in carbon nanotube materials should come from the large-scale production procedures, post fabrication and post-purification treatments. The analytical results determined by inductively-coupled plasma mass spectrometry show that a further deep purification using conventional acid reflux cannot completely remove the metallic impurities from carbon nanotubes. Post-production clean up is difficult and often incompletely.
Journal of Nanoscience and Nanotechnology 03/2011; 11(3):2389-97. · 1.56 Impact Factor
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ABSTRACT: Endohedral metallofullerenes have unique chemical and physical properties that are essential for biomedical applications. They can be used as a radiotracer in magnetic resonance and X-ray imaging (MRI and XRI). Polyhydroxylated metallofullerene Gd@C82(OH)x has been studied as a new high efficient contrast agents for MRI and has also shown high efficiency for antitumor growth. Previous studies have shown that Gd@C82(OH)22 mainly accumulated in bone, pancreas, liver and kidney after intraperitoneal administration. However, whether the nanoparticles can enter into cells and the site of their potential action remains unclear. In this work, the distribution patterns of Gd@C82(OH)22 in subcellular compartments were studied using the techniques of differential centrifugation and ICP-MS analysis. The results indicate that the Gd@C82(OH)22 can enter into cells and the subcellular distribution patterns are significantly different from that of GdCl3. GdCl3 has much higher bioavailability for mice than Gd@C82(OH)22. Therefore, the present data suggest that Gd@C82(OH)22 in living systems may be not decomposed to release free Gd3+ ion and may be metabolized as a pristine carbon cage.
Journal of Nanoscience and Nanotechnology 12/2010; 10(12):8597-602. · 1.56 Impact Factor
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Fang Jiao,
Ying Qu,
Guoqiang Zhou,
Ying Liu,
Wei Li,
Cuicui Ge, Yufeng Li,
Wei Hu,
Bai Li,
Yuxi Gao,
Chunying Chen
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ABSTRACT: Oxidative stress is considered to be one of the important mechanisms involved in carcinogenesis. To investigate the effect of [Gd@C82(OH)22]n and [C60(OH)20]n nanoparticles on the oxidative stress in the tumor-bearing mice, several antioxidative enzymes and antioxidants were tested for mice with or without tumor inoculation. Transplanted tumors were grown in mice by subcutaneous inoculation of a metastatic Lewis lung carcinoma in female C57/BL mice. More importantly, the tumor cells can metastasize into the normal lung tissues gradually. Therefore, in present paper, the activities of copper-zinc superoxide dismutase (CuZn-SOD), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST), as well as the levels of reduced glutathione (GSH) and malondialdehyde (MDA) in the tumor-invaded lung tissues of the tumor-bearing mice were compared to the nomal lung tissues of normal mice. After treatment with nanoparticles, the activities of GSH-Px and GST and other parameters related to the oxidative stress were downregulated and tended closely to the normal levels. Pulmonary histopathological results also showed that two different types of water-soluble fullerenes can prevent lungs from inflammatory lesion and tumor invasion. These findings indicate two different types of water-soluble fullerenes materials can downregulate the oxidative stress status by scavenging excessive free radicals and inhibiting the lipid peroxidation in tumor-bearing mice, which can partly explain their protective roles on the pulmonary oxidative-damage induced by the tumor metastasis to lung tissues.
Journal of Nanoscience and Nanotechnology 12/2010; 10(12):8632-7. · 1.56 Impact Factor
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ABSTRACT: Gold nanorods (Au NRs) have been recognized as promising materials for biomedical applications, like sensing, imaging, gene and drug delivery and therapy, but their toxicological issues are still controversial, especially for the Au NRs synthesized with seed-mediated method. In this study, we investigated the influence of aspect ratio and surface coating on their toxicity and cellular uptake. The cellular uptake is highly dependent on the aspect ratio and surface coating. However, the surface chemistry has the dominant roles since PDDAC-coated Au NRs exhibit a much greater ability to be internalized by the cells. The present data demonstrated shape-independent but coating-dependent cytotoxicity. Both the CTAB molecules left in the suspended solution and on the surface of Au NRs were identified as the actual cause of cytotoxicity. CTAB can enter cells with or without Au NRs, damage mitochondria, and then induce apoptosis. The effects of surface coating upon toxicity and cellular uptake were also examined using Au NRs with different coatings. When Au NRs were added into the medium, the proteins were quickly adsorbed onto the Au NRs that made the surface negatively charged. The surface charge may not directly affect the cellular uptake. We further demonstrated that the amount of serum proteins, especially for BSA, adsorbed on the Au NRs had a positive correlation with the capacity of Au NRs to enter cells. In addition, we have successfully revealed that the cationic PDDAC-coated Au NRs with an aspect ratio of 4 possess an ideal combination of both negligible toxicity and high cellular uptake efficiency, showing a great promise as photothermal therapeutic agents.
Biomaterials 10/2010; 31(30):7606-19. · 7.40 Impact Factor
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Yang Liu,
Yuxi Gao,
Lili Zhang,
Tiancheng Wang,
Jiangxue Wang,
Fang Jiao,
Wei Li,
Ying Liu, Yufeng Li,
Bai Li,
Zhifang Chai,
Gang Wu,
Chunying Chen
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ABSTRACT: The purpose of this study is to evaluate the overall toxicity of nasal instilled nanoscale copper particles (23.5 nm) in mice. Pathological examination, target organs identification, and blood biochemical assay of experimental mice were carried out in comparison with micro-sized copper particles (17 microm). However, only in the high-dose group of copper nanoparticles (40 mg/kg body weight instilled for three times in one week), the body weight of mice were retarded and significant pathological changes were observed. There were hydropic degeneration around the central vein and the spotty necrosis of hepatocytes in the liver and swelling in the renal glomerulus, while, severe lesion associated with the decreased number of olfactory cells and the dilapidated laminated structure were also observed in the olfactory bulb. The serum biochemical assay also indicated the sign of renal and hepatic lesion. However, there were no obvious pathological and physiological damages in the mice after instilling different-sized copper nanoparticles with low dose of 1 mg/kg body weight. The retention and distribution of copper in various tissues show that the liver, kidneys and olfactory bulb are the main accumulated tissues for copper particles, which were determined by high sensitive element-specific technique of ICP-MS. The copper contents of the liver, kidneys and the olfactory bulb increase significantly at the group of 40 mg/kg compared to the control group, which is in agreement with the histological changes. Therefore, the data indicate that nasal inhaled copper particles at very high dosage can translocate to other organs and tissues and further induce certain lesions. The present results are helpful to get better understanding of the risk assessment and evaluation for copper nanoparticles.
Journal of Nanoscience and Nanotechnology 11/2009; 9(11):6335-43. · 1.56 Impact Factor
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Ying Liu,
Fang Jiao,
Yang Qiu,
Wei Li,
Ying Qu,
Chixia Tian, Yufeng Li,
Ru Bai,
Fang Lao,
Yuliang Zhao,
Zhifang Chai,
Chunying Chen
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ABSTRACT: Publications concerning the mechanism of biological activity, especially the immunological mechanism of C(60)(OH)(20) nanoparticles, are relatively limited. However, the structure and characteristics of this carbon allotrope have been widely investigated. In this paper, we have demonstrated that water-soluble C(60)(OH)(20) nanoparticles have an efficient anti-tumor activity in vivo, and show specific immunomodulatory effects to the immune cells, such as T cells and macrophages, both in vivo and in vitro. For example, C(60)(OH)(20) nanoparticles can increase the production of T-helper cell type 1 (Th1) cytokines (IL-2, IFN- gamma and TNF-alpha), and decrease the production of Th2 cytokines (IL-4, IL-5 and IL-6) in serum samples. On the other hand, C(60)(OH)(20) nanoparticles show almost no adverse effect to the viability of immune cells in vitro but stimulate the immune cells to release more cytokines, in particular TNF- alpha, which plays a key role in the cellular immune process to help eliminate abnormal cells. TNF- alpha production increased almost three-fold in treated T lymphocytes and macrophages. Accordingly, we conclude that C(60)(OH)(20) nanoparticles have an efficient anti-tumor activity and this effect is associated with an increased CD(4)(+)/CD(8)(+) lymphocyte ratio and the enhancement of TNF- alpha production. The data suggest that C(60)(OH)(20) nanoparticles can improve the immune response to help to scavenge and kill tumor cells.
Nanotechnology 10/2009; 20(41):415102. · 3.98 Impact Factor
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ABSTRACT: Metal impurities in carbon nanotubes (CNTs) are undesirable for their uses in diverse applications, for instance, they may potentially have a negative health impact when using in biomedical fields. However, so far there is a lack of analysis methods able to quantify metallic impurities in CNTs. In this paper, using the neutron activation analysis (NAA) technique as a nondestructive standard quantification method and inductively coupled plasma mass spectrometry (ICPMS) as a practical approach, we established an analytical method for quantitative determination of metallic impurities in CNTs. ICPMS, one of the most sensitive analytical techniques used for coincident multielement measurements, has become a common tool in many laboratory, and thus it is easily available and a good selection for determining the metal impurities in CNTs. However, because of their extremely stable structure and the encapsulated metals in the defect structure, CNTs must undergo special pretreatments before ICPMS. We investigated different sample pretreatment procedures for ICPMS analysis, including dry ashing coupled with acid extraction, wet digestion, and a combination of dry ashing with acid digestion. With the reference data from the nondestructive analytical method of NAA, we found that the quantitative determination of metal impurities in CNTs is highly dependent on the sample pretreatment in which the conditions are largely different from those used for conventional biological samples or environmental materials. This paper not only provides the practical method and analysis conditions for quantifying the metal impurities of CNTs but also the first protocol for pretreatment processes of CNT samples.
Analytical Chemistry 12/2008; 80(24):9426-34. · 5.86 Impact Factor
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Jiangxue Wang,
Chunying Chen,
Ying Liu,
Fang Jiao,
Wei Li,
Fang Lao, Yufeng Li,
Bai Li,
Cuicui Ge,
Guoqiang Zhou,
Yuxi Gao,
Yuliang Zhao,
Zhifang Chai
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ABSTRACT: Nanoscale titanium dioxide (TiO(2)) is massively produced and widely used in living environment, which hence make the potential risk to human health. Central nervous system (CNS) is the potential susceptible target of inhaled nanoparticles, but the studies on this aspect are limited so far. We report the accumulation and toxicity results in vivo of two crystalline phases of TiO(2) nanoparticles (80nm, rutile and 155nm, anatase; purity >99%). The female mice were intranasally instilled with 500microg of TiO(2) nanoparticles suspension every other day for 30 days. Synchrotron radiation X-ray fluorescence analysis (SRXRF) and inductively coupled plasma mass spectrometry (ICP-MS) were used to determine the contents of titanium in murine brain. Then, the pathological examination of brain tissue, oxidative stress-mediated responses, and levels of neurochemicals in the brain of exposed mice were also analyzed. The obvious morphological changes of hippocampal neurons and increased GFAP-positive astrocytes in the CA4 region were observed, which were in good agreements with higher Ti contents in the hippocampus region. Oxidative stress occurred obviously in whole brain of exposed mice such as lipid peroxidation, protein oxidation and increased activities of catalase, as well as the excessive release of glutamic acid and nitric oxide. These findings indicate anatase TiO(2) nanoparticles exhibited higher concern on some tested biological effects. To summarize, results provided the preliminary evidence that nasal instilled TiO(2) nanoparticles could be translocated into the central nervous system and cause potential lesion of brain, and the hippocampus would be the main target within brain.
Toxicology Letters 10/2008; 183(1-3):72-80. · 3.23 Impact Factor
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Jiangxue Wang,
Ying Liu,
Fang Jiao,
Fang Lao,
Wei Li,
Yiqun Gu, Yufeng Li,
Cuicui Ge,
Guoqiang Zhou,
Bai Li,
Yuliang Zhao,
Zhifang Chai,
Chunying Chen
[show abstract]
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ABSTRACT: Nanoparticles can be administered via nasal, oral, intraocular, intratracheal (pulmonary toxicity), tail vein and other routes. Here, we focus on the time-dependent translocation and potential damage of TiO(2) nanoparticles on central nervous system (CNS) through intranasal instillation. Size and structural properties are important to assess biological effects of TiO(2) nanoparticles. In present study, female mice were intranasally instilled with two types of well-characterized TiO(2) nanoparticles (i.e. 80 nm, rutile and 155 nm, anatase; purity>99%) every other day. Pure water instilled mice were served as controls. The brain tissues were collected and evaluated for accumulation and distribution of TiO(2), histopathology, oxidative stress, and inflammatory markers at post-instillation time points of 2, 10, 20 and 30 days. The titanium contents in the sub-brain regions including olfactory bulb, cerebral cortex, hippocampus, and cerebellum were determined by inductively coupled plasma mass spectrometry (ICP-MS). Results indicated that the instilled TiO(2) directly entered the brain through olfactory bulb in the whole exposure period, especially deposited in the hippocampus region. After exposure for 30 days, the pathological changes were observed in the hippocampus and olfactory bulb using Nissl staining and transmission electron microscope. The oxidative damage expressed as lipid peroxidation increased significantly, in particular in the exposed group of anatase TiO(2) particles at 30 days postexposure. Exposure to anatase TiO(2) particles also produced higher inflammation responses, in association with the significantly increased tumor necrosis factor alpha (TNF-alpha) and interleukin (IL-1 beta) levels. We conclude that subtle differences in responses to anatase TiO(2) particles versus the rutile ones could be related to crystal structure. Thus, based on these results, rutile ultrafine-TiO(2) particles are expected to have a little lower risk potential for producing adverse effects on central nervous system. Although understanding the mechanisms requires further investigation, the present results suggest that we should pay attention to potential risk of occupational exposure for large-scaled production of TiO(2) nanoparticles.
Toxicology 09/2008; 254(1-2):82-90. · 3.68 Impact Factor
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ABSTRACT: Mercury (Hg)-, selenium (Se)-, and arsenic (As)- containing proteins in liver tissues of bighead carp and grass carp sampled from a mercury-polluted area of Wanshan, Guizhou Province, China, were separated by thin-layer isoelectric focusing. The relative content of Hg, Se, and As in protein bands was measured with synchrotron radiation x-ray fluorescence. The results indicated that there were at least 3 Hg-containing bands with pI 3.7, 4.8, and 6.2 in liver of bighead carp and 1 Hg-containing band with pI 6.2 in grass carp. Se and As were found in the Hg-containing bands 3.7 in bighead carp and 6.2 in grass carp. The bands may be corresponding to the antagonistic effect of Se against the toxicity of Hg and As. In addition, Hg and As often coexist in the same band, suggesting that the two elements may be involved in the same metabolic processes.
Journal of Toxicology and Environmental Health Part A 01/2008; 71(18):1266-9. · 1.83 Impact Factor
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Jiangxue Wang,
Guoqiang Zhou,
Chunying Chen,
Hongwei Yu,
Tiancheng Wang,
Yongmei Ma,
Guang Jia,
Yuxi Gao,
Bai Li,
Jin Sun, Yufeng Li,
Fang Jiao,
Yuliang Zhao,
Zhifang Chai
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ABSTRACT: In order to evaluate the toxicity of TiO(2) particles, the acute toxicity of nano-sized TiO(2) particles (25 and 80nm) on adult mice was investigated compared with fine TiO(2) particles (155nm). Due to the low toxicity, a fixed large dose of 5g/kg body weight of TiO(2) suspensions was administrated by a single oral gavage according to the OECD procedure. In 2 weeks, TiO(2) particles showed no obvious acute toxicity. However, the female mice showed high coefficients of liver in the nano-sized (25 and 80nm) groups. The changes of serum biochemical parameters (ALT/AST, LDH) and pathology (hydropic degeneration around the central vein and the spotty necrosis of hepatocytes) of liver indicated that the hepatic injury was induced after exposure to mass different-sized TiO(2) particles. In addition, the nephrotoxicity like increased BUN level and pathology change of kidneys was also observed in the experimental groups. The significant change of serum LDH and alpha-HBDH in 25 and 80nm groups showed the myocardial damage compared with the control group. However, there are no abnormal pathology changes in the heart, lung, testicle (ovary), and spleen tissues. Biodistribution experiment showed that TiO(2) mainly retained in the liver, spleen, kidneys, and lung tissues, which indicated that TiO(2) particles could be transported to other tissues and organs after uptake by gastrointestinal tract.
Toxicology Letters 02/2007; 168(2):176-85. · 3.23 Impact Factor
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Jiangxue Wang,
Chunying Chen,
Bai Li,
Hongwei Yu,
Yuliang Zhao,
Jin Sun, Yufeng Li,
Gengmei Xing,
Hui Yuan,
Jun Tang,
Zhen Chen,
Huan Meng,
Yuxi Gao,
Chang Ye,
Zhifang Chai,
Chuanfeng Zhu,
Baocheng Ma,
Xiaohong Fang,
Lijun Wan
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ABSTRACT: Oxidative stress is considered to be one of the important mechanisms involved in carcinogenesis. In our previous study, gadolinium endohedral metallofullerenol ([Gd@C82(OH)22]n nanoparticles) have shown high inhibitory activity on hepatoma cell (H22) growth in mice. To explore the antioxidative functions of nanoparticles, we investigated the biodistribution of [Gd@C82(OH)22]n nanoparticles, the changes of blood coagulation profiles, the metabolism of reactive oxygen species (ROS) in the tumor-bearing mice as well as the possible relationships between nanoparticles treatment and ROS production in this paper. The activities of hepatic superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) and catalase (CAT) as well as the levels of reduced glutathione (GSH), protein-bound thiols and malondialdehyde (MDA) were compared between the tumor-bearing mice and normal mice. Transplanted tumors were grown in mice by subcutaneous injection of murine hepatoma cells in the mice. The comparison of the above parameters between nanoparticles and cyclophosphamide (CTX) therapy were also investigated. [Gd@C82(OH)22]n administration can efficiently restore the damaged liver and kidney of the tumor-bearing mice. All the activities of enzymes and other parameters related to oxidative stress were reduced after [Gd@C82(OH)22]n treatment and tended closely to the normal levels. The results suggest that [Gd@C82(OH)22]n nanoparticle treatment could regulate ROS production in vivo.
Biochemical Pharmacology 04/2006; 71(6):872-81. · 4.70 Impact Factor
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ABSTRACT: The purpose was to examine the anti-tumor and antimetastatic activities of fullerenol and their related mechanisms. Thirty EMT-6 tumor-bearing mice were injected intraperitoneally with 0.1 ml saline or 0.1 ml saline containing fullerenol C60(OH)20 (0.08 and 0.4 mg/ml) daily for 16 days. Using tumor tissues, we investigated imbalances in the oxidative defense system and the expression of several angiogenesis factors. C60(OH)20 exhibits anti-tumor and antimetastatic activities in EMT-6 breast cancer metastasis model. Treatment with C60(OH)20 was found to modulate oxidative stress significantly. The expression of several angiogenesis factors was reduced in tumor tissues after treatment with fullerenol. Importantly, CD31 (also known as PECAM-1, platelet endothelial cell adhesion molecule) expression and vessel density were markedly reduced in tumors from fullerenol-treated mice compared with controls. Modulation of oxidative stress in tumor tissues, inhibition of the formation of angiogenesis factors, and subsequent reduction in tumor vessel density and the nutrient supply to tumor cells could be important mechanisms by which fullerenol aggregates inhibit tumor growth and suppress carcinoma metastasis in vivo.
Carbon.
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Jiangxue Wang,
Ying Liu,
Fang Jiao,
Fang Lao,
Wei Li,
Yiqun Gu, Yufeng Li,
Cuicui Ge,
Guoqiang Zhou,
Bai Li,
Yuliang Zhao,
Zhifang Chai,
Chunying Chen
[show abstract]
[hide abstract]
ABSTRACT: Nanoparticles can be administered via nasal, oral, intraocular, intratracheal (pulmonary toxicity), tail vein and other routes. Here, we focus on the time-dependent translocation and potential damage of TiO2 nanoparticles on central nervous system (CNS) through intranasal instillation. Size and structural properties are important to assess biological effects of TiO2 nanoparticles. In present study, female mice were intranasally instilled with two types of well-characterized TiO2 nanoparticles (i.e. 80 nm, rutile and 155 nm, anatase; purity > 99%) every other day. Pure water instilled mice were served as controls. The brain tissues were collected and evaluated for accumulation and distribution of TiO2, histopathology, oxidative stress, and inflammatory markers at post-instillation time points of 2, 10, 20 and 30 days. The titanium contents in the sub-brain regions including olfactory bulb, cerebral cortex, hippocampus, and cerebellum were determined by inductively coupled plasma mass spectrometry (ICP-MS). Results indicated that the instilled TiO2 directly entered the brain through olfactory bulb in the whole exposure period, especially deposited in the hippocampus region. After exposure for 30 days, the pathological changes were observed in the hippocampus and olfactory bulb using Nissl staining and transmission electron microscope. The oxidative damage expressed as lipid peroxidation increased significantly, in particular in the exposed group of anatase TiO2 particles at 30 days postexposure. Exposure to anatase TiO2 particles also produced higher inflammation responses, in association with the significantly increased tumor necrosis factor alpha (TNF-α) and interleukin (IL-1β) levels. We conclude that subtle differences in responses to anatase TiO2 particles versus the rutile ones could be related to crystal structure. Thus, based on these results, rutile ultrafine-TiO2 particles are expected to have a little lower risk potential for producing adverse effects on central nervous system. Although understanding the mechanisms requires further investigation, the present results suggest that we should pay attention to potential risk of occupational exposure for large-scaled production of TiO2 nanoparticles.
Toxicology.
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Yuxi Gao,
Nianqing Liu,
Chunying Chen,
Yunfeng Ac,
Luo, Yufeng Li,
Zhiyong Zhang,
Yuliang Zhao,
Baolu Zhao,
Atsuo Iida,
Zhifang Chai
[show abstract]
[hide abstract]
ABSTRACT: To investigate the toxicological effects of nanomaterials, experimental studies on the absorption and accumulation in organisms are of broad interest. In the present study, Caenorhabditis elegans (C. elegans) was used as a ''model'' organism to investigate the bioaccumulation and toxicological effects of engineered copper nanoparticles with a scanning technique of microbeam synchrotron radiation X-ray fluorescence (m-SRXRF). The adult hermaphrodite is anatomically simple with 959 somatic cells and 1 mm in length. The mapping results of the whole organism indicate that the exposure to copper nanoparticles can result in an obvious elevation of Cu and K levels, and a change of bio-distribution of Cu in nematodes. Accumulation of Cu occurs in the head and at a location 1/3 of the way up the body from the tail compared to the un-exposed control. In contrast, a higher amount of Cu was detected in other portion of worm body, especially in its excretory cells and intestine when exposed to Cu 2+ . The results compared well with total Cu levels in nematodes, which were 4.10 AE 0.54, 12.32 AE 0.49 and 5.22 AE 0.63 mg g À1 dry weight for the PBS, Cu 2+ and Cu nanoparticle groups, respectively, measured by ICP-MS. The nondestructive and multi-elemental m-SRXRF provides an important tool for mapping the elemental distribution in the whole body of a single tiny nematode at lower levels.
