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  • Repeated administrations of Mn3O4 nanoparticles cause testis damage and fertility decrease through PPAR-signaling pathway
    Nanotoxicology (IF 5.955) Pub Date : 2020-01-07
    Xiao Zhang; Zongkai Yue; Haijun Zhang; Lu Liu; Xiaomeng Zhou

    Potential health hazards of nanomaterials on male reproductive system have received raising concerns. Even though Mn3O4 nanoparticles (Mn3O4-NPs) is highly effective in clinical diagnostic and therapeutic applications of human disease, its potential toxic effect on the male reproductive system has not been reported. In this study, the testis damage and fertility decrease of male rats were conducted to testify the experimental reproductive injury induced by Mn3O4-NPs. After repeated tail vein injection with 10 mg/kg/week Mn3O4-NPs for 0, 60 and 120 days, Mn3O4-NPs accumulated in the testes resulted in oxidative stress and disorder of normal serum sex hormones. Experiments in vivo and in vitro indicated that mitochondria-mediated cell apoptosis were triggered via oxidative stress, demonstrated by the upregulation of malondialdehyde (MDA) and the depolarization of mitochondrial membrane potential. Notably, Mn3O4-NPs significantly resulted in a reduction of the quantity/quality of sperm and finally caused astonishing fertility decrease. Our preliminary result implied that the application of Mn3O4-NPs could be a double-edged sword and careful consideration should be given to the clinical uses.

  • Relative potency factor approach enables the use of in vitro information for estimation of human effect factors for nanoparticle toxicity in life-cycle impact assessment
    Nanotoxicology (IF 5.955) Pub Date : 2020-01-13
    Beatrice Salieri; Jean-Pierre Kaiser; Matthias Rösslein; Bernd Nowack; Roland Hischier; Peter Wick

    The major theme of the NRC report “Toxicity Testing in the Twenty-first Century” is to replace animal testing by using alternative in vitro methods. Therefore, it can be expected that in the future in vivo data will be replaced with in vitro data. Hence, there is a need for new strategies to make use of the increasing amount of in vitro data when developing human toxicological effect factors (HEF) to characterize the impact category of human toxicity in life cycle assessment (LCA). Here, we present a new approach for deriving HEF for manufactured nanomaterials (MNMs) based on the combined use of in vitro toxicity data and a relative potency factor (RPF) approach. In vitro toxicity tests with nano-CuO, nano-Ag and nano-ZnO and their corresponding ions were performed on THP-1, CaCo-2 and Hep-G2 cell lines. The ratio of the here calculated EC50 of the ionic form and the nanoform corresponds to the Relative Potency Factor (RPF). Using this approach, HEFs (case/kgintake) for the aforementioned nanoparticles were obtained. Non-carcinogenic HEFs (case/kgintake) for exposure via ingestion of 5.9E-01, 7.5E-03 and 2.5 E-02 were calculated for nano-Ag, nano-CuO and nano-ZnO, respectively. The HEF values here proposed were compared with HEF values extrapolated from in vivo toxicity data reported in the literature. The here presented procedure is the most appropriate approximation currently available for using in vitro toxicity data on MNM for application in the field of LCIA.

  • Fate of GdF3 nanoparticles-loaded PEGylated carbon capsules inside mice model: a step toward clinical application
    Nanotoxicology (IF 5.955) Pub Date : 2020-01-13
    Binapani Mahaling; Madhu Verma; Gargi Mishra; Surabhi Chaudhuri; Debjani Dutta; Sri Sivakumar

    The successful translation of nanostructure-based bioimaging and/or drug delivery system needs extensive in vitro and in vivo studies on biocompatibility, biodistribution, clearance, and toxicity for its diagnostic applications. Herein, we have investigated the in vitro cyto-hemocompatibility, in vivo biodistribution, clearance, and toxicity in mice after systemic administration of GdF3 nanoparticles loaded PEGylated mesoporous carbon capsule (GdF3-PMCC)-based theranostic system. In vitro cyto-hemocompatibility study showed a very good biocompatibility up to concentration of 500 µg/ml. Biodistribution studies carried out from 1 h to 8 days showed that GdF3-PMCC was found in major organs, such as liver, kidney, spleen, and muscle till 4th day and it was negligible in any tissue after 8th day. The clearance study was carried out for a period of 8 days and it was observed that the urinary system is the main route of excretion of GdF3-PMCC. The tissue toxicity study was done for 15 days and histopathological analysis indicated that the GdF3-PMCC based theranostic system does not have any adverse effect in tissues. Thus, PMCCs are nontoxic and can be applied as theranostic agents in contrast to the other carbon-based systems (PEGylated carbon nanotubes and PEGylated graphene oxide) which showed significant toxicity.

  • Comment on ‘endoplasmic reticulum stress mediates inflammatory response triggered by ultra-small superparamagnetic iron oxide nanoparticles in hepatocytes’
    Nanotoxicology (IF 5.955) Pub Date : 2020-01-08
    Chengyu Yang; Xuefei Shen; Ruixia Ma; Xuemei Liu; Yan Xu

    (2020). Comment on ‘endoplasmic reticulum stress mediates inflammatory response triggered by ultra-small superparamagnetic iron oxide nanoparticles in hepatocytes’. Nanotoxicology. Ahead of Print.

  • In vitro and in vivo immunotoxicity of PEGylated Cd-free CuInS2/ZnS quantum dots
    Nanotoxicology (IF 5.955) Pub Date : 2020-01-07
    Tingting Chen; Li Li; Xiaotan Lin; Zhiwen Yang; Wenyi Zou; Yajing Chen; Jiangyao Xu; Dongmeng Liu; Xiaomei Wang; Guimiao Lin

    The annual increase in the production and the use of engineering quantum dots (QDs) have led to concern about exposure and safety of QDs. To resolve the risk of Cd release from QDs, a series of Cd-free QDs, represented by CuInS2/ZnS QDs, has been developed in recent years. However, the toxicological profile of CuInS2/ZnS QDs has not been fully elucidated, especially, their immunotoxicity. Here, we performed a detailed in vitro cytotoxicity study on PEGylated CuInS2/ZnS QDs using the DC2.4 cell line and investigated their in vivo immunotoxicity using BALB/c mice. In vitro experiments showed that CuInS2/ZnS QDs were taken up by cells, promoted cell viability, enhanced release of tumor necrosis factor-α, and decreased the level of interleukin (IL)-6 in response to lipopolysaccharide stimulation. More than 5000 genes at the transcriptome level were observed by high-throughput RNA sequencing after CuInS2/ZnS QD exposure. In vivo study showed that CuInS2/ZnS QDs increased the levels of IL-4 on day 1 and enhanced the levels of IL-10 and IL-13 on day 28 in mice. There was no obvious difference in the number of spleen-derived lymphocytes, organic index, hematology and immune organ histology on days 1 and 28 after treatment. These findings demonstrated that PEGylated CuInS2/ZnS QDs disturbed the function of DC2.4 immune cells in vitro, but caused no obvious toxicity to immune system in vivo, suggesting that PEGylated CuInS2/ZnS QDs are biocompatible and have potential for bioapplication in the future.

  • Aggravation of atherosclerosis by pulmonary exposure to indium oxide nanoparticles
    Nanotoxicology (IF 5.955) Pub Date : 2020-01-07
    Dong-Keun Lee; Hyung Seok Jang; Hyunji Chung; Soyeon Jeon; Jiyoung Jeong; Jae-Hoon Choi; Wan-Seob Cho

    The use of indium oxide (In2O3) and indium-metal hybrids for various applications, including the manufacture of batteries and liquid crystal displays, increases the chances of human exposure to In2O3 via inhalation, especially in occupational settings. However, there is little information available on the toxic effects of In2O3 nanoparticles (NPs) on secondary organs following pulmonary exposure. In this study, we evaluated the effect of In2O3 NPs on atherosclerotic plaque formation and the related mechanisms after pulmonary exposure in low-density lipoprotein receptor knockout (Ldlr−/−) mice. At 10 weeks after a single pharyngeal aspiration, In2O3 NPs caused chronic active inflammation, pulmonary alveolar proteinosis, and accumulation of inflammatory cells in the peribronchial and perivascular areas of the lungs. The expression of pro-inflammatory cytokines in the lung tissue, including TNF-α and MCP-1, was markedly increased by treatment with In2O3 NPs. In the In2O3 NP-treated groups, the levels of total cholesterol and low-density lipoprotein in the plasma were increased, whereas HDL cholesterol showed no significant changes compared to vehicle control. The formation of atherosclerotic lesions was increased by treatment with In2O3 NPs. Real-time PCR analysis of the aorta showed that IL-6 and MCP-1 expression was up-regulated upon treatment with In2O3 NPs. These results suggested that the pulmonary inflammation induced by In2O3 NPs aggravates the progression of atherosclerotic plaque formation, possibly by the alteration of the plasma lipid profile and enhancement of the aortic inflammatory processes.

  • 28-Day inhalation toxicity study with evaluation of lung deposition and retention of tangled multi-walled carbon nanotubes
    Nanotoxicology (IF 5.955) Pub Date : 2019-12-19
    Jin Kwon Kim; Mi Seong Jo; Younghun Kim; Tae Gyu Kim; Jae Hoon Shin; Boo Wook Kim; Hoi Pin Kim; Hong Ku Lee; Hee Sang Kim; Kangho Ahn; Seung Min Oh; Wan-Seob Cho; Il Je Yu

    Lung deposition and retention measurements are now required by the newly revised OECD inhalation toxicity testing guidelines 412 and 413 when evaluating the clearance and biopersistence of poorly soluble nanomaterials, such as multi-walled carbon nanotubes (MWCNTs). However, evaluating the lung deposition concentration is challenging with certain nanomaterials, such as carbon-based and iron-based nanomaterials, as it is difficult to differentiate them from endogenous elements. Therefore, the current 28-day inhalation toxicity study investigated the lung retention kinetics of tangled MWCNTs. Male Sprague Dawley rats were exposed to MWCNTs at 0, 0.257, 1.439, and 4.253 mg/m3 for 28 days (6 h/day, 5 days/week, 4 weeks). Thereafter, the rats were sacrificed at day 1, 7, and 28 post-exposure and the pulmonary inflammatory response evaluated by analyzing the bronchoalveolar lavage fluid. Plus, the blood biochemistry, hematology, and histopathology of the lungs were also examined. The lung deposition and retention of MWCNTs were determined based on the elemental carbon content in the lungs after tissue digestion. The number of polymorphonuclear cells and LDH concentration were both found to be significantly higher with the medium and high concentrations (1.439 and 4.253 mg/m3) and dose dependent. The estimated retention half-life for the high concentration (4.253 mg/m3) was about 35 days. The results of this study indicate that tangled MWCNTs seem to have a relatively shorter retention half-life when compared to previous reports on rigid MWCNTs, and the no-observed adverse effect level (NOAEL) for the tested tangled MWCNTs was 0.257 mg/m3 in a previous rat 28-day subacute inhalation toxicity study.

  • Pharmacokinetics, tissue distribution and safety of gold nanoparticle/PKC Delta inhibitor peptide hybrid in rats
    Nanotoxicology (IF 5.955) Pub Date : 2019-12-18
    Hisato Konoeda; Hiromitsu Takizawa; Annette Gower; Michael Zhao; Oyedele A. Adeyi; Mingyao Liu

    Gold nanoparticles (GNPs) are extremely useful for drug delivery, due in part to their highly tunable nature. However, this variability has prevented a clear understanding of the pharmacokinetics and toxicity of GNPs for drug delivery. Here, we present the clearance, organ distribution and acute toxicity testing of our drug delivery system which uses GNPs and two penta-peptides, to deliver a rationally designed peptide drug. We found that with or without our therapeutic, the GNP/peptide hybrid cleared rapidly from the blood in rats and accumulated mostly in the liver and spleen, although it was also detectable in several other organs. There were subtle but detectable differences between the behavior of our GNP hybrids with or without the therapeutic peptide. The GNP/peptide hybrid showed no evidence of toxicity at single doses up to 16 times the therapeutic dose, as measured by a battery of tests including, blood cell makeup, levels of markers of liver, kidney and spleen function, organ mass indexes, and histology. These results underline the importance of testing the pharmacokinetics and toxicity of all GNP preparations, as even minor changes to the surface coatings of GNPs can influence their behavior. On the other hand, the results herein can help guide the design and use of similar GNP/peptide drug delivery systems.

  • Enhanced osteogenic activity and antibacterial ability of manganese–titanium dioxide microporous coating on titanium surfaces
    Nanotoxicology (IF 5.955) Pub Date : 2019-12-09
    Quan-Ming Zhao, Yu-Yu Sun, Chun-Shuai Wu, Jian Yang, Guo-Feng Bao, Zhi-Ming Cui

    Titanium (Ti) and its alloys are widely used in clinical practice as preferred materials for bone tissue repair and replacement because of their good mechanical properties; however, as Ti lacks biological activity, clinical application has been limited. Herein, we prepared a manganese–titanium dioxide (Mn–TiO2) microporous biotic coating on Ti surfaces by micro-arc oxidation (MAO). The coating showed good surface topography and was uniformly doped with Mn, and the Mn ions were slowly released. In vitro, the Mn–TiO2 microporous biotic coating promoted the adhesion, proliferation, differentiation, and mineralization of MC3T3-E1 osteoblasts. Moreover, in vivo experiments showed that the coating promoted early osseointegration. We also conducted a preliminary investigation to explore the molecular mechanism underlying the regulation of the function of osteoblasts by the coating. Furthermore, we found that the coating could inhibit the growth of Escherichia coli in vitro, demonstrating reliable antibacterial ability. To conclude, Mn–TiO2 microporous biotic coating can improve the biological activity of Ti implants, which can potentially improve their clinical applications.

  • Do the joint effects of size, shape and ecocorona influence the attachment and physical eco(cyto)toxicity of nanoparticles to algae?
    Nanotoxicology (IF 5.955) Pub Date : 2019-11-28
    Fazel Abdolahpur Monikh, Daniel Arenas-Lago, Petr Porcal, Renato Grillo, Peng Zhang, Zhiling Guo, Martina G. Vijver, Willie J. G. M. Peijnenburg

    We systematically investigated how the combinations of size, shape and the natural organic matter (NOM)-ecocorona of gold (Au) engineered nanoparticles (ENPs) influence the attachment of the particles to algae and physical toxicity to the cells. Spherical (10, 60 and 100 nm), urchin-shaped (60 nm), rod-shaped (10 × 45, 40 × 60 and 50 × 100 nm), and wire-shaped (75 × 500, 75 × 3000 and 75 × 6000 nm) citrate-coated and NOM-coated Au-ENPs were used. Among the spherical particles only the spherical 10 nm Au-ENPs caused membrane damage to algae. Only the rod-shaped 10 × 45 nm induced membrane damage among the rod-shaped Au-ENPs. Wire-shaped Au-ENPs caused no membrane damage to the algae. NOM ecocorona decreased the membrane damage effects of spherical 10 nm and rod-shaped 10 × 45 nm ENPs. The spherical Au-ENPs were mostly loosely attached to the cells compared to other shapes, whereas the wire-shaped Au-ENPs were mostly strongly attached compared to particles with other shapes. NOM ecocorona determined the strength of Au-ENPs attachment to the cell wall, leading to the formation of loose rather than strong attachment of Au-ENPs to the cells. After removal of the loosely and strongly attached Au-ENPs, some particles remained anchored to the surface of the algae. The highest concentration was detected for spherical 10 nm Au-ENPs followed by rod-shaped 10 × 45 nm Au-ENPs, while the lowest concentration was observed for the wire-shaped Au-ENPs. The combined effect of shape, size, and ecocorona controls the Au-ENPs attachment and physical toxicity to cells.

  • The early onset and persistent worsening pulmonary alveolar proteinosis in rats by indium oxide nanoparticles
    Nanotoxicology (IF 5.955) Pub Date : 2019-11-27
    Sung-Hyun Kim, Soyeon Jeon, Dong-Keun Lee, Seonghan Lee, Jiyoung Jeong, Jong Sung Kim, Wan-Seob Cho

    Workplace inhalation exposure to indium compounds has been reported to produce ‘indium lung disease’ characterized by pulmonary alveolar proteinosis (PAP), granulomas, and pulmonary fibrosis. However, there is little information about the pulmonary toxicity of nano-sized indium oxide (In2O3), which is widely used in various applications such as liquid crystal displays. In this study, we evaluated the time-course and dose-dependent lung injuries by In2O3 nanoparticles (NPs) after a single intratracheal instillation to rats. In2O3 NPs were instilled to female Wistar rats at 7.5, 30, and 90 cm2/rat and lung injuries were evaluated at day 1, 3, 7, 14, 30, 90, and 180 after a single intratracheal instillation. Treatment of In2O3 NPs induced worsening diverse pathological changes including PAP, persistent neutrophilic inflammation, type II cell hyperplasia, foamy macrophages, and granulomas in a time- and dose-dependent manner. PAP was induced from day 3 and worsened throughout the study. The concentrations of interleukin-1β, tumor necrosis factor-α, and monocyte chemoattractant protein-1 in bronchoalveolar lavage fluid (BALF) showed dose- and time-dependent increases and the levels of these inflammatory mediators are consistent with the data of inflammatory cells in BALF and progressive lung damages by In2O3 NPs. This study suggests that a single inhalation exposure to In2O3 NPs can produce worsening lung damages such as PAP, chronic active inflammation, infiltration of foamy macrophages, and granulomas. The early onset and persistent PAP even at the very low dose (7.5 cm2/rat) implies that the re-evaluation of occupational recommended exposure limit for In2O3 NPs is urgently needed to protect workers.

  • Nanosized silver, but not titanium dioxide or zinc oxide, enhances oxidative stress and inflammatory response by inducing 5-HETE activation in THP-1 cells
    Nanotoxicology (IF 5.955) Pub Date : 2019-11-27
    Wing-Lam Poon, Jetty Chung-Yung Lee, Kin Sum Leung, Harri Alenius, Hani El-Nezami, Piia Karisola

    Bioactive, oxygenated metabolites of polyunsaturated fatty acids (PUFAs) are important indicators of inflammation and oxidative stress but almost nothing is known about their interactions with nanomaterials (NMs). To investigate the effects of nano-sized materials (n-TiO2, n-ZnO, n-Ag) and their bulk-sized or ionic (b-TiO2, b-ZnO, i-Ag) counterpart, we studied the status of oxidative stress and PUFA metabolism in THP-1 cells at low-toxic concentrations (<15% cytotoxicity) 6 h or 24 h after the particle exposures by LC/MS and microarray. N-Ag had a significant and sustained impact on cellular antioxidant defense, seen as incremental synthesis and accumulation of glutathione (GSH) in the cell, and reduction of superoxide dismutase (SOD) activity. The cellular particle doses were largely dependent on exposure duration and particle dissolution, and active transporter mechanisms controlled the concentration of Zn in cytosol. Even at these sub-toxic concentrations, n-Ag was able to induce statistically significant elevation in the 5-HETE: arachidonic acid ratio at 24 h, which suggests association to oxidative stress and induction of pro-inflammatory responses. This was supported by the enhanced gene expression of chemotaxis-related genes. Overall, THP-1 cells internalized all tested particles, but only n-Ag led to low level of oxidative stress through ROS production and antioxidant balance disruption. N-Ag stimulated arachidonic acid oxidation to form 5-HETE which further magnified the inflammatory responses by enhancing the production of mitochondrial superoxide and leukocyte chemokines. Since the sustained n-Ag uptake was detected, the effects may last long and function as a trigger for the low-grade inflammation playing role in the chronic inflammatory diseases.

  • A multi-omics approach reveals mechanisms of nanomaterial toxicity and structure–activity relationships in alveolar macrophages
    Nanotoxicology (IF 5.955) Pub Date : 2019-11-27
    Anne Bannuscher, Isabel Karkossa, Sophia Buhs, Peter Nollau, Katja Kettler, Mihaela Balas, Anca Dinischiotu, Bryan Hellack, Martin Wiemann, Andreas Luch, Martin von Bergen, Andrea Haase, Kristin Schubert

    In respect to the high number of released nanomaterials and their highly variable properties, novel grouping approaches are required based on the effects of nanomaterials. Proper grouping calls for a combination of an experimental setup with a higher number of structurally similar nanomaterials and for employing integrated omics approaches to identify the mode of action. Here, we analyzed the effects of seven well-characterized NMs comprising different chemical compositions, sizes and chemical surface modifications on the rat alveolar macrophage cell line NR8383. The NMs were investigated at three doses ranging from 2.5 to 10 µg/cm2 after 24 h incubation using an integrated multi-omics approach involving untargeted proteomics, targeted metabolomics, and src homology 2 (SH2) profiling. By using Weighted Gene Correlation Network Analysis (WGCNA) for the integrative data, we identified correlations of molecular pathways with physico-chemical properties and toxicological endpoints. The three investigated SiO2 variants induced strong alterations in all three omics approaches and were, therefore, be classified as “active.” Two organic phthalocyanines showed minor responses and Mn2O3 induced a different molecular response pattern than the other NMs. WGCNA revealed that agglomerate size and surface area as well as LDH release are among the most important parameters correlating with nanotoxicology. Moreover, we identified key drivers that can serve as representative biomarker candidates, supporting the value of multi-omics approaches to establish integrated approaches to testing and assessment (IATAs).

  • Exposure to Al2O3 nanoparticles facilitates conjugative transfer of antibiotic resistance genes from Escherichia coli to Streptomyces
    Nanotoxicology (IF 5.955) Pub Date : 2019-09-27
    Xiaomei Liu, Jingchun Tang, Benru Song, Meinan Zhen, Lan Wang, John P. Giesy

    The spread of antibiotic resistance genes (ARGs) has become a global environmental issue; it has been found that nanoparticles (NPs) can promote the transfer of ARGs between bacteria. However, it remains unclear whether NPs can affect this kind of conjugation in Streptomyces, which mainly conjugate with other bacteria via spores. In the present study, we demonstrated that Al2O3 NPs significantly promote the conjugative transfer of ARGs from Escherichia coli (E. coli) ET12567 to Streptomyces coelicolor (S. coelicolor) M145 without the use of heat shock method. The number of transconjugants induced by Al2O3 particles was associated with the size and concentration of Al2O3 particles, exposure time, and the ratio of E. coli and spores. When nanoparticle size was 30 nm at a concentration of 10 mg/L, the conjugation efficiency reached a peak value of 182 cfu/108 spores, which was more than 60-fold higher than that of the control. Compared with nanomaterials, bulk particles exhibited no significant effect on conjugation efficiency. We also explored the mechanisms by which NPs promote conjugative transfer. After the addition of NPs, the intracellular ROS content increased and the expression of the classical porin gene ompC was stimulated. In addition, ROS enhanced the mRNA expression levels of conjugative genes by inhibiting global regulation genes. Meanwhile, expression of the conjugation-related gene intA was also stimulated, ultimately increasing the number of transconjugants. Our results indicated that Al2O3 NPs significantly promoted the conjugative transfer of ARGs from bacteria to spores and aggravated the diffusion of resistance genes in the environment.

  • Evaluation of interactive effects of UV light and nano encapsulation on the toxicity of azoxystrobin on zebrafish
    Nanotoxicology (IF 5.955) Pub Date : 2019-11-18
    Yueyang Zhang, Claudia Sheedy, Denise Nilsson, Greg G. Goss

    The use of nanotechnology to enhance pesticide formulations holds the promise of reduced pesticide use, reduced mobility in soils, and overall improvements in agricultural practices while simultaneously maintaining yields. However, the toxicity of nano-enabled pesticides, including azoxystrobin (Az), has not been well studied compared with their conventional form. This study investigates both lethal and sub-lethal endpoints in zebrafish embryos up to 120 h post-fertilization (hpf) under either laboratory light or simulated UV light. The median lethal concentration (LC50) value of nano-enabled Az (nAz) was significantly lower than the conventional form (Az). Interestingly, artificial UV light significantly increased toxicity (decreased LC50) of both Az and nAz. Malformations were not observed but the remaining yolk sac volume was significantly increased in both types of Az at both light conditions. This decreased yolk consumption is in agreement with reduced oxygen consumption and heart rate. Catalase enzyme activity was only reduced to UV light while superoxide dismutase activity was significantly reduced by co-exposure of UV light, and either type of Az at a nominal concentration of 100 μg L−1. The co-exposure of Az at 100 μg L−1 and UV light significantly upregulated sod1, sod2, and gpx1b expression and both types of Az significantly reduced gpx1a expression. Lipid peroxidation was significantly increased in nAz and Az at 100 μg L−1 under laboratory light, while UV light induced even higher level of lipid peroxidation. The results will provide important information on the toxicity of nAz under ecologically realistic conditions.

  • Length-dependent toxicity of TiO2 nanofibers: mitigation via shortening
    Nanotoxicology (IF 5.955) Pub Date : 2019-11-15
    Massimiliano G. Bianchi, Luisa Campagnolo, Manfredi Allegri, Simona Ortelli, Magda Blosi, Martina Chiu, Giuseppe Taurino, Valentina Lacconi, Antonio Pietroiusti, Anna L. Costa, Craig A. Poland, Daniel Baird, Rodger Duffin, Ovidio Bussolati, Enrico Bergamaschi

    Length and aspect ratio represent important toxicity determinants of fibrous nanomaterials. We have previously shown that anatase TiO2 nanofibers (TiO2 NF) cause a dose-dependent decrease of cell viability as well as the loss of epithelial barrier integrity in polarized airway cell monolayers. Herein we have investigated the impact of fiber shortening, obtained by ball-milling, on the biological effects of TiO2 NF of industrial origin. Long TiO2 NF (L-TiO2 NF) were more cytotoxic than their shortened counterparts (S-TiO2 NF) toward alveolar A549 cells and bronchial 16HBE cells. Moreover, L-TiO2 NF increased the permeability of 16HBE monolayers and perturbed the distribution of tight-junction proteins, an effect also mitigated by fiber shortening. Raw264.7 macrophages efficiently internalized shortened but not long NF, which caused cell stretching and deformation. Compared with L-TiO2 NF, S-TiO2 NF triggered a more evident macrophage activation, an effect suppressed by the phagocytosis inhibitor cytochalasin B. Conversely, a significant increase of inflammatory markers was detected in either the lungs or the peritoneal cavity of mice exposed to L-TiO2 NF but not to S-TiO2 NF, suggesting that short-term macrophage activation in vitro may not be always a reliable indicator of persistent inflammation in vivo. It is concluded that fiber shortening mitigates NF detrimental effects on cell viability and epithelial barrier competence in vitro as well as inflammation development in vivo. These data suggest that fiber shortening may represent an effective safe-by-design strategy for mitigating TiO2 NF toxic effects.

  • The effects of nano-sized PbO on biomarkers of membrane disruption and DNA damage in a sub-chronic inhalation study on mice
    Nanotoxicology (IF 5.955) Pub Date : 2019-11-15
    Lucie Bláhová, Zuzana Nováková, Zbyněk Večeřa, Lucie Vrlíková, Bohumil Dočekal, Jana Dumková, Kamil Křůmal, Pavel Mikuška, Marcela Buchtová, Aleš Hampl, Klára Hilscherová, Luděk Bláha

    Although the production of engineered nanoparticles increases our knowledge of toxicity and mechanisms of bioactivity during relevant exposures is lacking. In the present study mice were exposed to PbO nanoparticles (PbONP; 192.5 µg/m3; 1.93 × 106 particles/cm3) for 2, 5 and 13 weeks through continuous inhalation. The analyses addressed Pb and PbONP distribution in organs (lung, liver, kidney, brain) using electrothermal atomic absorption spectrometry and transmission electron microscopy, as well as histopathology and analyses of oxidative stress biomarkers. New LC-MS/MS methods were validated for biomarkers of lipid damage F2-isoprostanes (8-iso-prostaglandins F2-alpha and E2) and hydroxylated deoxoguanosine (8-OHdG, marker of DNA oxidation). Commonly studied malondialdehyde was also measured as TBARS by HPLC-DAD. The study revealed fast blood transport and distribution of Pb from the lung to the kidney and liver. A different Pb accumulation trend was observed in the brain, suggesting transfer of NP along the nasal nerve to the olfactory bulbs. Long-term inhalation of PbONP caused lipid peroxidation in animal brains (increased levels of TBARS and both isoprostanes). Membrane lipid damage was also detected in the kidney after shorter exposures, but not in the liver or lung. On the contrary, longer exposures to PbONP increased levels of 8-OHdG in the lung and temporarily increased lung weight after 2 and 5 weeks of exposure. The histopathological changes observed mainly in the lung and liver indicated inflammation and general toxicity responses. The present long-term inhalation study indicates risks of PbONP to both human health and the environment.

  • Iron nanoparticle bio-interactions evaluated in Xenopus laevis embryos, a model for studying the safety of ingested nanoparticles
    Nanotoxicology (IF 5.955) Pub Date : 2019-11-13
    Patrizia Bonfanti, Anita Colombo, Melissa Saibene, Luisa Fiandra, Ilaria Armenia, Federica Gamberoni, Rosalba Gornati, Giovanni Bernardini, Paride Mantecca

    Abstract Iron nanoparticles (NPs) have been proposed as a tool in very different fields such as environmental remediation and biomedical applications, including food fortification against iron deficiency, even if there is still concern about their safety. Here, we propose Xenopus laevis embryos as a suitable model to investigate the toxicity and the bio-interactions at the intestinal barrier of Fe3O4 and zerovalent iron (ZVI) NPs compared to Fe(II) and (III) salts in the 5 to 100 mg Fe/L concentration range using the Frog Embryo Teratogenesis Assay in Xenopus (FETAX). Our results demonstrated that, at concentrations at which iron salts induce adverse effects, both iron NPs do not cause acute toxicity or teratogenicity even if they accumulate massively in the embryo gut. Prussian blue staining, confocal and electron microscopy allowed mapping of iron NPs in enterocytes, along the paracellular spaces and at the level of the basement membrane of a well-preserved intestinal epithelium. Furthermore, the high bioaccumulation factor and the increase in embryo length after exposure to iron NPs suggest greater iron intake, an essential element for organisms. Together, these results improve the knowledge on the safety of orally ingested iron NPs and their interaction with the intestinal barrier, useful for defining the potential risks associated with their use in food/feed fortification.

  • Cyclooxygenase-2 modulates ER-mitochondria crosstalk to mediate superparamagnetic iron oxide nanoparticles induced hepatotoxicity: an in vitro and in vivo study
    Nanotoxicology (IF 5.955) Pub Date : 2019-11-08
    Lin Che, Huan Yao, Chuan-Li Yang, Ni-Jun Guo, Jing Huang, Zi-Li Wu, Li-Yin Zhang, Yuan-Yuan Chen, Gang Liu, Zhong-Ning Lin, Yu-Chun Lin

    Mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) are central microdomains of the ER that interact with mitochondria. MAMs provide an essential platform for crosstalk between the ER and mitochondria and play a critical role in the local transfer of calcium (Ca2+) to maintain cellular functions. Despite the potential uses of superparamagnetic iron oxide nanoparticles (SPIO-NPs) in biomedical applications, the hepatotoxicity of these nanoparticles (NPs) is not well characterized and little is known about the involvement of MAMs in ER-mitochondria crosstalk. We studied SPIO-NPs-associated hepatotoxicity in vitro and in vivo. In vitro, human normal hepatic L02 cells were exposed to SPIO-NPs (2.5, 7.5, and 12.5 μg/mL) for 6 h and SPIO-NPs (12.5 μg/mL) was found to induce apoptosis. In vivo, SPIO-NPs induced liver injury when mice were intravenously injected with 20 mg/kg body weight SPIO-NPs for 24 h. Based on both in vitro and in vivo studies, we found that the structure and Ca2+ transport function of MAMs were perturbated and an accumulation of cyclooxygenase-2 (COX-2) in MAMs fractions was increased upon treatment of SPIO-NPs. The interaction between COX-2 and the components of MAMs, in terms of IP3R-GRP75-VDAC1 complex, was also revealed. Furthermore, the role of COX-2 in SPIO-NPs-associated hepatotoxicity was investigated by modifying the expression of COX-2. We demonstrated that COX-2 increases the structural and functional ER-mitochondria coupling and enhances the efficacy of ER-mitochondria Ca2+ transfer through the MAMs, thus sensitizing hepatocytes to a mitochondrial Ca2+ overload-dependent apoptosis. Taken together, our findings link SPIO-NPs-triggered hepatotoxicity with ER-mitochondria Ca2+ crosstalk which is mediated by COX-2 and provide mechanistic insight into the impact of interorganelle ER-mitochondria communication on hepatic nanotoxicity.

  • Copper oxide nanoparticles alter cellular morphology via disturbing the actin cytoskeleton dynamics in Arabidopsis roots
    Nanotoxicology (IF 5.955) Pub Date : 2019-11-05
    Honglei Jia, Sisi Chen, Xiaofeng Wang, Cong Shi, Kena Liu, Shuangxi Zhang, Jisheng Li

    Copper oxide nanoparticles (CuO NPs) have severe nano-toxic effects on organisms. Limited data is available on influence of CuO NPs on plant cells. Here, the molecular mechanisms involved in the toxicity of CuO NPs are studied. Exposure to CuO NPs significantly increased copper content in roots (0.062–0.325 mg/g FW), but CuO NPs translocation rates from root to shoot were low (1.1–2.8%). Presented data were significant at p < 0.05 compared to control. CuO NPs inhibited longitudinal growth and promoted transverse growth in root tip cells. However, CuO NPs did not affect the leaf cells, implying that the transfer ability of CuO NPs was weak, and toxicity mainly affected roots. CuO NPs can conjugate with actin protein. The actin cytoskeleton experienced reorganization in the presence of CuO NPs. The longitudinal filamentous actin (F-actin) decreased, and the transverse F-actin increased. CuO NPs inhibited actin polymerization and promoted depolymerization. The behavior of individual F-actin was at steady state with time-lapse under CuO NPs treatment by time-lapse reflection fluorescence (TIRF) microscopy. The growth rate of actin filaments was weakened by CuO NPs. CuO NPs disturbed the subcellular localization of PINs and the gradient of auxin distribution in root tips in an actin-dependent manner. In conclusion, CuO NPs conjugated with actin and disturbed F-actin dynamics, triggering abnormal cell growth in the root tip, and findings provide theoretical basis for further study nano-toxicity in plants.

  • Lung deposition patterns of MWCNT vary with degree of carboxylation.
    Nanotoxicology (IF 5.955) Pub Date : 2019-05-22
    Andrij Holian,Raymond F Hamilton,Zhequion Wu,Sanghamitra Deb,Kevin L Trout,Zhiqian Wang,Rohit Bhargava,Somenath Mitra

    Functionalization of multi-walled carbon nanotubes (MWCNT) is known to affect the biological response (e.g. toxicity, inflammation) in vitro and in vivo. However, the reasons for these changes in vivo are not well described. This study examined the degree of MWCNT functionalization with regard to in vivo mouse lung distribution, particle retention, and resulting pathology. A commercially available MWCNT (source MWCNT) was functionalized (f-MWCNT) by systematically varying the degree of carboxylation on the particle's surface. Following a pilot study using seven variants, two f-MWCNT variants were chosen and for lung pathology and particle distribution using oropharyngeal aspiration administration of MWCNT in Balb/c mice. Particle distribution in the lung was examined at 7 and 28 days post-instillation by bright-field microscopy, CytoViva hyperspectral dark-field imaging, and Stimulated Raman Scattering (SRS) microscopy. Examination of the lung tissue by bright-field microscopy showed some acute inflammation for all MWCNT that was highest with source MWCNT. Hyperspectral imaging and SRS were employed to assess the changes in particle deposition and retention. Highly functionalized MWCNT had a higher lung burden and were more disperse. They also appeared to be associated more with epithelial cells compared to the source and less functionalized MWCNT that were mostly interacting with alveolar macrophages (AM). These results showing a slightly reduced pathology despite the extended deposition have implications for the engineering of safer MWCNT and may establish a practical use as a targeted delivery system.

  • Ultra-long silver nanowires induced mitotic abnormalities and cytokinetic failure in A549 cells.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-20
    Fengbang Wang,Ying Chen,Yuanyuan Wang,Yongguang Yin,Guangbo Qu,Maoyong Song,Hailin Wang

    Asbestos fiber has been associated with mesothelioma and lung cancer. However, the carcinogenic risks of other fiber nanomaterials with morphological similarities to asbestos have not been fully studied. Ultra-long silver nanowires (AgNWs) are increasingly used fiber-shaped nanomaterials with a high aspect ratio, but very few studies have investigated their health risks. Here, proliferation abnormalities of lung epithelial cells induced by ultra-long AgNWs were investigated. Ultra-long AgNW treatment induced dose- and diameter-dependent increase in the ratio of multinucleated cells. Further, proteins involved in mitosis and cytokinesis, including Aurora A, p-Histone 3 (ser10), RhoA, p-MLC, and myosin IIb, were significantly upregulated after an ultra-long AgNW treatment, leading to mitotic abnormalities and cytokinetic failure. Meanwhile, exposure to ultra-long AgNWs induced cell cycle arrest. Interestingly, a series of experiments demonstrated that ROS generation and Ag+ release were not responsible for the multinucleation induced by ultra-long AgNWs, but ultra-long AgNWs in the intercellular bridge might obstruct the contractile ring and inhibit abscission of the cytokinetic furrow by direct physical contact. Altogether, our findings indicate that ultra-long AgNWs can induce chromosomal instability, which has important consequences for the safety of ultra-long AgNWs to human health.

  • Adaptive tolerance to multigenerational silver nanoparticle (NM300K) exposure by the nematode Caenorhabditis elegans is associated with increased sensitivity to AgNO3.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-19
    Lisa M Rossbach,Erica Maremonti,Dag M Eide,Deborah H Oughton,Dag A Brede

    Toxic effects of silver nanoparticles (Ag NPs) are, in most cases, measured within a single generation, while information regarding multigenerational exposure remains scarce. The current study assessed changes in toxic response (reproduction, fertility, and development) towards Ag NPs (NM300K; uncoated, 16.7 ± 6.5 nm) compared to AgNO3 over six generations, following chronic exposure of the model organism Caenorhabditis elegans. This revealed that AgNO3 exposure was associated with no changes in susceptibility to Ag. In contrast, multigenerational exposure to sub-lethal concentrations of Ag NPs resulted in persistent delayed development, but rendered increased tolerance to Ag NP with respect to fertility and fecundity. The results thus permit inference of a difference in toxic mode of action of the two forms of Ag, which instigate different response patterns. Results reveal a novel mechanism for the adaptation toward Ag NPs, where increased reproductive fitness occurs at the expense of somatic growth. This adaptive mechanism was, however associated with increased susceptibility to AgNO3 with respect to growth, fertility and reproduction. The current study thus demonstrates that a nano-specific resistance can be developed by C. elegans. Importantly, this adaptation renders increased vulnerability to another environmental stressor, and thus exposure to a second contaminant could be detrimental to such populations.

  • Nanotoxicity of engineered nanomaterials (ENMs) to environmentally relevant beneficial soil bacteria - a critical review.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-15
    Ricky W Lewis,Paul M Bertsch,David H McNear

    Deposition of engineered nanomaterials (ENMs) in various environmental compartments is projected to continue rising exponentially. Terrestrial environments are expected to be the largest repository for environmentally released ENMs. Because ENMs are enriched in biosolids during wastewater treatment, agriculturally applied biosolids facilitate ENM exposure of key soil micro-organisms, such as plant growth-promoting rhizobacteria (PGPR). The ecological ramifications of increasing levels of ENM exposure of terrestrial micro-organisms are not clearly understood, but a growing body of research has investigated the toxicity of ENMs to various soil bacteria using a myriad of toxicity end-points and experimental procedures. This review explores what is known regarding ENM toxicity to important soil bacteria, with a focus on ENMs which are expected to accumulate in terrestrial ecosystems at the highest concentrations and pose the greatest potential threat to soil micro-organisms having potential indirect detrimental effects on plant growth. Knowledge gaps in the fundamental understanding of nanotoxicity to bacteria are identified, including the role of physicochemical properties of ENMs in toxicity responses, particularly in agriculturally relevant micro-organisms. Strategies for improving the impact of future research through the implementation of in-depth ENM characterization and use of necessary experimental controls are proposed. The future of nanotoxicological research employing microbial ecoreceptors is also explored, highlighting the need for continued research utilizing bacterial isolates while concurrently expanding efforts to study ENM-bacteria interactions in more complex environmentally relevant media, e.g. soil. Additionally, the particular importance of future work to extensively examine nanotoxicity in the context of bacterial ecosystem function, especially of plant growth-promoting agents, is proposed.

  • In vivo Toxicity Assessment of Silver Nanoparticles in Homeostatic versus Regenerating Planarians.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-15
    Nathalie Leynen,Frank G A J Van Belleghem,Annelies Wouters,Hannelore Bove,Jan-Pieter Ploem,Elsy Thijssen,Sabine A S Langie,Robert Carleer,Marcel Ameloot,Tom Artois,Karen Smeets

    Silver nanoparticles (AgNPs) belong to the most commercialized nanomaterials, used in both consumer products and medical applications. Despite its omnipresence, in-depth knowledge on the potential toxicity of nanosilver is still lacking, especially for developing organisms. Research on vertebrates is limited due to ethical concerns, and planarians are an ideal invertebrate model to study the effects of AgNPs on stem cells and developing tissues in vivo, as regeneration mimics development by triggering massive stem cell proliferation. Our results revealed a strong interference of AgNPs with tissue- and neuroregeneration which was related to an altered stem cell cycle. The presence of a PVP-coating significantly influenced toxicity outcomes, leading to elevated DNA-damage and decreased stem cell proliferation. Non-coated AgNPs had an inhibiting effect on stem cell and early progeny numbers. Overall, regenerating tissues were more sensitive to AgNP toxicity, and careful handling and appropriate decision making is needed in AgNP applications for healing and developing tissues. We emphasize on the importance of AgNP characterization, as we showed that changes in physicochemical properties influence toxicity.

  • Carboxylic acids accelerate acidic environment-mediated nanoceria dissolution.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-08
    Robert A Yokel,Matthew L Hancock,Eric A Grulke,Jason M Unrine,Alan K Dozier,Uschi M Graham

    Ligands that accelerate nanoceria dissolution may greatly affect its fate and effects. This project assessed the carboxylic acid contribution to nanoceria dissolution in aqueous, acidic environments. Nanoceria has commercial and potential therapeutic and energy storage applications. It biotransforms in vivo. Citric acid stabilizes nanoceria during synthesis and in aqueous dispersions. In this study, citrate-stabilized nanoceria dispersions (∼4 nm average primary particle size) were loaded into dialysis cassettes whose membranes passed cerium salts but not nanoceria particles. The cassettes were immersed in iso-osmotic baths containing carboxylic acids at pH 4.5 and 37 °C, or other select agents. Cerium atom material balances were conducted for the cassette and bath by sampling of each chamber and cerium quantitation by ICP-MS. Samples were collected from the cassette for high-resolution transmission electron microscopy observation of nanoceria size. In carboxylic acid solutions, nanoceria dissolution increased bath cerium concentration to >96% of the cerium introduced as nanoceria into the cassette and decreased nanoceria primary particle size in the cassette. In solutions of citric, malic, and lactic acids and the ammonium ion ∼15 nm, ceria agglomerates persisted. In solutions of other carboxylic acids, some select nanoceria agglomerates grew to ∼1 micron. In carboxylic acid solutions, dissolution half-lives were 800-4000 h; in water and horseradish peroxidase they were ≥55,000 h. Extending these findings to in vivo and environmental systems, one expects acidic environments containing carboxylic acids to degrade nanoceria by dissolution; two examples would be phagolysosomes and in the plant rhizosphere.

  • Identification of signaling cascade in the insulin signaling pathway in response to nanopolystyrene particles.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-08
    Huimin Shao,Zhongyu Han,Natalia Krasteva,Dayong Wang

    The molecular response of animals to nanoplastic particles is still largely unclear. In this study, we employed a modified prolonged exposure system to investigate the molecular response of Caenorhabditis elegans to nanopolystyrene particles. Exposure to nanopolystyrene particles (1 μg/L) significantly decreased expressions of daf-2 encoding an insulin receptor, age-1 encoding a PI3K, and akt-1 encoding an Akt/PKB, and increased expression of daf-16 encoding a FOXO transcriptional factor in insulin signaling pathway. Among these genes, mutation of daf-2, age-1, or akt-1 induced a resistance to toxicity of nanopolystyrene particles, whereas mutation of daf-16 induced a susceptibility to the toxicity of nanopolystyrene particles. RNAi knockdown of daf-16 could further suppress the resistance of daf-2, age-1, or akt-1 mutant to the toxicity of nanopolystyrene particles. The insulin signaling pathway acted in intestinal cells to regulate the toxicity of nanopolystyrene particles. Moreover, sod-3 encoding a manganese superoxide dismutase, mtl-1 encoding a metallothionein, and gpd-2 encoding a glyceraldehyde-3-phosphate dehydrogenase were identified as downstream targeted genes for daf-16 in the regulation of toxicity of nanopolystyrene particles. Therefore, a signaling cascade of DAF-2-AGE-1-AKT-1-DAF-16-SOD-3/MTL-1/GPD-2 was identified in response to nanopolystyrene particles in nematodes. Additionally, this signaling cascade in the insulin signaling pathway may mediate a protective response for nematodes against the adverse effects from nanopolystyrene particles.

  • Silver nanoparticles induce protective autophagy via Ca2+/CaMKKβ/AMPK/mTOR pathway in SH-SY5Y cells and rat brains.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-08
    Lin Li,Lu Li,Xuejiao Zhou,Yang Yu,Zengqiang Li,Daiying Zuo,Yingliang Wu

    Silver nanoparticles (AgNPs) are widely used for manufacturing products containing antibacterial agents, as well as food technologies such as edible films and food packaging. Routes of AgNPs exposure are principally derived by contacting with certain medical sprays, food, toothpaste, and purification products. Previously, we showed that AgNPs induce endoplasmic reticulum (ER) stress and promote apoptosis progression in SH-SY5Y cells; however, whether AgNP-induced ER stress is able to trigger autophagy in vivo and in vitro, and the role of autophagy in AgNP-induced cytotoxicity remain unclear. In the present study, we found that increased intracellular calcium (Ca2+) levels arising from AgNP-induced-ER stress resulted in activation of calmodulin-dependent protein kinase kinase β (CaMKKβ) and adenosine 5'-monophosphate-activated protein kinase (AMPK), which downregulated the level of mammalian target of rapamycin (mTOR) and upregulated Beclin-1 to activate autophagy in SH-SY5Y cells. Specifically, inhibition of autophagy by the addition of chloroquine (CQ) or silencing of Beclin-1 significantly enhanced the cytotoxicity of AgNPs, suggesting that autophagy plays a protective role in AgNP-induced cell apoptosis. Furthermore, we showed that oral administration of AgNPs for 28 continuous days induced ER stress-mediated apoptosis and autophagy in rats via activation of CaMKKβ and AMPK. In summary, this study is the first to report that AgNPs induce protective autophagy via a Ca2+/CaMKKβ/AMPK/mTOR pathway in vivo and in vitro. Therefore, public exposure to AgNPs should arouse concerns regarding environmental safety and human health. Highlight Silver nanoparticle-induced ER stress elicits protective autophagy via a Ca2+-dependent mechanism in SH-SY5Y cells. The Ca2+/CaMKKβ/AMPK/mTOR pathway is involved in autophagy. Orally administered silver nanoparticles induce ER stress-mediated autophagy and apoptosis in rats.

  • Differential transformation and antibacterial effects of silver nanoparticles in aerobic and anaerobic environment.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-08
    Feng Dong,Yan Zhou

    Silver nanoparticles (AgNP) undergo various transformations into different Ag species in the environment, which determines their toxicity in microorganisms. In aerobic condition, AgNPs release Ag+ that causes cell inactivation. Limited information is known about the AgNP-cell interaction in oxygen-free environment. Here we compared the transformation and antibacterial effects of AgNPs in aerobic and anaerobic environment. The bacterium Pseudomonas aeruginosa was relatively not susceptible to Ag+ or AgNP in anaerobic environment, indicated by near two orders of magnitude greater of anaerobic minimum inhibitory concentration (MIC) than the aerobic counterpart. In anaerobic environment, the dissolved Ag concentration decreased due to the reduction of Ag+. Electron microscopy images showed the formation of new AgNPs and aggregates, preferably on cell surface or associated with extracellular polymer substances (EPS) matrix. Accumulating AgNPs onto the cells could cause membrane damage, cytoplasm release or bacterial death. Meanwhile, EPS and cell lysate were very likely to bind AgNPs, facilitating the extensively assembling of AgNPs into large aggregates. This reduced the effective Ag exposure to cells and might contribute to the detoxification in anaerobic environment. Further, flow cytometry analysis quantified that bacterial membrane was largely intact under the treatment of AgNPs in anaerobic condition compared to the dose-response manner in aerobic condition.

  • The biodistribution and immuno-responses of differently shaped non-modified gold particles in zebrafish embryos.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-05
    M van Pomeren,W J G M Peijnenburg,R C Vlieg,S J T van Noort,M G Vijver

    Important questions raised in (nano)ecotoxicology are whether biodistribution of nanoparticles (NPs) is affected by particle shape and to what extent local adverse responses are subsequently initiated. For nanomedicine, these same questions become important when the labeled NPs lose the labeling. In this study, we investigated the biodistribution patterns of gold nanoparticles (AuNPs) as well as immune-related local and systemic sublethal markers of exposure and behavioral assessment. Hatched zebrafish embryos were exposed to four differently shaped non-coated AuNPs with comparable sizes: nanospheres, nanorods, nano-urchins, and nano-bipyramids. Shape-dependent trafficking of the particles resulted in a different distribution of the particles over the target organs. The differences across the distribution patterns indicate that the particles behave slightly different, although they eventually reach the same target organs - yet in different ratios. Mainly local induction of the immune system was observed, whereas systemic immune responses were not clearly visible. Macrophages were found to take AuNPs from the body fluid, be transferred into the veins and transported to digestive organs for clearance. No significant behavioral toxicological responses in zebrafish embryos were observed after exposure. The trafficking of the particles in the macrophages indicates that the particles are removed via the mononuclear phagocytic system. The different ratios in which the particles are distributed over the target organs indicate that the shape influences their behavior and eventually possibly the toxicity of the particles. The observed shape-dependent biodistribution patterns might be beneficial for shape-specific targeting in nanomedicine and stress the importance of incorporating shape-features in nanosafety assessment.

  • Toxicity evaluation of monodisperse PEGylated magnetic nanoparticles for nanomedicine.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-02
    Vitalii Patsula,Jana Tulinska,Štěpánka Trachtová,Miroslava Kuricova,Aurelia Liskova,Alena Španová,Fedor Ciampor,Ivo Vavra,Bohuslav Rittich,Monika Ursinyova,Mária Dusinska,Silvia Ilavska,Mira Horvathova,Vlasta Masanova,Iveta Uhnakova,Daniel Horák

    Innovative nanotechnology aims to develop particles that are small, monodisperse, smart, and do not cause unintentional side effects. Uniform magnetic Fe3O4 nanoparticles (12 nm in size) were prepared by thermal decomposition of iron(III) oleate. To make them colloidally stable and dispersible in water and cell culture medium, they were modified with phosphonic acid- (PA) and hydroxamic acid (HA)-terminated poly(ethylene glycol) yielding PA-PEG@Fe3O4 and HA-PEG@Fe3O4 nanoparticles; conventional γ-Fe2O3 particles were prepared as a control. Advanced techniques were used to evaluate the properties and safety of the particles. Completeness of the nanoparticle coating was tested by real-time polymerase chain reaction. Interaction of the particles with primary human peripheral blood cells, cellular uptake, cytotoxicity, and immunotoxicity were also investigated. Amount of internalized iron in peripheral blood mononuclear cells was 72, 38, and 25 pg Fe/cell for HA-PEG@Fe3O4, γ-Fe2O3, and PA-PEG@Fe3O4, respectively. Nanoparticles were localized within the cytoplasm and in the extracellular space. No cytotoxic effect of both PEGylated nanoparticles was observed (0.12-75 μg/cm2) after 24 and 72-h incubation. Moreover, no suppressive effect was found on the proliferative activity of T-lymphocytes and T-dependent B-cell response, phagocytic activity of monocytes and granulocytes, and respiratory burst of phagocytes. Similarly, no cytotoxic effect of γ-Fe2O3 particles was observed. However, they suppressed the proliferative activity of T-lymphocytes (75 μg/cm2, 72 h) and also decreased the phagocytic activity of monocytes (15 μg/cm2, 24 h; 3-75 μg/cm2, 72 h). We thus show that newly developed particles have great potential especially in cancer diagnostics and therapy.

  • Discovery of CRR1-targeted copper deficiency response in Chlamydomonas reinhardtii exposed to silver nanoparticles.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-02
    Songshan Wang,Jitao Lv,Shuzhen Zhang

    The molecular mechanisms behind the adaptive responses for interactions between organisms and nanoparticles, such as silver nanoparticles (AgNPs), are of great concern. In this study, the transcriptome of freshwater alga Chlamydomonas reinhardtii was characterized via RNA sequencing (RNA-seq) after exposure to a nontoxic concentration of AgNPs (0.5 mg/L). The cytochrome c6 (CYC6) and ferredoxin-5 (FDX5) genes were identified with the greatest increase in expression level, which were indications of the copper deficiency in the algae. Gene set enrichment analysis also showed significant enrichment of copper deficiency responsive genes in the transcriptome of algae exposed to AgNPs. These results indicated that AgNPs induced a copper deficiency response in algae, and the excessive intracellular copper content suggested this was due to functional copper deficiency. This deficiency response was further validated to be regulated by transcription factor CRR1 (copper response regulator 1) according to the assays on the mutant strain with defect of CRR1. To the best of our knowledge, this is the first corroboration of a CRR1-targeted copper deficiency response in algae following AgNP exposure. Given the function of copper in fundamental metabolic pathways, such as photosynthesis and respiration, we propose a potential role of CRR1-targeted copper deficiency as an adaptation of algae after exposure to AgNPs.

  • Inhibition of inhaled halloysite nanotube toxicity by trehalose through enhanced autophagic clearance of p62.
    Nanotoxicology (IF 5.955) Pub Date : 2019-02-02
    Rui Rong,Yongming Zhang,Yunjiao Zhang,Yi Hu,Wenjie Yang,Xiaowen Hu,Longping Wen,Qixing Zhang

    Nanomaterials are widely used in an ever-increasing number of consumer and industrial products. It is therefore essential that the toxic effects of nanomaterials are understood in order to improve product safety. Here we evaluate the toxicity of inhaled halloysite nanotubes (HNTs) by applying a purpose designed inhalation exposure system and succeed in suppressing HNTs toxicity using trehalose. By assessing apoptosis, oxidative stress, inflammatory response, and autophagy, it is found that HNTs can cause sub-chronic toxicity in mice. Further investigations indicate that HNTs induce autophagy blockade that results in the accumulation of sequestosome-1 (p62), which is responsible for the excessive apoptosis, inflammatory response and oxidative stress. We found that p62 can be eliminated by trehalose and the application of trehalose in vitro and in vivo successfully inhibits toxicity by accelerating the clearance of p62. Trehalose shows great potential for reducing nanoparticle toxicity.

  • The effect of capping agents on the toxicity of silver nanoparticles to Danio rerio embryos.
    Nanotoxicology (IF 5.955) Pub Date : 2019-01-30
    N Abramenko,T B Demidova,Yu A Krutyakov,P M Zherebin,E Y Krysanov,L M Kustov,W Peijnenburg

    Addition of capping agents like surfactants and polymers during the synthesis of nanoparticles may affect the stability and toxicity of dispersions of nanoparticles. This study revealed the impact of anionic, cationic, and amphoteric surfactants and a cationic polymer on the physical and chemical properties, stability and behavior of silver nanomaterials, as well as on the toxicity of nanosized silver particles with respect to zebrafish embryos. Some of the stabilizers applied were shown to significantly affect embryos of Danio rerio. Colloidal dispersions of stabilized silver nanoparticles were demonstrated to induce a complex mechanism of toxicity with respect to embryos of D. rerio, which is mainly explained by the toxicity of the organic ligand, while other parameters are somewhat inferior. The newly generated data on the toxicity of nanoparticles and their stabilizers with respect to D. rerio embryos reveal the complexity of the toxicity mechanism of nanoparticles impacting living systems.

  • Proteomic profiling of RAW264.7 macrophage cells exposed to graphene oxide: insights into acute cellular responses.
    Nanotoxicology (IF 5.955) Pub Date : 2019-01-18
    Xiaoliang Yang,Yan Zhang,Wenjia Lai,Zhichu Xiang,Bin Tu,Dan Li,Xiaohui Nan,Chunying Chen,Zhiyuan Hu,Qiaojun Fang

    Although the toxicity and molecular mechanisms of graphene oxide (GO) have been reported for several cell types, no proteomic study of GO has yet been conducted on macrophage cells. In this study, we used proteomics based on stable isotope labeling with amino acids in cell culture (SILAC) to quantify the proteomic changes in macrophage RAW 264.7 cells following GO treatment. We found 73 proteins that were significantly dysregulated after GO treatment. The down-regulated proteins included many ribosomal subunit proteins, indicating that GO affected cell growth. The most elevated proteins were lipoprotein lipase (LPL) and lysozyme 1 (LYZ1) which have not been reported before, and both can be used as candidate markers for GO exposure. Further enrichment analysis of the up-regulated proteins indicated these proteins are associated with the integrin complex and membrane rafts, as well as with two signal pathways: the phagosome and steroid biosynthesis pathways. We confirmed a GO concentration-dependent increase in membrane rafts and the production of phagosomes. GO exposure also induced necrotic cell death and an inflammation response in RAW 264.7 cells. We also observed an increase in the oxidative stress response (ROS) and autophagy, and the results suggest that ROS induced autophagy by the ROS-NRF2-P62 pathway.

  • N-Acetylcysteine reverses silver nanoparticle intoxication in rats.
    Nanotoxicology (IF 5.955) Pub Date : 2018-11-28
    Monique Culturato Padilha Mendonça,Luiz Bandeira Ferreira,Cintia Rizoli,Ângela Giovana Batista,Mário Roberto Maróstica Júnior,Emanueli do Nascimento da Silva,Solange Cadore,Nelson Durán,Maria Alice da Cruz-Höfling,Marcelo Bispo de Jesus

    The increasing use of silver nanoparticles (AgNPs) in consumer products raises the risk of human toxicity. Currently, there are no therapeutic options or established treatment protocols in cases of AgNPs intoxication. We demonstrated previously that thiol antioxidants compounds can reverse the cytotoxicity induced by AgNPs in Huh-7 hepatocarcinoma cells. Here, we investigated the use of N-acetylcysteine (NAC) against the systemic toxic effects of AgNPs (79.3 nm) in rats. Biochemical, histopathological, hematological, and oxidative parameters showed that a single intravenous injection of AgNPs (5 mg/kg b.w.) induced deleterious effects such as hepatotoxicity, potentially as a result of AgNPs accumulation in the liver. Treatment with a single intraperitoneal injection of NAC (1 g/kg b.w.) one hour after AgNPs exposure significantly attenuated all toxic effects evaluated and altered the bioaccumulation and release patterns of AgNPs in rats. The findings show that NAC may be a promising candidate for clinical management of AgNPs intoxication.

  • In vitro immunotoxicological assessment of a potent microbicidal nanocomposite based on graphene oxide and silver nanoparticles.
    Nanotoxicology (IF 5.955) Pub Date : 2018-11-20
    Luis Augusto Visani de Luna,Nahiara Esteves Zorgi,Ana Carolina Mazarin de Moraes,Douglas Soares da Silva,Sílvio Roberto Consonni,Selma Giorgio,Oswaldo Luiz Alves

    Graphene oxide (GO) and silver nanoparticles (AgNPs) can be formed into a hybrid nanomaterial, known as GOAg nanocomposite, which presents high antibacterial activity. The successful translation of this nanomaterial into medical use depends on critical information about its toxicological profile. In keeping with a Safe-by-design approach, we evaluated the immunotoxicity of GOAg using J774 and primary murine macrophages. The interaction between GOAg and macrophages was investigated with a scanning electron microscope (SEM). High-throughput technologies were employed to evaluate cell viability, apoptosis/necrosis, mitochondrial depolarization and lipid peroxidation. The inflammogenicity of nanomaterials was predicted after quantification of the cytokines IL-1β, TNF-α and IL-10 before and after stimulation with interferon-γ (IFN-γ). The ratio between CD80 and CD206 macrophage populations were also estimated. In addition, the production of nitric oxide (NO) was investigated. SEM surveys revealed the potential of GOAg to induce frustrated phagocytosis. GOAg induced a dose-dependent mitochondrial depolarization, apoptosis and lipid peroxidation to J774 macrophages. GOAg toxicity was not modified in an inflammatory microenvironment, but its toxicity was within the range of concentrations used in bacterial inactivation. GOAg did not induce primary macrophages to significantly produce inflammatory cytokines, and previous macrophage stimulation did not enhance GOAg inflammogenicity. Additionally, the pristine nanomaterials and GOAg do not shift macrophages polarization towards M1. Sublethal concentrations of GOAg did not impair macrophages NO production. Finally, we suggest options for improvement of GOAg nanocomposite in ways that may help minimize its possible adverse outcomes to human health.

  • Toxicity of copper oxide and basic copper carbonate nanoparticles after short-term oral exposure in rats.
    Nanotoxicology (IF 5.955) Pub Date : 2018-11-20
    Wim H De Jong,Eveline De Rijk,Alessandro Bonetto,Wendel Wohlleben,Vicki Stone,Andrea Brunelli,Elena Badetti,Antonio Marcomini,Ilse Gosens,Flemming R Cassee

    Copper oxide (CuO) nanoparticles (NPs) and copper carbonate nanoparticles (Cu2CO3(OH)2 NPs have applications as antimicrobial agents and wood preservatives: an application that may lead to oral ingestion via hand to mouth transfer. Rats were exposed by oral gavage to CuO NPs and Cu2CO3(OH)2 NPs for five consecutive days with doses from 1 to 512 mg/kg and 4 to 128 mg/kg per day, respectively, and toxicity was evaluated at days 6 and 26. Both CuO NPs and Cu2CO3(OH)2 NPs induced changes in hematology parameters, as well as clinical chemistry markers (e.g. increased alanine aminotransferase, ALT) indicative of liver damage For CuO NPs histopathological alterations were observed in bone marrow, stomach and liver mainly consisting of an inflammatory response, ulceration, and degeneration. Cu2CO3(OH)2 NPs induced morphological alterations in the stomach, liver, intestines, spleen, thymus, kidneys, and bone marrow. In spleen and thymus lymphoid, depletion was noted that warrants further immunotoxicological evaluation. The NPs showed partial dissolution in artificial simulated stomach fluids, while in intestinal conditions, the primary particles simultaneously shrank and agglomerated into large structures. This means that both copper ions and the particulate nanoforms should be considered as potential causal agents for the observed toxicity. For risk assessment, the lowest bench mark dose (BMD) was similar for both NPs for the serum liver enzyme AST (an indication of liver toxicity), being 26.2 mg/kg for CuO NPs and 30.8 mg/kg for Cu2CO3(OH)2 NPs. This was surprising since the histopathology evidence demonstrates more severe organ damage for Cu2CO3(OH)2 NPs than for CuO NPs.

  • The use of Drosophila melanogaster as a model organism to study immune-nanotoxicity.
    Nanotoxicology (IF 5.955) Pub Date : 2018-11-20
    Cheng Teng Ng,Liya E Yu,Choon Nam Ong,Boon Huat Bay,Gyeong Hun Baeg

    Nanomaterials (NMs) are widely used in consumer and industrial products, as well as in the field of nanomedicine. Despite their wide array of applications, NMs are regarded as foreign entities by the body and thus induce various immune reactions. In mammals, NMs trigger differential recognition by immune cells such as macrophages, causing perturbation of the immune system. Studies on the pattern recognition of NMs have revealed that the Toll-like receptor signaling pathway plays an essential role in NM-induced innate immunity. However, effects caused by physicochemical properties of NMs on immune response and how NMs are recognized by immune cells are not fully understood. Furthermore, the complexity of the mammalian immune system and interspecies variation are still being debated, and the discordant results warrant the need to address these issues. Drosophila melanogaster has gained popularity as a model to study nanotoxicity. Drosophila innate immunity has extensively been studied, providing insights into our understanding of key signaling cascades involved, and importantly it has conserved immune-related genes and mechanogenetic pathways that represents a useful basis for studying its biological response at molecular level to environmental contaminants such as NMs. Moreover, various genetic tools and reagents enable to elucidate the molecular mechanisms underlying the internalization of NMs by immune cells. Furthermore, numerous forward and reverse genetic approaches can be employed to dissect complex biological processes, such as identifying signal transduction pathways and their core components involved in NM-induced immune responses. This review presents an overview of Drosophila innate immunity, as well as summarizes the impact of NM exposure on immune response in Drosophila. We also highlight the recent advancement of suitable methodologies and tools regarding the use of Drosophila as a model for studying the immune-related toxicity of NMs, taking into account the limitations associated with studying NM-induced toxicity in the mammalian system.

  • Toward comprehension of multiple human cells uptake of engineered nano metal oxides: quantitative inter cell line uptake specificity (QICLUS) modeling.
    Nanotoxicology (IF 5.955) Pub Date : 2018-10-26
    Probir Kumar Ojha,Supratik Kar,Kunal Roy,Jerzy Leszczynski

    To address the nanomaterial exposure threat, it is imperative to understand how nanomaterials are recognized, internalized, and distributed within diverse cell systems. Targeting of nanomaterials to a specific cell type is generally attained through the modification of the nanoparticle (NP) surface leading to required cellular uptake. The enhanced cellular uptake to normal cells can direct to the higher interaction of NPs with subcellular organelles resulting the provocation of various signaling pathways. The successes of NPs rely on the prospect for the synthesis of functionalized NPs with necessary properties and their enhanced potential for cellular uptake for specific targeting. In the present study, we have modeled the cellular uptake of 109 surface modifiers of metal oxide nanoparticles (MNPs) for three different cell lines: HUVEC (Human endothelial cells), U937 (human macrophage cells), and PaCa2 (cancer cell lines). Along with the quantitative structure-activity relationship (QSAR) models, for the very first time we have developed and performed quantitative inter cell line uptake specificity (QICLUS) modeling to identify the physicochemical properties, as well as majorly structural fragments responsible for cellular uptake differences between two specific cell lines. The present work provides a comprehensive understanding of the cellular uptake of MNPs and the underlying structural parameters controlling the nano-cellular interactions. This phenomenon has also been analyzed from the QSAR and QICLUS models that concluded the functional groups of surface modifiers like amine, anhydride, halogen atoms, nitro group, acids have the dominating roles for the uptake of MNPs into the cell lines. Thus, the developed models may be used for designing of novel surface modifiers of MNPs of desired characteristics for proper cell-NPs interactions, as well as in the context of virtual screening aspect. Moreover, the MNP-cell interactions can give some idea about the toxicity for target-specific drug delivery treatment as higher cellular uptake is required for specific cells to treat the disease and lower uptake to the neighboring cells for lower toxicity.

  • Preclinical hazard evaluation strategy for nanomedicines.
    Nanotoxicology (IF 5.955) Pub Date : 2018-09-06
    Stefan Siegrist,Emre Cörek,Pascal Detampel,Jenny Sandström,Peter Wick,Jörg Huwyler

    The increasing nanomedicine usage has raised concerns about their possible impact on human health. Present evaluation strategies for nanomaterials rely on a case-by-case hazard assessment. They take into account material properties, biological interactions, and toxicological responses. Authorities have also emphasized that exposure route and intended use should be considered in the safety assessment of nanotherapeutics. In contrast to an individual assessment of nanomaterial hazards, we propose in the present work a novel and unique evaluation strategy designed to uncover potential adverse effects of such materials. We specifically focus on spherical engineered nanoparticles used as parenterally administered nanomedicines. Standardized assay protocols from the US Nanotechnology Characterization Laboratory as well as the EU Nanomedicine Characterisation Laboratory can be used for experimental data generation. We focus on both cellular uptake and intracellular persistence as main indicators for nanoparticle hazard potentials. Based on existing regulatory specifications defined by authorities such as the European Medicines Agency and the United States Food and Drug Administration, we provide a robust framework for application-oriented classification paired with intuitive decision making. The Hazard Evaluation Strategy (HES) for injectable nanoparticles is a three-tiered concept covering physicochemical characterization, nanoparticle (bio)interactions, and hazard assessment. It is cost-effective and can assist in the design and optimization of nanoparticles intended for therapeutic use. Furthermore, this concept is designed to be adaptable for alternative exposure and application scenarios. To the knowledge of the authors, the HES is unique in its methodology based on exclusion criteria. It is the first hazard evaluation strategy designed for nanotherapeutics.

  • Insights into possibilities for grouping and read-across for nanomaterials in EU chemicals legislation.
    Nanotoxicology (IF 5.955) Pub Date : 2018-09-06
    A Mech,K Rasmussen,P Jantunen,L Aicher,M Alessandrelli,U Bernauer,E A J Bleeker,J Bouillard,P Di Prospero Fanghella,R Draisci,M Dusinska,G Encheva,G Flament,A Haase,Y Handzhiyski,F Herzberg,J Huwyler,N R Jacobsen,V Jeliazkov,N Jeliazkova,P Nymark,R Grafström,A G Oomen,M L Polci,C Riebeling,J Sandström,B Shivachev,S Stateva,S Tanasescu,R Tsekovska,H Wallin,M F Wilks,S Zellmer,M D Apostolova

    This paper presents a comprehensive review of European Union (EU) legislation addressing the safety of chemical substances, and possibilities within each piece of legislation for applying grouping and read-across approaches for the assessment of nanomaterials (NMs). Hence, this review considers both the overarching regulation of chemical substances under REACH (Regulation (EC) No 1907/2006 on registration, evaluation, authorization, and restriction of chemicals) and CLP (Regulation (EC) No 1272/2008 on classification, labeling and packaging of substances and mixtures) and the sector-specific pieces of legislation for cosmetic, plant protection and biocidal products, and legislation addressing food, novel food, and food contact materials. The relevant supporting documents (e.g. guidance documents) regarding each piece of legislation were identified and reviewed, considering the relevant technical and scientific literature. Prospective regulatory needs for implementing grouping in the assessment of NMs were identified, and the question whether each particular piece of legislation permits the use of grouping and read-across to address information gaps was answered.

  • Grouping of nanomaterials to read-across hazard endpoints: a review.
    Nanotoxicology (IF 5.955) Pub Date : 2018-09-06
    L Lamon,K Aschberger,D Asturiol,A Richarz,A Worth

    The use of non-testing strategies like read-across in the hazard assessment of chemicals and nanomaterials (NMs) is deemed essential to perform the safety assessment of all NMs in due time and at lower costs. The identification of physicochemical (PC) properties affecting the hazard potential of NMs is crucial, as it could enable to predict impacts from similar NMs and outcomes of similar assays, reducing the need for experimental (and in particular animal) testing. This manuscript presents a review of approaches and available case studies on the grouping of NMs to read-across hazard endpoints. We include in this review grouping frameworks aimed at identifying hazard classes depending on PC properties, hazard classification modules in control banding (CB) approaches, and computational methods that can be used for grouping for read-across. The existing frameworks and case studies are systematically reported. Relevant nanospecific PC properties taken into account in the reviewed frameworks to support grouping are shape and surface properties (surface chemistry or reactivity) and hazard classes are identified on the basis of biopersistence, morphology, reactivity, and solubility.

  • Consumer exposures to laser printer-emitted engineered nanoparticles: A case study of life-cycle implications from nano-enabled products.
    Nanotoxicology (IF 5.955) Pub Date : 2014-11-12
    Sandra V Pirela,Georgios A Sotiriou,Dhimiter Bello,Martin Shafer,Kristin Lee Bunker,Vincent Castranova,Treye Thomas,Philip Demokritou

    It is well established that printers emit nanoparticles during their operation. To-date, however, the physicochemical and toxicological characterization of "real world" printer-emitted nanoparticles (PEPs) remains incomplete, hampering proper risk assessment efforts. Here, we investigate our earlier hypothesis that engineered nanomaterials (ENMs) are used in toners and ENMs are released during printing (consumer use). Furthermore, we conduct a detailed physicochemical and morphological characterization of PEPs in support of ongoing toxicological assessment. A comprehensive suite of state of the art analytical methods and tools was employed for the physicochemical and morphological characterization of 11 toners widely utilized in printers from major printer manufacturers and their PEPs. We confirmed that a number of ENMs incorporated into toner formulations (e.g. silica, alumina, titania, iron oxide, zinc oxide, copper oxide, cerium oxide, carbon black among others) and released into the air during printing. All evaluated toners contained large amounts of organic carbon (OC, 42-89%), metals/metal oxides (1-33%), and some elemental carbon (EC, 0.33-12%). The PEPs possess a composition similar to that of toner and contained 50-90% OC, 0.001-0.5% EC and 1-3% metals. While the chemistry of the PEPs generally reflected that of their toners, considerable differences are documented indicative of potential transformations taking place during consumer use (printing). We conclude that: (i) Routine incorporation of ENMs in toners classifies them as nano-enabled products (NEPs); (ii) These ENMs become airborne during printing; (iii) The chemistry of PEPs is complex and it reflects that of the toner and paper. This work highlights the importance of understanding life-cycle (LC) nano-EHS implications of NEPs and assessing real world exposures and associated toxicological properties rather than focusing on "raw" materials used in the synthesis of an NEP.

  • Role of p53 in the chronic pulmonary immune response to tangled or rod-like multi-walled carbon nanotubes.
    Nanotoxicology (IF 5.955) Pub Date : 2018-10-16
    Katherine S Duke,Elizabeth A Thompson,Mark D Ihrie,Alexia J Taylor-Just,Elizabeth A Ash,Kelly A Shipkowski,Jonathan R Hall,Debra A Tokarz,Mark F Cesta,Ann F Hubbs,Dale W Porter,Linda M Sargent,James C Bonner

    The fiber-like shape of multi-walled carbon nanotubes (MWCNTs) is reminiscent of asbestos, suggesting they pose similar health hazards when inhaled, including pulmonary fibrosis and mesothelioma. Mice deficient in the tumor suppressor p53 are susceptible to carcinogenesis. However, the chronic pathologic effect of MWCNTs delivered to the lungs of p53 heterozygous (p53+/-) mice has not been investigated. We hypothesized that p53+/- mice would be susceptible to lung tumor development after exposure to either tangled (t-) or rod-like (r-) MWCNTs. Wild-type (p53+/+) or p53+/- mice were exposed to MWCNTs (1 mg/kg) via oropharyngeal aspiration weekly over four consecutive weeks and evaluated for cellular and pathologic outcomes 11-months post-initial exposure. No lung or pleural tumors were observed in p53+/+ or p53+/- mice exposed to either t- or rMWCNTs. In comparison to tMWCNTs, the rMWCNTs induced the formation of larger granulomas, a greater number of lymphoid aggregates and greater epithelial cell hyperplasia in terminal bronchioles in both p53+/- and p53+/+ mice. A constitutively larger area of CD45R+/CD3+ lymphoid tissue was observed in p53+/- mice compared to p53+/+ mice. Importantly, p53+/- mice had larger granulomas induced by rMWCNTs as compared to p53+/+ mice. These findings indicate that a combination of p53 deficiency and physicochemical characteristics including nanotube geometry are factors in susceptibility to MWCNT-induced lymphoid infiltration and granuloma formation.

  • Differential toxicity of processed and non-processed states of CoCrMo degradation products generated from a hip simulator on neural cells.
    Nanotoxicology (IF 5.955) Pub Date : 2018-09-27
    Divya Rani Bijukumar,Abhijith Segu,YongChao Mou,Reza Ghodsi,Tolou Shokufhar,Mark Barba,Xue-Jun Li,Mathew Thoppil Mathew

    Physico-chemical characteristics of the CoCrMo degradation products have played an important role in cytotoxicity and clinical complications on the orthopedic patients who have metal implants. Previous studies have limited reflection on the physicochemical characteristics of the degradation products generated in vivo, which are very different from individual metal particles and/or ions obtained from different commercial sources. In this study, we aimed to understand the differences in toxicity induced by the degradation products in as-synthesized form as well as those obtained after post-processing. The degradation products were generated using a hip-simulator by maintaining physiological conditions closer to in vivo and separated into two batches, one with processing by washing and drying called processed degradation products (PDP) and another batch as 'as-synthesized' degradation product (DP). We studied the dose-dependent toxicity response by neural cells derived from induced pluripotent stem cells. The results of the study show that as-synthesized DPs are more toxic to neural cells even at lower concentrations studied with evident low TC50 (1-5 μg/ml) concentrations compared to PDP (25 μg/ml). Flow cytometric analysis showed a significant (p<.01) increase in uptake of the particles after 24 h and corresponding ROS production in DP-treated cells. RT-PCR analysis of oxidative specific gene expression showed, elevated mRNA levels of NADPH oxidase-1, nuclear transcription factor, superoxide dismutase-2 and glutaredoxin-2 in DP-treated cells after 6 h. The results of the study provided a clear evidence of the differential response of neural cells on the degradation products as a function of concentrations and their chemical nature.

  • Efficient anti-tumor nano-lipoplexes with unsaturated or saturated lipid induce differential genotoxic effects in mice.
    Nanotoxicology (IF 5.955) Pub Date : 2019-07-12
    Hari Krishnareddy Rachamalla,Sujan Kumar Mondal,Shruti S Deshpande,Kathyayani Sridharan,Kalpana Javaji,Madan Mohan Chandra Sekhar Jaggarapu,Sudhakar Jinka,Vishnusravan Bollu,Sunil Misra,Rajkumar Banerjee

    Cationic lipids are well-known excipients for nanometric liposomal gene delivery systems. However, because of the suspected, collateral toxicity in normal cells, the use of cationic lipids for the treatment of human tumor is largely limited. Recently, we developed a glucocorticoid receptor (GR)-targeted liposomal, anticancer delivery system (DXE nano-lipoplex), which carried cationic lipid of saturated twin aliphatic chains. It exhibited efficient anti-tumor effect in aggressive and drug-resistant tumor models. Toward exploring lipoplex's human clinical use, we incorporated another nano-lipoplex (D1XE) group that carried cationic lipid with one of its aliphatic chain carrying unsaturation and compared in vivo genotoxicological profiling-based safety assessment and the respective anti-tumor efficacy of the lipoplexes. Thus, both the lipoplexes differ only by the chemical identity of one of their constituent cationic lipid. Unsaturated aliphatic chains in lipid generally impart efficient cell surface fusogenic property in lipid formulations. Herein, we report that nanoplex with unsaturated cationic lipid (D1XE) exhibited better physical appearance with less flocculent behavior than nanoplex with saturated lipid (DXE). Upon multiple injections, D1XE nanoplex imparted better tumor regression but most importantly, exhibited much lower overall toxicity (e.g. genotoxicity, weight loss, etc.) than DXE nanoplex. With a higher antitumor effect but a lower genotoxic effect, D1XE is proved to be a better nanoplex than DXE for the potential clinical trial. Thus, this study clearly delineates the importance of incorporating a constituent lipid that carries a single unsaturated aliphatic chain toward developing efficient anti-tumor nano-lipoplexes with reduced genotoxicity.

  • Reactive oxygen species damage drives cardiac and mitochondrial dysfunction following acute nano-titanium dioxide inhalation exposure.
    Nanotoxicology (IF 5.955) Pub Date : 2017-12-16
    Cody E Nichols,Danielle L Shepherd,Quincy A Hathaway,Andrya J Durr,Dharendra Thapa,Alaeddin Abukabda,Jinghai Yi,Timothy R Nurkiewicz,John M Hollander

    Nanotechnology offers innovation in products from cosmetics to drug delivery, leading to increased engineered nanomaterial (ENM) exposure. Unfortunately, health impacts of ENM are not fully realized. Titanium dioxide (TiO2) is among the most widely produced ENM due to its use in numerous applications. Extrapulmonary effects following pulmonary exposure have been identified and may involve reactive oxygen species (ROS). The goal of this study was to determine the extent of ROS involvement on cardiac function and the mitochondrion following nano-TiO2 exposure. To address this question, we utilized a transgenic mouse model with overexpression of a novel mitochondrially-targeted antioxidant enzyme (phospholipid hydroperoxide glutathione peroxidase; mPHGPx) which provides protection against oxidative stress to lipid membranes. MPHGPx mice and littermate controls were exposed to nano-TiO2 aerosols (Evonik, P25) to provide a calculated pulmonary deposition of 11 µg/mouse. Twenty-four hours following exposure, we observed diastolic dysfunction as evidenced by E/A ratios greater than 2 and increased radial strain during diastole in wild-type mice (p < 0.05 for both), indicative of restrictive filling. Overexpression of mPHGPx mitigated the contractile deficits resulting from nano-TiO2 exposure. To investigate the cellular mechanisms associated with the observed cardiac dysfunction, we focused our attention on the mitochondrion. We observed a significant increase in ROS production (p < 0.05) and decreased mitochondrial respiratory function (p < 0.05) following nano-TiO2 exposure which were attenuated in mPHGPx transgenic mice. In summary, nano-TiO2 inhalation exposure is associated with cardiac diastolic dysfunction and mitochondrial functional alterations, which can be mitigated by the overexpression of mPHGPx, suggesting ROS contribution in the development of contractile and bioenergetic dysfunction.

  • Characterization of silver particles in the stratum corneum of healthy subjects and atopic dermatitis patients dermally exposed to a silver-containing garment.
    Nanotoxicology (IF 5.955) Pub Date : 2016-09-21
    Carlotta Bianco,Maaike J Visser,Olivier A Pluut,Vesna Svetličić,Galja Pletikapić,Ivone Jakasa,Christoph Riethmuller,Gianpiero Adami,Francesca Larese Filon,Diane Schwegler-Berry,Aleksandr B Stefaniak,Sanja Kezic

    Silver is increasingly being used in garments to exploit its antibacterial properties. Information on the presence of silver nanoparticles (AgNPs) in garments and their in vivo penetration across healthy and impaired skin from use is limited. We investigated the presence of AgNPs in a silver containing garment and in the stratum corneum (SC) of healthy subjects (CTRLs) and individuals with atopic dermatitis (AD). Seven CTRLs and seven AD patients wore a silver sleeve (13% Ag w/w) 8 h/day for five days on a forearm and a placebo sleeve on the other forearm. After five days, the layers of the SC were collected by adhesive tapes. The silver particles in the garment and SC were characterized by scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) and atomic force microscopy (AFM). AFM and SEM revealed the presence of sub-micrometre particles having a broad range of sizes (30-500 nm) on the surface of the garment that were identified as silver. On the SC tapes collected from different depths, aggregates with a wide range of sizes (150 nm-2 μm) and morphologies were found. Most aggregates contained primarily silver, although some also contained chlorine and sulfur. There was no clear difference in the number or size of the aggregates observed in SC between healthy and AD subjects. After use, AgNPs and their aggregates were present in the SC at different depths of both healthy subjects and AD patients. Their micrometre size suggests that aggregation likely occurred in the SC.

  • Respiratory toxicity and immunotoxicity evaluations of microparticle and nanoparticle C60 fullerene aggregates in mice and rats following nose-only inhalation for 13 weeks.
    Nanotoxicology (IF 5.955) Pub Date : 2016-09-13
    Brian C Sayers,Dori R Germolec,Nigel J Walker,Kelly A Shipkowski,Matthew D Stout,Mark F Cesta,Joseph H Roycroft,Kimber L White,Gregory L Baker,Jeffrey A Dill,Matthew J Smith

    C60 fullerene (C60), or buckminsterfullerene, is a spherical arrangement of 60 carbon atoms, having a diameter of approximately 1 nm, and is produced naturally as a by-product of combustion. Due to its small size, C60 has attracted much attention for use in a variety of applications; however, insufficient information is available regarding its toxicological effects. The effects on respiratory toxicity and immunotoxicity of C60 aggregates (50 nm [nano-C60] and 1 μm [micro-C60] diameter) were examined in B6C3F1/N mice and Wistar Han rats after nose-only inhalation for 13 weeks. Exposure concentrations were selected to allow for data evaluations using both mass-based and particle surface area-based exposure metrics. Nano-C60 exposure levels selected were 0.5 and 2 mg/m3 (0.033 and 0.112 m2/m3), while micro-C60 exposures were 2, 15 and 30 mg/m3 (0.011, 0.084 and 0.167 m2/m3). There were no systemic effects on innate, cell-mediated, or humoral immune function. Pulmonary inflammatory responses (histiocytic infiltration, macrophage pigmentation, chronic inflammation) were concentration-dependent and corresponded to increases in monocyte chemoattractant protein (MCP)-1 (rats) and macrophage inflammatory protein (MIP)-1α (mice) in bronchoalveolar lavage (BAL) fluid. Lung overload may have contributed to the pulmonary inflammatory responses observed following nano-C60 exposure at 2 mg/m3 and micro-C60 exposure at 30 mg/m3. Phenotype shifts in cells recovered from the BAL were also observed in all C60-exposed rats, regardless of the level of exposure. Overall, more severe pulmonary effects were observed for nano-C60 than for micro-C60 for mass-based exposure comparisons. However, for surface-area-based exposures, more severe pulmonary effects were observed for micro-C60 than for nano-C60, highlighting the importance of dosimetry when evaluating toxicity between nano- and microparticles.

  • Differential pro-inflammatory effects of metal oxide nanoparticles and their soluble ions in vitro and in vivo; zinc and copper nanoparticles, but not their ions, recruit eosinophils to the lungs.
    Nanotoxicology (IF 5.955) Pub Date : 2011-02-22
    Wan-Seob Cho,Rodger Duffin,Craig A Poland,Albert Duschl,Gertie Janneke Oostingh,William Macnee,Mark Bradley,Ian L Megson,Ken Donaldson

    Abstract Nickel, zinc, and copper oxide nanoparticles (NiONP, ZnONP, and CuONP) and their aqueous extracts (AEs) were applied to A549 lung epithelial cells to determine the cytotoxicity, IL-8 production, and activation of transcription factors. Nanoparticles (NPs) and their AEs were also instilled into rat lungs to evaluate acute and chronic inflammatory effects. In vitro AEs had specific effects; for example NiOAE had no effect and ZnOAE affected all parameters measured. NPs themselves all had cytotoxic effects but only ZnONP and CuONP impacted pro-inflammatory endpoints. The inflammatory cells in the BAL were also different from AEs and NPs with ZnONP and CuONP recruiting eosinophils and neutrophils whilst ZnOAE and CuOAE elicited only mild neutrophilic inflammation that had resolved by four weeks. NiONP recruited neutrophils only whilst NiOAE did not cause any inflammation. Understanding differences in the toxic role of the ionic components of metal oxide NPs will contribute to full hazard identification and characterisation.

  • Assessment of cellular toxicity of TiO2 nanoparticles for cardiac tissue engineering applications.
    Nanotoxicology (IF 5.955) Pub Date : 2010-09-23
    Hedeer Jawad,Aldo R Boccaccini,Nadire N Ali,Sian E Harding

    Because of the increased use of titanium dioxide (TiO2) nanoparticles (NPs) in tissue engineering (TE), and in new constructs for cardiac TE, their effect was studied on three relevant cell types: Adult rat ventricular cardiomyocytes, human embryonic stem cell-derived cardiomyocytes (hESC-CM) and fibroblasts. For adult rat myocytes, 10 μg/mL TiO2 NPs showed no significant effect on myocyte survival over 24 h or acute myocyte contractility. Increasing the concentration to 100 μg/mL was seen to reduce contraction amplitude (p < 0.05). For hESC-CM, 10 μg/mL TiO2 reduced the beating rate significantly by 24 h. No arrhythmias or cessation of beating were observed in either cell type. Culturing fibroblasts in 5-150 μg/mL TiO2 significantly reduced cell proliferation at day 4 and increased cell death. We conclude that there may be modest but potentially adverse effects of TiO2 NPs if used in fast degrading polymers for myocardial tissue engineering (MTE) applications.

  • Development and haematotoxicological evaluation of doped hydroxyapatite based multimodal nanocontrast agent for near-infrared, magnetic resonance and X-ray contrast imaging.
    Nanotoxicology (IF 5.955) Pub Date : 2011-07-26
    Anusha Ashokan,Parwathy Chandran,Aparna R Sadanandan,Chaitanya K Koduri,Archana P Retnakumari,Deepthy Menon,Shantikumar Nair,Manzoor Koyakutty

    Multimodal molecular imaging provides both anatomical and molecular information, aiding early stage detection and better treatment planning of diseased conditions. Here, we report development and nanotoxicity evaluation of a novel hydroxyapatite nanoparticle (nHAp) based multimodal contrast agent for combined near-infrared (NIR), MR and X-ray imaging. Under optimised wet-chemical conditions, we achieved simultaneous doping of nHAp (size ∼50 nm) with indocyanine green and Gd(3+) contributing to NIR contrast (∼750-850 nm), paramagnetic behaviour and X-ray absorption suitable for NIR, MR and X-ray contrast imaging, respectively. Haematocompatibility studies using stem cell viability, haemolysis, platelet activation, platelet aggregation and coagulation time analysis indicated excellent compatibility of doped nHAp (D-nHAp). Further, the immunogenic function studies using human lymphocytes (in vitro) showed that D-nHAp caused no adverse effects. Collectively, our studies suggest that D-nHAp with excellent biocompatibility and multifunctional properties is a promising nanocontrast agent for combined NIR, MR and X-ray imaging applications.

  • Biodistribution and biocompatibility of passion fruit-like nano-architectures in zebrafish.
    Nanotoxicology (IF 5.955) Pub Date : 2018-08-23
    Marta d'Amora,Domenico Cassano,Salvador Pocoví-Martínez,Silvia Giordani,Valerio Voliani

    Passion fruit-like nano-architectures (NAs) are all-in-one platforms of increasing interest for the translation of metal nanoparticles into clinics. NAs are nature-inspired disassembling inorganic theranostics, which jointly combine most of the appealing behaviors of noble metal nanoparticles with their potential organism excretion. Despite their unique and promising properties, NAs in vivo interactions and potential adverse effects have not yet been investigated. In this study, we employ zebrafish (Danio Rerio) to assess the development toxicity of NAs as well as their uptake and bioaccumulation at different stages of growth. The evaluation of multiple endpoints related to the toxicity clearly indicates that NAs do not induce mortality, developmental defects, or alterations on the hatching rate and behavior of zebrafish. Moreover, the analysis of nanostructures uptake and biodistribution demonstrates that NAs are successfully internalized and present a specific localization. Overall, our results demonstrate that NAs are able to pass through the embryos chorion and accumulate in specific tissues, exhibiting an impressive biocompatibility.

  • Disaggregation of gold nanoparticles by Daphnia magna.
    Nanotoxicology (IF 5.955) Pub Date : 2018-07-29
    Karin Mattsson,Ruben Aguilar,Oscar Torstensson,Diana Perry,Katja Bernfur,Sara Linse,Lars-Anders Hansson,Karin S Åkerfeldt,Tommy Cedervall

    The use of manufactured nanomaterials is rapidly increasing, while our understanding of the consequences of releasing these materials into the environment is still limited and many questions remain, for example, how do nanoparticles affect living organisms in the wild? How do organisms adapt and protect themselves from exposure to foreign materials? How does the environment affect the performance of nanoparticles, including their surface properties? In an effort to address these crucial questions, our main aim has been to probe the effects of aquatic organisms on nanoparticle aggregation. We have, therefore, carried out a systematic study with the purpose to disentangle the effects of the freshwater zooplankter, Daphnia magna, on the surface properties, stability, and aggregation properties of gold (Au) nanoparticles under different aqueous conditions as well as identified the proteins bound to the nanoparticle surface. We show that Au nanoparticles aggregate in pure tap water, but to a lesser extent in water that either contains Daphnia or has been pre-conditioned with Daphnia. Moreover, we show that proteins generated by Daphnia bind to the Au nanoparticles and create a modified surface that renders them less prone to aggregation. We conclude that the surrounding milieu, as well as the surface properties of the original Au particles, are important factors in determining how the nanoparticles are affected by biological metabolism. In a broader context, our results show how nanoparticles released into a natural ecosystem become chemically and physically altered through the dynamic interactions between particles and organisms, either through biological metabolism or through the interactions with biomolecules excreted by organisms into the environment.

  • Gold nanoparticles ingested by oyster larvae are internalized by cells through an alimentary endocytic pathway.
    Nanotoxicology (IF 5.955) Pub Date : 2018-07-13
    Seta Noventa,Christian Hacker,Ana Correia,Claudia Drago,Tamara Galloway

    The biological fate of nanoparticles (NPs) taken up by organisms from their environment is a crucial issue for assessing ecological hazard. Despite its importance, it has scarcely been addressed due to the technical difficulties of doing so in whole organism in vivo studies. Here, by using transmission electron microscopy and energy dispersive X-ray spectroscopy (TEM-EDS), we describe the key aspects that characterize the interaction between an aquatic organism of global ecological and economic importance, the early larval stage of the Japanese oyster (Crassostrea gigas), and model gold NPs dispersed in their environment. The small size of the model organism allowed for a high-throughput visualization of the subcellular distribution of NPs, providing a comprehensive and robust picture of the route of uptake, mechanism of cellular permeation, and the pathways of clearance counterbalancing bioaccumulation. We show that NPs are ingested by larvae and penetrate cells through alimentary pinocytic/phagocytic mechanisms. They undergo intracellular digestion and storage inside residual bodies, before excretion with feces or translocation to phagocytic coelomocytes of the visceral cavity for potential extrusion or further translocation. Our mechanistically-supported findings highlight the potential of oyster larvae and other organisms which feature intracellular digestion processes to be exposed to man-made NPs and thus any risks associated with their inherent toxicity.

  • Cationic polystyrene nanoparticle and the sea urchin immune system: biocorona formation, cell toxicity, and multixenobiotic resistance phenotype.
    Nanotoxicology (IF 5.955) Pub Date : 2018-06-28
    L F Marques-Santos,G Grassi,E Bergami,C Faleri,T Balbi,A Salis,G Damonte,L Canesi,I Corsi

    In order to assess the impact of nanoplastics on marine species, polystyrene nanoparticles (PS NPs) have been largely used as model particles. Here we studied the effects of 50 nm amino-modified PS-NH2 on Mediterranean sea urchin Paracentrotus lividus immune system cells (coelomocytes) in the presence of celomic fluid (CF) and at different NP concentrations (1, 5, 10, and 25 μg mL-1) and experimental conditions (absence or presence of EDTA). PS-NH2 acquired a protein corona once incubated with CF, dominated by the toposome precursor protein (TPP). In short-term cultures, a significant concentration- and time-dependent decrease in lysosomal membrane stability and apoptotic-like nuclear alterations were observed in phagocytes upon exposure to PS-NH2 (10 and 25 µg mL-1) in CF but they resulted abolished in the presence of EDTA confirming the role of TPP in triggering PS-NH2-coelomocytes interaction and toxicity. PS-NH2 did not alter MXR phenotype but the observed dose-dependent decrease in calcein accumulation suggests the ability of PS-NH2 to affect pump's efflux activity. Overall results encourage additional studies on positively charged nanoplastics, since the observed effects on sea urchin coelomocytes as well as the TPP corona formation might represent a first step for addressing their impact on sensitive marine species.

  • Silver nanoparticles inhibit neural induction in human induced pluripotent stem cells.
    Nanotoxicology (IF 5.955) Pub Date : 2018-06-16
    Shigeru Yamada,Daiju Yamazaki,Yasunari Kanda

    Silver nanoparticles (AgNPs) have been widely used as consumer products due to their antibacterial activities. Despite their extensive use, AgNPs have been reported to cause various types of cytotoxicity, including neurotoxicity. However, the potential action of AgNPs on early fetal development has not been elucidated. This study determined the effects of AgNPs on neural induction in human induced pluripotent stem cells (iPSCs), used as a model for human fetal stage development. It was observed that exposure to AgNPs reduced the expression of several neural differentiation marker genes, including OTX2, an early biomarker for neurogenesis in iPSCs. Since neural differentiation requires ATP as a source of energy, the intracellular ATP content was also measured. It was observed that AgNPs decreased intracellular ATP levels in iPSCs. Since AgNPs suppressed energy production, a critical mitochondrial function, the effects of AgNPs on mitochondrial dynamics were further studied. The results revealed that AgNPs induced mitochondrial fragmentation and reduced the level of mitochondrial fusion protein mitofusin 1 (Mfn1). Previously, we reported that knockdown of Mfn1 in iPSCs inhibited neural induction via OTX2 downregulation. This suggested that AgNPs could induce cytotoxicity, including neurodevelopmental toxicity, via Mfn1-mediated mitochondrial dysfunction in iPSCs. Thus, mitochondrial function in iPSCs can be used for assessing the cytotoxic effects associated with nanomaterials, including AgNPs.

  • Investigating oxidation state-induced toxicity of PEGylated graphene oxide in ocular tissue using gene expression profiles.
    Nanotoxicology (IF 5.955) Pub Date : 2018-06-12
    Wei Wu,Liang Yan,Siyu Chen,Qiyou Li,Zhanjun Gu,Haiwei Xu,Zheng Qin Yin

    Graphene and its derivatives are widely used for a variety of industrial, biomedical, and environmental applications. However, the potential harm caused by exposure of the eyes to graphene-based nanomaterials is scarce. Given the potential for these materials to be used in multiple applications, there is a pressing need to evaluate their ocular toxicity, and understand the relationships between their physico-chemical properties and the resulting toxicity. In this study, the toxicity of PEGylated graphene oxide (PEG-GO) with differing oxidation levels and/or surface charges (positive, negative and neutral charge) was evaluated using two in-vitro models of the eye: primary human corneal epithelial cells and human retinal capillary endothelial cells. The results showed that oxidation level, but not surface charge, had a pivotal effect on the toxicity of graphene-based nanomaterials. Typically, PEG-GO sample with a higher oxidation level caused more serious cytotoxicity than those with a lower oxidation level. Furthermore, by analysis of global gene expression profiles, we found that the foremost cellular response to PEG-GO sample with a high oxidation level was the oxidative stress response. Next, via exploring the underlying molecular mechanism of oxidative stress-induced cytotoxicity, we showed that PEG-GO sample with a high degree of oxidation induced reactive oxygen species (ROS) via NDUFB9-mediated biological pathway. This work has significant implications for design of safe graphene-based nanomaterials for biomedical applications.

  • Quantitation of cell-associated carbon nanotubes: selective binding and accumulation of carboxylated carbon nanotubes by macrophages.
    Nanotoxicology (IF 5.955) Pub Date : 2018-05-29
    Ruhung Wang,Michael Lee,Karina Kinghorn,Tyler Hughes,Ishwar Chuckaree,Rishabh Lohray,Erik Chow,Paul Pantano,Rockford Draper

    To understand the influence of carboxylation on the interaction of carbon nanotubes with cells, the amount of pristine multi-walled carbon nanotubes (P-MWNTs) or carboxylated multi-walled carbon nanotubes (C-MWNTs) coated with Pluronic® F-108 that were accumulated by macrophages was measured by quantifying CNTs extracted from cells. Mouse RAW 264.7 macrophages and differentiated human THP-1 (dTHP-1) macrophages accumulated 80-100 times more C-MWNTs than P-MWNTs during a 24-h exposure at 37 °C. The accumulation of C-MWNTs by RAW 264.7 cells was not lethal; however, phagocytosis was impaired as subsequent uptake of polystyrene beads was reduced after a 20-h exposure to C-MWNTs. The selective accumulation of C-MWNTs suggested that there might be receptors on macrophages that bind C-MWNTs. The binding of C-MWNTs to macrophages was measured as a function of concentration at 4 °C in the absence of serum to minimize the potential interference by serum proteins or temperature-dependent uptake processes. The result was that the cells bound 8.7 times more C-MWNTs than P-MWNTs, consistent with the selective accumulation of C-MWNTs at 37 °C. In addition, serum strongly antagonized the binding of C-MWTS to macrophages, suggesting that serum contained inhibitors of binding. Moreover, inhibitors of class A scavenger receptor (SR-As) reduced the binding of C-MWNTs by about 50%, suggesting that SR-As contribute to the binding and endocytosis of C-MWNTs in macrophages but that other receptors may also be involved. Altogether, the evidence supports the hypothesis that macrophages contain binding sites selective for C-MWNTs that facilitate the high accumulation of C-MWNTs compared to P-MWNTs.

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上海纽约大学William Glover