[Show abstract][Hide abstract] ABSTRACT: Monocytes/macrophages are important constituents of the innate immune system. Monocyte-macrophage differentiation is not only crucial for innate immune responses, but is also related to some cardiovascular diseases. Silver nanoparticles (AgNPs) are one of the most widely used nanomaterials because of their broad-spectrum antimicrobial properties. However, the effect of AgNPs on the functions of blood monocytes is scarcely reported. Here, we report the impedance effect of AgNPs on THP-1 monocyte differentiation, and that this effect was mediated by autophagy blockade and lysosomal impairment. Firstly, AgNPs inhibit phorbol 12-myristate 13-acetate (PMA)-induced monocyte differentiation by down-regulating both expression of surface marker CD11b and response to lipopolysaccharide (LPS) stimulation. Secondly, autophagy is activated during PMA-induced THP-1 monocyte differentiation, and the autophagy inhibitor chloroquine (CQ) can inhibit this process. Thirdly, AgNPs block the degradation of the autophagy substrate p62 and induce autophagosome accumulation, which demonstrates the blockade of autophagic flux. Fourthly, lysosomal impairments including alkalization and decrease of lysosomal membrane stability were observed in AgNP-treated THP-1 cells. In conclusion, we demonstrate that the impedance of monocyte-macrophage differentiation by AgNPs is mediated by autophagy blockade and lysosomal dysfunction. Our results suggest that crosstalk exists in different biological effects induced by AgNPs.
[Show abstract][Hide abstract] ABSTRACT: Nanomaterials (NMs) display many unique and useful physico-chemical properties. However, reliable approaches are needed for risk assessment of NMs. The present study was performed in the FP7-MARINA project, with the objective to identify and evaluate in vitro test methods for toxicity assessment in order to facilitate the development of an intelligent testing strategy (ITS). Six representative oxide NMs provided by the EC-JRC Nanomaterials Repository were tested in nine laboratories. The in vitro toxicity of NMs was evaluated in 12 cellular models representing 6 different target organs/systems (immune system, respiratory system, gastrointestinal system, reproductive organs, kidney and embryonic tissues). The toxicity assessment was conducted using 10 different assays for cytotoxicity, embryotoxicity, epithelial integrity, cytokine secretion and oxidative stress. Thorough physico-chemical characterization was performed for all tested NMs. Commercially relevant NMs with different physico-chemical properties were selected: two TiO2 NMs with different surface chemistry - hydrophilic (NM-103) and hydrophobic (NM-104), two forms of ZnO - uncoated (NM-110) and coated with triethoxycapryl silane (NM-111) and two SiO2 NMs produced by two different manufacturing techniques - precipitated (NM-200) and pyrogenic (NM-203). Cell specific toxicity effects of all NMs were observed; macrophages were the most sensitive cell type after short-term exposures (24-72h) (ZnO>SiO2>TiO2). Longer term exposure (7 to 21 days) significantly affected the cell barrier integrity in the presence of ZnO, but not TiO2 and SiO2, while the embryonic stem cell test (EST) classified the TiO2 NMs as potentially 'weak-embryotoxic' and ZnO and SiO2 NMs as 'non-embryotoxic'. A hazard ranking could be established for the representative NMs tested (ZnO NM-110 > ZnO NM-111 > SiO2 NM-203 > SiO2 NM-200 > TiO2 NM-104 > TiO2 NM-103). This ranking was different in the case of embryonic tissues, for which TiO2 displayed higher toxicity compared with ZnO and SiO2. Importantly, the in vitro methodology applied could identify cell- and NM-specific responses, with a low variability observed between different test assays. Overall, this testing approach, based on a battery of cellular systems and test assays, complemented by an exhaustive physico-chemical characterization of NMs, could be deployed for the development of an ITS suitable for risk assessment of NMs. This study also provides a rich source of data for modeling of NM effects.
PLoS ONE 05/2015; 10(5). DOI:10.1371/journal.pone.0127174 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To predict potential medical value or toxicity of nanoparticles (NPs), it is necessary to understand the chemical transformation during intracellular processes of NPs. However, it is a grand challenge to capture a high-resolution image of metallic NPs in a single cell and the chemical information of intracellular NPs. Here, by integrating synchrotron radiation-beam transmission X-ray microscopy (SR-TXM) and SR-X-ray absorption near edge structure (SR-XANES) spectrometry, we successfully capture the 3D distribution of silver NPs (AgNPs) inside a single human monocyte (THP-1), associated with the chemical transformation of silver. The results reveal that the cytotoxicity of AgNPs is largely due to the chemical transformation of particulate silver from elemental silver (Ag0)n, to Ag+ ions and Ag-O-, then Ag-S- species. These results provide direct evidence in the long-lasting debate on whether the nanoscale or the ionic form dominates the cytotoxicity of silver nanoparticles. Further, the present approach provides an integrated strategy capable of exploring the chemical origins of cytotoxicity of metallic nanoparticles.
[Show abstract][Hide abstract] ABSTRACT: Fullerene derivatives have attracted extensive attention in biomedical fields and polyhydroxyl fullerene (fullerenol), a water-soluble fullerene derivative, is demonstrated as a powerful antioxidant. To further assess their anti-aging and anti-stress potential, we employed Caenorhabditis elegans (C. elegans) as a model organism to evaluate the effects of fullerenol on the growth, development, behavior and anti-stress ability in vivo. The data show that fullerenol has no obviously toxic effect on nematodes and can delay C. elegans aging progress under normal condition. Further studies demonstrate that fullerenol attenuates endogenous levels of reactive oxygen species and provides protection to C. elegans under stress conditions by up-regulating stress-related genes in a DAF-16 depend manner and improving lifespan. In summary, our data suggest that fullerenol might be a safe and reasonable anti-aging candidate with great potential in vivo.
[Show abstract][Hide abstract] ABSTRACT: Engineered gold nanoparticles (AuNPs) have recently drawn an increased interest in disease diagnostics and therapies. However, reports on detailed studies of AuNPs regarding their pharmacodynamics, pharmacokinetics, biodistribution, metabolism and potential toxicity are limited. It is common knowledge that the in vivo behavior and fate of various AuNPs are influenced by their surface and size. However, a comprehensive description and understanding of all variables is crucial for their further development toward potential clinical use. In this article, we describe the pharmacokinetics and biodistribution of mesoporous silica-coated gold nanorods functionalized with polyethylene glycol or bovine serum albumin (AuNR@SiO2-PEG and AuNR@SiO2-BSA, respectively) in tumor-bearing balb/c mice. To gain further insight into the pharmacokinetics, biodistribution and tumor uptake, we also compare the results with BSA functionalized gold nanorods (AuNR-BSA) and gold clusters (AuNC-BSA). The results reveal that AuNR@SiO2-PEG have the longest blood half-life and the maximum percentage content in the tumor at 24 h and 3 days compared to other AuNPs. AuNR@SiO2-PEG, AuNR@SiO2-BSA and AuNR-BSA had primarily accumulated in the liver and spleen without apparent metabolism after 3 days, while the content of AuNC-BSA in the liver, spleen and kidneys showed an obvious decrease, indicating a size-dependent metabolism process. Our results demonstrate how to manipulate the size and surface chemistry of AuNPs to prolong their blood circulation time, improve delivery into target organs and achieve a safer design of nanomedicines.
[Show abstract][Hide abstract] ABSTRACT: With rapid development of novel nanomaterials (NMs), the state of the art technologies with high efficiency and high-throughput characteristics had been applied for nanosafety evaluation. Highcontent screening (HCS), a cell based multi-parametric image analysis technique, was adopted
in the evaluation of eight different NMs in this study. A set of different endpoints including reactive oxygen species (ROS) production, Ca2+ transient, mitochondrial membrane potential (MMP) and cellular pH levels were checked in human bronchial epithelial (16HBE) cells after incubating
with NMs for 24 hours. All NMs induced significant increase of intracellular ROS levels in 16HBE cells, although the decrease of cell viability was only found in Ag and ZnO NMs-treated cells. MMP level had a dose-response decrease in Ag, ZnO and CeO2 NMs-treated cells, while showed
a significant increase in TiO2 NMs-treated cells. All tested NMs showed significant up-regulation of cellular lysosomal pH levels. However, none of NMs caused significant changes in cellular Ca2+ level at 24-hour time point. HCS allows for efficient and reliable screening
of multiple responses of cells simultaneously within one screen test, which can avoid the problematic interpretation of investigations when carried on a single toxicological endpoint. Therefore, the present data provide insight and inspiration that HCS is an effective and powerful method for
image-based assessments with a broad set of biological endpoints in toxicity evaluation of nanomaterials.
Journal of Nanoscience and Nanotechnology 02/2015; 15(2). DOI:10.1166/jnn.2015.9032 · 1.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A number of studies have demonstrated that MWCNTs induce granuloma formation and fibrotic responses in vivo, and it has been recently reported that MWCNT-induced macrophage activation and subsequent TGF-β secretion contribute to pulmonary fibrotic responses. However, their direct effects against alveolar type-II epithelial cells and fibroblasts and the corresponding underlying mechanisms remain largely unaddressed. Here, MWCNTs are reported to be able to directly promote fibroblast-to-myofibroblast conversion and the epithelial-mesenchymal transition (EMT) through the activation of the TGF-β/Smad signaling pathway. Both of the cell transitions may play important roles in MWCNT-induced pulmonary fibrosis. Firstly, in-vivo and in-vitro data show that long MWCNTs can directly interact with fibroblasts and epithelial cells, and some of them may be uptaken into fibroblasts and epithelial cells by endocytosis. Secondly, long MWCNTs can directly activate fibroblasts and increase both the basal and TGF-β1-induced expression of the fibroblast-specific protein-1, α-smooth muscle actin, and collagen III. Finally, MWCNTs can induce the EMT through the activation of TGF-β/Smad2 signaling in alveolar type-II epithelial cells, from which some fibroblasts involved in pulmonary fibrosis are thought to originate. These observations suggest that the activation of the TGF-β/Smad2 signaling plays a critical role in the process of the fibroblast-to-myofibroblast transition and the EMT induced by MWCNTs.
Small 01/2015; 11(4). DOI:10.1002/smll.201303588 · 8.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The contemporary use of nanomedicines for cancer treatment has been largely limited to serving as carriers for existing therapeutic agents. Here, we provide definitive evidence that, the metallofullerenol nanomaterial Gd@C82(OH)22, while essentially not toxic to normal mammary epithelial cells, possesses intrinsic inhibitory activity against triple-negative breast cancer cells. Gd@C82(OH)22 blocks epithelial-to-mesenchymal transition with resultant efficient elimination of breast cancer stem cells (CSCs) resulting in abrogation of tumour initiation and metastasis. In normoxic conditions, Gd@C82(OH)22 mediates these effects by blocking TGF-β signalling. Moreover, under hypoxic conditions found in the tumour microenvironment, cellular uptake of Gd@C82(OH)22 is facilitated where it functions as a bi-potent inhibitor of HIF-1α and TGF-β activities, enhancing CSC elimination. These studies indicate that nanomaterials can be engineered to directly target CSCs. Thus, Gd-metallofullerenol is identified as a kind of non-toxic CSC specific inhibitors with significant therapeutic potential.
[Show abstract][Hide abstract] ABSTRACT: Under evolutionary pressure from chemotherapy, cancer cells develop resistance characteristics such as a low redox state, which eventually leads to treatment failures. An attractive option for combatting resistance is producing a high concentration of produced free radicals in situ. Here, we report the production and use of dispersible hollow carbon nanospheres (HCSs) as a novel platform for delivering the drug doxorubicine (DOX) and generating additional cellular reactive oxygen species using near-infrared laser irradiation. These irradiated HCSs catalyzed sufficiently persistent free radicals to produce a large number of heat shock factor-1 protein homotrimers, thereby suppressing the activation and function of resistance-related genes. Laser irradiation also promoted the release of DOX from lysosomal DOX@HCSs into the cytoplasm so that it could enter cell nuclei. As a result, DOX@HCSs reduced the resistance of human breast cancer cells (MCF-7/ADR) to DOX through the synergy among photothermal effects, increased generation of free radicals, and chemotherapy with the aid of laser irradiation. HCSs can provide a unique and versatile platform for combatting chemotherapy-resistant cancer cells. These findings provide new clinical strategies and insights for the treatment of resistant cancers.
Journal of the American Chemical Society 01/2015; 137(5):1947–1955. DOI:10.1021/ja511560b · 12.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The tremendous requirements of the market for carbon nanotubes lead to their massive production that presents an increasing risk through occupational exposure. Lung deposition of carbon nanotubes is known to cause acute localized pulmonary adverse effects. However, systemic cardiovascular damages associated with acute pulmonary lesion have not been thoroughly addressed. Four kinds of multiwall carbon nanotubes (MWCNTs) with different length or iron content were used to explore the potential sub-chronic toxicological effects in spontaneously hypertensive (SH) rats and normotensive control Wistar-Kyoto (WKY) rats after intratracheal instillation. The pulmonary toxicity and cardiovascular effects were assessed at days 7 and 30 post exposure. Compared to the WKY rats, transient influences on blood pressure and up to 30 days persistent decrease in the heart rate of SH rats were found by electrocardiogram monitoring. The sub-chronic toxicity especially the sustained inflammation of the pulmonary and cardiovascular system was disclosed at days 7 and 30 post-instillation in both SH and WKY rat models. Histopathological results showed obvious morphological lesions in abdominal arteries of SH rats at day 30 post exposure. Furthermore, MWCNTs penetrated the lung blood-gas barrier and accumulated in liver, kidneys and spleen, but not in heart, brain and aorta of SH rats. It is noted that these negative effects on higher blood pressure manifested severely in the SH rats. Our results suggest that more attention should be paid on the long term toxic effects of MWCNTs and particularly occupationally exposed workers with preexisting cardiovascular diseases.
Chemical Research in Toxicology 01/2015; 28(3). DOI:10.1021/tx5004003 · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Health impacts of inhalation exposure to engineered nanomaterials have attracted increasing attention. In this paper, integrated analytical techniques with high sensitivity were used to study the brain translocation and potential impairment induced by intranasally instilled copper nanoparticles (CuNPs). Mice were exposed to CuNPs in three doses (1, 10, 40 mg/kg bw). The body weight of mice decreased significantly in the 10 and 40 mg/kg group (p < 0.05) but recovered slightly within exposure duration. Inductively coupled plasma mass spectrometry (ICP-MS) analysis showed that CuNPs could enter the brain. Altered distribution of some important metal elements were observed by synchrotron radiation X-ray fluorescence (SRXRF). H&E Staining and immunohistochemical analysis showed that CuNPs produced damages to nerve cells and astrocyte might be the one of the potential targets of CuNPs. The changes of neurotransmitter levels in different brain regions demonstrate that the dysfunction occurred in exposed groups. These data indicated that CuNPs could enter the brain after nasal inhalation and induced damages to the central nervous system (CNS). Integration of effective analytical techniques for systematic investigations is a promising direction to better understand the biological activities of nanomaterials.
[Show abstract][Hide abstract] ABSTRACT: Coronaviruses belong to the family Coronaviridae, which primarily cause infection of the upper respiratory and gastrointestinal tract of hosts. Transmissible gastroenteritis virus (TGEV) is an economically significant coronavirus that can cause severe diarrhea in pigs. Silver nanomaterials (Ag NMs) have attracted great interests in recent years due to their excellent anti-microorganism properties. Herein, four representative Ag NMs including spherical Ag nanoparticles (Ag NPs, NM-300), two kinds of silver nanowires (XFJ011) and silver colloids (XFJ04) were selected to study their inhibitory effect on TGEV-induced host cell infection in vitro. Ag NPs were uniformly distributed, with particle sizes less than 20 nm by characterization of environmental scanning electron microscope and transmission electron microscope. Two types of silver nanowires were 60 nm and 400 nm in diameter, respectively. The average diameter of the silver colloids was approximately 10 nm. TGEV infection induced the occurring of apoptosis in swine testicle (ST) cells, down-regulated the expression of Bcl-2, up-regulated the expression of Bax, altered mitochondrial membrane potential, activated p38 MAPK signal pathway, and increased expression of p53 as evidenced by immunofluorescence assays, real-time PCR, flow cytometry and Western blot. Under non-toxic concentrations, Ag NPs and silver nanowires significantly diminished the infectivity of TGEV in ST cells. Moreover, further results showed that Ag NPs and silver nanowires decreased the number of apoptotic cells induced by TGEV through regulating p38/mitochondria-caspase-3 signaling pathway. Our data indicate that Ag NMs are effective in prevention of TGEV-mediated cell infection as a virucidal agent or as an inhibitor of viral entry and the present findings may provide new insights into antiviral therapy of coronaviruses.
[Show abstract][Hide abstract] ABSTRACT: Zinc oxide nanoparticles (ZnO NPs) have been widely used in cosmetics and sunscreens, advanced textiles, self-charging and electronic devices, the potential for human exposure and the health impact at each stage of their manufacture and use is attracting great concerns. In addition to pulmonary damage, nanoparticle exposure is also strongly correlated with the increase in incidences of cardiovascular diseases, however, their toxic potential remains largely unclear. Herein, we investigated the cellular responses and endoplasmatic reticulum (ER) stress induced by ZnO NPs in human umbilical vein endothelial cells (HUVECs) in comparison with the Zn2+ ions and CeO2 NPs. We found that the dissolved zinc ion was the most significant factor for cytotoxicity in HUVECs. More importantly, ZnO NPs at non-cytotoxic concentration, but not CeO2 NPs, can induce significant cellular ER stress response with higher expression of spliced xbp-1, chop and caspase-12 at the mRNA level, and associated ER marker proteins including BiP, Chop, GADD34, p-PERK, p-eIF2α and cleaved Caspase-12 at the protein levels. Moreover, ER stress was widely activated after treatment with ZnO NPs, while six of 84 marker genes significantly increased. ER stress response is a sensitive marker for checking the interruption of ER homeostasis by ZnO NPs. Furthermore, higher dosage of ZnO NPs (240 μM) quickly rendered ER stress response before inducing apoptosis. These results demonstrate that ZnO NPs activate ER stress-responsive pathway and the ER stress response might be used as an earlier and sensitive endpoint for nanotoxicological study.