The wide use of ZnO and CuO nanoparticles in research, medicine, industry, and other fields has raised concerns about their biosafety. It is therefore unavoidable to be discharged into the sewage treatment system. Due to the unique physical and chemical properties of ZnO NPs and CuO NPs, it may be toxic to the members of the microbial community and their growth and metabolism, which in turn affects the stable operation of sewage nitrogen removal. This study summarizes the toxicity mechanism of two typical metal oxide nanoparticles (ZnO NPs and CuO NPs) to nitrogen removal microorganisms in sewage treatment systems. Furthermore, the factors affecting the cytotoxicity of metal oxide nanoparticles (MONPs) are summarized. This review aims to provide a theoretical basis and support for the future mitigating and emergent treatment of the adverse effects of nanoparticles on sewage treatment systems.
Wastewater/toxicity* ; Sewage/chemistry* ; Zinc Oxide/chemistry* ; Waste Disposal, Fluid ; Nanoparticles/chemistry* ; Metal Nanoparticles/chemistry* ; Nitrogen/metabolism* ; Water Purification

OBJECTIVE: To comparatively study the toxicity of four metal-containing nanoparticles (MNPs) and their chemical counterparts to the air-blood barrier (ABB) permeability using an in vitro model. METHODS: ABB model, which was developed via the co-culturing of A549 and pulmonary capillary endothelium, was exposed to spherical CuO-NPs (divided into CuO-40, CuO-80, and CuO-100 based on particle size), nano-Al2O3 (sheet and short-rod-shaped), nano-ZnO, nano-PbS, CuSO4, Al2(SO4)3, Zn(CH3COO)2, and Pb(NO3)2 for 60 min. Every 10 min following exposure, the cumulative cleared volume (ΔTCL) of Lucifer yellow by the model was calculated. A clearance curve was established using linear regression analysis of ΔTCL versus time. Permeability coefficient (P) was calculated based on the slope of the curve to represent the degree of change in the ABB permeability. RESULTS: The results found the increased P values of CuO-40, CuO-80, sheet, and short-rod-shaped nano-Al2O3, Al2(SO4)3, and Pb(NO3)2. Among them, small CuO-40 and CuO-80 were stronger than CuO-100 and CuSO4; no difference was observed between Al2(SO4)3 and sheet and short-rod-shaped nano-Al2O3; and nano-PbS was slightly weaker than Pb(NO3)2. So clearly the MNPs possess diverse toxicity. CONCLUSION ABB permeability abnormality means pulmonary toxicity potential. More studies are warranted to understand MNPs toxicity and ultimately control the health hazards.
A549 Cells ; Blood-Air Barrier ; metabolism ; Epithelium ; metabolism ; Humans ; Metal Nanoparticles ; toxicity ; Particle Size ; Permeability

To address the controversial issue of the toxicity of dental alloys and silver nanoparticles in medical applications, an in vivo-like LO2 3-D model was constructed within polyvinylidene fluoride hollow fiber materials to mimic the microenvironment of liver tissue. The use of microscopy methods and the measurement of liver-specific functions optimized the model for best cell performances and also proved the superiority of the 3-D LO2 model when compared with the traditional monolayer model. Toxicity tests were conducted using the newly constructed model, finding that four dental castings coated with silver nanoparticles were toxic to human hepatocytes after cell viability assays. In general, the toxicity of both the castings and the coated silver nanoparticles aggravated as time increased, yet the nanoparticles attenuated the general toxicity by preventing metal ion release, especially at high concentrations.
Cells, Cultured ; Dental Casting Technique ; Hepatocytes/drug effects* ; Humans ; Metal Nanoparticles/toxicity* ; Silver/toxicity* ; Toxicity Tests

OBJECTIVEThis paper aims to elucidate the combined toxicity of magnetite nanoparticles/Chromium [MNPs/Cr(VI)] adducts.

METHODSThe HEK293 cell was exposed to either Cr(VI) or MNPs, or their adducts MNPs/Cr(VI). The cytotoxicity was evaluated by assessing the cell viability, apoptosis, oxidative stress induction, and cellular uptake.

RESULTSThe toxicity of formed adducts is significantly reduced when compared to Cr(VI) anions. We found that the cellular uptake of MNPs/Cr(VI) adduct was rare, only few particles were endocytosed from the extracellular fluid and not accumulated in the cell nucleus. On the other hand, the Cr(VI) anions entered cells, generated oxidative stress, induced cell apoptosis, and caused cytotoxicity.

CONCLUSIONThe results showed minor effects of the nanoadducts on the tested cells and supported that magnetite nanoparticles could be implemented in the wastewater treatment process in which advantageous properties outweigh the risks.

Chromium ; chemistry ; toxicity ; Environmental Restoration and Remediation ; methods ; Ferrosoferric Oxide ; chemistry ; toxicity ; HEK293 Cells ; Humans ; Metal Nanoparticles ; chemistry ; toxicity

OBJECTIVES: With recent advances in nanoparticle manufacturing and applications, potential exposure to nanoparticles in various settings is becoming increasing likely. No investigation has yet been performed to assess whether respiratory tract exposure to cerium oxide (CeO2) nanoparticles is associated with alterations in protein signaling, inflammation, and apoptosis in rat lungs. METHODS: Specific-pathogen-free male Sprague-Dawley rats were instilled with either vehicle (saline) or CeO2 nanoparticles at a dosage of 7.0 mg/kg and euthanized 1, 3, 14, 28, 56, or 90 days after exposure. Lung tissues were collected and evaluated for the expression of proteins associated with inflammation and cellular apoptosis. RESULTS: No change in lung weight was detected over the course of the study; however, cerium accumulation in the lungs, gross histological changes, an increased Bax to Bcl-2 ratio, elevated cleaved caspase-3 protein levels, increased phosphorylation of p38 MAPK, and diminished phosphorylation of ERK-1/2-MAPK were detected after CeO2 instillation (p<0.05). CONCLUSIONS: Taken together, these data suggest that high-dose respiratory exposure to CeO2 nanoparticles is associated with lung inflammation, the activation of signaling protein kinases, and cellular apoptosis, which may be indicative of a long-term localized inflammatory response.
Animals ; Apoptosis/*drug effects ; Caspase 3/metabolism ; Cerium/chemistry ; Inflammation ; Lung/*drug effects/metabolism/pathology ; Male ; Metal Nanoparticles/chemistry/*toxicity ; Mitogen-Activated Protein Kinase 1/metabolism ; Mitogen-Activated Protein Kinase 3/metabolism ; Mitogen-Activated Protein Kinases/*metabolism ; Phosphorylation/drug effects ; Proto-Oncogene Proteins c-bcl-2/metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction/*drug effects ; bcl-2-Associated X Protein/metabolism ; p38 Mitogen-Activated Protein Kinases/metabolism

Although metal nano materials have been widely used in various fields, the potential risks of it still could not be neglected. In this paper, the effects and mechanisms of genotoxicity caused by different nano materials were discussed. Human body can be exposed to metal nano materials through multiple pathways, metals nano follow the blood stream in circulatory system and distribute to organs. Metal nano particles are mainly uptaken into cells by endocytosis, and direct or indirect damages to genes can be induced by these particles after metabolism in cells. These damages would affect the course of cell cycle and the stability of the genome, resulting in gene mutation or chromosome aberration, and even leading to the death or malignant transformation of cells.
Cell Transformation, Neoplastic ; chemically induced ; DNA Damage ; Humans ; Metal Nanoparticles ; toxicity

Zinc oxide nanoparticle (nano-ZnO) has a size between 1 and 100 nm. Nano-ZnO has some special effects, such as small size effect, surface effect, quantum size effect, which makes it different from the ordinary ZnO, and is widely used in rubber industry, food processing, cosmetics and pharmaceutical fields. It has been reported that nano-ZnO has toxic effects in vitro and in vivo, but the mechanism of toxicity is still unclear. Therefore, it is important to evaluate the safety nano-ZnO by studying its biological toxic effects and related mechanisms. In this paper, we summarize the characterization, ingestion pathway, metabolism, systematic toxicity of nano-ZnO and its mechanisms, which may provide us with new strategy for the toxic research of nano-ZnO.
Animals ; Humans ; Metal Nanoparticles ; toxicity ; Zinc Oxide ; toxicity

OBJECTIVETo synthesize silver nanopaticles from leaves extract of Eucalyptus chapmaniana (E. chapmaniana) and test the antimicrobial of the nanoparticles against different pathogenic bacteria, yeast and its toxicity against human acute promyelocytic leukemia (HL-60) cell line.

METHODSTen milliliter of leaves extract was mixed with 90 mL of 0.01 mmol/mL or 0.02 mmol/mL aqueous AgNO3 and exposed to sun light for 1 h. A change from yellowish to reddish brown color was observed. Characterization using UV-vis spectrophotometery and X-ray diffraction analysis were performed. Antimicrobial activity against six microorganisms was tested using well diffusion method and cytoxicity test using 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole was obtained on the human leukemia cell line (HL-60).

RESULTSUV-vis spectral analysis showed silver surface plasmon resonance band at 413 nm. X-ray diffraction showed that the particles were crystalline in nature with face centered cubic structure of the bulk silver with broad beaks at 38.50° and 44.76°. The synthesized silver nanoparticles efficiently inhibited various pathogenic organisms and reduced viability of the HL-60 cells in a dose-dependent manner.

CONCLUSIONSIt has been demonstrated that the extract of E. chapmaniana leaves are capable of producing silver nanoparticles extracellularly and the Ag nanoparticles are quite stable in solution. Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial and anticancer activity of these particles.

Anti-Infective Agents ; chemical synthesis ; pharmacology ; toxicity ; Bacteria ; drug effects ; Candida albicans ; drug effects ; Cell Line, Tumor ; Eucalyptus ; chemistry ; Humans ; Metal Nanoparticles ; chemistry ; toxicity ; Plant Extracts ; chemistry ; pharmacology ; toxicity ; Plant Leaves ; chemistry ; Silver ; pharmacology ; toxicity

OBJECTIVETo study the biological effects of nanoscale copper oxide (nCuO), zinc oxide (nZnO), cerium dioxide (nCeO2) and their mixtures on Carassius auratus.

METHODSJuvenile fish (Carassius auratus) were exposed to aqueous suspensions of nCuO, nZnO, and nCeO2 (alone and in mixtures) at concentrations of 20, 40, 80, 160, and 320 mg/L. The biomarkers-acetylcholinesterase (AChE) in brain, sodium/potassium-activated ATPase (Na+/K+-ATPase) in gill, and superoxide dismutase (SOD) and catalase (CAT) in liver-were determined after 4 days of exposure. Integrated biomarker response (IBR) was calculated by combining multiple biomarkers into a single value.

RESULTSAChE and SOD activities were significantly inhibited by all test metal oxide nanoparticles (NPs) at high concentrations (⋝160 mg/L) with the exception of nCeO2. Na+/K+-ATPase induction exhibited bell-shaped concentration-response curves. CAT activity was significantly inhibited at concentrations equal to or higher than 160 mg/L. The order of IBR values was nCeO2 ≈ nZnO/nCeO2 ≈ nCuO/nCeO2 < nCuO/nZnO/nCeO2 < nZnO < nCuO < nCuO/nZnO. The joint effect seemed to be synergistic for nCuO/nZnO mixtures, additive for the ternary mixture and less than additive or antagonistic for the binary mixtures containing nCeO2.

CONCLUSIONConcentration-dependent changes of enzymatic activities (AChE, Na+/K+-ATPase, SOD, and CAT) were observed in fish exposed to nanoscale metal oxides. IBR analysis allowed good discrimination between the different exposures and might be a useful tool for the quantification of integrated negative effects induced by NPs toward fish.

Acetylcholinesterase ; metabolism ; Animals ; Biomarkers ; metabolism ; Brain ; drug effects ; enzymology ; Cerium ; toxicity ; Copper ; toxicity ; Gills ; drug effects ; enzymology ; Goldfish ; metabolism ; Liver ; drug effects ; enzymology ; Metal Nanoparticles ; toxicity ; Random Allocation ; Sodium-Potassium-Exchanging ATPase ; metabolism ; Superoxide Dismutase ; metabolism ; Toxicity Tests ; Water Pollutants, Chemical ; toxicity ; Zinc Oxide ; toxicity

This study aimed to characterize and MRI track the mesenchymal stem cells labeled with chitosan-coated superparamagnetic iron oxide (Chitosan-SPIO). Chitosan-SPIO was synthesized from a mixture of FeCl2 and FeCl3. The human bone marrow derived mesenchymal stem cells (hBM-MSC) were labeled with 50 microg Fe/mL chitosan-SPIO and Resovist. The labeling efficiency was assessed by iron content, Prussian blue staining, electron microscopy and in vitro MR imaging. The labeled cells were also analyzed for cytotoxicity, phenotype and differentiation potential. Electron microscopic observations and Prussian blue staining revealed 100% of cells were labeled with iron particles. MR imaging was able to detect the labeled MSC successfully. Chitosan-SPIO did not show any cytotoxicity up to 200 microgram Fe/mL concentration. The labeled stem cells did not exhibit any significant alterations in the surface markers expression or adipo/osteo/chondrogenic differentiation potential when compared to unlabeled control cells. After contralateral injection into rabbit ischemic brain, the iron labeled stem cells were tracked by periodical in vivo MR images. The migration of cells was also confirmed by histological studies. The novel chitosan-SPIO enables to label and track MSC for in vivo MRI without cellular alteration.
Animals ; Brain Ischemia/chemically induced/pathology/therapy ; Cell Differentiation ; Chitosan/*chemistry ; Coordination Complexes/*chemistry/toxicity ; Ferric Compounds/*chemistry ; Humans ; Magnetic Resonance Imaging ; Magnetics ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells/*chemistry/cytology ; Metal Nanoparticles/*chemistry ; Phenotype ; Rabbits