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Comparative study on the catalytic activity of Fe-doped ZrO2 nanoparticles without significant toxicity through chemical treatment under various pH conditions.
Song, HI, Hong, JA, Lee, H, Lim, KI
Scientific reports. 2019;(1):10965
Abstract
Despite advances in the construction of catalysts based on metal oxide nanoparticles (MO NPs) for various industrial, biomedical, and daily-life applications, the biosafety concerns about these NPs still remain. Recently, the need to analyze and improve the safety of MO NPs along with attempts to enhance their catalytic performance has been strongly perceived. Here, we prepared multiple variants of Fe-doped zirconium oxide (Fe@ZrO2) NPs under different pH conditions; then, we assessed their toxicity and finally screened the variant that exhibited the best catalytic performance. To assess the NP toxicity, the prepared NPs were introduced into three types of human cells originally obtained from different body parts likely to be most affected by NPs (skin, lung, and kidney). Experimental results from conventional cellular toxicity assays including recently available live-cell imaging indicated that none of the variants exerted severe negative effects on the viability of the human cells and most NPs were intracellular localized outside of nucleus, by which severe genotoxicity is unexpected. In contrast, Fe@ZrO2 NPs synthesized under a basic condition (pH = 13.0), exhibited the highest catalytic activities for three different reactions; each was biochemical (L-cysteine oxidation) or photochemical one (4-chlorophenol degradation and OH radical formation with benzoic acid). This study demonstrates that catalytic Fe@ZrO2 NPs with enhanced activities and modest or insignificant toxicity can be effectively developed and further suggests a potential for the use of these particles in conventional chemical reactions as well as in recently emerging biomedical and daily-life nanotechnology applications.
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Comparative study of cyto- and genotoxic potential with mechanistic insights of tungsten oxide nano- and microparticles in lung carcinoma cells.
Chinde, S, Poornachandra, Y, Panyala, A, Kumari, SI, Yerramsetty, S, Adicherla, H, Grover, P
Journal of applied toxicology : JAT. 2018;(6):896-913
Abstract
The exigency of semiconductor and super capacitor tungsten oxide nanoparticles (WO3 NPs) is increasing in various sectors. However, limited information on their toxicity and biological interactions are available. Hence, we explored the underlying mechanisms of toxicity induced by WO3 NPs and their microparticles (MPs) using different concentrations (0-300 μg ml-1 ) in human lung carcinoma (A549) cells. The mean size of WO3 NPs and MPs by transmission electron microscopy was 53.84 nm and 3.88 μm, respectively. WO3 NPs induced reduction in cell viability, membrane damage and the degree of induction was size- and dose-dependent. There was a significant increase in the percentage tail DNA and micronuclei formation at 200 and 300 μg ml-1 after 24 hours of exposure. The DNA damage induced by WO3 NPs could be attributed to increased oxidative stress and inflammation through reactive oxygen species generation, which correlated with the depletion of reduced glutathione content, catalase and an increase in malondialdehyde levels. Cellular uptake studies unveiled that both the particles were attached/surrounded to the cell membrane according to their size. In addition, NP inhibited the progression of the cell cycle in the G2 /M phase. Other studies such as caspase-9 and -3 and Annexin-V-fluorescein isothiocyanate revealed that NPs induced intrinsic apoptotic cell death at 200 and 300 μg ml-1 concentrations. However, in comparison to NPs, WO3 MPs did not incite any toxic effects at the tested concentrations. Under these experimental conditions, the no-observed-significant-effect level of WO3 NPs was determined to be ≤200 μg ml-1 in A549 cells.
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Entrococcus faecalis Elimination in Root Canals Using Silver Nanoparticles, Photodynamic Therapy, Diode Laser, or Laser-activated Nanoparticles: An In Vitro Study.
Afkhami, F, Akbari, S, Chiniforush, N
Journal of endodontics. 2017;(2):279-282
Abstract
INTRODUCTION The aim of this study was to compare the efficacy of silver nanoparticles (AgNPs), an 810-nm diode laser (DL), conventional photodynamic therapy (PDT) with the use of indocyanine green (ICG) photosensitizer, and modified PDT with the use of AgNPs for the disinfection of root canals inoculated with Enterococcus faecalis. METHODS The root canals of 65 extracted human single-rooted teeth were prepared, and E. faecalis was incubated in the root canals for 4 weeks. The teeth were then randomly divided into the following 4 experimental groups: the DL group: 810-nm DL irradiation (1 W, 4 times for 10 seconds), the AN group: 5 minutes of irrigation with 5 mL AgNPs (100 ppm), the ICG/DL group: conventional PDT with ICG (1 mg/mL)/810-nm DL (200 mW, 30 seconds), and the AN/ICG/DL group: modified PDT with AgNPs/ICG/810-nm DL (200 mW, 30 seconds). There was also a control group, which consisted of 5 minutes of irrigation with 5 mL 2.5% sodium hypochlorite (n = 9). Samples were obtained from dentin chips before and after the interventions. A reduction in colony count was assessed by counting the colony-forming units. RESULTS Significant reductions were noted in E. faecalis colony counts in all groups (P < .05). The greatest reduction in colony count (99.12%) was noted in the AN/ICG/DL group (AgNPs/ICG/810-nm diode laser); however, the differences in this respect between the AN/ICG/DL group and the DL (97.41%), AN (94.42%), and control groups (94.61%) were not significant (P > .05). CONCLUSIONS PDT with ICG, an 810-nm diode laser, and AgNPs has the potential to be used as an adjunct for disinfection of the root canal system.
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Mechanisms of toxic action of Ag, ZnO and CuO nanoparticles to selected ecotoxicological test organisms and mammalian cells in vitro: a comparative review.
Ivask, A, Juganson, K, Bondarenko, O, Mortimer, M, Aruoja, V, Kasemets, K, Blinova, I, Heinlaan, M, Slaveykova, V, Kahru, A
Nanotoxicology. 2014;:57-71
Abstract
Silver, ZnO and CuO nanoparticles (NPs) are increasingly used as biocides. There is however increasing evidence of their threat to "non-target" organisms. In such a context, the understanding of the toxicity mechanisms is crucial for both the design of more efficient nano-antimicrobials, i.e. for "toxic by design" and at the same time for the design of nanomaterials that are biologically and/or environmentally benign throughout their life-cycle (safe by design). This review provides a comprehensive and critical literature overview on Ag, ZnO and CuO NPs' toxicity mechanisms on the basis of various environmentally relevant test species and mammalian cells in vitro. In addition, factors modifying the toxic effect of nanoparticles, e.g. impact of the test media, are discussed. Literature analysis revealed three major phenomena driving the toxicity of these nanoparticles: (i) dissolution of nanoparticles, (ii) organism-dependent cellular uptake of NPs and (iii) induction of oxidative stress and consequent cellular damages. The emerging information on quantitative structure-activity relationship modeling of nanomaterials' toxic effects and the challenges of extrapolation of laboratory results to the environment are also addressed.