scholarly journals Antioxidant activity and dose enhancement factor of CeO2 nanoparticles synthesized by precipitation method

2018 ◽  
Vol 432 ◽  
pp. 012031 ◽  
Author(s):  
I Nurhasanah ◽  
W Safitri ◽  
Z Arifin ◽  
A Subagio ◽  
T Windarti
Keyword(s):  
Antioxidant Activity ◽  
Enhancement Factor ◽  
Ceo2 Nanoparticles ◽  
Precipitation Method ◽  
Dose Enhancement

scholarly journals THE CALCINATION TEMPERATURE EFFECT ON THE ANTIOXIDANT AND RADIOPROTECTION PROPERTIES OF CeO2 NANOPARTICLES

REAKTOR ◽  
2018 ◽  
Vol 18 (1) ◽  
pp. 22 ◽  
Author(s):  
Iis Nurhasanah ◽  
Weni Safitri ◽  
Tri Windarti ◽  
Agus Subagio
Keyword(s):  
Escherichia Coli ◽  
Temperature Effect ◽  
Crystallite Size ◽  
Calcination Temperature ◽  
Enhancement Factor ◽  
Antioxidant Properties ◽  
Ceo2 Nanoparticles ◽  
Precipitation Method ◽  
Dose Enhancement ◽  
X Ray

The CeO2 nanoparticles are very interesting to be studied as biomedical materials due to its unique physical and chemical properties. The non-stoichiometric properties of CeO2 play a role in the redox/catalytic processes that scavenging free radicals. These properties make CeO2 nanoparticles as being potentially antioxidant and radioprotector materials. In this paper, we report the calcination temperature effect on the antioxidant properties and  radioprotective effect of CeO2 nanoparticles synthesized by precipitation method. The CeO2 nanoparticles were synthesized by precipitation method at various calcinations temperatures (300oC – 700oC). The formation of CeO2 nanoparticles and crystallite size was analyzed using X-ray diffractometers. The DPPH method was used to investigate antioxidant properties of CeO2.  Dose Enhancement Factor (DEF) of CeO2 nanoparticles were determined by measurement of the absorbed dose of X-ray radiation (Linac 6 MV 200 MU). X-ray diffraction pattern showed formation of cubic fluorite of CeO2 nanoparticles with crystallite size in the range 9 nm-18 nm.  Calcination temperature of 500oC resulted in CeO2 nanoparticles with the best antioxidant properties and lowest DEF value. The radioprotection effect of CeO2 nanoparticles was evaluated based on Escherichia coli survival toward X-ray radiation with a dose of 2 Gy. The CeO2 nanoparticles increased Escherichia coli survival of about 24.8% order.  These results suggested that CeO2 nanoparticles may potentially be as radioprotector of X-ray Linac 6 MV. Keywords: Antioxidant, CeO2 nanoparticles, Dose Enhancement Factor (DEF), radioprotector

Synthesis and Characterization of Cerium Oxide (CeO2) Nanoparticles

2009 ◽  
Vol 609 ◽  
pp. 189-194 ◽  
Author(s):  
C. Benmouhoub ◽  
A. Kadri ◽  
N. Benbrahim ◽  
S. Hadji
Keyword(s):  
Crystallite Size ◽  
Cerium Oxide ◽  
Ceo2 Nanoparticles ◽  
Precipitation Method ◽  
Synthesis And Characterization

Nanoparticles of cerium oxide (CeO2) are synthesized with cerium (III) nitrates (Ce(NO3)3, 6H2O) by precipitation method in ammonium hydroxyl solution (NH4OH). The influence of several parameters such as nature of the solvent, synthesizing temperature and the calcination on the crystallite size is studied by XRD, TEM and BET methods. The results show that both calcinations and synthesizing temperature affect the particles size. Also, the nature of solvent has a great effect on the morphology of CeO2 nanoparticles.

scholarly journals Different distributions of gold nanoparticles on the tumor and calculation of dose enhancement factor by Monte Carlo simulation

2019 ◽  
Vol 5 (4) ◽  
pp. 361-371 ◽  
Author(s):  
Sajad Keshavarz ◽  
Dariush Sardari
Keyword(s):  
Gold Nanoparticles ◽  
Uniform Distribution ◽  
Enhancement Factor ◽  
Radiation Energy ◽  
Distribution Model ◽  
Distribution Models ◽  
Dose Enhancement ◽  
X Ray ◽  
Nanoparticle Distribution ◽  
Nanoparticle Sizes

Gold nanoparticles can be used to increase the dose of the tumor due to its high atomic number as well as being free from apparent toxicity. The aim of this study is to evaluate the effect of distribution of gold nanoparticles models, as well as changes in nanoparticle sizes and spectrum of radiation energy along with the effects of nanoparticle penetration into surrounding tissues in dose enhancement factor DEF. Three mathematical models were considered for distribution of gold nanoparticles in the tumor, such as 1-uniform, 2- non-uniform distribution with no penetration margin and 3- non-uniform distribution with penetration margin of 2.7 mm of gold nanoparticles. For this purpose, a cube-shaped water phantom of 50 cm size in each side and a cube with 1 cm side placed at depth of 2 cm below the upper surface of the cubic phantom as the tumor was defined, and then 3 models of nanoparticle distribution were modeled. MCNPX code was used to simulate 3 distribution models. DEF was evaluated for sizes of 20, 25, 30, 50, 70, 90 and 100 nm of gold nanoparticles, and 50, 95, 250 keV and 4 MeV photon energies. In uniform distribution model the maximum DEF was observed at 100 nm and 50 keV being equal to 2.90, in non-uniform distribution with no penetration margin, the maximum DEF was measured at 100 nm and 50 keV being 1.69, and in non-uniform distribution with penetration margin of 2.7 mm, the maximum DEF was measured at 100 nm and 50 keV as 1.38, and the results have been showed that the dose was increased by injecting nanoparticles into the tumor. It is concluded that the highest DEF could be achieved in low energy photons and larger sizes of nanoparticles. Non-uniform distribution of gold nanoparticles can increase the dose and also decrease the DEF in comparison with the uniform distribution. The non-uniform distribution of nanoparticles with penetration margin showed a lower DEF than the non-uniform distribution without any margin and uniform distribution. Meanwhile, utilization of the real X-ray spectrum brought about a smaller DEF in comparison to mono-energetic X-ray photons.

Estimation of microscopic dose enhancement factor around gold nanoparticles by Monte Carlo calculations

2010 ◽  
Vol 37 (7Part1) ◽  
pp. 3809-3816 ◽  
Author(s):  
Bernard L. Jones ◽  
Sunil Krishnan ◽  
Sang Hyun Cho
Keyword(s):  
Gold Nanoparticles ◽  
Monte Carlo ◽  
Enhancement Factor ◽  
Dose Enhancement ◽  
Monte Carlo Calculations

scholarly journals Preparation and Photocatalytic Properties of Heterostructured Ceria/Polyaniline Nanoparticles

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 732
Author(s):  
Yen-Sheng Li ◽  
Alex Fang ◽  
Gang-Juan Lee ◽  
Jerry J. Wu ◽  
Yu-Cheng Chang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Visible Light ◽  
High Efficiency ◽  
Ceo2 Nanoparticles ◽  
Precipitation Method ◽  
Sunlight Irradiation ◽  
Light Region ◽  
Structure Morphology ◽  
Catalytic Material ◽  
Polymerization Method

Cerium dioxide (CeO2, ceria), a promising and abundant catalytic material with high-efficiency, nontoxicity, photochemical stability, and affordability, can be used as a photocatalyst to photocatalytically degrade organics and split water for hydrogen production under ultraviolet (UV) irradiation (about 5% of solar energy). However, the applications of the CeO2 photocatalyst are limited due to low photocatalytic efficiency under sunlight irradiation. In this study, a nanosized CeO2 powder was prepared by the precipitation method. Subsequently, various amounts of polyaniline (PANI) nanoparticles were deposited onto the surface of the CeO2 nanoparticles to form a heterostructure by the polymerization method. The crystal structure, morphology, surface and optical properties of the CeO2/PANI nanoparticles were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-Vis) absorption spectroscopy, and photoluminescence (PL). Experimental results demonstrated that PANI deposition improved the light absorption of CeO2 nanoparticles in the visible light region. The heterostructured CeO2/PANI nanoparticle with 4 wt % PANI deposition exhibited optimal photocatalytic activities with a hydrogen production rate of 462 μmolg−1 within 6 h and a methyl orange (MO) degradation rate of 45% within 4 h under visible light irradiation. The photocatalytic mechanisms of the composite powder are also proposed in this report.

scholarly journals Study of Radiation Dose Enhancement to Capillary Endothelial Cells Due to the Presence of Heavy Metal Nanoparticles in Two Cell and Tumor Scales by Monte Carlo Method

2020 ◽  
Author(s):  
Aghdas Sohayli-Jabbareh-Naseroo ◽  
Ladan Rezaee
Keyword(s):  
Heavy Metal ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Energy Range ◽  
Metal Nanoparticles ◽  
Photon Energy ◽  
Enhancement Factor ◽  
Photon Energy Range ◽  
Dose Increase ◽  
Dose Enhancement

Introduction: Recently, the use of various sensitizers has been used to increase photon-induced doses in brachytherapy. One of these cases is the addition of heavy metal nanoparticles such as gold in the target area, which increases the production of ionizing electrons by increasing the possibility of photoelectric effects, and increases the efficacy of the treatment. In this study, the target of the irradiation was the endothelial cell in the wall of blood capillaries located inside the tumor, which, if destroyed, would result in abnormal blood cell counts and tumor cell death. Methods: The effect of using nanoparticles of gold, silver, bismuth and copper has been evaluated by calculating the dose increase ratio using Geant4 tool that was based on Monte Carlo method. These calculations were performed on two microscopic (cellular) and macroscopic (tumor dimensions) scale and the effects of different concentrations of these nanoparticles were compared. Also, the dose increase ratio has been evaluated to determine the most appropriate photon energy range. Results: As the concentration of nanoparticles increases, the dose enhancement factor increased in photon energy. In addition, for energies less than 70 keV, with increasing energy, dose enhancement factor increased and for energies above 80 keV, this quantity decreased with increasing energy. Conclusion: In terms of dose, gold is the best option, and in terms of the dose enhancement factor, silver and bismuth are better alternative among the four elements studied. Also, the most suitable photon energy range is 70 keV to 80 keV.

scholarly journals Evaluation of Gold Nanoparticle Size Effect on Dose Enhancement Factor in Megavoltage Beam Radiotherapy Using MAGICA Polymer Gel Dosimeter

2019 ◽  
Author(s):  
Zh Behrouzkia ◽  
R Zohdiaghdam ◽  
H R Khalkhali ◽  
F Mousavi
Keyword(s):  
Treatment Planning ◽  
Enhancement Factor ◽  
Photon Beam ◽  
Planning System ◽  
Nanoparticle Size ◽  
Treatment Planning System ◽  
Polymer Gel ◽  
Dose Enhancement ◽  
Gel Dosimeter ◽  
Polymer Gel Dosimeter

Background: Gold nanoparticles (GNPs) are among the most promising radiosensitive materials in radiotherapy. Studying the effective sensitizing factors such as nanoparticle size, concentration, surface features, radiation energy and cell type can help to optimize the effect and possible clinical application of GNPs in radiation therapy. In this study, the radiation sensitive polymer gel was used to investigate the dosimetric effect of GNP size in megavoltage (MV) photon beam radiotherapy.Material and Methods: GNPs with the size of 30nm, 50nm and 100nm in diameter were used. Transmission electron microscope (TEM) and dynamic light scattering (DLS) were applied to analyze the size of nanoparticles. The MAGICA polymer gel was synthesized and impregnated with different sizes of GNPs. The samples were irradiated with 6MV photon beam and 24 hours after irradiation, they were read using a Magnetic Resonance Imaging (MRI) scanner. Macroscopic Dose Enhancement Factor (DEF) was measured to compare the effect of GNP size. The MAGICA response of the 6MV x-ray beam was verified comparing Percentage Depth Dose (PDD) curve extracted from polymer gel dosimetry and Treatment Planning System (TPS).Results: MAGICA polymer gel dose response curve was linear in the range of 0 to 10 Gy. DEFs by adding 30nm, 50nm and 100nm GNPs were 1.1, 1.17 and 1.12, respectively. PDD curves of polymer gel dosimeter and treatment planning system were in good agreement.Conclusion: The results indicated a substantial increase in DEF uses a MV photon beam in combination with GNPs of different sizes and it was inconsistent with previous radiobiological studies. The maximum DEF was achieved for 50nm GNPs in comparison with 30nm and 100nm leading to the assumption of self-absorption effect by larger diameters. According to the outcomes of this work, MAGICA polymer gel can be recommended as a reliable dosimeter to investigate the dosimetric effect of GNP size and also a useful method to validate the current radiobiological and simulation studies. 

scholarly journals Evaluation of Gold Nanoparticle Size Effect on Dose Enhancement Factor in Megavoltage Beam Radiotherapy Using MAGICA Polymer Gel Dosimeter

2019 ◽  
Vol 9 (1Feb) ◽  
Author(s):  
Zh Behrouzkia ◽  
R Zohdiaghdam ◽  
H R Khalkhali ◽  
F Mousavi
Keyword(s):  
Treatment Planning ◽  
Enhancement Factor ◽  
Photon Beam ◽  
Planning System ◽  
Nanoparticle Size ◽  
Treatment Planning System ◽  
Polymer Gel ◽  
Dose Enhancement ◽  
Gel Dosimeter ◽  
Polymer Gel Dosimeter

Background: Gold nanoparticles (GNPs) are among the most promising radiosensitive materials in radiotherapy. Studying the effective sensitizing factors such as nanoparticle size, concentration, surface features, radiation energy and cell type can help to optimize the effect and possible clinical application of GNPs in radiation therapy. In this study, the radiation sensitive polymer gel was used to investigate the dosimetric effect of GNP size in megavoltage (MV) photon beam radiotherapy.Material and Methods: GNPs with the size of 30nm, 50nm and 100nm in diameter were used. Transmission electron microscope (TEM) and dynamic light scattering (DLS) were applied to analyze the size of nanoparticles. The MAGICA polymer gel was synthesized and impregnated with different sizes of GNPs. The samples were irradiated with 6MV photon beam and 24 hours after irradiation, they were read using a Magnetic Resonance Imaging (MRI) scanner. Macroscopic Dose Enhancement Factor (DEF) was measured to compare the effect of GNP size. The MAGICA response of the 6MV x-ray beam was verified comparing Percentage Depth Dose (PDD) curve extracted from polymer gel dosimetry and Treatment Planning System (TPS).Results: MAGICA polymer gel dose response curve was linear in the range of 0 to 10 Gy. DEFs by adding 30nm, 50nm and 100nm GNPs were 1.1, 1.17 and 1.12, respectively. PDD curves of polymer gel dosimeter and treatment planning system were in good agreement.Conclusion: The results indicated a substantial increase in DEF uses a MV photon beam in combination with GNPs of different sizes and it was inconsistent with previous radiobiological studies. The maximum DEF was achieved for 50nm GNPs in comparison with 30nm and 100nm leading to the assumption of self-absorption effect by larger diameters. According to the outcomes of this work, MAGICA polymer gel can be recommended as a reliable dosimeter to investigate the dosimetric effect of GNP size and also a useful method to validate the current radiobiological and simulation studies. 

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