scholarly journals In VitroSustained Release Study of Gallic Acid Coated with Magnetite-PEG and Magnetite-PVA for Drug Delivery System

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Dena Dorniani ◽  
Aminu Umar Kura ◽  
Samer Hasan Hussein-Al-Ali ◽  
Mohd Zobir Bin Hussein ◽  
Sharida Fakurazi ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Iron Oxide ◽  
Polyvinyl Alcohol ◽  
Gallic Acid ◽  
Magnetic Measurements ◽  
Spherical Shape ◽  
Average Diameter ◽  
Breast Cancer Cell Lines ◽  
X Ray Diffraction ◽  
X Ray

The efficacy of two nanocarriers polyethylene glycol and polyvinyl alcohol magnetic nanoparticles coated with gallic acid (GA) was accomplished via X-ray diffraction, infrared spectroscopy, magnetic measurements, thermal analysis, and TEM. X-ray diffraction and TEM results showed that Fe3O4nanoparticles were pure iron oxide having spherical shape with the average diameter of 9 nm, compared with 31 nm and 35 nm after coating with polyethylene glycol-GA (FPEGG) and polyvinyl alcohol-GA (FPVAG), respectively. Thermogravimetric analyses proved that after coating the thermal stability was markedly enhanced. Magnetic measurements and Fourier transform infrared (FTIR) revealed that superparamagnetic iron oxide nanoparticles could be successfully coated with two polymers (PEG and PVA) and gallic acid as an active drug. Release behavior of gallic acid from two nanocomposites showed that FPEGG and FPVAG nanocomposites were found to be sustained and governed by pseudo-second-order kinetics. Anticancer activity of the two nanocomposites shows that the FPEGG demonstrated higher anticancer effect on the breast cancer cell lines in almost all concentrations tested compared to FPVAG.

scholarly journals Magnetic nanoparticles preparation by chemical reduction for biomedical applications

2019 ◽  
Vol 201 ◽  
pp. 01002
Author(s):  
Zhazgul Kelgenbaeva ◽  
Bektemir Murzubraimov ◽  
Artem Kozlovsky ◽  
Ruslan Adil Akai Tegin ◽  
Ainur Turdubai kyzy ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Biomedical Applications ◽  
Chemical Reduction ◽  
Spherical Shape ◽  
Average Diameter ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Cubic Crystal ◽  
X Ray

This work presents Fe3O4 and AgFe nanoparticles with an average diameter of 25 and 15 nm synthesized by chemical reduction of corresponding salts under a mild condition. Cubic crystal structure and spherical shape of the nanoparticles were studied by X-ray diffraction, Field emission SEM and energy-dispersive spectroscopy analysis. For biomedical applications, the nanoparticles were tested against bacteria E.coli and results revealed AgFe nanoparticles’ antibacterial activity by forming lysis zone in scale of 0.5 mm.

scholarly journals Lubrication Effect of Polyvinyl Alcohol/Polyethylene Glycol Gel for Artificial Joints

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Shoujing Zhang ◽  
Feng Hu ◽  
Jianhui Li ◽  
Leifeng Lv ◽  
Hailin Lu
Keyword(s):  
Polyethylene Glycol ◽  
Wear Rate ◽  
Polyvinyl Alcohol ◽  
X Ray Diffraction ◽  
Artificial Joints ◽  
X Ray ◽  
Novel Technique ◽  
Biological Tests ◽  
Common Problems ◽  
Lubrication Effect

One of the most common problems encountered by patients using artificial joints is the high wear rate. In this study, a polyvinyl alcohol/polyethylene glycol (PVA/PEG) gel was prepared through the cross-linking reaction between polyvinyl alcohol (PVA) and polyethylene glycol (PEG) solutions. This gel can lubricate artificial joints, thereby lowering their coefficient of friction (COF) and increasing their service life. Various techniques, such as Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectra, X-ray photon spectroscopy, and thermogravimetric analyses, were used to analyze the structure of this synthetic gel. The tribological results indicated that the synthetic gel’s lubrication effect was the most optimum when it contained PVA (10 wt%) and PEG (15 wt%). An average COF of 0.05 was obtained under a load of 10 N and at a speed of 1.0 cm/s. In addition, the wear rate was reduced in comparison to distilled water. Furthermore, the biological tests proved that the PVA/PEG gel was highly biocompatible. Thus, this study introduces a novel technique to prepare PVA/PEG gels that improve the tribological performance of artificial joints.

scholarly journals Release of a liver anticancer drug, sorafenib from its PVA/LDH- and PEG/LDH-coated iron oxide nanoparticles for drug delivery applications

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mona Ebadi ◽  
Saifullah Bullo ◽  
Kalaivani Buskara ◽  
Mohd Zobir Hussein ◽  
Sharida Fakurazi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Drug Delivery ◽  
Polyethylene Glycol ◽  
Iron Oxide ◽  
Polyvinyl Alcohol ◽  
Drug Delivery System ◽  
Iron Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
X Ray ◽  
Coating Agents

AbstractThe use of nanocarriers composed of polyethylene glycol- and polyvinyl alcohol-coated vesicles encapsulating active molecules in place of conventional chemotherapy drugs can reduce many of the chemotherapy-associated challenges because of the increased drug concentration at the diseased area in the body. The present study investigated the structure and magnetic properties of iron oxide nanoparticles in the presence of polyvinyl alcohol and polyethylene glycol as the basic surface coating agents. We used superparamagnetic iron oxide nanoparticles (FNPs) as the core and studied their effectiveness when two polymers, namely polyvinyl alcohol (PVA) and polyethylene glycol (PEG), were used as the coating agents together with magnesium–aluminum-layered double hydroxide (MLDH) as the nanocarrier. In addition, the anticancer drug sorafenib (SO), was loaded on MLDH and coated onto the surface of the nanoparticles, to best exploit this nano-drug delivery system for biomedical applications. Samples were prepared by the co-precipitation method, and the resulting formation of the nanoparticles was confirmed by X-ray, FTIR, TEM, SEM, DLS, HPLC, UV–Vis, TGA and VSM. The X-ray diffraction results indicated that all the as-synthesized samples contained highly crystalline and pure Fe3O4. Transmission electron microscopy analysis showed that the shape of FPEGSO-MLDH nanoparticles was generally spherical, with a mean diameter of 17 nm, compared to 19 nm for FPVASO-MLDH. Fourier transform infrared spectroscopy confirmed the presence of nanocarriers with polymer-coating on the surface of iron oxide nanoparticles and the existence of loaded active drug consisting of sorafenib. Thermogravimetric analyses demonstrated the thermal stability of the nanoparticles, which displayed enhanced anticancer effect after coating. Vibrating sample magnetometer (VSM) curves of both produced samples showed superparamagnetic behavior with the high saturation magnetization of 57 emu/g for FPEGSO-MLDH and 49 emu/g for FPVASO-MLDH. The scanning electron microscopy (SEM) images showed a narrow size distribution of both final samples. The SO drug loading and the release behavior from FPEGSO-MLDH and FPVASO-MLDH were assessed by ultraviolet–visible spectroscopy. This evaluation showed around 85% drug release within 72 h, while 74% of sorafenib was released in phosphate buffer solution at pH 4.8. The release profiles of sorafenib from the two designed samples were found to be sustained according to pseudo-second-order kinetics. The cytotoxicity studies confirmed the anti-cancer activity of the coated nanoparticles loaded with SO against liver cancer cells, HepG2. Conversely, the drug delivery system was less toxic than the pure drug towards fibroblast-type 3T3 cells.

Chemical Precipitation Synthesis and Magnetic Properties of Hematite Nanorods

2009 ◽  
Vol 293 ◽  
pp. 77-82 ◽  
Author(s):  
Qiao Ling Li ◽  
Yong Fei Wang ◽  
Cun Rui Zhang
Keyword(s):  
Polyethylene Glycol ◽  
Point Defects ◽  
Magnetic Measurements ◽  
Slenderness Ratio ◽  
Average Diameter ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Growth Step ◽  
Transmission Electron

One-dimensional (1D) hematite (α-Fe2O3) nanorods have been successfully prepared using a chemical precipitation method. The sample was characterized by using a variety of techniques, such as X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The results showed that the nanorods obtained were monocrystalline, with an average diameter of about 60nm and a length of up to 800nm. In the preparation of α-Fe2O3, the length of α-Fe2O3 seemed to increase with the addition of polyethylene glycol (PEG), and the diameter seemed to decrease with the addition of Zn2+. Nanorods of α-Fe2O3 with a smaller diameter and superior slenderness ratio were prepared by adding both PEG and Zn2+. A possible growth mechanism effect of PEG and Zn2+ upon the morphology of α-Fe2O3 was as follows: α-FeOOH grew in a one-dimensioned orientation upon the surface of a polyethylene glycol template. In the meantime, the Fe3+ position in the α-FeOOH crystal was substituted by Zn2+; resulting in point defects in α-FeOOH crystal due to the radius discrepancy between Zn2+ and Fe3+. The growth-step energy was then reduced as a result of the point defects in the α-FeOOH crystal. The results of magnetic measurements of the hematite nanorods revealed a weak ferromagnetic property which might be related to the shape anisotropy.

scholarly journals Direct Production of a Novel Iron-Based Nanocomposite from the Laser Pyrolysis ofFe(CO)5/MMAMixtures: Structural and Sensing Properties

2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
R. Alexandrescu ◽  
I. Morjan ◽  
A. Tomescu ◽  
C. E. Simion ◽  
M. Scarisoreanu ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Gas Sensors ◽  
High Sensitivity ◽  
X Ray Diffraction ◽  
Direct Production ◽  
X Ray ◽  
Metallic Particles ◽  
Ir Laser ◽  
Iron Iron ◽  
Optimum Working

Iron/iron oxide-based nanocomposites were prepared by IR laser sensitized pyrolysis ofFe(CO)5and methyl methacrylate (MMA) mixtures. The morphology of nanopowder analyzed by TEM indicated that mainly core-shell structures were obtained. X-ray diffraction techniques evidence the cores as formed mainly by iron/iron oxide crystalline phases. A partially degraded (carbonized) polymeric matrix is suggested for the coverage of the metallic particles. The nanocomposite structure at the variation of the laser density and of the MMA flow was studied. The new materials prepared as thick films were tested for their potential for acting as gas sensors. The temporal variation of the electrical resistance in presence ofNO2, CO, andCO2, in dry and humid air was recorded. Preliminary results show that the samples obtained at higher laser power density exhibit rather high sensitivity towardsNO2detection andNO2selectivity relatively to CO andCO2. An optimum working temperature of200°Cwas found.

scholarly journals Dissimilatory Iron-Reducing Microorganisms Are Present and Active in the Sediments of the Doce River and Tributaries Impacted by Iron Mine Tailings from the Collapsed Fundão Dam (Mariana, MG, Brazil)

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 244
Author(s):  
Carolina N. Keim ◽  
Jilder D. P. Serna ◽  
Daniel Acosta-Avalos ◽  
Reiner Neumann ◽  
Alex S. Silva ◽  
...  
Keyword(s):  
Bottom Sediments ◽  
Magnetic Measurements ◽  
Culture Media ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ferric Oxyhydroxide ◽  
Transmission Electron ◽  
Iron Mine ◽  
Organic Matter Oxidation ◽  
Doce River

On 5 November 2015, a large tailing deposit failed in Brazil, releasing an estimated 32.6 to 62 million m3 of iron mining tailings into the environment. Tailings from the Fundão Dam flowed down through the Gualaxo do Norte and Carmo riverbeds and floodplains and reached the Doce River. Since then, bottom sediments have become enriched in Fe(III) oxyhydroxides. Dissimilatory iron-reducing microorganisms (DIRMs) are anaerobes able to couple organic matter oxidation to Fe(III) reduction, producing CO2 and Fe(II), which can precipitate as magnetite (FeO·Fe2O3) and other Fe(II) minerals. In this work, we investigated the presence of DIRMs in affected and non-affected bottom sediments of the Gualaxo do Norte and Doce Rivers. The increase in Fe(II) concentrations in culture media over time indicated the presence of Fe(III)-reducing microorganisms in all sediments tested, which could reduce Fe(III) from both tailings and amorphous ferric oxyhydroxide. Half of our enrichment cultures converted amorphous Fe(III) oxyhydroxide into magnetite, which was characterized by X-ray diffraction, transmission electron microscopy, and magnetic measurements. The conversion of solid Fe(III) phases to soluble Fe(II) and/or magnetite is characteristic of DIRM cultures. The presence of DIRMs in the sediments of the Doce River and tributaries points to the possibility of reductive dissolution of goethite (α-FeOOH) and/or hematite (α-Fe2O3) from sediments, along with the consumption of organics, release of trace elements, and impairment of water quality.

scholarly journals Discovery of Fe7O9: a new iron oxide with a complex monoclinic structure

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ryosuke Sinmyo ◽  
Elena Bykova ◽  
Sergey V. Ovsyannikov ◽  
Catherine McCammon ◽  
Ilya Kupenko ◽  
...  
Keyword(s):  
Applied Sciences ◽  
Crystal Structure ◽  
Iron Oxide ◽  
Iron Oxides ◽  
Industrial Applications ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Insight Into

Abstract Iron oxides are fundamentally important compounds for basic and applied sciences as well as in numerous industrial applications. In this work we report the synthesis and investigation of a new binary iron oxide with the hitherto unknown stoichiometry of Fe7O9. This new oxide was synthesized at high-pressure high-temperature (HP-HT) conditions, and its black single crystals were successfully recovered at ambient conditions. By means of single crystal X-ray diffraction we determined that Fe7O9 adopts a monoclinic C2/m lattice with the most distorted crystal structure among the binary iron oxides known to date. The synthesis of Fe7O9 opens a new portal to exotic iron-rich (M,Fe)7O9 oxides with unusual stoichiometry and distorted crystal structures. Moreover, the crystal structure and phase relations of such new iron oxide groups may provide new insight into the cycling of volatiles in the Earth’s interior.

Monoclinic FeO at high pressures

2008 ◽  
Vol 223 (7/2008) ◽  
Author(s):  
Innokenty Kantor ◽  
Alexander Kurnosov ◽  
Catherine McCammon ◽  
Leonid Dubrovinsky
Keyword(s):  
High Pressure ◽  
Iron Oxide ◽  
Single Crystal ◽  
Diffraction Study ◽  
High Pressures ◽  
X Ray Diffraction ◽  
X Ray

AbstractA high-pressure quasi-single crystal X-ray diffraction study of a synthetic iron oxide Fe

scholarly journals Structural Evolution in Wet Mechanically Alloyed Co-Fe-(Ta,W)-B Alloys

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 800
Author(s):  
Vladimír Girman ◽  
Maksym Lisnichuk ◽  
Daria Yudina ◽  
Miloš Matvija ◽  
Pavol Sovák ◽  
...  
Keyword(s):  
Structural Changes ◽  
Magnetic Measurements ◽  
Structural Evolution ◽  
High Energy ◽  
Control Agent ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
X Ray ◽  
Transmission Electron ◽  
X Ray Absorption

In the present study, the effect of wet mechanical alloying (MA) on the glass-forming ability (GFA) of Co43Fe20X5.5B31.5 (X = Ta, W) alloys was studied. The structural evolution during MA was investigated using high-energy X-ray diffraction, X-ray absorption spectroscopy, high-resolution transmission electron microscopy and magnetic measurements. Pair distribution function and extended X-ray absorption fine structure spectroscopy were used to characterize local atomic structure at various stages of MA. Besides structural changes, the magnetic properties of both compositions were investigated employing a vibrating sample magnetometer and thermomagnetic measurements. It was shown that using hexane as a process control agent during wet MA resulted in the formation of fully amorphous Co-Fe-Ta-B powder material at a shorter milling time (100 h) as compared to dry MA. It has also been shown that substituting Ta with W effectively suppresses GFA. After 100 h of MA of Co-Fe-W-B mixture, a nanocomposite material consisting of amorphous and nanocrystalline bcc-W phase was synthesized.

scholarly journals Investigation and Modeling of the Electrical Conductivity of Graphene Nanoplatelets-Loaded Doped-Polypyrrole

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1034
Author(s):  
Oladipo Folorunso ◽  
Yskandar Hamam ◽  
Rotimi Sadiku ◽  
Suprakas Sinha Ray ◽  
Neeraj Kumar
Keyword(s):  
Electrical Conductivity ◽  
Structural Changes ◽  
Spherical Shape ◽  
Graphene Nanoplatelets ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Energy Storage Applications ◽  
Electrical Conductivity Data

In this study, a hybrid of graphene nanoplatelets with a polypyrrole having 20 wt.% loading of carbon-black (HGPPy.CB20%), has been fabricated. The thermal stability, structural changes, morphology, and the electrical conductivity of the hybrids were investigated using thermogravimetric analyzer, differential scanning calorimeter, X-ray diffraction analyzer, scanning electron microscope, and laboratory electrical conductivity device. The morphology of the hybrid shows well dispersion of graphene nanoplatelets on the surface of the PPy.CB20% and the transformation of the gravel-like PPy.CB20% shape to compact spherical shape. Moreover, the hybrid’s electrical conductivity measurements showed percolation threshold at 0.15 wt.% of the graphene nanoplatelets content and the curve is non-linear. The electrical conductivity data were analyzed by comparing different existing models (Weber, Clingerman and Taherian). The results show that Taherian and Clingerman models, which consider the aspect ratio, roundness, wettability, filler electrical conductivity, surface interaction, and volume fractions, closely described the experimental data. From these results, it is evident that Taherian and Clingerman models can be modified for better prediction of the hybrids electrical conductivity measurements. In addition, this study shows that graphene nanoplatelets are essential and have a significant influence on the modification of PPy.CB20% for energy storage applications.

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