scholarly journals Superspinglass state in functionalized zeolite 5A-maghemite nanoparticles

AIP Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 035223 ◽  
Author(s):  
Juan A. Ramos-Guivar ◽  
Edson Caetano Passamani ◽  
Jochen Litterst
Keyword(s):  
Maghemite Nanoparticles ◽  
Zeolite 5A

scholarly journals Grafting TRAIL through Either Amino or Carboxylic Groups onto Maghemite Nanoparticles: Influence on Pro-Apoptotic Efficiency

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 502
Author(s):  
Hanene Belkahla ◽  
Andrei Alexandru Constantinescu ◽  
Tijani Gharbi ◽  
Florent Barbault ◽  
Alexandre Chevillot-Biraud ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Cancer Therapy ◽  
Computational Study ◽  
Carcinoma Cells ◽  
Maghemite Nanoparticles ◽  
Carboxylic Acid Groups ◽  
Lung Carcinoma Cells ◽  
Biological Studies ◽  
Apoptotic Effect ◽  
Carboxylic Groups

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF cytokine superfamily. TRAIL is able to induce apoptosis through engagement of its death receptors DR4 and DR5 in a wide variety of tumor cells while sparing vital normal cells. This makes it a promising agent for cancer therapy. Here, we present two different ways of covalently grafting TRAIL onto maghemite nanoparticles (NPs): (a) by using carboxylic acid groups of the protein to graft it onto maghemite NPs previously functionalized with amino groups, and (b) by using the amino functions of the protein to graft it onto NPs functionalized with carboxylic acid groups. The two resulting nanovectors, NH-TRAIL@NPs-CO and CO-TRAIL@NPs-NH, were thoroughly characterized. Biological studies performed on human breast and lung carcinoma cells (MDA-MB-231 and H1703 cell lines) established these nanovectors are potential agents for cancer therapy. The pro-apoptotic effect is somewhat greater for CO-TRAIL@NPs-NH than NH-TRAIL@NPs-CO, as evidenced by viability studies and apoptosis analysis. A computational study indicated that regardless of whether TRAIL is attached to NPs through an acid or an amino group, DR4 recognition is not affected in either case.

scholarly journals Heterogeneity of population of microorganisms grown in presence of iron oxide maghemite nanoparticles

2018 ◽  
Vol 185 ◽  
pp. 10002 ◽  
Author(s):  
Tatyana P. Denisova ◽  
Elena V. Simonova ◽  
Lubov A. Kokorina ◽  
Evgenia N. Maximova ◽  
Oleg M. Samatov ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Intercellular Communication ◽  
Maghemite Nanoparticles ◽  
Cultivation Temperature ◽  
Large White ◽  
Laser Target ◽  
Water Based

In this work γ-Fe2O3 MNPs were obtained by laser target evaporation and water based suspensions were prepared. Maximum permissive dose of iron in water (MPD) is 0.3 mg/L. It was found that 100 MPD dose of iron induces formation of non-typical colonies after 72 or 96 hours exposition: against a background of small black colonies large white colonies appeared due to a disruption in tyrosine synthesis. Multiple re-cloning of the white colonies grown with MNPs showed that they retained their properties both under standard conditions (temperature of 24 °C) and at the temperatures up to 37o C. E.nigrum grown with MNPs demonstrated very scant extension of small colonies at the cultivation temperature of 24o C, their growth was completely blocked at 37°C. Significant changes in the structure of the population were noted. First of all, large cells with pronounced aggregation were observed among the black colonies. These aggregates consisted of large cells connected to each other by matrix. In the white colonies the appearance of very long threadlike cells connecting different groups of the cells establishing an intercellular communication was evident. Fe2O3 MNPs induce an increase in the heterogeneity of the population, expressed as a change in morpho-physiological states.

scholarly journals Improved biocompatibility and efficient labeling of neural stem cells with poly(L-lysine)-coated maghemite nanoparticles

2016 ◽  
Vol 7 ◽  
pp. 926-936 ◽  
Author(s):  
Igor M Pongrac ◽  
Marina Dobrivojević ◽  
Lada Brkić Ahmed ◽  
Michal Babič ◽  
Miroslav Šlouf ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Neural Stem Cells ◽  
Cellular Uptake ◽  
Cell Tracking ◽  
Cellular Migration ◽  
Cell Labeling ◽  
Blue Staining ◽  
Maghemite Nanoparticles ◽  
Acetoxymethyl Ester

Background: Cell tracking is a powerful tool to understand cellular migration, dynamics, homing and function of stem cell transplants. Nanoparticles represent possible stem cell tracers, but they differ in cellular uptake and side effects. Their properties can be modified by coating with different biocompatible polymers. To test if a coating polymer, poly(L-lysine), can improve the biocompatibility of nanoparticles applied to neural stem cells, poly(L-lysine)-coated maghemite nanoparticles were prepared and characterized. We evaluated their cellular uptake, the mechanism of internalization, cytotoxicity, viability and proliferation of neural stem cells, and compared them to the commercially available dextran-coated nanomag®-D-spio nanoparticles. Results: Light microscopy of Prussian blue staining revealed a concentration-dependent intracellular uptake of iron oxide in neural stem cells. The methyl thiazolyl tetrazolium assay and the calcein acetoxymethyl ester/propidium iodide assay demonstrated that poly(L-lysine)-coated maghemite nanoparticles scored better than nanomag®-D-spio in cell labeling efficiency, viability and proliferation of neural stem cells. Cytochalasine D blocked the cellular uptake of nanoparticles indicating an actin-dependent process, such as macropinocytosis, to be the internalization mechanism for both nanoparticle types. Finally, immunocytochemistry analysis of neural stem cells after treatment with poly(L-lysine)-coated maghemite and nanomag®-D-spio nanoparticles showed that they preserve their identity as neural stem cells and their potential to differentiate into all three major neural cell types (neurons, astrocytes and oligodendrocytes). Conclusion: Improved biocompatibility and efficient cell labeling makes poly(L-lysine)-coated maghemite nanoparticles appropriate candidates for future neural stem cell in vivo tracking studies.

Novel Ceric Ammonium Nitrate-Stabilized Maghemite Nanoparticles (CAN-γ-Fe2O3) for Ultrasound Assisted Synthesis of β-Amino Derivatives

2021 ◽  
Author(s):  
Anurag Kumar ◽  
Yifat Harel ◽  
Jean-paul Lellouche ◽  
Suman L. Jain
Keyword(s):  
Carbonyl Compounds ◽  
Addition Reaction ◽  
Ceric Ammonium Nitrate ◽  
Reusable Catalyst ◽  
Maghemite Nanoparticles ◽  
Reaction Conditions ◽  
Recyclable Catalysts ◽  
Nucleophilic Addition Reaction ◽  
Amino Derivatives ◽  
Positively Charged

Abstract Owing to their inherent features like smaller size and higher surface area exposed to reactants, nanoparticles have gained enormous interest and are extensively used as magnetically recyclable catalysts for various organic reactions. Herein, we report highly hydrophilic, non-aggregated, and strongly positively charged (ζ potential: +45.7 mV) ultra-small cerium cations/complexes- stabilized maghemite nanoparticles in water as an efficient and reusable nanoscaled magnetically active catalyst for the nucleophilic addition reaction of various amines with α,β-unsaturated carbonyl compounds to give corresponding β-amino derivatives under ultrasonic irradiation. The developed protocol provides several merits such as high product yields, mild reaction conditions, reusable catalyst and easy workup.

Initial Dynamic Susceptibility of Maghemite Nanoparticles Dispersed in Surface-Treated Polymeric Template

2021 ◽  
Vol 21 (11) ◽  
pp. 5694-5697
Author(s):  
A. F. R. Rodriguez ◽  
R. F. Lacerda ◽  
L. E. Maggi ◽  
Hory Mohammadpour ◽  
Mohammad Niyaifar ◽  
...  
Keyword(s):  
Ex Situ ◽  
Transmission Electron Microscopy Data ◽  
Dynamic Susceptibility ◽  
Maghemite Nanoparticles ◽  
X Ray Diffraction ◽  
Chemical Treatments ◽  
Dynamical Susceptibility ◽  
Transmission Electron ◽  
Microscopy Data ◽  
Polymeric Template

Magnetic nanocomposites based on maghemite nanoparticles supported (ex situ route) on styrene- divinilbenzene (Sty-DVB) copolymer templates were produced and characterized for their structure and morphology. The as-produced nanocomposites were further chemically-treated with different oxidant agents and surface-coated with stearic acid. X-ray diffraction and transmission electron microscopy data show that the incorporated nanoparticles are preserved despite the aggressive chemical treatments employed. From the dynamical susceptibility measurements performed on the nanocomposites, the values of the saturation magnetization (76 emu/g) and the effective magnetic anisotropy (1.7 × 104 J/m3) were obtained, in excellent agreement with the values reported in the literature for maghemite. This finding strongly supports the preservation of the magnetic properties of the supported nanosized maghemite throughout the entire samples’ processing.

Evaluation for Protein Binding Affinity of Maghemite and Magnetite Nanoparticles

2007 ◽  
Vol 7 (11) ◽  
pp. 3706-3708 ◽  
Author(s):  
Se Chan Kang ◽  
Yong Jun Jo ◽  
Jong Phil Bak ◽  
Ki-Chul Kim ◽  
Young-Sung Kim
Keyword(s):  
Protein Binding ◽  
Binding Affinity ◽  
Magnetite Nanoparticles ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Human Lung Cancer ◽  
Maghemite Nanoparticles ◽  
Binding Ability ◽  
Sds Page ◽  
Lung Cancer A549 Cell

We investigated the protein binding affinity of magnetite (Fe3O4) and maghemite (γ-Fe2O3) nanoparticles with against non-characterized protein from human lung cancer A549 cell line on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The binding ability of maghemite was 400 ng/mg. According to the SDS-PAGE results, the protein binding affinity of maghemite nanoparticles is stronger than magnetite nanoparticles. These data suggest that a protein can be detected with maghemite nanoparticles.

Rapid Synthesis and Characterization of Maghemite Nanoparticles

2008 ◽  
Vol 8 (2) ◽  
pp. 861-866 ◽  
Author(s):  
Bilsen Tural ◽  
Macit Özenbaş ◽  
Selçuk Atalay ◽  
Mürvet Volkan
Keyword(s):  
Particle Size ◽  
Elevated Temperatures ◽  
Sol Gel ◽  
Volume Ratio ◽  
Silica Matrix ◽  
Superparamagnetic Nanoparticles ◽  
Maghemite Nanoparticles ◽  
Gelation Temperature ◽  
Iron Oxide Particles ◽  
Evaporation Surface

Fe2O3–SiO2 nanocomposites were prepared by a sol–gel method using various evaporation surface to volume (S/V) ratios ranging from 0.03 to 0.2. The Fe2O3–SiO2 sols were gelated at various temperatures ranging from 50 °C to 70 °C, and subsequently they were calcined in air at 400 °C for 4 hours. The structure and the magnetic properties of the prepared Fe2O3–SiO2 nanocomposites were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), differential thermal analysis (DTA), and vibrating sample magnetometer (VSM) measurements. The gelation temperature of the Fe2O3–SiO2 sols influenced strongly the particle size and crystallinity of the maghemite nanoparticles. It was observed that the particle size of maghemite nanoparticles increased with the increasing of the gelation temperature of the sols, which may be due to the agglomeration of the maghemite particles at elevated temperatures inside the microporosity of the silica matrix during the gelation process, and the subsequent calcination of these gels at 400 °C resulted in the formation of large size iron oxide particles. Magnetization studies at temperatures of 10, 195, and 300 K showed superparamagnetic behavior for all the nanocomposites prepared using the evaporation surface to volume ratio (S/V) of 0.1, 0.2, 0.09, and 0.08. The saturation magnetization, Ms, values measured at 10K were 5.5, 8.5, and 9.5 emu/g, for the samples gelated at 50, 60, and 70 °C, respectively. At the gelation temperature of 70 °C, γ-Fe2O3 crystalline superparamagnetic nanoparticles with the particle size of 9±2 nm were formed in 12 hours for the samples prepared at the S/V ratio of 0.2.

scholarly journals Plasma-Enhanced Chemical Vapor Deposition of Indene for Gas Separation Membrane

2019 ◽  
Vol 19 (1) ◽  
pp. 47 ◽  
Author(s):  
Myat Kyaw ◽  
Shinsuki Mori ◽  
Nathaniel Dugos ◽  
Susan Roces ◽  
Arnel Beltran ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Barrier Properties ◽  
Gas Barrier ◽  
Membrane Performance ◽  
Membrane Characterization ◽  
Separation Membrane ◽  
Zeolite 5A ◽  
Ft Ir

Polyindene (PIn) membrane was fabricated onto a zeolite 5A substrate by using plasma-enhanced chemical vapor deposition (PECVD) at low temperature. Membrane characterization was done by taking Scanning Electron Microscopy (SEM) and FT-IR measurements and the new peak was found in the plasma-derived PIn film. Membrane performance was analyzed by checking permeability of pure gases (H2, N2, and CO2) through the membrane. PECVD-derived PIn membrane showed high gas barrier properties and selectivities of 8.2 and 4.0 for H2/CO2 and H2/N2, respectively, at room temperature

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