Loading...
Search for: superparamagnetism
0.006 seconds
Total 80 records

    Aggregation and detection of magnetic nanoparticles in microfluidic channels

    , Article Journal of Electrical Engineering ; Volume 63, Issue 7 SUPPL , 2012 , Pages 27-30 ; 13353632 (ISSN) Sarreshtedari, F ; Kokabi, H ; Gamby, J ; Ngo, K. A ; Krause, H. J ; Fardmanesh, M ; Sharif University of Technology
    2012
    Abstract
    Incorporating numerical simulation with COMSOL Multiphysics, the aggregation and detection of superparamagnetic nanoparticles in microfluidic channels are investigated. Considering the physical specifications of the implemented microchannels, the parameters which determine the ability of the system for aggregation and detection of the particles are examined and simulated. Based on the simulation results, we propose a new approach for both capturing and detecting of the magnetic nanoparticles passing through microchannels  

    Size-controlled synthesis of superparamagnetic iron oxide nanoparticles and their surface coating by gold for biomedical applications [electronic resource]

    , Article Journal of Magnetism and Magnetic Materials ; Volume 324, Issue 23, November 2012, Pages 3997–4005 Maleki H. (Homa) ; Simchi, A ; Imani, M ; Costa, B.F.O ; Sharif University of Technology
    Abstract
    The size mono-dispersity, saturation magnetization, and surface chemistry of magnetic nanoparticles (NPs) are recognized as critical factors for efficient biomedical applications. Here, we performed modified water-in-oil inverse nano-emulsion procedure for preparation of stable colloidal superparamagnetic iron oxide NPs (SPIONs) with high saturation magnetization. To achieve mono-dispersed SPIONs, optimization process was probed on several important factors including molar ratio of iron salts [Fe3+ and Fe2+], the  

    Preparation and biological evaluation of [67 Ga]-labeled-superparamagnetic iron oxide nanoparticles in normal rats

    , Article Journal of Nuclear Science and Technology ; Volume 97, Issue 1 , September , 2009 , Pages 51–56 Jalilian, A. R ; Panahifar, A ; Mahmoudi, M. (Morteza) ; Akhlaghi, M. (Mahdi) ; Simchi, A. (Abdolreza) ; Sharif University of Technology
    Abstract
    Gallium-67 labeled superparamagnetic iron oxide nanoparticles were prepared and evaluated for their altered biodistribution in normal rats. Superparamagnetic iron oxide nanoparticles with narrow size distribution were synthesized by co-precipitation technique using ferric and ferrous salts at molar ratio Fe3+/Fe2+=2:1 followed by structure identification using XRD, thermo gravimetric analysis , differential scanning calorimetric , vibrating sample magnetometer, high-resolution scanning electron microscopy,transmission electron microscopy and fourier transform infrared absorption techniques. In order to trace superparamagnetic iron oxide nanoparticles bio-distribution, the radiolabeled iron... 

    Preparation and biological evaluation of [67Ga]-labeled- superparamagnetic nanoparticles in normal rats

    , Article Radiochimica Acta ; Volume 97, Issue 1 , 2009 , Pages 51-56 ; 00338230 (ISSN) Jalilian, A. R ; Panahifar, A ; Mahmoudi, M ; Akhlaghi, M ; Simchi, A ; Sharif University of Technology
    R. Oldenbourg Verlag GmbH  2009
    Abstract
    Gallium-67 labeled superparamagnetic iron oxide nanoparticles ([ 67Ga]-SPION were prepared and evaluated for their altered biodistribution in normal rats. Superparamagnetic iron oxide nanoparticles (SPION) with narrow size distribution were synthesized by a co-precipitation technique using ferrous salts at Fe3+/Fe2+ = 2 molar ratio followed by structure identification using XRD, TGA, DSC, VSM, HRSEM, TEM and FT-IR techniques (≈ 5 nm diameter). In order to trace SPION bio-distribution, the radiolabeled iron oxide nanoparticles were prepared using 67Ga with a high labeling efficiency (over 96%, RTLC method) and they also showed an excellent stability at room temperature for at least 4 d. The... 

    Highly biocompatible multifunctional hybrid nanoparticles based on Fe3O4 decorated nanodiamond with superior superparamagnetic behaviors and photoluminescent properties

    , Article Materials Science and Engineering C ; Volume 114 , September , 2020 Salkhi Khasraghi, S ; Shojaei, A ; Sundararaj, U ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    The multifunctional nanostructures with superparamagnetic and luminescent properties undergo revolution in the field of bio-nanotechnology. In this article, we reported a facile and efficient one-step modified co-precipitation method to load superparamagnetic Fe3O4 nanoparticle on oxidized nanodiamond (Ox-ND). Subsequently, the as-prepared Ox-ND/Fe3O4 hybrid nanoparticle was surface functionalized with vinyltrimethoxysilane (VTMS) to enhance its compatibility with organic media. The structure, morphology, magnetic, and optical properties of the nanohybrid were systematically investigated. The results confirmed successful loading of crystalline Fe3O4 on the surface of Ox-ND. Ox-ND/Fe3O4... 

    Study of the Effect of Surfactant and Fe Concentration on the Size and Physical Properties of Magnetic Fe-Au Core-Shell Nano Particles, Synthesized Via Reverse Nicelle

    , M.Sc. Thesis Sharif University of Technology Molavi Kakhki, Amin (Author) ; Simchi, Abdolreza (Supervisor) ; Abachi, Parvin (Supervisor)
    Abstract
    The aim of this research is to study the effect of surfactant type and the concentration reactants on the size, shape and magnetic properties of iron-gold core-shell magnetic nanoparticles (NPs) useable for biomedical application. The reverse micelle procedure was employed to synthesize iron NPs using two surfactants of CTAB and SDS. A gold shell with a thickness in the range of 10 to 40 nm was induced by reverse micelle method in order to prevent oxidation of the iron core. The size and morphology of NPs were studied by transition electron microscopy (TEM). It was found that the size of NPs increases by the increasing the reactants concentration while the morphology of the NPs was not... 

    Structural, magnetic, and optical properties of zinc-and copper-substituted nickel ferrite nanocrystals

    , Article Journal of Superconductivity and Novel Magnetism ; Volume 25, Issue 7 , 2012 , Pages 2443-2455 ; 15571939 (ISSN) Tehrani, F. S ; Daadmehr, V ; Rezakhani, A. T ; Akbarnejad, R. H ; Gholipour, S ; Sharif University of Technology
    Springer  2012
    Abstract
    Ferrite nanocrystals are an interesting material due to their rich physical properties. Here we add nonmagnetic dopants Zn and Cu to nickel ferrite nanocrystals, Ni1-xMxFe2O4 (0 ≤ x ≤ 1, M = Cu, Zn), and study how relevant properties of the samples are modified accordingly. Basically, these dopings cause a rearrangement of Fe +3 ions into the two preexisting octahedral and tetrahedral sites. In fact, this, we show, induces pertinent magnetic properties of the doped samples. In the case of the Cu-doping, the Jahn-Teller effect also emerges, which we identify through the Fourier Transform Infra-Red Spectroscopy of the samples. Moreover, we show an increase in the lattice parameters of the... 

    α-Arylation of oxindoles using recyclable metal oxide ferrite nanoparticles: Comparison between the catalytic activities of nickel, cobalt and copper ferrite nanoparticles

    , Article Catalysis Communications ; Volume 75 , 2016 , Pages 37-41 ; 15667367 (ISSN) Matloubi Moghaddam, F ; Tavakoli, G ; Latifi, F ; Saeednia, B ; Sharif University of Technology
    Elsevier 
    Abstract
    Three different spinel metal oxide catalytic systems including NiFe2O4, CuFe2O4 and CoFe2O4 were synthesized using co-precipitation technique and their catalytic activities were compared to each other in α-arylation of oxindole derivatives under the optimized reaction conditions. Both nickel ferrite and copper ferrite magnetic nanoparticles show approximately the same behavior in these reactions but cobalt ferrite ones indicate slightly different properties and were not as good as the other two catalysts. These superparamagnetic catalysts allowed that α-arylation of different types of oxindoles will occur in high yields under mild conditions and at very short times  

    Superparamagnetic enzyme-graphene oxide magnetic nanocomposite as an environmentally friendly biocatalyst: Synthesis and biodegradation of dye using response surface methodology

    , Article Microchemical Journal ; Volume 145 , 2019 , Pages 547-558 ; 0026265X (ISSN) Kashefi, S ; Borghei, S. M ; Mahmoodi, N. M ; Sharif University of Technology
    Elsevier Inc  2019
    Abstract
    The unique properties of graphene oxide (GO) nanosheets were integrated with the superparamagnetic characteristics of the CuFe2O4 nanoparticles to synthesize the magnetic graphene oxide (MGO), which was chemically modified with 3-amino propyl trimethoxy silane (APTMS) to functionalize the amine group on MGO (MGO-NH2). Afterward, MGO-NH2 was activated with glutaraldehyde (GLU) as a crosslinking agent to synthesize the functionalized MGO (fMGO) and its capability toward covalent Laccase immobilization was investigated. The comprehensive structural analysis using various characterization techniques, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating... 

    Synthesis, characterization and in vitro analysis of superparamagnetic iron oxide nanoparticles for targeted hyperthermia therapy

    , Article Chemical Papers ; 2020 Hedayatnasab, Z ; Dabbagh, A ; Abnisa, F ; Karimian, H ; Abu Kasim, N. H ; Wan Daud, W. M. A ; Sharif University of Technology
    Springer  2020
    Abstract
    Abstract: Superparamagnetic iron oxide nanoparticles (SPIONs) are considered as promising magnetic nanoheating agents for diagnostic as well as therapeutic applications due to their biocompatibility and tunability of magnetic properties. These nanoheating agents are commonly synthesized by coprecipitation of two iron precursors, though applying less amount of these chemicals may minimize the toxicity risks for biomedical purposes. The aim of this study is to address this issue by considering the high oxidation vulnerability of ferrous ions to ferric ions to synthesize SPIONs via a single-iron precursor under four varied oxidative conditions. The obtained results implied that the properties... 

    Synthesis, characterization and in vitro analysis of superparamagnetic iron oxide nanoparticles for targeted hyperthermia therapy

    , Article Chemical Papers ; Volume 75, Issue 2 , 2021 , Pages 669-679 ; 03666352 (ISSN) Hedayatnasab, Z ; Dabbagh, A ; Abnisa, F ; Karimian, H ; Abu Kasim, N. H ; Wan Daud, W. M. A ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Abstract
    Abstract: Superparamagnetic iron oxide nanoparticles (SPIONs) are considered as promising magnetic nanoheating agents for diagnostic as well as therapeutic applications due to their biocompatibility and tunability of magnetic properties. These nanoheating agents are commonly synthesized by coprecipitation of two iron precursors, though applying less amount of these chemicals may minimize the toxicity risks for biomedical purposes. The aim of this study is to address this issue by considering the high oxidation vulnerability of ferrous ions to ferric ions to synthesize SPIONs via a single-iron precursor under four varied oxidative conditions. The obtained results implied that the properties... 

    Preparation and Evaluation of Doxorubicin-loaded Fe3O4\Chitosan Magnetic Nanocomposite for Drug Delivery System in Cancer Therapy

    , M.Sc. Thesis Sharif University of Technology Tajeri, Razieh (Author) ; Maddah Hosseini, Hamid Reza (Supervisor)
    Abstract
    Recent drug delivery strategies have attempted to maximize the concentration of chemotherapeutic molecules into the tumors, while minimizing their systemic distribution. Doxorubicin has been widely used for a variety of cancers, successfully producing regression in acute leukaemia, lymphomas, soft-tissue and osteogenic sarcomas, paediatric malignancies and adult solid tumours, in particular breast and lung carcinomas. Common adverse effects of doxorubicin include hair loss, myelosuppression, nausea and vomiting, oral mucositis, oesophagitis, diarrhoea, skin reactions and serious reactions include hypersensitivity reactions, radiation recall, heart damage and liver dysfunction. Chitosan has... 

    Superparamagnetic zinc ferrite spinel-graphene nanostructures for fast wastewater purification

    , Article Carbon ; Vol. 69 , April , 2014 , pp. 230-238 ; ISSN: 00086223 Meidanchi, A ; Akhavan, O ; Sharif University of Technology
    Abstract
    Superparamagnetic ZnFe2O4/reduced graphene oxide (rGO) composites containing ZnFe2O4 nanoparticles (with ∼5-20 nm sizes) attached onto rGO sheets (with ∼1 μm lateral dimensions) were synthesized by hydrothermal reaction method. By increasing the graphene content of the composite from 0 to 40 wt%, the size as well as the number of the ZnFe2O4 nanoparticles decreased and the saturated magnetization of the composites reduced from 10.2 to 1.8 emu/g, resulting in lower responses to external magnetic fields. Concerning this, the time needed for 90% separation of ZnFe2O4/rGO (40 wt%) composite from its solution (2 mg/mL in ethanol) was found 60 min in the presence of an external magnetic field (∼1... 

    Lipase immobilisation on magnetic silica nanocomposite particles: Effects of the silica structure on properties of the immobilised enzyme

    , Article Journal of Materials Chemistry ; Volume 22, Issue 17 , 2012 , Pages 8385-8393 ; 09599428 (ISSN) Kalantari, M ; Kazemeini, M ; Tabandeh, F ; Arpanaei, A ; Sharif University of Technology
    2012
    Abstract
    Uniformly sized superparamagnetic single-shell nonporous (S1) and double-shell mesoporous silica nanocomposite particles with ∼130 nm magnetite cluster cores are synthesised in this study. Mesoporous particles are prepared with two BJH pore sizes (2.44 and 3.76 nm, designated as S2 and S3 particles, respectively). Once the lipase was immobilised on particles, our results showed that the enzyme loading capacities of mesoporous structures, i.e. S2 and S3, are higher than that for nonporous particles (S1). Hydrolytic activity tests reveal that immobilised lipases retain about 90% of the free enzyme's activity. Furthermore, comparing to the free enzyme, the thermal stability of immobilised... 

    Superparamagnetic nanoparticles for epilepsy detection

    , Article World Congress on Medical Physics and Biomedical Engineering, 2015, 7 June 2015 through 12 June 2015 ; Volume 51 , June , 2015 , Pages 1237-1240 ; 16800737 (ISSN) ; 9783319193878 (ISBN) Pedram, M. Z ; Shamloo, A ; Alasty, A ; Ghafar Zadeh, E ; Jaffray D. A ; Sharif University of Technology
    Springer Verlag  2015
    Abstract
    Epilepsy is the most common neurological disorder that is known with uncontrolled seizure. Around 30% of patients with epilepsy resist to all forms of medical treatments and therefore, the removal of epileptic brain tissue is the only solution to get these patients free from chronical seizures. The precise detection of an epileptic zone is key to its treatment. In this paper, we propose a method of epilepsy detection using brain magnetic field. The possibility of superparamagnetic nanoparticle (SPMN) as sensors for the detection of the epileptic area inside the brain is investigated. The aggregation of nanoparticles in the weak magnetic field of epileptic brain is modeled using potential... 

    Study the effect of ultrasonic irradiation and surfactant/fe ions weight ratio on morphology and particle size of magnetite nanoparticles synthesised by co-precipitation for medical application

    , Article World Academy of Science, Engineering and Technology ; Volume 64 , 2010 , Pages 457-460 ; 2010376X (ISSN) Azimipour Meibod, S. S ; Pourafshary, P ; Madaah Hosseini, H. R ; Sharif University of Technology
    2010
    Abstract
    A biocompatible ferrofluid have been prepared by coprecipitation of FeCl 2.4H 2O and FeCl 3.6H 2O under ultrasonic irradiation and with NaOH as alkaline agent. Cystein was also used as capping agent in the solution. Magnetic properties of the produced ferrofluid were then determined by VSM test and magnetite nanoparticles were characterized by XRD and TEM techniques. The effect of surfactant to Fe ion weight ratio was also studied during this project by using two different amount of Dextran. Results showed the presence of a biocompatible superparamagnetic ferrofluid including magnetite nanoparticles with particle size ranging under 20 nm. The increase in the surfactant content results in the... 

    Optimal magnetic field for crossing super-para-magnetic nanoparticles through the Brain Blood Barrier: A computational approach

    , Article Biosensors ; Volume 6, Issue 2 , 2016 ; 20796374 (ISSN) Pedram, M. Z ; Shamloo, A ; Alasty, A ; Ghafar Zadeh, E ; Sharif University of Technology
    MDPI AG  2016
    Abstract
    This paper scrutinizes the magnetic field effect to deliver the superparamagnetic nanoparticles (SPMNs) through the Blood Brain Barrier (BBB). Herein we study the interaction between the nanoparticle (NP) and BBB membrane using Molecular Dynamic (MD) techniques. The MD model is used to enhance our understanding of the dynamic behavior of SPMNs crossing the endothelial cells in the presence of a gradient magnetic field. Actuation of NPs under weak magnetic field offers the great advantage of a non-invasive drug delivery without the risk of causing injury to the brain. Furthermore, a weak magnetic portable stimulator can be developed using low complexity prototyping techniques. Based on MD... 

    Size-controlled synthesis of superparamagnetic iron oxide nanoparticles and their surface coating by gold for biomedical applications

    , Article Journal of Magnetism and Magnetic Materials ; Volume 324, Issue 23 , November , 2012 , Pages 3997-4005 ; 03048853 (ISSN) Maleki, H ; Simchi, A ; Imani, M ; Costa, B. F. O ; Sharif University of Technology
    2012
    Abstract
    The size mono-dispersity, saturation magnetization, and surface chemistry of magnetic nanoparticles (NPs) are recognized as critical factors for efficient biomedical applications. Here, we performed modified water-in-oil inverse nano-emulsion procedure for preparation of stable colloidal superparamagnetic iron oxide NPs (SPIONs) with high saturation magnetization. To achieve mono-dispersed SPIONs, optimization process was probed on several important factors including molar ratio of iron salts [Fe 3 and Fe 2], the concentration of ammonium hydroxide as reducing agent, and molar ratio of water to surfactant. The biocompatibility of the obtained NPs, at various concentrations, was evaluated via... 

    Comparison of using formaldehyde and carboxy methyl chitosan in preparation of Fe3O4 superparamagnetic nanoparticles-chitosan hydrogel network: Sorption behavior toward bovine serum albumin

    , Article Process Safety and Environmental Protection ; Volume 102 , 2016 , Pages 119-128 ; 09575820 (ISSN) Sadeghi, M ; Hanifpour, F ; Taheri, R ; Javadian, H ; Ghasemi, M ; Sharif University of Technology
    Institution of Chemical Engineers 
    Abstract
    A novel and cost effective method of bio-separation developed recently is magnetic separation technology. In this study, super paramagnetic Fe3O4 nanoparticles are used for separation of bovine serum albumin (BSA) protein from plasma/serum samples at optimized conditions. The synthesis of chitosan hydrogel networks by two variant approaches that involve (1) crosslinking of chitosan with formaldehyde and (2) formation of carboxy methyl chitosan mediated complex, was investigated and the percent of gelation, swelling ratio and equilibrium water content were calculated. The results revealed the formation of better quality hydrogel from the first approach. In step 1, to quantify the BSA... 

    Mechanistic understanding of the interactions between nano-objects with different surface properties and α-synuclein

    , Article ACS Nano ; Volume 13, Issue 3 , 2019 , Pages 3243-3256 ; 19360851 (ISSN) Mohammad Beigi, H ; Hosseini, A ; Adeli, M ; Ejtehadi, M. R ; Christiansen, G ; Sahin, C ; Tu, Z ; Tavakol, M ; Dilmaghani Marand, A ; Nabipour, I ; Farzadfar, F ; Otzen, D. E ; Mahmoudi, M ; Hajipour, M. J ; Sharif University of Technology
    American Chemical Society  2019
    Abstract
    Aggregation of the natively unfolded protein α-synuclein (α-syn) is key to the development of Parkinson's disease (PD). Some nanoparticles (NPs) can inhibit this process and in turn be used for treatment of PD. Using simulation strategies, we show here that α-syn self-assembly is electrostatically driven. Dimerization by head-to-head monomer contact is triggered by dipole-dipole interactions and subsequently stabilized by van der Waals interactions and hydrogen bonds. Therefore, we hypothesized that charged nano-objects could interfere with this process and thus prevent α-syn fibrillation. In our simulations, positively and negatively charged graphene sheets or superparamagnetic iron oxide...