Preparation, characterization and MRI application of carboxymethyl dextran coated magnetic nanoparticles

2011 ◽  
Vol 257 (15) ◽  
pp. 6711-6717 ◽  
Author(s):  
G. Liu ◽  
R.Y. Hong ◽  
L. Guo ◽  
Y.G. Li ◽  
H.Z. Li
Keyword(s):  
Magnetic Nanoparticles ◽  
Carboxymethyl Dextran

(Carboxymethyl-Dextran)-Modified Magnetic Nanoparticles Conjugated to Octreotide for MRI Applications

2010 ◽  
Vol 2010 (34) ◽  
pp. 5455-5461 ◽  
Author(s):  
Guo-Cheng Han ◽  
Yang Ouyang ◽  
Xue-Ying Long ◽  
Yu Zhou ◽  
Meng Li ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Modified Magnetic Nanoparticles ◽  
Carboxymethyl Dextran

scholarly journals Epoxy Functionalized Carboxymethyl Dextran Magnetic Nanoparticles for Immobilization of Alcohol Dehydrogenase

2020 ◽  
Vol 67 (4) ◽  
pp. 1172-1179
Author(s):  
Katja Vasić ◽  
Željko Knez ◽  
Sanjay Kumar ◽  
Jitendra K. Pandey ◽  
Maja Leitgeb
Keyword(s):  
Magnetic Nanoparticles ◽  
Alcohol Dehydrogenase ◽  
Residual Activity ◽  
Enzyme Concentration ◽  
Process Conditions ◽  
Microbial Inhibition ◽  
Ft Ir ◽  
Cross Linker ◽  
And Staphylococcus Aureus ◽  
Carboxymethyl Dextran

Microbial inhibition of carboxymethyl dextran (CMD) magnetic nanoparticles (MNPs) was investigated on two different bacterial cultures, Escherichia coli and Staphylococcus aureus, where inhibition properties of CMD-MNPs were confirmed, while uncoated MNPs exhibited no inhibition properties. To such CMD-MNPs, enzyme alcohol dehydrogenase (ADH) from Saccharomyces cerevisiae was immobilized. Later on, CMD-MNPs were functionalized, using an epoxide cross-linker epiclorohydrin (EClH) for another option of ADH immobilization. Residual activities of immobilized ADH onto epoxy functionalized and non-functionalized CMD-MNPs were determined. Effect of cross-linker concentration, temperature of immobilization and enzyme concentration on residual activities of immobilized ADH were determined, as well. With optimal process conditions (4% (v/v) EClH, 4 °C and 0.02 mg/mL of ADH), residual activity of immobilized ADH was 90%. Such immobilized ADH was characterized using FT-IR, SEM and DLS analysis.

The effect of grafting method on the colloidal stability and in vitro cytotoxicity of carboxymethyl dextran coated magnetic nanoparticles

2010 ◽  
Vol 20 (39) ◽  
pp. 8539 ◽  
Author(s):  
Mar Creixell ◽  
Adriana P. Herrera ◽  
Magda Latorre-Esteves ◽  
Vanessa Ayala ◽  
Madeline Torres-Lugo ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Colloidal Stability ◽  
In Vitro Cytotoxicity ◽  
Carboxymethyl Dextran

scholarly journals Immobilization of alcohol dehydrogenase from Saccharomyces cerevisiae onto carboxymethyl dextran-coated magnetic nanoparticles: a novel route for biocatalyst improvement via epoxy activation

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Katja Vasić ◽  
Željko Knez ◽  
Maja Leitgeb
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Magnetic Nanoparticles ◽  
Alcohol Dehydrogenase ◽  
Rotation Speed ◽  
Enzyme Concentration ◽  
Novel Method ◽  
Activating Agent ◽  
Epoxy Groups ◽  
Thermal Stability Of ◽  
Carboxymethyl Dextran

Abstract A novel method is described for the immobilization of alcohol dehydrogenase (ADH) from Saccharomyces cerevisiae onto carboxymethyl dextran (CMD) coated magnetic nanoparticles (CMD-MNPs) activated with epoxy groups, using epichlorohydrin (EClH). EClH was used as an activating agent to bind ADH molecules on the surface of CMD-MNPs. Optimal immobilization conditions (activating agent concentration, temperature, rotation speed, medium pH, immobilization time and enzyme concentration) were set to obtain the highest expressed activity of the immobilized enzyme. ADH that was immobilized onto epoxy-activated CMD-MNPs (ADH-CMD-MNPs) maintained 90% of the expressed activity. Thermal stability of ADH-CMD-MNPS after 24 h at 20 °C and 40 °C yielded 79% and 80% of initial activity, respectively, while soluble enzyme activity was only 19% at 20 °C and the enzyme was non-active at 40 °C. Expressed activity of ADH-CMD-MNPs after 21 days of storage at 4 °C was 75%. Kinetic parameters (KM, vmax) of soluble and immobilized ADH were determined, resulting in 125 mM and 1.2 µmol/min for soluble ADH, and in 73 mM and 4.7 µmol/min for immobilized ADH.

scholarly journals Structural and magnetic characteristics of carboxymethyl dextran coated magnetic nanoparticles: From characterization to immobilization application

2020 ◽  
Vol 148 ◽  
pp. 104481 ◽  
Author(s):  
Katja Vasić ◽  
Željko Knez ◽  
Elizaveta A. Konstantinova ◽  
Alexander I. Kokorin ◽  
Sašo Gyergyek ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetic Characteristics ◽  
Carboxymethyl Dextran

scholarly journals Magnetic Nanoparticles with High Specific Absorption Rate at Low Alternating Magnetic Field

Nano LIFE ◽  
2015 ◽  
Vol 05 (02) ◽  
pp. 1550002 ◽  
Author(s):  
K. Kekalo ◽  
I. Baker ◽  
R. Meyers ◽  
J. Shyong
Keyword(s):  
Magnetic Field ◽  
Magnetic Nanoparticles ◽  
Magnetic Nanoparticle ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Alternating Magnetic Field ◽  
Hyperthermia Treatment ◽  
Specific Absorption ◽  
New Type ◽  
Carboxymethyl Dextran

This paper describes the synthesis and properties of a new type of magnetic nanoparticle (MNP) for use in the hyperthermia treatment of tumors. These particles consist of 2–4 nm crystals of gamma- Fe 2 O 3 gathered in 20–40 nm aggregates with a coating of carboxymethyl-dextran, producing a zetasize of 110–120 nm. Despite their very low saturation magnetization (1.5–6.5 emu/g), the specific absorption rate (SAR) of the nanoparticles is 22–200 W/g at applied alternating magnetic field (AMF) with strengths of 100–500 Oe at a frequency of 160 kHz.

Thermal Conductivity of Nanofluid with Magnetic Nanoparticles

PIERS Online ◽  
2009 ◽  
Vol 5 (3) ◽  
pp. 231-234 ◽  
Author(s):  
Tsung-Han Tsai ◽  
Long-Sheng Kuo ◽  
Ping-Hei Chen ◽  
Chin-Ting Yang
Keyword(s):  
Thermal Conductivity ◽  
Magnetic Nanoparticles

Ferromagnetic Resonance Biosensor for Homogeneous and Volumetric Detection of DNA

2017 ◽  
Author(s):  
Bo Tian ◽  
Peter Svedlindh ◽  
Mattias Strömberg ◽  
Erik Wetterskog
Keyword(s):  
Magnetic Nanoparticles ◽  
Ferromagnetic Resonance ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Rolling Circle Amplification ◽  
Resonance Field ◽  
Isothermal Amplification ◽  
Detection Sensitivity ◽  
Serum Samples ◽  
Rolling Circle

In this work, we demonstrate for the first time, a ferromagnetic resonance (FMR) based homogeneous and volumetric biosensor for magnetic label detection. Two different isothermal amplification methods, <i>i.e.</i>, rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) are adopted and combined with a standard electron paramagnetic resonance (EPR) spectrometer for FMR biosensing. For RCA-based FMR biosensor, binding of RCA products of a synthetic Vibrio cholerae target DNA sequence gives rise to the formation of aggregates of magnetic nanoparticles. Immobilization of nanoparticles within the aggregates leads to a decrease of the net anisotropy of the system and a concomitant increase of the resonance field. A limit of detection of 1 pM is obtained with an average coefficient of variation of 0.16%, which is superior to the performance of other reported RCA-based magnetic biosensors. For LAMP-based sensing, a synthetic Zika virus target oligonucleotide is amplified and detected in 20% serum samples. Immobilization of magnetic nanoparticles is induced by their co-precipitation with Mg<sub>2</sub>P<sub>2</sub>O<sub>7</sub> (a by-product of LAMP) and provides a detection sensitivity of 100 aM. The fast measurement, high sensitivity and miniaturization potential of the proposed FMR biosensing technology makes it a promising candidate for designing future point-of-care devices.<br>

Magnetic Nanoparticles for Extracting DNA from Blood Cells

2020 ◽  
Vol 84 (11) ◽  
pp. 1362-1365
Author(s):  
A. V. Komina ◽  
R. N. Yaroslavtsev ◽  
Y. V. Gerasimova ◽  
S. V. Stolyar ◽  
I. A. Olkhovsky ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Blood Cells
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