The Selective Protein Separations with Polyaminofunctionality on Controlled Silica Coating-Layers of Magnetic Nanoparticles

2007 ◽  
pp. 903-906
Author(s):  
Moo Eon Park ◽  
Ki Ho Kang ◽  
Kyung Ja Kim ◽  
Jeong Ho Chang
Keyword(s):  
Magnetic Nanoparticles ◽  
Silica Coating ◽  
Protein Separations ◽  
Coating Layers

The Selective Protein Separations with Polyaminofunctionality on Controlled Silica Coating-Layers of Magnetic Nanoparticles

2007 ◽  
Vol 124-126 ◽  
pp. 903-906 ◽  
Author(s):  
Moo Eon Park ◽  
Ki Ho Kang ◽  
Kyung Ja Kim ◽  
Jeong Ho Chang
Keyword(s):  
Magnetic Nanoparticles ◽  
Protein Separation ◽  
Separation Efficiency ◽  
Sol Gel ◽  
Silica Coating ◽  
Chemical Precipitation ◽  
Molar Ratio ◽  
Basic Solution ◽  
Particle Sizes ◽  
Protein Separations

This work reported the development of the high throughput protein separation process with molecularly assembled silica-coated magnetic nanoparticles as a function of amino group numbers such as mono-, di-, and tri-aminofunctionality, in which the range of silica coating thicknesses were optimized to be interacted with protein. The protein separation efficiency was demonstrated as a function of each aminofunctional group and the particle sizes of the silica coated magnetic nanoparticles. The particles were prepared by the chemical precipitation of Fe2+ and Fe3+ salts with a molar ratio of 1:2 under basic solution. The silica coated magnetic nanoparticles were directly produced by the sol-gel reaction of a tetraethyl orthosilicate (TEOS) precursor, in which the coating layer serves as a biocompatible and versatile group for further biomolecular functionalization. To effectively capture the proteins, silica coated magnetic nanoparticles need to be functionalized reproducibly on the silica surface, and three kinds of amino functional groups were adapted as a function of number of amine using the mono-, di-, and tri-aminopropylalkoxysilanes.

Coated Magnetic Nanoparticles for Acidic Nuclear Waste Separation

2010 ◽  
Vol 1265 ◽  
Author(s):  
Maninder Kaur ◽  
Hongmei Han ◽  
Andrew Johnson ◽  
Jesof Kaczor ◽  
Andrzej Paszczynski ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Solvent Extraction ◽  
Ion Exchange ◽  
Nuclear Waste ◽  
Cost Effective ◽  
Silica Coating ◽  
Coating Process ◽  
Acidic Conditions ◽  
Allylamine Hydrochloride ◽  
Waste Separation

AbstractActinide specific chelator (che) conjugated with magnetic nanoparticles (MNPs) have been developed to separate nuclear waste in acidic conditions. Compared to the traditional nuclear waste treatments, such as solvent extraction and ion exchange, this method is a simple, compact and cost-effective process that generates minimum secondary waste. In this paper, we focus on the coating process of MNPs to achieve a combination of good acidic resistance, high chelator loading density and efficient magnetic separation. An optimized silica coating process before conjugates chelator directly onto MNPs significantly improves the acidic resistance of the MNP-che complex. Chelator loading density is significantly increased by attaching a linear polyamine polymer poly(allylamine hydrochloride) (PAH) to the surface of the MNPs using chemical and physical approaches.

Continuous Synthesis of Inorganic Magnetic Nanocomposites by Laser Pyrolysis for Biomedical Applications

2006 ◽  
Vol 962 ◽  
Author(s):  
Sabino Veintemillas ◽  
Brigitte Bouchet-Fabre ◽  
Maria Puerto Morales ◽  
Yann Leconte ◽  
R Costo ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetic Measurements ◽  
Reaction Times ◽  
Organic Matrix ◽  
Silica Coating ◽  
Step Method ◽  
Magnetic Composites ◽  
Laser Pyrolysis ◽  
Pyrolysis Method ◽  
Inorganic Matrix

ABSTRACTNanocomposite particles made from encapsulation of magnetic nanoparticles in an inorganic matrix have a real interest in biomedicine due to their high resistance against biodegradation compared with nanoparticles encapsulated in an organic matrix and little work has been published concerning such materials. In this work we use the laser pyrolysis method for the preparation of magnetic composites of Fe-based nanoparticles dispersed in silica and carbon. The precursor is an aerosol of a precursor which can be easily used in a safe way. Important advantages of the laser pyrolysis method are the reproducibility, simplicity (one step method) and continuity which allows producing significant amounts of nanoparticles. The short reaction times (ms) involved in the nucleation of the powders insure the nanometric particle size of both the magnetic component and the inorganic matrix.This paper is focused on the synthesis and characterization of the Fe@SiO2 and Fe@C nanopowders generated by laser pyrolysis of ferrocene diluted in toluene and carried to the reaction zone in aerosol form. The silica coating was formed by the addition of tetraethoxysilane (TEOS) to the reactant. The samples were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), transmission electron microscopy (TEM), specific surface area determination (BET) and magnetic measurements. In the case of Fe@SiO2 the process generates rather homogeneous iron/magnetite particles smaller than 10 nm in diameter surrounded by a SiO2 coating of about 20 nm. In the case Fe@C the process generate iron based magnetic nanoparticles of complex composition smaller than 11 nm surrounded by a graphitic carbon layer of 50 nm. Stable aqueous dispersions at physiological pH were produced for both systems by means of strong oxidation in aqueous solutions, which is a very encouraging result for application in the field of living tissues.

Magneto-Structural and Antimicrobial Properties of Sodium Doped Lanthanum Manganite Magnetic Nanoparticles for Biomedical Applications: Influence of Silica Coating

2018 ◽  
Vol 37 ◽  
pp. 117-127 ◽  
Author(s):  
Cyril O. Ehi-Eromosele ◽  
J.A.O. Olugbuyiro ◽  
A. Edobor-Osoh ◽  
A.A. Adebisi ◽  
O.A. Bamgboye ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Magnetic Nanoparticles ◽  
Structural Properties ◽  
Biomedical Applications ◽  
Colloidal Stability ◽  
Antimicrobial Properties ◽  
Silica Coating ◽  
Coated Sample ◽  
Lanthanum Manganites ◽  
Doped Lanthanum Manganites

Coating of magnetic nanoparticles (MNPs) is usually a requirement prior to their utilization in biomedical applications. However, coating can influence the magneto-structural properties of MNPs thereby imparting their applications. The present work highlights the combustion synthesis of Na-doped lanthanum manganites (LNMO) and the influence of silica coatings on the magneto-structural properties, colloidal stability and antimicrobial properties of LNMO MNPs with their biomedical applications in mind. The crystalline perovskite structure was the same both for the bare and silica coated LNMO samples while there was a slight increase in crystallite size after coating. The FTIR spectral analysis, reduction in agglomeration of the particles and the elemental composition of the coated nanoparticles confirmed the presence of silica. The magnetization values of 34 emu/g and 29 emu/g recorded for bare and coated LNMO samples, respectively show that LNMO MNPs retained its ferromagnetic behaviour after silica coating. The pH dependent zeta potentials of the coated sample is-22.20 mV at pH 7.4 (physiological pH) and-18 mV at pH 5.0 (cell endosomal pH). Generally, silica coating reduced the antibacterial activity of the sample except forBacillussppwhere the antibacterial activity was the same with the bare sample. These results showed that while silica coating had marginal effect on the crystalline structure, size and magnetization of LNMO MNPs, it reduced the antibacterial activity of LNMO MNPs and enhanced greatly the colloidal stability of LNMO nanoparticles. Keywords: Na-doped lanthanum manganites, Silica coating, magnetic nanoparticles, biomedical applications, antimicrobial properties, colloidal stability

scholarly journals Covalent immobilization of coagulation factor VIII on magnetic nanoparticles for aptamer development

2018 ◽  
Vol 16 (3) ◽  
pp. 161-170 ◽  
Author(s):  
Maryam Tabarzad ◽  
Zeinab Sharafi ◽  
Jaber Javidi
Keyword(s):  
Magnetic Nanoparticles ◽  
Factor Viii ◽  
Coagulation Factor ◽  
Silica Coating ◽  
Covalent Immobilization ◽  
Coagulation Factor Viii ◽  
Aptamer Selection ◽  
Selection Processes ◽  
Reactive Groups

Introduction: Magnetic nanoparticles (MNPs) are one of the most useful particulate systems in analytical applications such as specific aptamer selection. Proteins are the most noted targets of aptamer selection. Generally, covalently immobilized protein coated MNPs are more stable structures. Methods: In this study, coagulation factor VIII (FVIII) was immobilized on MNPs. A silica coating provided isocyanate functional groups was considered to interact covalently with reactive groups of the protein, resulting in a stable protein immobilization. The reactions was run in dried toluene. At end, these MNPs were applied for affinity determination of a previously selected FVIII specific aptamers. Results: Immobilization of 1 mg FVIII (~ 3 nmol) on 5 mg particles was achieved with no significant particle aggregation. Using a fluorescence-based method, affinity measurement resulted in a calculated dissociation constant of 120 ± 5.6 nM for the FVIII-specific aptamer to the FVIII-coated MNPs. Conclusion: The final product could be a suitable protein-coated solid support for magnetic-based aptamer selection processes.

Synthesize and Characterization of Multifunctional Silica Coated Magnetic Nanoparticles Using Polyvinylpyrrolidone (PVP) as a Mediator

2012 ◽  
Vol 16 ◽  
pp. 43-48 ◽  
Author(s):  
Mirabdullah Seyed Sadjadi ◽  
F. Fathi ◽  
Nazanin Farhadyar ◽  
K. Zare
Keyword(s):  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Cell Protein ◽  
Protein Separations ◽  
X Ray Diffraction ◽  
Magnetic Iron Oxide Nanoparticles ◽  
Coated Nanoparticles ◽  
Transmission Electron ◽  
Iron Oxide Magnetic Nanoparticles

Magnetic iron oxide nanoparticles with proper surface coatings are increasingly being evaluated for clinical applications such as hyperthermia, drug delivery, magnetic resonance imaging, transfection and cell/protein separations. In this work, silica coated iron oxide magnetic nanoparticles, which are very useful for delivering chemotherapeutic drugs, has been prepared by precipitation in an aqueous solution of iron (II) and iron (III) chlorides under basic condition. In this process, polyvinylpyrrolidone (PVP) has been used as a stablizer. Surface modifications of the as-prepared Fe3O4 Nps have been carried out by using tetraethoxysilane (TEOS). Silica coated nanoparticles have been characterized by Fourier transform infrared (FTIR) spectroscopy, Powder X- ray diffraction (XRD), Transmission electron microscopy (TEM) and Infrared (IR) spectroscopy

scholarly journals Synthesis and characterization of magnetic nanoparticles of cobalt ferrite coated with silica

2019 ◽  
Vol 10 (1) ◽  
pp. 4908-4913
Keyword(s):  
Particle Size ◽  
Magnetic Nanoparticles ◽  
Cobalt Ferrite ◽  
Silica Coating ◽  
Ferrite Nanoparticles ◽  
Synthesis And Characterization ◽  
Mean Particle Size ◽  
Cobalt Ferrites ◽  
Coated Nanoparticle

There are several methods available for magnetic nanoparticles (MNP) synthesis, and in this study the coprecipitation method is employed. The cobalt ferrites (CF) were prepared using aqueous solutions of Co2+ and Fe3+ chloride with a stoichiometry proportion of Co:Fe = 1:2. Thus, the aging temperatures were 27, 27/98, 60, 80 and 98 ºC, during which the precipitation occurred at 27 °C and the aging one at 98 °C for the FC27/98 sample. As a result, the study showed that a single crystal phase material was obtained at the aging temperature of 98 °C during 1 h and with a mean particle size of 42 nm ± 7.4 nm and degree of polydispersity of 18%. The FC98/SiOH coated nanoparticle had a surface area of 11 m2 g-1, saturation magnetization of 10.05 emu g-1 a mean particle size of 773.4 nm ± 131.1 nm and a degree of polydispersity of 17 %. It was possible to confirm that it had a silica coating of cobalt ferrite nanoparticles by DRIFT and EDX indicated the presence of silica.

Silica coating of Fe3O4 magnetic nanoparticles with PMIDA assistance to increase the surface area and enhance peptide immobilization efficiency

2021 ◽  
Author(s):  
Alexander M. Demin ◽  
Aleksei I. Maksimovskikh ◽  
Alexander V. Mekhaev ◽  
Dmitry K. Kuznetsov ◽  
Artyom S. Minin ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Surface Area ◽  
Silica Coating ◽  
Fe3o4 Magnetic Nanoparticles
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