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Superparamagnetic Magnetite Nanoparticles (superparamagnetic + magnetite_nanoparticle)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

Heparinized Magnetic Nanoparticles: In-Vitro Assessment for Biomedical Applications,

ADVANCED FUNCTIONAL MATERIALS, Issue 13 2006
C. Wuang
Abstract Superparamagnetic magnetite nanoparticles are of great interest owing to their numerous existing and potential biomedical applications. In this study, superparamagnetic magnetite nanoparticles with average diameters of 6,8,nm have been prepared and surface-functionalized with poly(N -isopropylacrylamide) (poly(NIPAAM)) via a surface-initiated atom-transfer radical polymerization, followed by immobilization of heparin. The success of the various surface-functionalization steps has been ascertained using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The rate of internalization of the as-synthesized and surface-functionalized magnetite nanoparticles by mouse macrophage cells has been investigated. The nanoparticle internalization into the macrophages has been visualized using optical microscopy and quantified by inductively coupled plasma spectroscopy. The effectiveness of the heparinized nanoparticles in preventing thrombosis has been determined using the plasma recalcification time. The results indicate that the above-mentioned surface modifications of the magnetite nanoparticles are effective in delaying phagocytosis and preventing blood clotting in vitro. Such properties can be expected to enable their use in biomedical applications. [source]

Chitosan-induced synthesis of magnetite nanoparticles via iron ions assembly

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9 2008
Yongliang Wang
Abstract Superparamagnetic magnetite nanoparticles were synthesized induced by chitosan hydrogel under ambient conditions via iron ions assembly, and the inducing effect of chitosan hydrogel was discussed. Results of X-ray diffraction and transmission electron microscopy indicate that the nanoparticles were inverse cubic spinel structure magnetite with diameter about 16,nm, and the superparamagnetic nanoparticles with narrow size distribution dispersed uniformly in chitosan. The magnetization measurements indicated that the nanoparticles showed the typical superparamagnetic behavior. The crystallinity, morphology, and magnetic properties of magnetite nanoparticles were remarkably influenced by the pH values of iron ion solutions. The interaction between magnetite and chitosan was illustrated by FT-IR and thermogravimetric analysis, which concluded that the magnetite nanoparticles were coated by a chitosan layer via the amino groups of chitosan. The chitosan hydrogel assisted in the synthesis of superparamagnetic magnetite nanoparticles through chelation by amino groups. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Heparinized Magnetic Nanoparticles: In-Vitro Assessment for Biomedical Applications,

ADVANCED FUNCTIONAL MATERIALS, Issue 13 2006
C. Wuang
Abstract Superparamagnetic magnetite nanoparticles are of great interest owing to their numerous existing and potential biomedical applications. In this study, superparamagnetic magnetite nanoparticles with average diameters of 6,8,nm have been prepared and surface-functionalized with poly(N -isopropylacrylamide) (poly(NIPAAM)) via a surface-initiated atom-transfer radical polymerization, followed by immobilization of heparin. The success of the various surface-functionalization steps has been ascertained using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The rate of internalization of the as-synthesized and surface-functionalized magnetite nanoparticles by mouse macrophage cells has been investigated. The nanoparticle internalization into the macrophages has been visualized using optical microscopy and quantified by inductively coupled plasma spectroscopy. The effectiveness of the heparinized nanoparticles in preventing thrombosis has been determined using the plasma recalcification time. The results indicate that the above-mentioned surface modifications of the magnetite nanoparticles are effective in delaying phagocytosis and preventing blood clotting in vitro. Such properties can be expected to enable their use in biomedical applications. [source]

Chitosan-induced synthesis of magnetite nanoparticles via iron ions assembly

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9 2008
Yongliang Wang
Abstract Superparamagnetic magnetite nanoparticles were synthesized induced by chitosan hydrogel under ambient conditions via iron ions assembly, and the inducing effect of chitosan hydrogel was discussed. Results of X-ray diffraction and transmission electron microscopy indicate that the nanoparticles were inverse cubic spinel structure magnetite with diameter about 16,nm, and the superparamagnetic nanoparticles with narrow size distribution dispersed uniformly in chitosan. The magnetization measurements indicated that the nanoparticles showed the typical superparamagnetic behavior. The crystallinity, morphology, and magnetic properties of magnetite nanoparticles were remarkably influenced by the pH values of iron ion solutions. The interaction between magnetite and chitosan was illustrated by FT-IR and thermogravimetric analysis, which concluded that the magnetite nanoparticles were coated by a chitosan layer via the amino groups of chitosan. The chitosan hydrogel assisted in the synthesis of superparamagnetic magnetite nanoparticles through chelation by amino groups. Copyright © 2008 John Wiley & Sons, Ltd. [source]