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Superparamagnetic Iron Oxide Nanoparticles (superparamagnetic + iron_oxide_nanoparticle)

Distribution by Scientific Domains

Polymers and Materials Science	28%

Selected Abstracts

Superparamagnetic Iron Oxide Nanoparticle,Aptamer Bioconjugates for Combined Prostate Cancer Imaging and Therapy

CHEMMEDCHEM, Issue 9 2008
Andrew
Multifunctional superparamagnetic iron oxide nanoparticles: Herein we report a novel, targeted, iron oxide nanoparticle for combined prostate cancer imaging and therapy. By conjugating an aptamer to a thermally stable iron oxide nanoparticle, we have demonstrated that bioconjugates can detect prostate cancer cells with high sensitivity and specificity. Furthermore, the bioconjugates can be used to deliver targeted chemotherapy. [source]

EPR studies on Na-oleate coated Fe3O4 nanoparticles

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2004
Y. Köseo
Abstract Superparamagnetic iron oxide nanoparticles were prepared by the co-precipitation technique. Then, fine iron oxide nanoparticles were coated by Na-oleate. Magnetic properties of Na-oleate coated and uncoated iron oxide nanoparticles were investigated by Electron Paramagnetic Resonance (EPR) technique. At room temperature, a single, strong and broad EPR signal was observed for both samples with effective g-values of 2,0839 and 2,18838 for coated and uncoated samples, respectively. The intensity, line width and the resonance field for both coated and uncoated samples are strongly temperature dependent. When the sample is coated with Na-oleate, the line width and the resonance field values of the EPR signal increase due to the decrease in the magnetic interaction between the particles. The total effective magnetic moment of such coated particles is found to decrease, which is most likely due to a non-collinear spin structure originated from the pinning of the surface spins and coated surfactant at the interface of nanoparticles. [source]

PEI,PEG,Chitosan-Copolymer-Coated Iron Oxide Nanoparticles for Safe Gene Delivery: Synthesis, Complexation, and Transfection

ADVANCED FUNCTIONAL MATERIALS, Issue 14 2009
Forrest M. Kievit
Abstract Gene therapy offers the potential of mediating disease through modification of specific cellular functions of target cells. However, effective transport of nucleic acids to target cells with minimal side effects remains a challenge despite the use of unique viral and non-viral delivery approaches. Here, a non-viral nanoparticle gene carrier that demonstrates effective gene delivery and transfection both in vitro and in vivo is presented. The nanoparticle system (NP,CP,PEI) is made of a superparamagnetic iron oxide nanoparticle (NP), which enables magnetic resonance imaging, coated with a novel copolymer (CP,PEI) comprised of short chain polyethylenimine (PEI) and poly(ethylene glycol) (PEG) grafted to the natural polysaccharide, chitosan (CP), which allows efficient loading and protection of the nucleic acids. The function of each component material in this nanoparticle system is illustrated by comparative studies of three nanoparticle systems of different surface chemistries, through material property characterization, DNA loading and transfection analyses, and toxicity assessment. Significantly, NP,CP,PEI demonstrates an innocuous toxic profile and a high level of expression of the delivered plasmid DNA in a C6 xenograft mouse model, making it a potential candidate for safe in vivo delivery of DNA for gene therapy. [source]

Injectable Superparamagnetic Ferrogels for Controlled Release of Hydrophobic Drugs

ADVANCED MATERIALS, Issue 13 2009
Jian Qin
A ferrogel for magnetically controlled release of drugs is prepared by integration of superparamagnetic iron oxide nanoparticles and Pluronic F127 gels. The hydrophobic drug indomethacin is loaded in the ferrogel owing to the oil-in-water micellar structure. The characteristic sol,gel transition property renders the ferrogel an injectable drug carrier that will be, in principle, free from surgical implant procedure. [source]

ESR studies on superparamagnetic Fe3O4 nanoparticles

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2004
Y. Köseo
Abstract In this study we have investigated temperature and frequency dependence of magnetic properties of superparamagnetic iron oxide nanoparticles (SPION). ESR measurements have been carried out in a temperature range of 10,300 K. A single, relatively broad and temperature dependent EPR signal was observed at all measurement temperatures. The linewidth slightly increases with decreasing temperature down to 100 K, then it sharply increases down to 60 K. Below 60 K the trend is reversed and the linewidth start to decrease. The resonance field remains almost constant down to 100 K and decreases sharply as the temperature is decreased further. The resonance field of the ESR spectra of Fe3O4 shows a linear dependence on microwave frequency. By using experimental results, the effective g-value and internal field are deduced as 1.9846 and ,40 G, respectively. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Surface-Functionalized Ultrasmall Superparamagnetic Nanoparticles as Magnetic Delivery Vectors for Camptothecin

CHEMMEDCHEM, Issue 6 2009
Feride Cengelli
Abstract Drug,nanoparticle conjugates: The anticancer drug camptothecin (CPT) was covalently linked at the surface of ultrasmall superparamagnetic iron oxide nanoparticles (USPIOs) via a linker, allowing drug release by cellular esterases. Nanoparticles were hierarchically built to achieve magnetically-enhanced drug delivery to human cancer cells and antiproliferative activity. The linking of therapeutic drugs to ultrasmall superparamagnetic iron oxide nanoparticles (USPIOs) allowing intracellular release of the active drug via cell-specific mechanisms would achieve tumor-selective magnetically-enhanced drug delivery. To validate this concept, we covalently attached the anticancer drug camptothecin (CPT) to biocompatible USPIOs (iron oxide core, 9,10,nm; hydrodynamic diameter, 52,nm) coated with polyvinylalcohol/polyvinylamine (PVA/aminoPVA). A bifunctional, end-differentiated dicarboxylic acid linker allowed the attachment of CPT to the aminoPVA as a biologically labile ester substrate for cellular esterases at one end, and as an amide at the other end. These CPT,USPIO conjugates exhibited antiproliferative activity in,vitro against human melanoma cells. The intracellular localization of CPT,USPIOs was confirmed by transmission electron microscopy (iron oxide core), suggesting localization in lipid vesicles, and by fluorescence microscopy (CPT). An external static magnetic field applied during exposure increased melanoma cell uptake of the CPT,USPIOs. [source]