Magnetic nanoparticle-mediated intracellular hyperthermia has been a largely experimental modality of hyperthermia, but this treatment modality has the potential to achieve tumor targeted heating without any side effects. The technique consists of targeting magnetic nanoparticles to tumor tissue and then applying an external alternating magnetic field to induce heat generation by the magnetic n...

Magnetotactic bacteria contain magnetosomes--intracellular, membrane-bounded, magnetic nanocrystals of magnetite (Fe(3)O(4)) or greigite (Fe(3)S(4))--that cause the bacteria to swim along geomagnetic field lines. We isolated a greigite-producing magnetotactic bacterium from a brackish spring in Death Valley National Park, California, USA, strain BW-1, that is able to biomineralize greigite and ...

Formation of magnetite nanocrystals by magnetotactic bacteria is controlled by specific proteins which regulate the particles' nucleation and growth. One such protein is Mms6. This small, amphiphilic protein can self-assemble and bind ferric ions to aid in magnetite formation. To understand the role of Mms6 during in vitro iron oxide precipitation we have performed in situ pH titrations. We fin...

This work presents a new method to prepare poly(sodium acrylate) magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA) as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate) as shell. Fou...

Iron (hydr)oxides are ubiquitous earth materials that have high adsorption capacities for toxic elements and degradation ability towards organic contaminants. Many studies have investigated the reactivity of synthetic magnetite, while little is known about natural magnetite. Here, we first report the reactivity of natural magnetites with a variety of elemental impurities for catalyzing the deco...

[1] Magnetic measurements of samples with precisely controlled magnetic mineralogy, grain size, and interparticle spacing are needed to provide crucial experimental rock magnetic underpinning for paleomagnetic studies. We report a novel nanofabrication method for producing two-dimensional arrays of cylindrical synthetic magnetite particles with well-defined composition, particle size, and inter...

The teeth of the Polyplacophora Chiton Acanthochiton Rubrolinestus contain biomineralized magnetite crystallites whose biological functions in relation to structure and magnetic properties are not well understood. Here, using superconducting quantum interference device (SQUID) magnetometry, we find that the saturation magnetization (σ(s)) and the Verwey transition temperature (T(v)) of tooth pa...

Magnetite-ENR polymer electrolytes doped with various % wt of LiCF3SO3 salt were synthesized in-situ in the presence of ENR and cast into film doped with LiCF3SO3. XRD results confirmed the purity of the as-formed magnetite particles. The diffraction peaks assigned for LiCF3SO3 become more intense as the concentration of salt is increased. FTIR analyses showed that both “free” (dissociation) an...

Magnetic nanoparticles made of magnetite have the advantage to be biocompatible and to have a good saturation magnetisation. In this work we show that magnetite nanoparticles change their magnetic and chemical characteristics over time, depending on their storage conditions. To determine the oxidation state of the iron in the core of the nanoparticles Mössbauer spectroscopy was used at 4.2 K. T...

The pH-dependent adsorption of humic acid (HA) on magnetite and its effect on the surface charging and the aggregation of oxide particles were investigated. HA was extracted from brown coal. Synthetic magnetite was prepared by alkaline hydrolysis of iron(II) and iron(III) salts. The pH-dependent particle charge and aggregation, and coagulation kinetics at pH approximately 4 were measured by las...