The performance of magnetic nanoparticles is intimately entwined with their structure, mean size and magnetic anisotropy. This was nicely shown in a recent article by Carlos Martinez-Boubeta et al. They reported on an experimental and theoretical analysis of magnetic hyperthermia. Experimentally, they demonstrated that single-domain cubic iron oxide particles resembling bacterial magnetosomes have superior magnetic heating efficiency compared to spherical particles of similar sizes. Monte Carlo simulations at the atomic level corroborate the larger anisotropy of the cubic particles in comparison with the spherical ones, thus evidencing the beneficial role of surface anisotropy in the improved heating power.
The article is available on Scientific Reports 3, 1652 (2013).
Two new publications are advancing the in vivo use of magnetic particles.
The first is a research paper by Johannes Riegler et al. about the use of magnetically loaded stem cells to improve cell retention in cell therapies for treating vascular injuries. This is a joint research project carried out in both University College London and the National University of Ireland. The article can be downloaded here.
The other is a book chapter included in the last edition of the Specialist Periodical Reports published by the Royal Society of Chemistry (RSC). It is co-authored by Daniel Ortega and Quentin Pankhurst, and it covers the basic physical-chemical-biological aspects of magnetic hyperthermia, including a review of some clinical case studies. If you are interested, you can find it here.
Prof. Roger Y. Tsien, 2008 Nobel Laureate in Chemistry, will deliver a keynote speech on Magnetic Particle Imaging (MPI) at the upcoming International Workshop on MPI (IWMPI 2013) to take place at University of California, Berkeley on March 23-24, 2013.
When bacteria build up in the blood, it's bad news. The condition can lead to a serious infection known as sepsis, which can turn deadly even with aggressive treatment using antibiotics. Researchers at Massachusetts Institute of Technology and Harvard Medical School may have found a way to pluck bacterial invaders from blood by magnetic separation. Daniel S. Kohane and coworkers coated magnetic nanoparticles with zinc coordinated bis(dipicolylamine), a complex known to bind strongly to anionic phospholipids that densely decorate the surfaces of bacteria. The researchers added these modified nanoparticles to blood tainted with Escherichia coli and ran the blood through a magnetic microfluidic device. They were able to pull almost all of the bacteria from the blood, even at blood flow rates of 60 mL per hour. The technology, the researchers say. could be adapted to treat sepsis in people, which in the U.S. has become the seventh-leading cause of infant mortality and the 11th-leading cause of death.
For more info, check out the preprint.
Anna C. Samia at Case Western Reserve University in Cleveland, Ohio, one of our own magnetic nanoparticle researchers, specializes in metallic nanostructures. She has just been awarded a five-year $600,000 National Science Foundation-CAREER grant to create new materials and equipment to test ultra-high molecular weight polyethylene used to make artificial joints. She and her team of researchers will also develop magnetic particle imaging techniques to monitor degradation and wear.
The ultimate goal is to give manufacturers targets they can home in on to make the implant material more resistant to the environment inside us, so that implants last a lifetime.
Tania Dey has recently edited an interesting new book about nanostructured materials and their use in water purification.These materials include carbon nanotubes, silver-impregnated cyclodextrin nanocomposites, nanostructured iron-zeolites, carbo-iron nanomaterials, photocatalytic titania nanoparticles, nanofiltration membranes and functionalized silica nanoparticles, in addition to magnetic nanoparticles. Tania contributed the first (review) chapter to this book, which elucidates the role of magnetic nanoparticles. “Especially the naturally occurring ones, such as magnetite, maghemite, zero valent iron, mixed oxides (Co-ferrites, Ni-ferrites etc) as well as cellulosic nanofibers can be used as an effective adsorbent for water remediation, making the process cost-effective and sustainable. Being a dispersed system, these adsorbents eliminate the need of high pressure streams for water purification."
See information about the book here: http://universal-publishers.com/book.php?method=ISBN&book=1612336191
How can solar energy be stored so that it can be available any time, day or night, when the sun shining or not? EPFL scientist Kevin Sivula and colleagues are developing a technology that can transform light energy into a clean fuel that has a neutral carbon footprint: hydrogen. The basic ingredients of the recipe are water and metal oxides, such as iron oxide, better known as rust. The team purposefully limited itself to inexpensive materials and easily scalable production pro-cesses in order to enable an economically viable method for solar hydrogen production. They hope to attain efficiencies of 10% in a few years, for less than $80 per square meter, a price competitive with traditional methods of hydrogen production.
Maybe we can further improve on this process by using magnetic particles?
Check it out at http://swissinnovation.org/news/web/2012/06-121111-ce.html
A new issue of the Magnetics Magazine is available: Winter 2012. This industry driven magazine reviews applications of magnets in the "real" world, like for example in wind turbines, discusses permanent magnets and rare earth availability, shows magnetic design software and many more engineering related issues (Spintronics etc).
This Winter 2012 issue also includes an industry outlook, a description of the upcoming Magnetics 2013 conference, and the newest resource guide in the Magnetism world with all the businesses and industries.
For more information, check out our Archives.