A research team led by Julian Eastoe of England’s University of Bristol recently developed an iron-based surfactant that responds to a magnetic field. The researchers showed that their detergent, composed of an alkane chain with a cationic head group and a tetrachloroferrate(III) counterion (FeCl4–), is capable of being drawn from an aqueous phase through an organic solvent by a small magnet. With small-angle neutron scattering, the team also proved that in water, their magnetic surfactant forms small clusters called micelles. Conventional soaps and detergents also form these structures, which give the cleaners their functionality.
When asked why he and his team decided to try making a surfactant that’s switched on by a magnet, Eastoe says they were motivated by “good old-fashioned scientific curiosity.” There has to be a place for that type of inquiry
in science, he contends. To read more, check this Angewandte Chemie article here.
Sometime in 2011, a special issue about magnetic nanoparticles was published in two different journals, the International Journal of Molecular Sciences and the Materials journal. Professor Jon Dobson was the guest editor. Check it out! It is open access and can be accessed here:
Researchers from the Institute of Experimental Physics at the Slovak Academy of Sciences (IEP SAS) in Kosice are investigating the interaction of albumin-modified magnetic fluids with insulin amyloid aggregates. The research tackles complications associated with diabetes, where amyloid deposits (fibrils) can form in patients near the site of insulin injections. Results indicate that incubation of insulin amyloid fibrils with albumin-modified magnetic fluid leads to the significant destruction of aggregates. The extent of the depolymerizing activity was affected by the amount of albumin used for magnetic fluid modification and mainly depends on the size of nanoparticles.
The team's findings represent a starting point for the application of active albumin-modified magnetic fluids as therapeutic agents targeting insulin amyloidosis. For the original paper, check out this link.
Elena Rozhkova from Argonne National Lab wrote a nice review article on recent progress in the development of advanced nanoscale photoreactive, magnetic and multifunctional materials applicable to brain cancer diagnostics, imaging, and therapy, with an emphasis on the latest contributions and the novelty of the approach, along with the most promising emergent trends. Check it out here.
Nguyen TK Thanh at the Davy Faraday Research Laboratory, University College London and the Royal Institution, and colleagues, believe they have now a better way of tracking neural stem cells after a transplant over long periods of time. They have developed hollow biocompatible cobalt-platinum nanoparticles and attached them to the stem cells. The nanoparticles are stable for months and have a high magnetic moment - tendency to align with a magnetic field - so that low concentrations can be detected using magnetic resonance imaging (MRI).
The team labelled stem cells with biocompatible cobalt-platinum nanoparticles, injected them into spinal cord slices and took images of their progress over time. They found that low numbers of the nanoparticle-loaded stem cells could still be detected two weeks after transplantation. 'The new method demonstrates the feasibility of reliable, noninvasive MRI imaging of nanoparticle-labelled cells,' says Thanh.
Thanh hopes that her stem cell tracking method will be used during stem cell replacement therapy for many central nervous system diseases. Her team is working towards developing nanoparticles that can be used to diagnose and treat these diseases.
Microstructure is crucial to obtain very strong composite materials (e.g., teeth, bone and sea shell structures). Randall Erb, Andre Studart et al. at the Federal Institute of Technology in Zurich, Switzerland now published a method how to elegantly and easily do this in a low magnetic field of 1 to 10 milliTeslas.
Using micrometer-sized reinforcing particles coated with minimal concentrations of superparamagnetic nanoparticles (0.01 to 1 volume percent) synthetic composites with tuned three-dimensional orientation and distribution of reinforcements were produced. A variety of structures was achieved with this simple method, leading to composites with tailored local reinforcement, wear resistance, and shape memory effects.
See for yourself: Science 335, 199-204 (2012).
A couple of recent papers highlight the importance of carefully analyzing toxicity and cell uptake when magnetic nanoparticles are to be used in a biological context. Prof. Morteza Mahmoudi at the Laboratory of Nano-Bio Interactions, Pasteur Institute in Teheran, Iran is an expert in these investigations. Two interesting papers can be found here (review) or here, and many other recent articles by Dr. Mahmoudi can be found online.
Despite the emergence of new treatments, only 15 percent of lung cancer patients survive. Researchers at the Peggy and Charles Stephenson Cancer Center hope to change that with a new approach that utilizes new nanoparticle technology.
“If you can quickly make the determination of treatment effectiveness, the physicians can have the opportunity to make a decision as to whether they need to continue with the drug that they have chosen, or whether they need to change the treatment,” said Rajagopal Ramesh, Ph.D., who also holds the Jim and Christy Everest Endowed Chair in Cancer Developmental Therapeutics in the Department of Pathology at the University of Oklahoma Health Sciences Center.
While there are drugs that effectively attack cancer cells, the challenge for physicians is how to quickly assess whether a particular drug is effective for a particular patient. Frequently, there is a lag of several days between treatment and the determination, via molecular imaging, of whether the drug used is actually targeting and killing the cancer cells. It is thus important to combine effective therapy with real-time imaging.
Recently, Ramesh and colleagues tested new multi-functional magnetic nanoparticles with a gold layer useful for imaging and thermotherapy. In addition, they attached to the surface of the nanoparticles the FDA-approved antibody Cetuximab. The antibody targets a specific protein (epidermal growth factor receptor or EGFR) that is expressed at high levels on the surface of non-small cell lung cancer cells and at low levels in normal cells. Have a look at their just published research paper here.
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