Nanoparticles and magnetism might enhance immune response to viruses and cancer

Johns Hopkins University researchers have used nanoparticles and magnets to enhance the endogenous immune response to viruses and cancers. When the approach was tested on mice with skin tumors, six of eight that were treated survived longer than four weeks with no signs of tumor growth, while none of the untreated mice survived. Details of the study appear in the journal ACS Nano.

“Size was key to this experiment,” says Jonathan Schneck, M.D., Ph.D., a professor of pathology, medicine and oncology at the Johns Hopkins University School of Medicine’s Institute for Cell Engineering. “By using small enough particles, we could, for the first time, see a key difference in cancer-fighting cells, and we harnessed that knowledge to enhance the immune attack on cancer.”

Dr. Schneck’s team has pioneered the development of artificial white blood cells, so-called artificial antigen-presenting cells (aAPCs), which show promise in training animals’ immune systems to fight diseases such as cancer. To do that, the aAPCs must interact with naive T cells that are already present in the body, awaiting instructions about which specific invader they will battle. The aAPCs bind to specialized receptors on the T cells’ surfaces and present them with distinctive proteins called antigens. This process activates the T cells, programming them to battle a specific threat such as a virus, bacteria or tumor, as well as to make more T cells.

Superconductivity Switched on by Magnetic Field

Strong magnetic fields typically interfere with superconductivity. However, researchers at the Paul Scherrer Institute have discovered a material, CeCoIn5, where a magnetic field creates superconductivity. The superconducting state is in addition to, and simultaneous with, a first superconducting state that appears at low temperatures. Furthermore, an addi-tional antiferromagnetic order was observed, and it was discovered with the SINQ neutron source. This discovery ultimately demonstrates the direct control of quantum states, an im-portant discovery for future quantum computers.

http://www.psi.ch/media/superconductivity-switched-on-by-magnetic-field

Microchip Revolution in Cell Sorting

Microchip-based cell sorting is being used in basic and clinical research to isolate a variety of cell types for investigative purposes: stem cells from bone marrow and immune or cancer cells from blood, for example. This same technology technology expands now into cell sorting: Based on cutting-edge microchip technology, the MACSQuant® Tyto ensures high-speed, high-purity, fluorescence-based cell sorting in a fully enclosed, sterile cartridge system. Owl Biomedical Inc developed the chip, and Miltenyi Biotec is now selling it for everyday use.

Advantages of this system are supposedly

- high cell viability, no sheath fluids, no droplet formation

- high-speed valve allowing for the sorting of high numbers of cells in a short period of time

- contamination free enclosed system that also prevents operator from contact with potentially harmful sample materials.

For more information, check out Miltenyi's recent MACS&more Vol 15-2, 2013 magazine.

Ionic Liquid Helps Recycle Rare Earth Elements

Rare-earth magnets are indispensable components in computer hard drives, wind turbines, audio speakers, and electric vehicles. Because of the insecure supply chain and price fluctuations of rare-earth metals, scientists are interested in developing efficient, safe, and environmentally friendly methods for recycling magnets to recover the metals.

Tom Vander Hoogerstraete, Koen Binnemans, and coworkers at the University of Leuven, in Belgium, have come up with such a method, one that relies on extracting the metals with an ionic liquid ( Green Chem., DOI: 10.1039/c3gc40198g ). A common way to separate metal ions is by liquid-liquid extraction of acidic aqueous solutions of dissolved metal ions with an organic solvent containing an extraction agent. Rather than using a volatile, flammable solvent as is customary, the Leuven researchers tried ionic liquids, which are nonvolatile, nonflammable organic-based salts with low melting points. By using a tetraalkylphosphonium chloride ionic liquid, which functions as both a solvent and extraction agent, the researchers separated cobalt from samarium and iron from neodymium with better than 99.98% efficiency. They focused on those metal combinations because samariumcobalt and neodymium-iron-boron magnets are two of the most common types of rareearth magnets. After the extractions, the researchers stripped the cobalt and iron out of the ionic liquid so they could reuse it.

Measuring Magnetic Nanoforces Under the Microscope

NanoScan specializes in the measurement of magnetic properties of materials at the nanoscale, using scanning probe microscopy. The Swiss company aims to achieve the best magnetic lateral resolution in direct space, with minimal time for measurement. To achieve this, its team of physicists, electrical engineers and software engineers develops the
company’s microscopes, from the mechanical parts to the electronics controller and the software, with the desire to provide high-resolution scanning probe microscopes that fulfill present and future analytical needs on nanometer-sized
surface structures.

Dr Raphaëlle Dianoux, NanoScan’s CEO, says: “Our aim was to establish a niche application, and that was magnetic force microscopy. Designed for research, development and quality control of magnetic storage media and other magnetic material, our product, the hr-MFM (high-resolution magnetic force microscope), is an analytical and quantitative magnetic imaging system.” For an imaging example, see the magnetic force microscopy image to the right of a commercial hard disk, taken with the hr-MFM. The single bits are clearly recongnizable as bright (dark) patterns magnetized in the direction opposite (parallel) to the tip magnetization. The high resolution of the microsccope reveals the slightly curved and even grainy substructure of the bits.

The article about NanoScan was published in the Journal "Magnetic Technology International 2013". For even more articles, check out  http://ukipme.com/pub-magnetics.php.

Synthesis of Anisotropic 3D Magnetic Microspheres

Navid Hakimi and others in Dae Kun Hwang's research group at Ryerson University, Toronto, Canada are masters of making strangely shaped three-dimensional anisotropic microparticles using a simple one-step microfluidic based method.

The method exploits the non-uniformity of the polymerizing UV light, UV absorption by opaque nanoparticles in the precursor solution, and discontinuous photomask patterns to make magnetic and non-magnetic microparticles in a two-dimensional microchannel. Numerical simulations of monomer conversion in the microfluidic channel are performed to predict the manufactured particle shape.

For more details, check out the article here: DOI: 10.1002/adma.201304378.

Magnetic Particle Workshop (IWMPI) 2013

The 3rd International Workshop on Magnetic Particle Imaging (IWMPI) was held in Berkeley, CA USA on March 23-24, 2013. This year, there were a total of 70 presentations (44 oral and 26 poster presentations), and 4 keynote speeches. Please see the Workshop Program for details.

The proceedings are now available online at IEEEXplore.

For those who were not able to attend the workshop, there are the videos of keynote speeches available online. Check it out here: http://iwmpi.berkeley.edu.

And then don't forget, the next meeting will come soon, in Berlin in March 2014!

Nanotherapeutic Shows Promise in Eliminating Lethal Tumors

Researchers have created a nanotherapeutic based on gold nanoparticles coated with nucleic acids (SNAs). It is capable of penetrating the blood-brain barrier and blocked the expression of a gene associated with tumor growth. Testing on mice, researchers found reduced Bcl2L12 expression and a lower burden of brain tumors without adverse side effects. SNAs could work in therapeutic gene regulation that could help address various types of disease, according to the study published in Science Translational Medicine.

Although these "spherical nucleic acids" are not magnetic, maybe we can do the same thing with very small magnetic nanoparticles. Try!