The Institute of Physics (IOP) has just released a new book of the series IOP-Concise-Physics. ‘Designing Hybrid Nanoparticles’ provides a new insight into one of the most promising 'bottom-up' techniques, the modified magnetron-sputtering-based inert-gas-condensation (MS-IGC) system. The book, authored by Dr. Maria Benelmekki, SEPMAG’s scientific advisor, starts with an introduction to nanoparticles and nanotechnology. The chapter providesinteresting examples of their use to obtain different end-products –not just state-of-the art, but also looking back until classical times-. The most relevant of the chapter is the proposed classification of the nanoparticles based on their dimension, morphology and chemical composition. For the people interested on magnetic application, it isworthy to pay attention to the discussion on nanoparticle uniformity and agglomerations.
Scientists in Paris, France have engineered liposomes containing iron-oxide nanoparticles and photosensitizers, and have used them to ablate cancerous tumors in mice. While current experimental cancer treatments employ either magnetic hyperthermia techniques or photodynamic therapy, this work is a new attempt to combine the two techniques into one self-contained injectable vessel. Liposomes are spherical, self-assembling, lipid bilayer structures. In the lowest energy state the hydrophobic tails touch inside the bilayer, which forms a sphere with a hydrophilic outer shell and a hydrophilic inner cage useful for carrying drugs, or in this case iron-oxide nanoparticles.
Leading physicists and materials scientists from around the world will be migrating to Barcelona, Spain this July to discuss their newest and most exciting work with like-minded colleagues. The week-long conference will feature plenary and semi-plenary lectures, symposia, oral presentations, poster sessions, and plenty of opportunities for scientists to discuss their current research, find inspiration or answers, and spark ideas for future work.
In June of 2014, a group in Dublin, Ireland created a novel assay to detect Herpes Simplex Virus-1 (HSV-1) using magnetic separation and flow cytometry. Previous methods of detection relied on cell culture, polymerase chain reaction, enzyme immunoassay, or fluorescent antibody diagnostics. Those methods, while quite effective, are time consuming and require a full laboratory. Magnetic separation takes seconds, and the emergence of portable flow cytometry systems makes this new assay feasible for use in the field.
Many bioengineering laboratories are actively researching how to produce synthetic or natural scaffolds seeded with human mesenchymal stem cells (MSCs). The aim of this work is to implant the structures into diseased or damaged sites and encourage healing by introducing a healthy pluripotent cell population on an anatomically correct form. Current research is particularly focused on including small molecules within the scaffold in order to steer MSCs to differentiate to a desired cell type. The number of possible combinations of scaffold material, biomolecular cues, and fabrication methods is vast and holds a lot of therapeutic potential.
Percutaneous transluminal angioplasty is a common procedure to clear blocked arteries. This is often accomplished by inserting a balloon catheter. At the site of the blockage the balloon is inflated and pushes against the arterial wall for a few minutes before being removed. In many cases this is sufficient to open the artery. However, the balloon often damages the arterial wall and it is important that the endothelium repairs itself quickly in order to prevent blood clots and excessive proliferation of smooth muscle (hyperplasia). A common method to stimulate endothelial growth is to introduce vascular endothelial growth factor (VEGF) locally or through the bloodstream. Unfortunately, the half-life of VEGF is short and the large amount needed for efficacy is expensive. This motivated researchers from the Harbin Medical University in the Heilongjiang Province of China to develop a way to locally deliver the VEGF gene to the site of a ballon-injured artery.
Researchers at the Shanghai Key Laboratory of Tuberculosis have improved upon a tool for detecting mycobacterium tuberculosis (MTB) in human samples of deep-lung mucus. The tool combines magnetic, fluorescent, and immunologic sorting techniques to increase test sensitivity and portability. Tuberculosis-specific antibodies and proteins are conjugated to the surfaces of quantum dots (QDs) and magnetic microspheres (MMSs). In this functionalized state the quantum dots and microspheres can freely bind to the mycobacterium. At optimal concentrations, along with sufficient incubation time, the QDs and MMSs each serve as a slice of bread in a QD-MTP-MMS sandwich. The sample is magnetically sorted to collect the MMSs before quantifying the amount of QD fluorescence with a spectrofluorometer.
Bioengineers at the University of California, Los Angeles have developed a new technique for patterning magnetic material onto polydimethyl-siloxane (PDMS), a flexible polymer known as an elastomer. The resulting product has promising biotechnical applications. Its flexibility allows it to conform to many different shapes, and its magnetic field can be tuned by the application of an external magnet.
Although magnetic particles have proven exceedingly useful in nanotherapy protocols, applications making use of external magnets have been limited to surface or shallow targets. The ability to use external magnets to focus on deeper targets has remained a challenge. To this end, a collaboration between researchers from the University of Maryland and Weinberg Medical Physics LLC has devised a way to use pulsed magnetic fields to direct particles to hard-to-reach targets.
Core/shell nanoparticles offer an additional degree of flexibility to nanoparticle-based applications. Comprised of an inorganic core and one or more shell layers, such particles enable a wider range of physical properties than would be possible for each of the component materials taken separately. In the case of bi-magnetic core/shell nanoparticles, the constituent materials exhibit distinct magnetic properties, yielding an extra layer of customization to the particle, based on the exchange interaction between the components.
