Magnetic Cellular ‘Legos’ For Tissue Engineering

By incorporating magnetic nanoparticles in cells and developing a system using miniaturized magnets, researchers from 3 associated universities* in Paris (France) , have succeeded in creating cellular magneticLegos.” They were able to aggregate cells using only magnets and without an external supporting matrix, with the cells then forming a tissue that can be deformed at will. This approach, which is detailed in Nature Communications, could prove to be a powerful tool for biophysical studies, as well as the regenerative medicine of tomorrow.

Nanotechnology has quickly swept across the medical field by proposing sometimes unprecedented solutions at the furthest limits of current treatments, thereby becoming central to diagnosis and therapy, notably for the regeneration of tissue. A current challenge for regenerative medicine is to create a cohesive and organized cellular assembly without using an external supporting matrix. This is a particularly substantial challenge when it involves synthesizing thick and/or large-sized tissue, or when these tissues must be stimulated like their in vivo counterparts (such as cardiac tissue or cartilage) in order to improve their functionality.

The researchers met this challenge by using magnetism to act on the cells at a distance, in order to assemble, organize, and stimulate them. Cells, which are the building blocks of tissue, are thus magnetized in advance through the incorporation of magnetic nanoparticles, thus becoming true cellular magnetic “Legos” that can be moved and stacked using external magnets. In this new system acting as a magnetic tissue stretcher, the magnetized cells are trapped on a first micromagnet, before a second, mobile magnet traps the aggregate formed by the cells. The movement of the two magnets can stretch or compress the resulting tissue at will.

Researchers first used embryonic stem cells to test their system. They began by showing that the incorporation of nanoparticles had no impact on either the functioning of the stem cell or its capacity for differentiation. These functional magnetic stem cells were then tested in the stretcher, in which they remarkably differentiated toward cardiac cell precursors when stimulation imposed “magnetic beating” imitating the contraction of the heart. These results demonstrate the role that purely mechanical factors can play in cell differentiation.

This “all-in-one” approach, which makes it possible to build and manipulate tissue within the same system, could thus prove to be a powerful tool both for biophysical studies and tissue engineering.

* Laboratoire Matière et Systèmes Complexes (CNRS/Université Paris Diderot), in collaboration with the Laboratoire Adaptation Biologique et Vieillissement (CNRS/UPMC) and the Centre de Recherche Cardiovasculaire de Paris (Inserm/Université Paris Descartes)


Tiny Diamonds Revolutionize Nanotechnology

Nanomaterials have the potential to improve many next-generation technologies. They promise to speed up computer chips, increase the resolution of medical imaging devices and make electronics more energy efficient. But imbuing nanomaterials with the right properties can be time consuming and costly. A new, quick and inexpensive method for constructing diamond-based hybrid nanomaterials in bulk could launch the field from research to applications. University of Maryland (UMD) researchers developed a method to build diamond-based hybrid nanoparticles in large quantities from the ground up, thereby circumventing many of the problems with current methods.

The process begins with tiny, nanoscale diamonds that contain a specific type of impurity: a single nitrogen atom where a carbon atom should be, with an empty space right next to it, resulting from a second missing carbon atom. This “nitrogen vacancyimpurity gives each diamond special optical and electromagnetic properties. By attaching other materials to the diamond grains, such as metal particles or semiconducting materials known as “quantum dots,” the researchers can create a variety of customizable hybrid nanoparticles, including nanoscale semiconductors and magnets with precisely tailored properties.


If you pair one of these diamonds with silver or gold nanoparticles, the metal can enhance the nanodiamond’s optical properties. If you couple the nanodiamond to a semiconducting quantum dot, the hybrid particle can transfer energy more efficiently,” said Min Ouyang, an associate professor of physics at UMD and senior author on the study.

The technique is described in the June 8 issue of the journal Nature Communications.


Engineered Nanoparticles Replace Rare-earth Materials

Technologies from wind turbines to electric vehicles rely on critical materials called rare-earth elements. These elements, though often abundant, can be difficult and increasingly costly to come by. Now, scientists from the Laboratory of Molecular Magnetism (LAMM) of the University of Florence in Italy,  looking for alternatives have reported in ACS’ journal Chemistry of Materials a new way to make nanoparticles that could replace some rare-earth materials and help ensure the continued supply of products people have come to depend on.

rare-earth element

Rare-earth elements have unique characteristics that make them very useful. For example, the world’s strongest magnets are made with neodymium. A little too powerful for your refrigerator, these magnets are incorporated into computer disk drives, or nanocoputers, power windows and wind turbines. But rare earths are challenging to mine and process, and prices can rise quickly in a short period of time. Given the increasing demand for rare earths, Alberto López-Ortega, Claudio Sangregorio and colleagues (LAMM) set out to find substitutes for use in strong magnets.

The researchers used a mixed iron-cobalt oleate complex in a one-step synthetic approach to produce magnetic core-shell nanoparticles. The resulting materials showed strong magnetic properties and energy-storing capabilities. Their approach could signal an efficient new strategy toward replacing rare earths in permanent magnets and keeping costs stable, the researchers say.


Wind Turbines Generate Electricity Without Rotating

A suspension bridge in the United States stretching – and collapsing – in high winds in 1940… …inspires a silent, swaying new-look wind turbine in Spain today. The bladeless turbine generates power from a single conewobbling‘ in the wind. It’s just like an opera singer hitting the high notes and shattering glass, says the developer.


We have all seen how a soprano who sings at a glass, by matching the tone of the voice to the glass, can breaking it. This type of resonance is a great way to transmit energy. What we do is, instead of using sound waves, is use the swirls, the vortices that are generated by a structure with wind“, says David Yanez, who co-founded the Spanish start-up, Vortex Bladeless.
The six-metre windmill, made from fibreglass and carbon fibre, uses those wind vortices to create patterns of movement that can be converted into energy. The magnets at the base of the cone-shaped blade allow its movements to adjust according to the wind speed.

What we have is a mast, which is the top piece, and acts as a blade, it’s constructed from the same material as a conventional generator, and what it does is oscillate transmitting its oscillation to a conventional alternator which by its own oscillation converts the wind’s energy into electric energy.” Vortex says its turbine will cost around 40 percent less than conventional three-bladed windmills, with a smaller carbon footprint and much lower maintenance costs. And it’s much safer for passing birds. Encouraged by the results so far, Vortex is testing a smaller prototype for domestic use in developing countries.
What we are trying to do now is develop a very small energy distribution sample that is less than three metres high and can be set up on the rooftops of homes“, adds David Yanez.

Vortex‘s new turbine could prove a boost for renewable energy after Spain’s financial crisis hit the industry hard. With investment, the start-up hopes generating energy from wind will be a breeze.