Ever-Evolving Identity of Magnetic Nanoparticles within Human Cells: The Interplay of Endosomal Confinement, Degradation, Storage, and Neocrystallization

Claire Wilhelm at the Laboratoire Matiere et Systemes Complexes in Paris and three co-authors Aurore van de Walle, Jelena Kolosnjaj-Tabi and Yoann Lalatonne wrote a beautiful account about the changes magnetic nanoparticles undergo over time within human cells. 

They describe their contribution as "Nanoparticles’ identities evolve in distinct biological environments and over different periods of time. In this Account, we focus on the remodeling of magnetic nanoparticles’ identities following their journey inside cells. For instance, nanoparticles’ functions, such as heat generation or MRI, can be highly impacted byendosomal confinement. Structural degradation of nanoparticles was also evidenced and quantified in cells and correlates with the loss of magnetic nanoparticle properties. Remarkably, in human stem cells, the nonmagnetic products of nanoparticles’ degradation could be subsequently reassembled into neosynthesized, endogenous magnetic nanoparticles. This stunning occurrence might account for the natural presence of magnetic particles in human organs, especially the brain. However, mechanistic details and the implication of such phenomena in homeostasis and disease have yet to be completely unraveled. This Account aims to assess the short- and long-term transformations of magnetic iron oxide nanoparticles in living cells, particularly focusing on human stem cells. Precisely, we herein overview the multiple and ever-evolving chemical, physical, and biological magnetic nanoparticles’ identities and emphasize the remarkable intracellular fate of them."

Check it out in the journal "Accounts of Chemical Research" at https://doi.org/10.1021/acs.accounts.0c00355'

Digital IWMPI 2020 - Free Live Stream

The International Workshop on Magnetic Particle Imaging (IWMPI) is the premier platform for researchers, developers, manufacturers, and users of this new method of magnetic nanoparticle spectroscopy and imaging and will be held this year for free on Sep 7-8, 2020. The concept includes a combination of live streaming of the talks and interactive poster presentations. Check it out here: https://www.iwmpi.org/home.

For this IWMPI 2020, 80 accepted contributions from 12 countries will show the rapid progress of the field. Following topics of MPI will be presented at the conference: Medical, pre-clinical, and non-medical applications - Coil and field generator design - Data acquisition and signal pre-processing - Signal generation, amplification and filter design - Magnetic field simulation and system modeling - Magnetic particle spectroscopy (MPS) - Molecular imaging - Nanoparticle development - Particle physics and simulations - Reconstruction methods - Sequences, acquisition protocols and spatial coding - Scanner geometries and system design.

Lawrence L. Wald, Ph.D., Martinos Center for Biomedical Imaging, Harvard, USA will give the Keynote on „The Do's and Don'ts of MPI Scanner Instrumentation“.

Moving Bubbles Under Water with Magnets

Moving gas bubbles underwater on a surface could help scientists and engineers in the lab and in industry. But it’s not an easy task. Previous methods have relied on slippery silicone oil coatings, but bubbles move slowly on these surfaces and only in one direction. Now, researchers at the University of Science and Technology of China and the Chinese Academy of Sciences have developed a ferrofluid-based surface that lets them move bubbles quickly and in any direction with the help of a magnet (Nano Lett. 2020, DOI: 10.1021/acs.nanolett.0c02091). Using this so-called FLAM surface, the researchers were able to drag bubbles down tilted surfaces and even tow objects more than 500 times their own mass. The authors envision their method being useful for applications such as electrochemical reactions and wastewater treatment.

Freshly printed magnets in 3D

Researchers at Empa, the Swiss Federal Laboratories for Materials Science and Technology near Zurich have developed an innovative method to precisely produce different alloy compositions in a single component, using a 3D laser printer. Until recently, 3D printing has presented unique challenges to metal processing, as temperatures nearly instantaneously exceed 2,500 degrees Celsius in the melting zone, which can alter the properties of alloys as some components evaporate. However, a team at Empa, led by Aryan Arabi-Hashemi and Christian Leinenbach, discovered that by varying the power and duration of the laser beam, they could modify the alloys with micrometer precision, thereby “producing new materials with completely new functionalities.” Prospective applications include manufacturing “smart” shape memory alloys and designing more efficient electric motors.

The picture shows iron filings sticking to a mini chessboard with four millimeter edge length. The partially magnetic structure was produces from a single type of steel power at different temperatures. For more information, check it out here.

The World's Lightest Electromagnetic Shielding Material

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring components or the transmission of signals. However, the thin metal sheets or metallized foils that are conventionally used for this purpose are often too heavy or too rigid for many applications. To address this shortcoming, Empa researchers recently succeeded in applying very light aerogels, based on cellulose nanofibers, to microelectronics, which can effectively shield electromagnetic radiation over a wide frequency range. Cellulose fibers are obtained from wood, and due to their chemical structure, enable a wide range of chemical modifications, which are maintained even after being subjected to strong mechanical stress. Combined with two-dimensional nanoplates of titanium carbide, the material has proven to be the lightest electromagnetic shield in the world.

For more details, see here.

Microgripper Captures Single Cells with Magnetic Help

Sampling diseased tissue, which can contain many different types of cells, calls for precise biomedical tools. Current methods for manipulating single cells, like laser microdissection, require complicated setups and can damage cells. Now, researchers led by David H. Gracias at Johns Hopkins University have developed devices that could offer a simpler and less-harmful way to isolate single cells (Nano Lett. 2020, DOI: 10.1021/acs.nanolett.0c01729). Remotely guided by a magnetic field, these so-called microgrippers can wrest single cells from a tissue sample and carry them on demand. Though the tiny grippers require more optimization and testing, the researchers hope one day to use them to perform single-cell biopsies inside a human body.

For more information, and a movie, check it out here.

Special Issue Planned About Magnetic Cell Separation

Our colleague Dr. Marie Frenea-Robin is the guest editor of a special issue of magnetochemistry, titled "Magnetic Cell Separation". Magnetic cell separation has become a key methodology for the isolation of target cell populations from biological suspensions, covering a wide spectrum of applications from diagnosis and therapy in biomedicine to environmental applications or fundamental research in biology. This Special Issue aims to create a forum of discussion to share advances and address current challenges in magnetic cell separation. For more details, check out this flyer.

The deadline for your manuscript submission will be November 30, 2020.

List of Cancelled Magnetic Conferences / Potential Jobs in Magnetism

The European Magnetism Society just sent out a newsletter with a list of cancelled magnetism-related meetings. Check it out here:

http://magnetism.eu/news/144/38-news.htm

Also, while the Covid-19 situation is still dire, the curve seems flattened in many countries, and governments are carefully starting to reopen schools etc. This also means that more people are looking for jobs again.

In the magnetism area, EMA also updated their lists of available jobs. Please check it out too:

http://magnetism.eu/5-job-market.htm

And if you are an employer who is looking for a new employee, please advertise at EMA, or also send us an e-mail so we can advertise on magneticmicrosphere.com.