To fear or not to fear? Nanoplastics, electron microscopy image, colored, 150.000x. Empa / ETH

The images leave no one cold: giant vortices of floating plastic trash in the world's oceans with sometimes devastating consequences for their inhabitants – the sobering legacy of our modern lifestyle. Weathering and degradation processes produce countless tiny particles that can now be detected in virtually all ecosystems. But how dangerous are the smallest of them, so-called nanoplastics? Are they a ticking time bomb, as alarming media reports suggest? In the latest issue of the journal Nature Nanotechnology, a team from Empa and ETH Zurich examines the state of current knowledge – or lack thereof – and points out how these important questions should be addressed.

A comparison of different light microscopy techniques: STED (bottom left) improves the sharpness of detail drastically compared to conventional confocal microscopy (top left). MINSTED (right) achieves a resolution that is yet ten times higher. © Michael Weber / Max Planck Institute for Biophysical Chemistry

Scientists working with Stefan Hell at the Max Planck Institute (MPI) for Biophysical Chemistry in Göttingen and the Heidelberg-based MPI for Medical Research have developed another light microscopy method, called MINSTED, which resolves fluorescently labeled details with molecular sharpness. With MINSTED, Nobel laureate Hell has come full circle. “A good 20 years ago, we fundamentally broke the diffraction resolution limit of fluorescence microscopy with STED. Until then, that was considered impossible,” says Hell. “Back then we dreamed: With STED we want to become so good that one day we will be able to separate individual molecules that are only a few nanometers apart. Now we've succeeded.” At that time, the STED principle amounted to a revolution in light microscopy. For this conceptual leap and subsequent developments, Hell received the Nobel Prize in Chemistry in 2014.

The phantom used for hyperpolarized imaging, with an illustration of imaging slices acquired using the new technique. photo/©: Laurynas Dagys, University of Southampton

New technique using nuclear spin hyperpolarization of hydrogen paves the way for further advances in the field of MRI. Magnetic resonance imaging (MRI) is already widely used in medicine for diagnostic purposes. Hyperpolarized MRI is a more recent development and its research and application potential has yet to be fully explored. Researchers at Johannes Gutenberg University Mainz (JGU) and the Helmholtz Institute Mainz (HIM) have now unveiled a new technique for observing metabolic processes in the body. Their singlet-contrast MRI method employs easily-produced parahydrogen to track biochemical processes in real time. The results of their work have been published in Angewandte Chemie International Edition and chosen by the editors as a "hot paper", i.e., an important publication in a rapidly-developing and highly significant field.

Magnetosomes isolated from magnetic bacteria.

Magnetic nanoparticles biosynthesized by bacteria might soon play an important role in biomedicine and biotechnology. Researchers of the University of Bayreuth have now developed and optimised a process for the isolation and purification of these particles from bacterial cells. In initial tests, magnetosomes showed good biocompatibility when incubated with human cell lines. The results presented in the journal "Acta Biomaterialia" are therefore a promising step towards the biomedical use of magnetosomes in diagnostic imaging techniques or as carrier in magnetic drug delivery applications.

The new photovoltaic modules can be manufactured in the desired colour. © Fraunhofer ISE

Photovoltaic and solar thermal systems are not always considered aesthetically enhancing to a building. The coloured modules, however, being developed at the Fraunhofer ISE are refreshingly challenging this perspective. Inspired by the phenomen that causes the shimmerings shades of blue or green of the wings of the morpho butterfly, the underlying mechanism of spectrally selective reflectance allows the finished modules to be a homogenously uniform colour. Whether you want gorgeous bright tones or more subdued greys it is possible to design the solar module colour to enhance or blend with the building to which the module will be mounted.

Figure 1: The ear is a portal of entry for nanoparticles via the external auditory canal. The connection of ear to inner ear offers an entrance to the most central parts for the particles. Nanoparticles go through the tympanic membrane to enter via the tympanic cavity all other parts of the inner ear and can even delocalize via the vestibular nerve, the cochlear nerve and the blood to the entire body, especially the brain. The particles can be from lead oxide, lead acetate and lead acetate coated solarium dioxide nanoparticles.

The Beethoven’s deafness and its development are a riddle. In a previous article the authors (Luthe and Bischoff, 2020) suggested poisoning by ultrafine particles through lead corrosion of e.g. organ pipes. In the present article, they propose that Beethoven’s health problems, especially his deafness, were caused by a combination of exposure to lead-containing micro- and nanoparticles. In addition, high alcohol consumption weakened the defense against radical oxidative stress. The authors further hypothesize that the ear is a major portal of entry for nanoparticles, in this case causing lead poisoning of the inner ear. 

Figure 1: (A) Distribution of the particular matter into the follicles in a schematic presentation. (B) Particle size determines deposition in lung and penetration depth in hair follicle. In hair follicles penetration is highest for particles of a size ~ 643 nm with a depth of ~ 1200 µm.

In this article the authors (Luthe and Bischoff, 2020) connect recent findings in nano-toxicology with the investigations in Ludwig van Beethoven’s supposed saturnism. Namely, contradicting measurements of lead concentration in Beethoven’s hair and bone cannot be explained by the current hypothesis discussed among scientists. This mismatch may be called the key to the conundrum. It is also of broader interest to toxicologists, as the circumstances of Beethoven’s poisoning elucidate a general issue of particle uptake and resulting effects, which is quite neglected until now. They suggest that lead containing micro- and nanoparticles, i.e. lead oxides and acetate are the basis for the contradicting lead levels. The different portal of entry discriminates the concentrations in the bones when compared to the hair follicles. The authors also consider the source for these ultrafine lead-containing particles in Beethoven’s environment, and propose a complete explanation for his saturnism. 

Dr. Sergey Korchak, Dr. Stefan Glöggler, and Dr. Anil Jagtap (from left) with their home-made portable MRI unit. Frederik Köpper. Max Planck Institute for Biophysical Chemistry

Magnetic resonance imaging (MRI) is indispensable in medical diagnostics. However, MRI units are large and expensive to acquire and operate. With smaller and cost-efficient systems, MRI would be more flexible and more people could benefit from the technique. Such mini MRI units generate a much weaker signal that is difficult to analyze, though. Researchers at the Max Planck Institute (MPI) for Biophysical Chemistry and the Center for Biostructural Imaging of Neurodegeneration have now developed a method amplifying the signal so much that they could monitor a metabolic reaction in real time with a miniature MRI. This is an important contribution to making flexible small MRI devices usable.

Photons in a cavity can be equipped with particular properties to control the resulting light-matter hybrid states and could be specifically designed to break specific symmetries. Umberto de Giovannini / Hannes Hübener, MPSD

Crystal symmetry is one of the decisive physical attributes that determines the properties of a material. In particular, the behaviour of an electron is largely affected by the symmetry of the crystal which in turn governs the fundamental behaviour of the material, such as its conductive or optical properties. With recent developments of experimental techniques and advances in ultrafast laser experiments, another symmetry besides the crystal has turned out to influence the electrons: the symmetry of light.

Midbrain organoids from smNPCs in the microscope: Left: outer region of an organoid, middle: whole organoid, right: center of the organoid. Henrik Renner, Jan Bruder | Max Planck Institute for Molecular Biomedicine

Max Planck Innovation licenses process for the generation of organ-like tissue aggregates to biotech company StemoniX
***Sometimes hundreds of thousands of potential therapeutics need to be tested in large-scale, fully automated experiments to identify a single effective drug. Most compounds do not work as desired, and some are even toxic. Since the development of the induced Pluripotent Stem (iPS) Cell technology in 2006, researchers have been able to produce stem cells from skin biopsies and blood samples. To approach physiological conditions in the laboratory, many researchers use iPS cell technology to produce three-dimensional, organ-like tissue aggregates (organoids).

Fig. 1: (a) Rotational excitation of H2 in the pump pulse: starting the "internal clock". (b) The two possible mechanisms of molecular cleavage (ATD and EI) in the probe pulse and detection of the fragments. MPIK

Using a new method, physicists at the Heidelberg Max Planck Institute for Nuclear Physics have investigated the ultrafast fragmentation of hydrogen molecules in intense laser fields in detail. They used the rotation of the molecule triggered by a laser pulse as an "internal clock" to measure the timing of the reaction that takes place in a second laser pulse in two steps. Such a “rotational clock” is a general concept applicable to sequential fragmentation processes in other molecules. [Physical Review Letters, Oct 23rd 2020]

Cryo-EM visualizes individual atoms in a protein for the first time. The cartoon shows a part of the apoferritin protein (yellow) with a tyrosine side chain highlighted in grey. Atoms are individually recognizable (red grid structures). © Holger Stark / Max Planck Institute for Biophysical Chemistry

A crucial resolution barrier in cryo-electron microscopy has been broken. Holger Stark and his team at the Max Planck Institute (MPI) for Biophysical Chemistry have observed single atoms in a protein structure for the first time and taken the sharpest images ever with this method. Such unprecedented details are essential to understand how proteins perform their work in the living cell or cause diseases. The technique can in future also be used to develop active compounds for new drugs.

Schematic representation of zeptosecond measurement. The photon (yellow, coming from the left) produces electron waves out of the electron cloud (grey) of the hydrogen molecule (red: nucleus), which interfere with each other (interference pattern: violet-white). The interference pattern is slightly skewed to the right, allowing the calculation of how long the photon required to get from one atom to the next. Photo: Sven Grundmann, Goethe University Frankfurt

In the global race to measure ever shorter time spans, physicists from Goethe University Frankfurt have now taken the lead: together with colleagues at the accelerator facility DESY in Hamburg and the Fritz-Haber-Institute in Berlin, they have measured a process that lies within the realm of zeptoseconds for the first time: the propagation of light within a molecule. A zeptosecond is a trillionth of a billionth of a second (10 exp -21 seconds).

To fight cancer by a newly developed substance shredding carcinogenic aurora proteins: This is the aim of a new study by scientists at universities in Würzburg and Frankfurt. Dr. Sandy Pernitzsch

Researchers at the universities of Würzburg and Frankfurt have developed a new compound for treating cancer. It destroys a protein that triggers its development.
The villain in this drama has a pretty name: Aurora – Latin for dawn. In the world of biochemistry, however, Aurora (more precisely: Aurora-A kinase) stands for a protein that causes extensive damage. There, it has been known for a long time that Aurora often causes cancer. It triggers the development of leukemias and many pediatric cancers, such as neuroblastomas.

The physical structures of cancer cells are disrupted by a web forming inside of the cells – which activates their self destruction mechanism. © MPI-P

According to the Federal Statistical Office of Germany, cancer is one of the most frequent causes of death, accounting for almost 25% of all deaths cases. Chemotherapy is often used as a treatment, but also brings side effects for healthy organs. Scientists around David Ng, group leader at the Max Planck Institute for Polymer Research, are now trying to take a completely different approach: By means of targeted and localized disruption of the cancer cells’ structure, its self-destruction mechanism can be activated. In laboratory experiments, they have already demonstrated initial successes.

The new electrocatalyst for hydrogen fuel cells consists of a thin platinum-cobalt alloy network and, unlike the catalysts commonly used today, does not require a carbon carrier. Gustav Sievers

An international research team led by the University of Bern has succeeded in developing an electrocatalyst for hydrogen fuel cells which, in contrast to the catalysts commonly used today, does not require a carbon carrier and is therefore much more stable. The new process is industrially applicable and can be used to further optimize fuel cell powered vehicles without CO2 emissions.