Heart valves from the 3D printer
Why is? About scaffolds for artificial heart valves.
Why is that important? Four heart valves ensure that the blood flows in the right direction in the human body. It is essential that the valves open and close correctly, which is why the heart valve tissue must have a heterogeneous structure. It has now been possible to imitate this structure for the first time using a 3D printing process that enables individual patterns to be created precisely: melt electrowriting. Here, high electrical voltage is used to form structures from a very thin polymer fiber, which measures only between five and 50 micrometers in diameter. The patterns are “written” using a computer-controlled collection platform that moves and catches the fiber exiting the printhead in a programmed path – “much like a slice of bread being moved back and forth under a dripping spoonful of honey,” says the researchers. The length, diameter or cross-section can be adjusted using software so that individualized heart valve frameworks are created. Medically approved polycaprolactone (PCL), which is compatible with cells and biodegradable, was used as the material. The goal of the scientists: After the implantation, the body’s own cells should grow on the scaffold and form new tissue. This has already been observed in the first cell culture studies. The 3D printed heart valves were tested in an artificial circulatory system, opening and closing as desired.
Who invented it? A research team led by Petra Mela, Professor of Medical Materials and Implants at the Technical University of Munich (TUM), and Professor Elena De-Juan Pardo from the University of Western Australia. Franz Schilling, Professor of Biomedical Magnetic Resonance, and Sonja Berensmeier, Professor of Selective Separation Technology at TUM, were involved in the further development of the PCL material.
Petra Mela in a laboratory at the Technical University of Munich in front of a melt electrowriting system.
(Photo: Andreas Heddergott/TUM)
What’s next? In the long term, heart valve implants that grow with the patient should be created using this method. Such would be particularly important for children, because the currently available flaps have to be replaced over the years. “Our heart valves, on the other hand, imitate the complexity of the body’s own heart valves and are designed in such a way that they enable the patient’s body cells to infiltrate the supporting structure,” says Petra Mela. The next step? Preclinical studies in animal models.
A microwave refrigerator for molecules
Why is? A new method to cool gases to near absolute zero.
Why is that important? Close to absolute zero, matter begins to behave unusually and assume new, exotic states, and quantum effects can be studied. The results could have far-reaching consequences, for example for quantum computers, which are regarded as one of the key technologies of the 21st century. For their experiments, the researchers used a gas composed of sodium-potassium molecules (NaK), which were confined in an optical trap by laser light. Then the so-called evaporative cooling was used – a method that works similar to the principle that can be observed in a cup of hot coffee: water molecules constantly collide there and exchange part of their kinetic energy. If two particularly high-energy molecules collide, one of them can become fast enough to escape the coffee – it steams out of the cup. The other molecule is left with less energy. In this way, the coffee gradually cools down. However, NaK molecules are complex. Their movements during collisions are difficult to control, and the molecules can easily get caught up in one another. To prevent this, the scientists used a trick: they created an electromagnetic field that served as an energetic shield for the molecules and prevented them from clumping. This field was generated by a strong, rotating microwave field. The result: a new cold record was set after only a third of a second; For the first time, a gas made up of polar molecules cooled down to 21 nanokelvins – that is a few billionths of a degree above absolute zero at minus 273.15 degrees Celsius and well below the temperature at which quantum effects determine the behavior of a gas and bizarre phenomena become noticeable make.
Who found out? A team led by quantum physicist Immanuel Bloch, professor at the Ludwig Maximilians University (LMU) and director at the Max Planck Institute for Quantum Optics (MPQ) in Garching.
Immanuel Bloch is one of the most frequently cited physicists.
(Photo: LMU)
What’s next? Max Planck researcher Xin-Yu Luo is convinced that even lower temperatures are possible through technical refinements of the experimental setup. “Since the new cooling technology is so simple that it can also be integrated into most experimental setups with ultracold polar molecules, the method should soon be widely used – and contribute to a number of new findings,” believes Immanuel Bloch: “It could also be used be useful in quantum technologies.” For example in quantum computers, where data could perhaps be stored using ultracold molecules.
Artist traces in exile
Why is? An art historical project that shows how globally networked artistic modernism was and enables virtual city walks in the footsteps of emigrated artists.
Why is that important? Emigration and flight are global issues that come up again and again. The project started in 2017, after the refugee movements in 2015/16. Since then, many Syrian artists have settled in Berlin. “Big cities are extremely attractive to artists,” says Burcu Dogramaci. The professor at the Institute for Art History at the Ludwig-Maximilians-Universität (LMU) believes: “A great parallel can be drawn between today and the beginning of the 20th century. We learn from the past how migrants formed in the cities. And vice versa, we observe phenomena in the present that can be historicized.” With the project, she wants to show that artistic modernism was not only concentrated in the European metropolises, and how much the cities in which artists sought refuge moved the exiles and influenced their work. London, New York, Istanbul, Buenos Aires, Mumbai (formerly Bombay), Shanghai: These six cities were chosen. The results were brought together in a database via the website metromod.net it is now possible to follow in the footsteps of the artists and to visualize the works created in exile. For example, you can experience how the works of German-speaking photographers like Andreas Feininger, who emigrated to New York, were created in the 1930s and 1940s.
Who came up with it? An interdisciplinary research team led by Burcu Dogramaci, Professor at the Institute for Art History at LMU. The European Research Council (ERC) funded.
On the trail of artists: Burcu Dogramaci, professor at the LMU Institute for Art History.
(Photo: LMU)
What’s next? The project aims to reach as many people as possible and convey the message: “Refugee movements are not isolated phenomena. In the 20th century in particular, there were also opposing refugee movements from Europe into the world. It is often forgotten that our present also has a history.”