Silk is a fascinating material, not just in fashion, but also in science and engineering, because the outstanding mechanical properties of these whisper-thin threads made by insects easily overshadow most man-made fibers.
German researchers have now taken inspiration from the lacewing, which lays its eggs on stalks made of silk with extremely high tensile strength. As they report in the journal Angewandte Chemie, they successfully produced synthetic egg stalks from biotechnologically generated proteins modeled on an egg-stalk protein.
Lacewings are light-green insects with transparent wings that are used by farmers to combat aphids. In order to protect their own offspring from predators, lacewings lay their eggs on very fine but extremely resilient silk stalks. To do this, the lacewing sticks a drop of silk dope from its abdomen to the underside of a leaf. It then presses an egg into the drop and pulls it downward. In this way, it pulls a thread that hardens within a few seconds in the air – the egg is now secured under the leaf. The threads are significantly finer than a human hair, but are so strong that they do not bend under the weight of the egg when the leaf is turned over.
The lacewing’s silk dope secretion contains several different proteins. One of the proteins contains a core domain with many repeated similar sequences. This area is flanked by small terminal domains that essentially control the properties of the silk proteins.
Thomas Scheibel and Felix Bauer at the University of Bayreuth wanted to produce an egg stalk with properties as similar as possible to the lacewing stalks. They thus developed a synthetic egg-stalk protein made of eight repeated building blocks consisting of 48 amino acids based on the repeating units of the natural silk protein. The end units were copied exactly from the original. The researchers synthesized a gene segment that codes for this artificial protein and introduced it into bacteria that then produce the protein.
Imitating silk stalk formation, the researchers dipped tweezers into a drop of protein solution, pulled out a filament, and attached the end of the stalk to a piece of aluminum foil. After drying, the stalks had similar tensile strength and elasticity to the natural version. At higher humidity, lacewing egg stalks are superior: they can be stretched out to up to six times their original length without tearing. The reason for this is the special accordion-like structure of other silk components. The researchers are confident that they will also be able to imitate this.
Possible applications for future synthetic silks range from the vehicle construction, for example in airbags, to medical applications, such as synthetic nerve conduits or drug delivery.About the Author
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201200591
North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich
Researchers Discover New Anti-Cancer Protein
22.03.2018 | Universität Basel
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
22.03.2018 | Trade Fair News
22.03.2018 | Earth Sciences
22.03.2018 | Earth Sciences