For modern implants and the growth of artificial tissue and organs, it is important to generate materials with characteristics that closely emulate nature.
However, the tissue in our bodies has a combination of traits that are very hard to recreate in synthetic materials: It is both soft and very tough. A team of Australian and Korean researchers led by Geoffrey M. Spinks and Seon Jeong Kim has now developed a novel, highly porous, sponge-like material whose mechanical properties closely resemble those of biological soft tissues. As reported in the journal Angewandte Chemie, it consists of a robust network of DNA strands and carbon nanotubes.
Soft tissues, such as tendons, muscles, arteries, and skin or other organs, obtain their mechanical support from the extracellular matrix, a network of protein-based nanofibers. Different protein morphologies in the extracellular matrix produce tissue with a wide range of stiffness. Implants and scaffolding for tissue growth require porous, soft materials -- which are usually very fragile. Because many biological tissues are regularly subjected to intense mechanical loads, it is also important that the implant material have comparable elasticity in order to avoid inflammation. At the same time, the material must be very strong and resilient, or it may give out.
The new concept uses DNA strands as a matrix; the strands completely “wrap” the scaffold-forming carbon nanotubes in the presence of an ionic liquid, networking them to form a gel. This gel can be spun: just as silk and synthetic fibers can be wet-spun for textiles, the gel can be made into very fine threads when injected into a special bath. The dried fibers have a porous, sponge-like structure and consist of a network of intertwined 50 nm-wide nanofibers. Soaking in a calcium chloride solution further cross-links the DNA, causing the fibers to become denser and more strongly connected.
These spongy fibers resemble the collagen fiber networks of the biological extracellular matrix. They can also be knotted, braided, or woven into textile-like structures. This results in materials that are as elastic as the softest natural tissues while simultaneously deriving great strength from the robust DNA links.
An additional advantage is the electrical conductivity of the new material, which can thus also be used in electrodes for mechanical actuators, energy storage, and sensors. For example, the researchers were able to produce a hydrogen peroxide sensor. The carbon nanotubes catalyze the oxidation of hydrogen peroxide, which results in a measurable current. Hydrogen peroxide plays a role in normal heart function and certain heart diseases. A robust sensor with elasticity similar to the heart muscle would be of great help in researching these relationships.
Author: Geoffrey M. Spinks, University of Wollongong (Australia), http://www.uow.edu.au/science/research/ipri/people/UOW001340.html
Title: Tough Supersoft Sponge Fibers with Tunable Stiffness from a DNA Self-Assembly Technique
Angewandte Chemie International Edition, doi: 10.1002/anie.200804788
Geoffrey M. Spinks | Angewandte Chemie
Further reports about: > Angewandte Chemie > Artificial pump > DNA > DNA strand > DNA-wrapped carbon nanotubes > biological soft tissues > biological tissue > calcium chloride > carbon nanotubes > extracellular matrix > hydrogen peroxide > protein morphologies > scaffold-forming carbon nanotubes > synthetic materials > wet-spun for textiles
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