14 DAY TRIAL // Experts at ETH Zurich have recently developed a new kind of biodegradable material that may constitute the basis of bone-fracture treatments in the future, experts announce. In a paper published in the latest issue of the scientific journal Nature Materials, its creators inform that the metallic glass could replace the metallic plates and screws currently used to promote bone healing. The life span of the material could be adjusted in such a way that it gets absorbed into the organism just as the bone finishes healing, AlphaGalileo reports.
When a serious fracture occurs, bones need to be kept straight, so that a correct healing can take place. At this point, this is done using metallic-plate implants, made either from surgical steel or from titan. They are kept in place with metallic screws. When the bone is healed, further surgery needs to be undertaken, and the aids removed. This causes patients to undergo a longer healing period, but it is the best option at this point. The new metallic glass stemmed from the necessity for a better treatment method that surgeons and orthopedists had been advocating for many years.
In charge of the new research was ETH Zurich Professor of Metal Physics and Technology Jorg Loffler, who led the team behind the magnesium-zinc-calcium alloy. The design improved on the previous one, where only magnesium was used. The structures were indeed biodegradable, but they also released hydrogen in the area around the bones. The gas formed bubbles, which hindered bone growth and delayed healing. By adding zinc, the Swiss team determined that this issue would be overcome. The final composition of the material consists of 35% zinc and 5% calcium atoms, with the rest made up of magnesium.
The main role that the zinc has in the new setup is to change the corrosion behavior of magnesium considerably. And, indeed, it does, the team says. Clinical trials have shown that no hydrogen was essentially being produced around the implant area thanks to the new chemical makeup. The metallic glass is produced by rapidly heating and cooling the metals, which prevents their atoms from arranging in their specific crystalline structure. Rather, they adhere to each other in the amorphous structures characteristic to glass.