Biodegradable Composites for Medical Implant Technology
Evonik Industries AG, Essen, Germany, is conducting cutting-edge research into biodegradable high-strength composites. These materials could potentially replace metal in implants used for the internal fixation of fractured bones.
Implants play a key role in supporting bones until they heal. Today’s metallic devices typically remain in the body for the rest of the patient’s life or require additional surgery for removal. By contrast, devices made with Evonik’s new composites will be absorbed by the body gradually once the bone healing process has taken place. These materials consist of polymers and of substances that naturally occur in bones. Evonik’s research is still in its early stages – however, the possible benefits for patients are already clear. Patients will no longer need to undergo additional surgical procedures to remove the implanted devices. Specific device designs may also help bones regenerate faster.
The project is one of a number currently being conducted at the Medical Devices Project House in Birmingham, AL/USA, which employs a team of more than 20 experts. Its mission is to develop new medical technology solutions and materials, with a particular emphasis on implants. There is a significant need for high-strength biodegradable materials. The number of implants required for the fixation of bone fractures is substantial: osteoporosis, for example, is responsible for 8.9 million fractures every year. Additionally, the 300 billion-euro global medical technology market is growing at around six percent annually. The USA commands the largest share of the global market by far, with 40 %. Moreover, American companies are major players in implant technology. Other key medical technology markets include Europe and Japan.
"Our leading position in polylactic acid-based polymers is an excellent foundation for the development of materials and solutions for regenerative medicine," explains Dr. Andreas Karau, Head of the Project House. The polymers break down into carbon dioxide and water. Degradation time depends on their molecular composition, chain length, and crystallinity. They can last from a few weeks to many months – providing plenty of time for bones or other tissues to regenerate. The researchers at Medical Devices Project House are exploring composite materials that reinforce biodegradable polymers with inorganic substances, such as derivatives of calcium phosphate. Not only do these additives strengthen the material, they enhance its biocompatibility. "As the polymers gradually break down, calcium and phosphate can be absorbed into the newly formed bone tissue," Karau explains.
Moreover, the researchers’ vision goes even further. With the right materials, they could harness 3-D printing to create made-to- measure implants for individual patients. One of the goals of Evonik’s researchers in Birmingham is to make its biodegradable polymers suitable for this additive manufacturing process. Karau adds: "In the long term, we intend to develop polymeric scaffolds that could be colonized with living cells – creating a true biological implant." This approach would make it possible to regenerate cartilage, for example – or to replace damaged heart tissue with healthy tissue. However, the researchers must first find ways to improve the materials’ biocompatibility.
Evonik Industries AG
Would you like to subscribe to our Newsletters on plastics technology and profit from the latest information?
Looking for a new challenge? Check out our jobs market!
Patents encourage innovation: Stay on the ball with the latest innovations in the plastics industry in our patents section.