The secret: carbon nanotubes on anodized titanium. The engineers took titanium – the most popular implant material around – and chemically treated it and applied an electrical current to it. This process, called anodization, creates a pitted coating in the surface of the titanium. The researchers packed those pits with a cobalt catalyst and then ran the samples through a chemical process that involved heating them to a scorching 700° C. That caused carbon nanotubes to sprout from each pit.
The Researchers then placed human osteoblasts, or bone-forming cells, onto the nanotube-covered samples as well as onto samples of plain and anodized titanium. The samples were placed in an incubator. After three weeks, the team found that the bone cells grew twice as fast on the titanium covered in nanotubes. Cells interacting with the nanotubes also made significantly more calcium – the essential ingredient for healthy bones.
"What we found is possibly a terrific new material for joint replacement and other implants," said Webster, associate professor of engineering at Brown University. "Right now, bone doesn’t always properly meld to implants. Osteoblasts don’t grow or grow fast enough. Adding carbon nanotubes to anodized titanium appears to encourage that cell growth and function."
Webster’s long-term vision for the new material is ambitious. With it, Webster hopes to create a new class of implants – ones that can sense bone growth then send that information to an external device. Doctors could monitor the output and determine whether to inject growth hormones or otherwise intervene to avoid additional surgery. Right now, implant patients must get an X-ray or undergo a bone scan to monitor bone growth.
COMPAMED.de; Source: Brown University