For orthopaedic implants to be successful, bone must meld to the metal that these artificial hips, knees and shoulders are made of. A team of Brown University engineers, led by Thomas Webster, has discovered a new material that could significantly increase this success rate.

The team 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. Webster and his team 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.

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…