Scientists describe development of tantalum nanotube materials

In an advance toward a new generation of improved hip and other joint replacements, scientists are describing development of a potential implant material that flexes more like natural bone, fosters the growth of bone that keeps implants firmly in place and is less likely to fail and require repeat surgery. Their study on these so-called tantalum nanotube materials appears in ACS Applied Material & Interfaces.

Hongyi Li, Jinshu Wang and Zhenting Zhang explain that the metal tantalum has advantages over titanium, stainless steel and other metals used in the current generation of bone implants. For example, tantalum implants are more porous than titanium, encouraging bone growth and making the implants rougher and more elastic, like natural bone. So far, however, tantalum has found use mainly in devices that bridge fractures and other defects in bone, rather than in hip joint replacements and other joint implants. The scientists set out to find a new coating for tantalum to make better implants.

The results suggest that a film of tantalum oxide nanotubes - each more than 1,000 times thinner than a human hair - can help tantalum joint replacements integrate better with existing bone. The coating improves the anticorrosion, biocompatibility and other beneficial aspects of pure tantalum. The films also helped spur bone growth in tests with animal bone cells used as stand-ins for human bone.