Scientists have discovered a process to produce new metal surfaces that could lead to superior medical implants that enhance healing and are less likely to be rejected.

"Using chemical modification, we have produced metals with intelligent surfaces that positively interact with cells and help control the biological healing response," said Antonio Nanci, the study's senior author and a professor at the Universite de Montreal's Faculty of Dentistry. "These will be the building-blocks of new and improved metal implants that are expected to significantly affect the success of orthopaedic, dental and cardiovascular protheses."

The researchers applied chemical compounds to modify the surface of common biomedical metals such as titanium and found that exposing the metals to selected etching mixtures of acids and oxidants resulted in surfaces with a sponge-like pattern of nano-sized pits. Some cells were better able to stick to these surfaces than traditional smooth ones.

The researchers then tested the effects of the chemically-produced nanoporous titanium surfaces on cell growth and development. They showed that the treated surfaces increased growth of bone cells, decreased growth of unwanted cells and stimulated stem cells, relative to untreated smooth ones. In addition, expression of genes required for cell adhesion and growth were increased when in contact with the nanoporous surfaces.

Uncontrolled growth of cells on an implant is not ideal. For example, when using cardiovascular stents, it is important to limit the growth of certain cells in order not to interfere with blood flow. Also, in some cases, cells can form an undesirable capsule around dental implants causing them to fall. The scientists demonstrated that treatment with specific etchants reduced the growth of unwanted cells.

Dr Antonio Nanci claims the finding is groundbreaking and that this innovative approach may ultimately hold the key to developing intelligent materials that are not only easily accepted by the human body but that can actively respond to the surrounding biological environment.

*Article courtesy of NanoMagazine (www.nanomagazine.co.uk)