Researchers coat titanium with polymer to improve integration of joint re...( Research at the Georgia Institute of...)

Research at the Georgia Institute of Technology shows that coating a titanium implant with a new biologically inspired material enhances tissue healing, improves bone growth around the implant and strengthens the attachment and integration of the implant to the bone.

"We designed a coating that specifically communicates with cells and we're telling the cells to grow bone around the implant," said Andrs Garca, professor and Woodruff Faculty Fellow in Georgia Tech's Woodruff School of Mechanical Engineering and the Petit Institute for Bioengineering and Bioscience.

Details of the new coating appear in the July issue of the journal Biomaterials. The research was supported by the National Institutes of Health, the Arthritis Foundation and the Georgia Tech/Emory National Science Foundation Engineering Research Center on the Engineering of Living Tissues.

Total knee and hip replacements typically last about 15 years until the components wear down or loosen. For many younger patients, this means a second surgery to replace the first artificial joint. With approximately 40 percent of the 712,000 total hip and knee replacements in the United States in 2004 performed on younger patients 45-64 years old, improving the lifetime of the titanium joints and creating a better connection with the bone becomes extremely important.

Current clinical practice includes roughening the surface of the titanium implant or coating it with a flaky, hard-to-apply ceramic that bonds directly to bone.

In collaboration with Georgia Tech School of Chemistry and Biochemistry professor David Collard, graduate students Tim Petrie and Jenny Raynor, and research technician Kellie Burns, Garca coated the titanium with a thin, dense polymer.

"Our coating consists of a high density of polymer strands, akin to the bristles on a toothbrush, that we can then modify to present our bio-inspired, bioactive protein," explained Garca.'/>"/>