"Ideally, you want endothelial cells to quickly attach to stents and form a coating only one cell layer thick, which we call a monolayer," Webster said. "Otherwise, if the metal is not entirely coated, blood cells passing through the repaired artery come into contact with the metal and recognize it as foreign."
Findings will be presented on April 28 during the Society for Biomaterials' 2005 Annual Meeting and Exposition in Memphis, Tenn. The work was conducted by graduate student Saba Choundhary, Webster and Karen Haberstroh, an assistant professor of biomedical engineering.
The researchers placed titanium discs possessing the nano-features into petri plates containing a suspension of endothelial cells. After one hour, the discs were washed and a microscope was used to count how many of the dyed cells adhered to the material. The researchers found that nearly three times as many cells stuck to the discs containing the nano-bumps, as compared to ordinary titanium.
"After one hour, we get three times more endothelial cell coverage of the metal if it has nano- features," Webster said.
Numerous surgeries involving stents are performed annually worldwide, with sales of "vascular biomaterials" adding up to more than $1 billion each year.
The research has been funded by the National Science Foundation. Webster's lab is affiliated with the Birck Nanotechnology Center and the Bindley Bioscience Center, which are in Purdue's Discovery Park, the university's hub for high-tech research.
Further research is planned that will replace the titanium disks with tube-shaped pieces of the nano-featured metal, which will resemble the actual shape of real stents.