The Daily Item, Sunbury, PA

November 1, 2011

Bucknell president’s invention could make cardiac stents safer


The Daily Item

— LEWISBURG — Bucknell University president John Bravman has developed a patented coating that may make coronary stents safer for heart disease patients.

A scholar in the field of thin-film materials, Bravman worked on designing the coating before he became president of Bucknell and while he was a professor of materials science and engineering at Stanford University.

There, he worked with co-inventor Dimitrios Pantelidis to create an inorganic mesoporous oxide coating that adheres to organic polymers, metals and other bio-compatible materials. Pantelidis was Bravman’s post-doctoral fellow at that time.

The coating is especially useful when it performs as a sustained-release drug-delivery device, said Bravman.

“When stents are inserted into arteries there is often a concern over restenosis, or the formation of a new blood clot around the stent. There are various approaches to this problem, one being to use a coating on the stent that releases a drug to prevent restenosis. Our process provides the coating in such a way that the drug is released at the proper rate.”

Bravman said he and his fellow researchers faced a complex set of requirements in developing the coating.

“It had to adhere well to the stent, it had to be biologically inert, it had to provide a reservoir for the drug, and it had to release that drug at the prescribed rate. Our approach addresses all of these issues by creating on the surface of the stent a highly porous coating that is incredibly thin. The porosity is controlled to allow for different drugs and elution rates.”

The coating is applied using a ‘sol-gel’ process that starts with a colloidal solution, or ‘sol,’ which includes a solvent and the material to be left behind -- the coating. The sol is a precursor to the ‘gel,’ which when dried leaves behind a network of porous material on the stent. In July, the U.S. Patent Office issued patent # 7,981,441 to Pantelidis and Bravman for the invention, “Drug Delivery Systems Using Mesoporous Oxide Films.”

Bravman said the process can be easily applied to large-scale manufacturing and that other, non-stent applications for localized drug delivery are covered by the patent. “We previously developed this coating for applications in microelectronic packaging,” said Bravman. “This is a good example of how research on one field can have an impact in an entirely different field.”