Updated April 3, 2012
By Molly O'Brien-Foelsch
LEWISBURG, Pa. — 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.
A solution to blood clot risk
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."
Versatile applications for patent
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." In January, 2012, the two, along with co-inventors Johnathan Rothbard and Richard L. Klein, received a second patent, "Bioactive Material Delivery Systems Comprising Sol-gel Compositions," for their work on using sol-gel compositions as drug-delivery reservoirs and to improve adhesion or organic and inorganic substrates.
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."
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