HOUSTON, May 12, 1999 -- Rice University researchers recently conducted the first detailed biological study showing what happens to carbon fullerene material--the buckyball and its relatives--in mice, proving that fullerenes with radioactive metals inside can be cleared from the body and that they are attracted to bone.

The find gives promise to developing fullerenes--hollow, cagelike carbon molecules discovered at Rice in 1985--for use in medical applications such as nuclear medicine, magnetic resonance imaging (MRI) and drug delivery.

Using a rugby-shaped ball of a C82 fullerene containing radioactive holmium atoms, Rice chemist Lon Wilson and graduate student Dawson Cagle created a radiotracer similar to those that doctors use to image patients' diseased organs or kill cancerous tumors. They injected the material into mice and rats and observed where it went, how long it stayed there and how it cleared from the body.

Research collaborators include Michael Alford of TDA Research Inc. in Wheat Ridge, Colo., Stephen Kennel and Saed Mirzadeh at the Oak Ridge National Laboratory in Oak Ridge, Tenn., and Gary Ehrhardt of the University of Missouri.

Their results were published in the April 27 issue of the Proceedings of the National Academy of Sciences.

"This work shows that fullerene materials can be engineered to do their work and be cleared from the body," Wilson says. The material cleared from the blood, it was not toxic, and it was specifically attracted to bone tissue. These qualities make fullerenes and metallofullerenes worth pursuing as new medical materials, Wilson and Cagle say.

The researchers made the fullerene material water soluble by putting hydroxy chemical groups on the surface of the metallofullerenes to make them resemble "stealth liposomes," which are materials invisible to the immune system.

The Rice chemists saw clearance of about 20 percent of the material o
'"/>

Contact: Lia Unrau
unrau@rice.edu
713-831-4793
Rice University
12-May-1999