Silica particles may improve drug delivery

RICHLAND, Wash., May 25 (UPI) -- U.S. scientists say they've found packaging anti-cancer drugs in chemically modified silica particles hikes the drugs' ability to fight skin cancer in mice.

Researchers at the U.S. Department of Energy's Pacific Northwest National Laboratory and the University of Washington said they found the honeycombed particles can help anti-cancer antibodies prevent tumor growth and prolong the lives of mice.

"We are very excited by our preliminary results," said biochemist Chenghong Lei, one of the researchers. "We hope the results hold up well enough to take it to clinical trials somewhere down the road."

Anti-cancer antibodies target a particular protein on cancer cells and then kill the cells. However, such treatments require intravenous drips that expose healthy tissue to the antibody, causing side effects.

But the scientists say packaging antibodies into particles would concentrate them at the tumor and possibly reduce side effects. Other research has shown silicon to be well tolerated by cells, animals and people. So, in collaboration with University of Washington Associate Professor Karl Erik Hellstrom's group, the scientists explored particles made from material called mesoporous silica.

"The silica's mesoporous nature provides honeycomb-like structures that can pack lots of individual drug molecules," said PNNL researcher Jun Liu. "We've been exploring the material for energy and environmental problems, but it seemed like a natural fit for drug delivery."

The study appears in the Journal of the American Chemical Society.