Quote:
U-M researchers develop targeted chemo procedure
Drugs delivered only to cancer cells and avoid toxic side effects, scientists report
Wednesday, June 15, 2005
BY TRACY DAVIS
News Staff Reporter
Using nanotechnology, University of Michigan researchers have found a way to deliver chemotherapeutic drugs to tumor cells in animals. That not only increased the drugs' effectiveness, it reduced toxic side effects.
Previous studies employing cell cultures had suggested that nanotechnology could be an effective vehicle for the delivery of cancer drugs. But this is the first study to show the effectiveness of nanotechnology drug delivery systems in living animals. The study will be published in the peer-reviewed journal Cancer Research today.
Study director Dr. James R. Baker Jr., the Ruth Dow Doan Professor of Biologic Nanotechnology at the University of Michigan, said he thinks nanotechnology will improve cancer treatment.
"The truly unique thing here is we can show for the first time we can take a cancer drug ... and get it inside the cancer cells," said Baker, who directs U-M's Michigan Nanotechnology Institute for Medicine and the Biological Sciences. "So we give chemotherapy just to cancer cells, and avoid the toxic side effects."
Baker said he thought the research would have applications for many types of chemotherapy drugs, and many types of cancer. He and colleagues hope to have human clinical trials under way within 18 months, he said.
"It's very exciting work," said Max Wicha, director of the University of Michigan's Comprehensive Cancer Center. He said other types of nanotechnology employing imaging capability allowed doctors to better know where tumors had spread.
Piotr Grodzinski, program director for cancer nanotechnology at the National Cancer Institute, said research of the sort Baker and his colleagues are doing - finding more effective ways to deliver older cancer treatments - would likely change how people are treated for cancer in the future.
He cautioned that animal studies don't always mean scientists can get the same outcome in human clinical trials. But he added, "if this works in people then we've really got something. It's a significant step forward."
Nanotechnology involves the use of tiny molecules. In this case, the molecules scientists used were so small, less than five nanometers in diameter, they could slip through the walls of cell membranes. A nanometer equals one-billionth of a meter.
To deliver the particle to cancer cells, scientists attach folic acid molecules. Cancer cells soak up more folate than regular cells through additional receptor sites on the cell surface. That helps prevent the cancer cells from developing resistance to drugs, and it helps the cells immediately internalize the particle, with the cancer drug attached.
In conventional chemotherapy, cancer drugs diffuse slowly over a cell membrane to get inside the cancer cell. That takes a long time, and it usually requires higher concentrations of the drug, which can lead to damage of normal cells and tissue.
The research was funded by the National Cancer Institute. The University of Michigan has filed a patent application on targeted nanoparticle technology. A licensing agreement is currently being negotiated with Avidimer Therapeutics, an Ann Arbor biopharmaceutical company in which Baker holds a financial interest, according to U-M.
Tracy Davis can be reached at
tdavis@annarbornews.com or (734) 994-6856.
© 2005 Ann Arbor News. Used with permission
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Our lives are the songs that sing the universe into existence.~David Zindell
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