Previous studies in cell cultures have suggested that attaching anticancer drugs to nanoparticles for targeted delivery to tumor cells could increase the therapeutic response. Now, U-M scientists have shown that this nanotechnology-based treatment is effective in living animals.
"This is the first study to demonstrate a nanoparticle-targeted drug actually leaving the bloodstream, being concentrated in cancer cells, and having a biological effect on the animal's tumor," says James R. Baker Jr., M.D., the Ruth Dow Doan Professor of Biologic Nanotechnology at the University of Michigan, who directed the study.
"We're very optimistic that nanotechnology can markedly improve cancer therapy," says Baker, who directs the Michigan Nanotechnology Institute for Medicine and the Biological Sciences. "Targeting drugs directly to cancer cells reduces the amount that gets to normal cells, increases the drug's anti-cancer effect and reduces its toxicity. By improving the therapeutic index of cancer drugs, we hope to turn cancer into a chronic, manageable disease."
Results of the study will be published in the June 15, 2005, issue of Cancer Research.
The drug delivery vehicle used by U-M scientists is a manmade polymer molecule called a dendrimer. Less than five nanometers in diameter, these dendrimers are small enough to slip through tiny openings in cell membranes. One nanometer equals one-billionth of a meter, which means it would take 100,000 nanometers lined up side-by-side to equal the diameter of a human hair.
Dendrimers have a tree-like structure with many branches where scientists can attach a variety of molecules, including drugs. In experiments reported in Cancer Rese