Fighting Cancer from the Inside Out

A polymer against cancer

The recent creation by M-NIMBS scientists of what James R. Baker Jr., M.D., Ruth Dow Doan Professor of Biologic Nanotechnology at the University of Michigan calls the “nanotechnology equivalent of a Trojan horse” is a manmade nanoparticle called a dendrimer designed to smuggle a powerful anti-cancer drug inside tumour cells. Less than five nanometers in diameter, the particle is small enough to slip through tiny openings in cell membranes.

Dendrimers have a tree-like structure with many branches. U-M scientists attached methotrexate, a powerful anticancer drug, to one branch of the dendrimer. On another branch, they attached their secret ingredient – folic acid.

Folic acid, or folate, is an important vitamin required for the healthy functioning of all cells. But cancer cells, in particular, seem to need more than average amounts. By taking advantage of a cancer cell's appetite for folate, U-M scientists were able to concentrate more of the toxic drug in cancer cells, while reducing side-effects on normal cells.

“It's like a Trojan horse,” Baker explains. “The cancer cell thinks it’s bringing in food. Once inside, however, there’s a poison on the nanoparticle that kills the cell.

When Baker and his research team gave the nanoparticle-methotrexate combination to mice with tumours, they found it was more effective than giving the cancer-killing drug alone. “Effectively, we delayed the growth of tumors in mice for 30 days,” Baker says. “That is significant, when you consider that one month for a mouse is the equivalent of about three years for a person.”

Although still in the experimental stage, Baker is very positive about nanotechnology’s potential to fundamentally change the way physicians treat cancer.

MEDICA.de; Source: University of Michigan Health System