A Tiny Trojan Horse
The chemotherapy drug, arsenic trioxide, is packed into a very tiny Trojan horse called a nanobin. The nanobin consists of nano-size crystalline arsenic particles densely packed and encapsulated in a fat bubble. The fat bubble, a liposome, disguises the deadly cargo -- half a million drug molecules.
"You have to wallop the tumor with a significant dose of arsenic but at the same time prevent exposure to normal tissue from the drug," said O'Halloran. The fat bubble is hundreds of times smaller than the average human cell. It is the perfect size to stealthily slip through holes in the leaky blood vessels that rapidly grow to feed tumors. The local environment of the tumor is often slightly acid; it is this acid that causes the nanobin to release its drug cargo and deliver a highly effective dose of arsenic where it is needed.
The scientists show this approach to packaging and delivering the active drug has the desired effect on the tumor cells but prevents damage to ovarian tissue, follicles or eggs.
While the drug is gentle on fertility, it is ferocious on cancer. When tested against lymphoma, it was more potent than the drug in its traditional free form.
"The drug was designed to maximize its effectiveness but reduce fertotoxicity," said O'Halloran, also the Morrison Professor of Chemistry in the Weinberg College of Arts and Sciences at Northwestern. "Many cancer drugs cause sterilization, that's why the reproductive tract is really important to focus on in the new stages of drug design. Other body systems get better when people stop taking the drug, but fertility you can't recover."
Arsenic trioxide was approved a few years ago for treating some types of blood cancers such as leukemia i
|Contact: Marla Paul|