MRI guides cancer drug directly to liver

Scientists have made some progress in using magnetic particles to guide cancer drugs to specific tumor sites, following other efforts to reduce the toxic effects of the treatments. In a lab study, researchers from the Nanorobotics Laboratory at École de Polytechnique Montréal used microscopic carrier molecules and an "upgraded" magnetic resonance imaging (MRI) scanner to achieve this feat.

The group's so-called therapeutic magnetic microcarriers were made with biodegradable polymer particles loaded with magnetic, iron-cobalt nanoparticles and the anti-cancer drug doxorubicin. The carrier particles were injected into a living rabbit and guided through the hepatic artery with the upgraded MRI scanner to specific areas of the liver, where they were released in a sustained manner over several days. The study was recently published in the journal Biomaterials.

While external magnets have been studied previously to aid in site-specific cancer drug delivery, such approaches have been hampered by the reduced control of the treatments as they move farther away from the magnets, according to the researchers. The group was able to use their "magnetic resonance navigation" for endovascular steering through the hepatic artery four centimeters below the surface of the skin.

A potential use of the technology could be improving upon chemoembolization, an existing treatment for liver cancer that involves surgery to block the blood suppy of tumors and dosing them with relatively large amounts of chemotherapy. Pierre Pouponneau, a PhD candidate at Polytechnique Montréal, developed the microcarriers used in the experiment. This research builds on the previous work of one of his academic advisors, professor Sylvain Martel, who also contributed to this recent study.

- here's École Polytechnique de Montréal's report
- check out the abstract from the Biomaterials paper