World First: Localized Delivery of an Anti-Cancer Drug by Remote-Controlled Microcarriers

ScienceDaily (Mar. 16, 2011) — Soon, drug delivery that precisely targets cancerous cells without exposing the healthy surrounding tissue to the medication's toxic effects will no longer be an oncologist's dream but a medical reality, thanks to the work of Professor Sylvain Martel, Director of the Nanorobotics Laboratory at Polytechnique Montréal.

Left: Navigation using magnetic resonance in the hepatic artery. Right: Image of liver using magnetic resonance. Key: Blue dots represent therapeutic magnetic microcarriers (TMMC); + represent anticancer agents; Red oval is part of the liver; Red bar is the catheter.

Known for being the world's first researcher to have guided a magnetic sphere through a living artery, Professor Martel is announcing a new breakthrough in the field of nanomedicine. Using a magnetic resonance imaging (MRI) system, his team successfully guided microcarriers loaded with a dose of anti-cancer drug through the bloodstream of a living rabbit, right up to a targeted area in the liver, where the drug was successfully administered. This is a medical first that will help improve chemoembolization, a current treatment for liver cancer.

Microcarriers on a mission

The therapeutic magnetic microcarriers (TMMCs) were developed by Pierre Pouponneau, a PhD candidate under the joint direction of Professors Jean-Christophe Leroux and Martel. These tiny drug-delivery agents, made from biodegradable polymer and measuring 50 micrometers in diameter -- just under the breadth of a hair -- encapsulate a dose of a therapeutic agent (in this case, doxorubicin) as well as magnetic nanoparticles.

Essentially tiny magnets, the nanoparticles are what allow the upgraded MRI system to guide the microcarriers through the blood vessels to the targeted organ. During the experiments, the TMMCs injected into the bloodstream were guided through the hepatic artery to the targeted part of the liver where the drug was progressively released.

The results of these in-vivo experiments have recently been published in the journal Biomaterials and the patent describing this technology has just been issued in the United States.