Fantastic voyage, from fiction to reality

Fantastic voyage, from fiction to reality

École Polytechnique de Montréal researchers make new inroads for cancer treatment by using MRI to track and propel devices through the bloodstream
July 1, 2007
In the same vein as the 1960s classic movie, Fantastic Voyage, where a crew of scientists are miniaturized and injected into the bloodstream, Sylvain Martel, director of the NanoRobotics Laboratory at École Polytechnique de Montréal, has successfully made travel through a living animal’s bloodstream possible. “This is really what we are doing, except that we don’t send tiny humans of course,” he says with a laugh. Instead, Martel is developing tiny robots or nanorobots that can trek through blood vessels. Until recently, the study of nanorobotics has been theoretical, but Martel has demonstrated its potential application with magnetic resonance imaging (MRI).
 

Martel is the first in the world to use MRI to show the feasibility of propelling and controlling nanorobots inside a living body. With his team, Martel developed software that allowed him to harness the magnetic power of an MRI to successfully move and control a magnetic bead through the artery of a living pig []. “We are using the magnetic fields of nanoparticles to track them through the bloodstream.” The success of his experiment opens the door to promising new cancer treatments, including non-invasive cures.

“This could lead to a revolution in interventional radiology,” adds Gilles Soulez, a member of the research team. Interventional radiology is a branch of medicine that diagnoses and treats disease using small needles, guide wires, and catheters. The instruments are introduced through tiny incisions and then guided by x-ray, ultrasound, or other forms of radiological imaging.

Though more testing still needs to be done with MRI propulsion, Martel and his team can now work on applications for this new technology. “We have proven that it is possible to deliver anti-cancer drugs to precise areas of the body, and thus reduce side effects of treatments to the whole body,” he explains.

The widespread use and availability of MRI in every hospital also makes the development of nanorobot technology very attractive. MRI is not as invasive as x-rays, and it provides a 3-D image. Therefore, adapting existing MRI systems to perform the tasks that will be required by nanorobot technology would be very feasible without spending millions of dollars to develop a custom imaging platform. “You can put our program on a 35-cent CD, and implement it in each hospital,” affirms Martel. He hopes for a nanorobot clinical trial in much smaller blood vessels within the next five years.

In the meantime, researchers focus on finding appropriate materials for the nanostructures. “There is a catalogue of particles that we can use depending on different types of applications. If we were to send the nanorobots to the brain, we would use a different material and design than for the liver,” explains Martel. To achieve that goal, Martel has recruited Jean-Christophe Leroux, a pharmaceutical scientist with expertise in biodegradable polymer materials. “We are at a preliminary stage, but we know we want a polymer that will be biodegradable in the body,” explains Leroux. “At this point, we know it works. All we need is fine tuning.”

Benefits

Sylvain Martel’s successful MRI navigation of a magnetic bead through a live bloodstream holds great promise for medicine and bioengineering. Because the human bloodstream is made up of close to 100,000 kilometres of pathways, it offers access to every part of the body. Such localized access could make it possible for novel cancer treatments, such as confined hyperthermia, which involves increasing the temperature at a specific area to potentially kill cancerous tumours. It could also lead to the development of new, minimally invasive surgical techniques.

For bioengineering in particular, Martel’s discovery has led to efficient work at the nanoscale. Researchers can control devices and have direct access to the human body at a scale invisible to the naked eye. The computer platform required to perform such activities is extremely complex and unique, and was made possible through the highly interdisciplinary environment in which Martel and his team operate.

Martel’s studies involve teams of researchers and graduate students from various backgrounds, including medicine, microbiology, physics, chemistry, fluid dynamics, material sciences, nanotechnology, micromechanics, microelectronics, software, and computer engineering. This research setting has delivered results at the academic level as well. For instance, six MA students working with Martel now plan to pursue doctorate degrees with hopes of advancing their own research in the field of nanomedicine.

Partners

Sylvain Martel had 11 team members for his nanorobotic research using MRI—all from the NanoRobotics Laboratory at École Polytechnique de Montréal (EPM). They helped develop the computer software to track objects in the bloodstream, which requires eliminating distortion when the object is moving, and increasing resolution using many algorithms. The computer program makes 24 decisions every second to constantly adjust the movement of the object. “No human being is capable of making decisions this quick, and in this sense, our computer program is infallible,” says Martel. In the next phase of the project, the team aims to find the right material to eliminate all risks of toxicity, and to ensure biodegradability once the nanovehicle has accomplished its task. He also collaborates with other researchers at McGill University, l’Université de Montréal and the Centre hospitalier de l’Université de Montréal.

Learn More

Read the full report of Martel’s research results from Applied Physics Letter, a weekly journal featuring new findings in applied physics.