Treating Liver Cancer With Microrobots Piloted by a Magnetic Field

Canadian researchers led by Montreal radiologist Gilles Soulez have developed a novel approach to treat liver tumours using magnet-guided microrobots in an MRI device.

Guided by an external magnetic field, miniature biocompatible robots, made of magnetizable iron oxide nanoparticles, can theoretically provide medical treatment in a very targeted manner.

Until now, there has been a technical obstacle: the force of gravity of these microrobots exceeds that of the magnetic force, which limits their guidance when the tumour is located higher than the injection site.

While the magnetic field of the MRI is high, the magnetic gradients used for navigation and to generate MRI images are weaker.

Published in Science Robotics, this proof of concept could change the interventional radiology approaches used to treat liver cancers. The most common of these, hepatocellular carcinoma, is responsible for 700,000 deaths per year worldwide, and is currently most often treated with transarterial chemoembolization.

Requiring highly qualified personnel, this invasive treatment involves administering chemotherapy directly into the artery feeding the liver tumour and blocking the blood supply to the tumour using microcatheters guided by X-ray.

Thanks to the development of an MRI-compatible microrobot injector, the scientists were able to assemble “particle trains,” aggregates of magnetizable microrobots. As these have a greater magnetic force, they are easier to pilot and detect on the images provided by the MRI device.

In this way, the scientists can ensure not only that the train is going in the right direction, but also that the treatment dose is adequate. Over time, each microrobot will carry a portion of the treatment to be delivered, so it’s essential that radiologists know how many there are.

Despite this scientific progress, clinical application of this technology is still a long way off.

Scientists will also need to model blood flow, patient positioning and magnetic field direction using software that simulates the flow of fluids through the vessels. This will make it possible to assess the impact of these parameters on the transport of the microrobots to the target tumour, thus improving the accuracy of the approach.


Ning Li, Phillip Fei, Cyril Tous, Mahdi Rezaei Adariani, Marie-Lou Hautot, Inès Ouedraogo, Amina Hadjadj, Ivan P. Dimov, Quan Zhang, Simon Lessard, Zeynab Nosrati, Courtney N. Ng, Katayoun Saatchi, Urs O. Häfeli, Charles Tremblay, Samuel Kadoury, An Tang, Sylvain Martel, Gilles Soulez. Human-scale navigation of magnetic microrobots in hepatic arteries. Science Robotics, 2024; 9 (87) DOI: 10.1126/scirobotics.adh8702

University of Montreal Hospital Research Centre (CRCHUM). (2024, February 14). Treating liver cancer with microrobots piloted by a magnetic field. ScienceDaily. Retrieved February 16, 2024 from

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