Treating liver cancer with microrobots

This novel approach, leveraging the precision of microscopic robots guided by magnetic fields, promises to usher in a new era of targeted medical treatments for one of the most challenging forms of cancer.

The concept of utilising microrobots for healing purposes, while seemingly futuristic, is grounded in current scientific research. These minuscule biocompatible robots, crafted from magnetisable iron oxide nanoparticles, are designed to deliver treatments directly to specific areas, minimising harm to surrounding healthy cells. However, the challenge of overcoming gravity's influence on these microrobots, especially when targeting tumours above the injection site, has been a significant hurdle.

This research, published in Science Robotics, has the potential to transform the way liver cancers, particularly hepatocellular carcinoma – a leading cause of cancer deaths worldwide –are treated. The current standard, transarterial chemoembolisation, requires specialised personnel and involves invasive procedures that could benefit from the precision and less invasive nature of this microrobot-guided approach.

“Our magnetic resonance navigation approach can be done using an implantable catheter like those used in chemotherapy,” Soulez noted, highlighting the advantages of MRI over traditional X-ray for visualising tumours. This collaboration involved teams from Polytechnique Montreal and the University of British Columbia, with postdoctoral fellow Ning Li playing a crucial role as the study's first author.

The researchers developed an MRI-compatible microrobot injector, capable of assembling ‘particle trains’ of these microrobots, which are easier to control and detect within the MRI. Such precision ensures not only the correct direction of treatment but also the appropriate dosage, as each microrobot carries a portion of the therapeutic agent.

Testing the technology on pigs to closely replicate human anatomical conditions, the team demonstrated the microrobots' ability to navigate targeted branches of the hepatic artery and reach the intended destination. "This proved conclusive: the microrobots preferentially navigated the branches of the hepatic artery which were targeted by the algorithm and reached their destination,” said Soulez.

Further tests using an anatomical atlas of human livers on patients previously treated with chemoembolisation showed that in over 95% of cases, the tumour locations were compatible with the navigation algorithm, underscoring the potential of this technology.

Despite these promising results, the clinical application of magnet-guided microrobots is still on the horizon. The next steps involve leveraging artificial intelligence to optimise real-time navigation and addressing challenges such as blood flow modelling and the impact of patient positioning on the microrobots' journey to the tumour.

As the Canadian Cancer Society reports, liver cancer remains a significant health challenge, with 4,700 Canadians diagnosed in 2023 alone. This research offers hope for a future where liver tumours can be treated more effectively, precisely, and with fewer side effects, marking a significant step forward in the battle against cancer.