2024-02-24 05:00:03
The idea of injecting microscopic robots into the bloodstream to heal the human body is not new. It’s not science fiction either.
Guided using an external magnetic field, miniature and biocompatible robots, made of magnetizable iron oxide nanoparticles, can theoretically deliver a drug in a very easy way. s targeted.
Until now, a technical obstacle persisted: the force of gravity of these microrobots exceeds that of the magnetic force, which limits their guidance when the tumor is located higher than the site of ‘injection. Although the magnetic field of an MRI machine is high, the magnetic gradients used for navigation (Navigation is the science and set of techniques that make it possible to 🙂 microrobots and to produce images, are weaker.
“To solve this problem, we designed an algorithm that determines what position the patient’s body should be in in the MRI machine to take advantage of gravity and combine it with magnetic navigation force”, explains the Dr Gilles Soulezprofessor atUniversity of Montreal (The University of Montreal is one of the four educational establishments…) et searcher (A researcher (female researcher) designates a person whose job consists of doing…) at the CHUM Research Center.
“This combined effect facilitates the movement of the microrobots towards the arterial branches which will nourish the tumor, he says. By varying the direction of the magnetic field, we can guide them with precision towards the sites to treat and thus preserve healthy cells.”
Towards more precision
Published in the journal Science Roboticsthis proof of concept could modify 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 often treated today by transarterial chemoembolization.
Requiring highly qualified personnel, this invasive treatment consists of administering chemotherapy directly into the artery feeding the liver tumor and blocking the blood supply using guided microcatheters ©s by X-rays.
“Our magnetic resonance navigation approach could be done using an implantable catheter like those used in chemotherapy,” indicates Dr.r Lift up. The other advantage is that MRI allows tumors to be visualized better than X-rays.”
For this study, the D teamr Soulez collaborated with those of Sylvain Martel (Polytechnique Montréal) and Urs O. Häfeli (University of British Columbia). The first author of the study, Ning Li, is a postdoctoral fellow in the laboratory of Dr Relax.
Thanks to the development of an injector for microrobots compatible with MRI, scientists were able to assemble “particle trains”, aggregates of magnetizable microrobots, on demand. Equipped with greater magnetic force, they are more easily controllable and visible on the images provided by the MRI machine.
The team can thus ensure not only that the train is going in the right direction, but also that the dose of medication is adequate. Because, ultimately, each microrobot will carry a portion of the treatment to be administered. Knowing their number is therefore essential for radiologists.
A good sense of direction
“We carried out tests on 12 pigs in order to get as close as possible to the anatomical conditions of humans. This proved conclusive: the microrobots navigated preferentially in the branches of the human artery. “patic who were targeted by the algorithm and reached their destination”, mentions the Dr Relax.
His team ensured that the location of the tumor in different parts of the liver did not influence the effectiveness of such an approach.
“Thanks to an anatomical atlas of human livers, we were able to simulate the control of microrobots on 19 patients treated by transarterial chemoembolization,” he emphasizes. “They had a total of around thirty tumors placed at different locations of their liver. In more than 95% of cases, the location of the tumor was compatible with the navigation algorithm to reach the tumor target.”
Despite this scientific advance, the clinical application of this technology (The word technology has two meanings in fact 🙂 is not for tomorrow.
“We must first optimize, thanks to artificial intelligence, the real-time navigation of the microrobots by detecting their location in the liver and also possible blockages of the branches of the hepatic artery nourishing the tumor”, specifies the Dr Relax.
Scientists will also have to model blood flow, the patient’s position and the direction of the magnetic field using software simulating the flow of fluids in the vessels. This will make it possible to evaluate the impact of these parameters on the transport of microrobots to the target tumor and thus improve the precision of the approach.
According to the Canadian Cancer Society, 4,700 Canadians will be diagnosed with liver or intrahepatic bile duct cancer in 2023.
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