At the tip of a finger: this is the tiny size of the latest microrobot developed at ETH Zurich. It delivers medication to the site of action and then dissolves.
Tiny magnet opens the door to new ways of treating strokes, serious infections and even tumors.
One magnetic microrobotcapable of transporting and releasing drugs extremely precisely within the human body, wants to navigate through your blood vessels to the exact location where treatment is needed and then dissolve, once its mission is completed.
The innovative technology developed by researchers at ETH Zurich, in Switzerland, opens the door to new ways of treating cerebrovascular accidents (CVA), serious infections and even tumorsreducing side effects on healthy tissues to a minimum.
Instead of medicines circulating throughout the body, the objective is to guide them like a “mini vehicle” to the critical point, according to the university.
The robot is, in practice, a microscopic spherical capsule, made of a dissolvable gel with iron oxide nanoparticles incorporated, which give it magnetic properties. Thanks to these particles, scientists are able to control and follow the movement of the capsule inside the blood vessels, using X-ray imaging systems.
Obstacles overcome
As the blood vessels in the human brain are extremely narrow, the size of the capsule is one of the major challenges. The researchers had to ensure that, despite being tiny, the capsule maintained sufficient magnetic properties to be controlled remotely by electromagnetic fields.
Another obstacle was navigating within the dense and complex network of vessels, with curves, forks and blood flowing at great speed. To overcome this problem, the team developed three different ways to “drive” the microrobot using external electromagnets. Depending on the type of magnetic force applied, the capsule can roll along the vessel wall or be pulled in a specific direction.
With these methods, the microrobot can move with or against the bloodstream, reaching speeds of around 4 millimeters per second. According to researchers, the magnetic fields used penetrate deeply into the body and, at the intensities and frequencies in question, do not cause tissue damage.
When the capsule arrives at its destination, scientists apply a high-frequency magnetic field to heat it slightly. This heating causes the gel capsule to dissolve, releasing the medicine directly at the target point.
So far, the technology has been tested on silicone models that imitate human and animal blood vessels, on several pigs and also on the brain of a sheep.
The next step for the ETH Zurich team is to prepare clinical trials on humans, with the ambition of bringing these microrobots to hospital operating rooms in the near future.
