Magnetic nanoparticles that successfully navigate complex blood vessels may be ready for clinical trials

Every year, 12 million people worldwide suffer a stroke; many die or are permanently impaired. Currently, drugs are administered to dissolve the thrombus that blocks the blood vessel.

These drugs spread throughout the entire body, meaning a high dose must be administered to ensure that the necessary amount reaches the thrombus. This can cause serious side effects, such as internal bleeding.

Since medicines are often only needed in specific areas of the body, medical research has long been searching for a way to use microrobots to deliver pharmaceuticals to where they need to be: in the case of a stroke, directly to the stroke-related thrombus.

Now, a team of researchers at ETH Zurich has made major breakthroughs on several levels. The microrobot the researchers use comprises a proprietary spherical capsule made of a soluble gel shell that they can control with magnets and guide through the body to its destination. Iron oxide nanoparticles in the capsule provide the magnetic properties.

"Because the vessels in the human brain are so small, there is a limit to how big the capsule can be. The technical challenge is to ensure that a capsule this small also has sufficient magnetic properties," explains Fabian Landers, lead author of the paper and a postdoctoral researcher at the Multi-Scale Robotics Lab at ETH Zurich.

Image source: Luca Donati / lad.studio Zurich.