Magnetic microrobots from ETH Zurich help clot drugs work faster

How do the blood clot microrobots work?

A blood clot is a lump of blood that has solidified. If it blocks a vessel, blood stops flowing beyond it, which can lead to a stroke or a heart attack. Drugs that dissolve clots exist, but when flow is obstructed the drug has trouble getting to the clot in the first place.

The researchers' answer is a robot about 8 micrometres (0.008 mm) long, roughly the size of a red blood cell. It is made of a body-friendly gel with tiny iron oxide particles embedded in it, which respond to magnets.

When a magnetic field is applied from outside the body, the robots start to rotate. They move along the vessel wall and stir up small currents around them, and those currents help carry the drug to the clot.

What did the tests show?

The team first used a silicone model of a blood vessel. With clots made from pig blood, adding the robots dissolved the clots six times faster than the drug alone.

They then blocked a pig artery with a clot. After 30 minutes, the stretch of vessel where blood flow had returned was twice as long as with the drug only.

Is it ready for patients?

No. These are animal results, no human trials have taken place, and the paper describing the work is still under peer review. The team says it still needs to study long-term safety and test the approach in a model that mimics a heart attack.