Blood clot microbots helped drugs clear blocked vessels in laboratory and pig tests, ETH Zurich said on November 9, 2026. However, the Swiss university said the work has not reached human trials.
ETH said the tiny devices stir fluid near a clot, helping medicine reach a spot where blood flow has slowed. The study remains under peer review, and the university’s report gives no sample size.
How blood clot microbots move
According to ETH, the gel bots contain iron oxide particles and measure about eight micrometers long. An external magnetic field makes them tumble along vessel walls, moving nearby fluid. A catheter brings the bots and medicine close to the clot.
ETH reported sixfold faster clot breakdown in a vessel model using pig blood. In live pigs, the vessel area with restored flow was twice as large after 30 minutes as with medicine alone.
Dissolving a clot differs from removing it
For example, the US National Institute of Neurological Disorders and Stroke describes two ways to restore flow after a stroke caused by a clot. Drugs called thrombolytics break down the blockage. Instead, doctors can pass a catheter into a blocked brain artery and remove the clot.
The institute also distinguishes clot-dissolving drugs from blood-thinning medicines, which help prevent clots. It also says strokes caused by bleeding need treatment to find and control that bleeding. These different problems require different care.
MedlinePlus says bleeding is the most common risk of clot-dissolving treatment. Doctors therefore weigh a patient’s medical history and the treatment’s risks before using these drugs. Faster clot breakdown is only one part of that decision.
Longer safety tests come next
Next, ETH said researchers plan longer animal safety tests for the blood clot microbots. Tests in models of specific diseases, including heart attacks, would also be needed. Its announcement sets no date for patient use.
Sources: ETH Zurich, NINDS, MedlinePlus
