Screw-Shaped Magnetic Microrobots to Transform Treatment for Patients with Inoperable Blood Clots

By HospiMedica International staff writers
Posted on 26 Feb 2025

Image: The magnetics microrobots removed blood clots from sheep iliac artery (Photo courtesy of University of Twente)

Cardiovascular conditions such as thrombosis pose a significant global health issue, with blood clots being responsible for one in four deaths worldwide each year. A blood clot can obstruct a blood vessel, preventing oxygenated blood from reaching certain parts of the body. Traditional treatments often struggle to address clots located in hard-to-reach areas. Now, the development of magnetic microrobots offers new hope for patients dealing with otherwise inoperable blood clots.

Researchers at the University of Twente (Enschede, Netherlandsl) and Radboud University Medical Center (Nijmegen, Netherlands) have successfully developed wireless magnetic robots to remove blood clots. This cutting-edge innovation is poised to revolutionize the treatment of life-threatening vascular conditions such as thrombosis. The robots are 3D-printed in the shape of tiny screws, each containing a small permanent magnet. The magnet, measuring only one millimeter in length and diameter, is strategically positioned to allow the "screw" to rotate in both directions. This capability enables the robot to move against the blood flow and then reverse direction to swim back, making it highly maneuverable. The screw design enhances its ability to effectively drill through blood clots. These microrobots are controlled wirelessly, enabling them to navigate through the complex network of blood vessels.

The study explored three approaches for removing blood clots: mechanical fragmentation, chemical dissolution, and a combination of both. The combined approach proved to be the most reliable and safe, as it both fragments the clots and dissolves the resulting pieces. Using X-ray guidance, the tiny robots can precisely target clots within intricate blood vessels. In a recent study published in Applied Physics Reviews, the researchers demonstrated the potential of these microrobots for precise, minimally invasive clot removal. During their experiments, the robots were able to remove enough of a blood clot in the iliac artery, sourced from sheep, to restore blood flow. The iliac artery was chosen due to its straight and accessible structure, which made it an ideal model for testing. Beyond just breaking up blood clots and restoring blood flow, the technology also shows promise for other applications, such as targeted drug delivery. The robots can deliver medication directly to specific areas in the body, reducing the risk of side effects in unaffected regions.

“These robots are designed to swim and perform surgeries deep inside the body, but researchers have been limited to using clear models and video cameras, or ultrasonic probes with limited range," said Aaron Becker, researcher at the University of Houston. “Real-time X-ray guidance of these tiny robots is an essential leap forward in this area. We’ve long imagined what it looks like, but now we have 3D reconstructions of blood clots as the robot dissolves them.”