Watch: Microrobots fight brain tumors in mice

Scientists have created a microrobot that can pass the near-impenetrable blood-brain barrier to treat brain tumors in mice, they report in a new study in Science Robotics.

Researchers at the Harbin Institute of Technology and Harbin Medical University in China were able to combine the natural abilities of neutrophils — bacteria fighting blood cells that can pass through the blood-brain barrier and remain undetected by the immune system — with the powers of magnetic microswimmers. The magnetic particles contained a cancer drug and were coated in E. coli so the neutrophils would consume them. They call these biohybrids “neutrobots,” and found they were effective in keeping mice alive longer than those that were untreated.

While microrobots have long been seen as holding clinical potential, the inability to pass the blood-brain barrier has proved a major hurdle. More work still needs to be done before human patients can benefit from clinical application. Human bodies are much larger than mice and therefore tricker to navigate magnetically. Current imaging systems aren’t able to see or follow neutrobots in real time, but the use of neutrophils for microrobot experiments is still a promising new development.