Robots Made from Algae, Powered by Magnets Can Kill Cancer, Swim Through Blood

In In The News by Barbara Jacoby

By: Daniel Starkey


When you think of algae, your first thought probably isn’t “robot-making material,” but a group of researchers are hoping that not only will the green stuff be instrumental in making bots, but that it could be a new step towards miniature, bloodborne robots that help protect humans from and perhaps even cure disease.

Spirulina, as its name suggests, looks a bit like a corkscrew. Its tiny, and coiled, and it responds to magnetic pulses. This is key, because engineers at the University of Hong Kong believe it could be key to delivering drugs to specific parts of the body where they are most needed, dramatically cutting side effects. And, as ScienceMag reports, they may even be able to outright kill cancer cells.

The key, of course, is the magnets. Spirulina is conveniently shaped for moving through body fluids, but humans are a long way off from having electronic circuits small enough to pack into such a teeny cell. That means no motors and no steering without outside help.

Magnets bridge the gap, though, because they’re essentially harmless to humans — we use MRIs for a reason. This allows, with precise control, doctors to guide the bot wherever it needs to be.

Li Zhang, lead author of the study, has been working with spirulina for some time, initially as a foundation for his own customized micro-bot. But, a recent study has dropped all the extra bits and simply used the alga. The results are pretty stunning. Bioluminescence allows scientists to track the cells through the body, and, thanks to a combination of that and a medical imaging technique known as nuclear magnetic resonance or NMR. It’s similar to an MRI, but with the addition of magnetic particles for more precise scanning.

Combining all of that, Zhang and his colleagues developed a technique for coating Spirulina with specialized iron nanoparticles. When the bot is close to the skin, researchers can use the natural fluorescence to track them, but the magnetic coating helps as the bots head further in.

“It’s a step forward that you can track these swimmers in the body,” Joseph Wang, a nanoengineer at the University of California San Diego who was not involved in the study told ScienceMag. “And it’s biocompatible and low cost.”

Biocompatibility simply means that its safe in the human body. The body will naturally dissolve in a short time and *probably* doesn’t pose any significant risk to humans. It does, however, wreck cancer like nobody’s business — and it wasn’t even a major focus of the study. Even so, 90% of exposed cancer cells died after being exposed to spirulina for 48 hours.

All of the research done so far has been in rats, but the results are extremely promising. It’ll be some time yet, before the bots are ready to carry drugs and treatments throughout the body, or take on cancer in a living, human patient. But it’s extraordinary stuff. I, for one, can’t wait until we strap cameras to the things and get to relive the Magic School Bus. And to think, it all comes from algae.