As Elon Musk commits to journeying the world in electric cars, scientists have been working tirelessly on a journey of a much smaller scale--cell size, in fact. The goal? Create a robot that can move safely through your body to deliver drugs, do microsurgery or otherwise heal you from within. And while there's still work to do, that finish line is closer than ever, thanks to So Li Zhang, materials scientist at the Chinese University of Hong Kong.
As Elizabeth Pennisi of Science Magazine explains, Zhang and his colleagues are developing a micro-robot based out of something you might have added to your morning smoothie or taken like a vitamin--spirulina, a type of algae. Zhang's team developed a way to coat the spirulina with iron oxide nanoparticles. Those particles let researchers direct the spirulina via magnetism. The team also can track the spirulina, either by detecting its natural fluorescence, or with with nuclear magnetic resonance (NMR), a type of medical imaging technology.
As mentioned above, spirulina's fluorescence gives experts a simple way to see where the micro-robot is in your body. But it has three other major features that make it attractive for micro-biorobotics, as well.
Spirulina also has a coil-like shape. Twirling helical bodies like spirulina can achieve great mobility, which is what you want to get medicine or super tiny tools past proteins and other molecules quickly. The spirulina means that researchers don't have to use other forms of toxic fuel to propel the micro-robot.
Neither the spirulina and the iron oxide coating will harm you or make you sick. The micro-robot will degrade naturally in as little as a few hours, depending on how thick the iron oxide coating is.
Spirulina grows naturally in the wild and is relatively easy to cultivate. Subsequently, it's cheap as far as medical equipment goes. You can buy a little over a pound of the stuff on Amazon, for example, for around $20. The cheaper the micro-robot is to make, the less professionals have to charge people who need to use it for their health. It also means that, if a particular micro-robot doesn't function as it should, replacing it won't break the bank, either.
An unexpected bonus
Spirulina is known as a superfood for a reason. It's high in protein and contains a range of nutrients like iron, calcium and beta-carotene. As a result, researchers suspect it can boost health in a myriad of ways, although evidence isn't definitive yet. That's important for anyone, but it's especially meaningful for people who are sick or have other conditions requiring healing.
With this potential in mind, researchers have discovered that, while spirulina doesn't hurt healthy cells, it does a serious number on cancer. In fact, when tested in lab dishes, spirulina killed 90 percent of tumor cells over a 48-hour exposure. The result comes from a compound the spirulina makes. This could make the micro-robot the ideal weapon for delivering cancer drugs.
A few more steps to go
Zhang's progress is undeniably laudable, but he cautions that it likely will be a solid decade before the micro-robot is doctor's-office ready. His team needs to ensure the micro-robot can carry cargo and deliver it better than current options do. Even so, if successful, the cell-sized innovation might transform medical science in a way that's truly gigantic.