In the future, when we want to deliver a drug to a particular part of the body, we won’t use a pill or a needle. We’ll employ a tiny machine that can swim to a spot and deliver a treatment. In fact, it’s already possible, albeit in mice.
Researchers at the University of California, San Diego, recently demonstrated zinc-coated “micromotors” that react with stomach acid to produce hydrogen and propel themselves along. About one-fifth the width of a human hair, the devices successfully carried gold particles (in lieu of actual drugs) delivering cargo to a mouse’s stomach wall.
Several groups are working on nano-machines for drug delivery or diagnosis, but two things make the U.C.S.D. work stand out. The device moves under its own steam; other nanobots are metal-plated and controlled by magnets outside the body. Also, the experiment was the first to be conducted with an actual live animal. It wasn’t just in a petri dish.
Nanobots potentially offer more accurate and effective drug delivery. In the experiment, the mice were given a solution of micro-machines through a stomach tube. They carried over two times more gold particle to the stomach wall compared to an oral method.
“Our results demonstrate that the self-propulsion of the micromotors leads to a dramatically improved retention of their payloads in the stomach lining compared to the common passive diffusion and dispersion of orally administrated payloads,” says a paper discussing the findings.
Joseph Wang, who was involved with the work, says the next step is to test the method with larger animals and use actual drugs. He claims the zinc is safe, because it’s fully dissolved with the acid and passes out. But only time will tell exactly what nanobot propulsion method proves the best. At the moment, there are still plenty of ideas to try out.