TechSci Column: Nanobots rule the world

Jackie Peterson, B&W Staff

Nanobots have become a large up-and-coming subject in science and tech. The medical field, especially, can stand to benefit greatly from these tiny helpers.

The nanobots, which can be as small as 0.1 micrometers, are being tested for drug delivery, cancer treatment and a variety of other uses. Some may soon be working alongside white blood cells to repair tissue, while others may be used to monitor the health of those with diseases or disorders such as diabetes.

However, there are a few issues with nanobots: How would you power them, and how would they move throughout the body? There are multiple responses to these questions, but the most recent development in nanomotor technology comes from the University of Texas. Students at the Cockrell School of Engineering have developed a nanomotor so miniscule that it could fit into a single cell. This means that it could fit inside a nanobot the size of a single cell. Patients could take a capsule and release a whole horde of nanobots to fight their diseases and treat their disorders for them.

As for the issue of transportation — well, human sperm have that covered. Since nanobots can get as small as human cells, scientists needed a proper self-propelling system for them. Professor Andrew Travis, an assistant professor at Cornell University, explains, “At that scale, biology provides the best functional motors.”

So, scientists looked to sperm — a decidedly mobile cell — to solve the issue. The small tail attached to a mobile sperm, called a flagellum, allows sperm to swim so quickly that if a human were to swim the same number of body-lengths per hour, the American long-distance swimming record would be shattered. Hopefully, scientists will be able to successfully lend the mobility of sperm to their nanobots. They have found that proteins along a sperm’s flagellum will stick to a scaffold-like surface, which is unusual for proteins. They used this example to attach some proteins from a mouse sperm cell to a gold chip covered with nickel ions. This approach has been successful so far, which creates an interesting meld of biological pathways and man-made surfaces.

The potential for these kinds of technologies in medicine is huge. Scientists have already tested them in cockroaches, and it’s believed that they have a future delivering drugs to very specific parts of the body. They could help repair a retina, seek out cancerous cells to administer therapies, swim through the body to the heart to deliver drugs… the possibilities are almost endless, and these tiny robots will be able to go where even the world’s best surgeons can’t reach.

For example, today’s cancer treatments usually end up doing more harm than good; like chemotherapy, which blasts all of a certain kind of cell, harming even healthy ones. Nanobots with tumor recognition modules could find only the affected cells and inject them directly, leaving healthy cells unharmed.

The bots tested on cockroaches are DNA computers, known as origami robots. They work by folding and unfolding strands of DNA, traveling around the body and interacting with the insect’s cells as well as each other. When they meet a certain kind of protein, they unravel and release the drugs carried in their folds. If certain sequences are created in the nanobots, they can be made to unfurl only when they come in contact with certain molecules— diseased cells, for example.

There is also a considerable market for implantable micro-devices that don’t move throughout the body. These are slightly larger and would be used to monitor vitals, especially in those with certain diseases or disorders. There are already several prototypes of swallow-able technology used for image capture and simpler tasks, like monitoring blood sugar level in diabetics. Google has even started developing a smart contact lens which measures blood sugar by using tears. A team led by Stanford electrical engineer Ada Poon has also developed an electronic device the size of a grain of rice that can be powered wirelessly. These sorts of inventions can be used for new implantable technology as well as improving on things like pacemakers. In fact, Poon’s technology has already been used successfully in a rabbit’s pacemaker.

There has already been controversy on the idea of inserting nanotech into human bodies, and there will likely be more in the coming years. However, the FDA does regulate nanotech on the basis of size — it regulates anything that acts as a drug by chemical or physical means, so don’t worry about unregulated science making your body into a nanobot-controlled puppet.