We’ve seen it in 1966 film A Fantastic Voyage, and again in Joe Dante’s Innerspace in the 80s: some guy in a fancy capsule gets shrunk and injected into a human body and, voila, here we are, sailing in the blood stream and fighting white blood cells space-invaders style.
While science is not any closer to reduce human size further than your average diet would, we have in fact a good chance to actually sail the blood stream using .. nanobots! Listen to the Powerpuff Girls for the best definition I’ve found so far … 😀
Do you fancy some tiny thing with a mind of its own moving inside your body? Well, you might if you need it. Specially is the option is major surgery of the difficult kind. Of course, we all know that medicine has evolved a lot. Instead of the classic cut and sew approach, surgeons may now use a probe with a tiny camera to get into our body and work inside to cope with micro-problems. However, there are narrow areas where catheters might puncture an artery wall, or areas that are way too maze-like to reach.
Similarly, if we have to interact with a large number of places spread in large areas of the body (think, for example of cancerous cells), it makes more sense to send tiny robots in a search and destroy mission than to try to find, isolate and extract every single cell or use more agressive treatment like chemo or radiotherapy.
In these cases, nanobots may come handy: think of a tiny smart device capable of travelling through your veins to whatever destination is necessary to perform maintenance at microscale. Cool, right? In the video below, they offer animations of the different possibilities of nanobots in microsurgery.
There are many problems related to nanobot construction, but, since technology allows development of really, really tiny chips, the two major ones nowadays are batteries and motors, since they can not be reduced as much as processing units. The first solution to these challenges are offered by bio-bots or smart molecules. These nanoparticles are reportedly capable of navigating towards defined goals for precise drug delivery. In practice, though, they are more often than not swept out of the bloodstream and into the liver,
It has been reported in Science Translational Medicine, though, that BIND-014 might do the trick. Originally developed at MIT and currently commercialized by BIND therapeutics, BIND-014 core is a polymer that slowly releases the chemotherapy drug docetaxel. Its surface is covered with small molecules, some of which are used to fool our immunological bodyguards, whereas others bind with a particular protein found on prostate tumors and on the newly forming blood vessels that feed the growth of other types of solid tumors. Apparently, in tests animals receving docetaxel via these nanobots presented a (localized) concentration 1000 times higher than the rest.
Not thrilled with your nanobot being yet just another fancy molecule? We’ve got cyborgbots too. Professor Sylvain Martel, at the École Polytechnique de Montréal, in Canada, has already created nanobots using live, swimming bacteria coupled to polymer beads and injected through the carotid artery of a living pig. These guys travel at 10 centimeters per second (360 m/h, which is not a lot, taking into account that our circulatory system is almost 100000 km long) and have been tracked using magnetic resonance imaging (MRI) after addition of magnetic particles. They move using tiny corkscrew-like tails, or flagella.
Still disappointed for the lack of your good ol’ motors and circuits? No prob, they are also on the way. Professor James Friend, from Monash University has published in the Journal of Micromechanics and Microengineering that he might have a solution to our huge battery/motor problem. The idea is to use a piezoelectric motor to rotate the nanobot flagella and move it. Piezoelectricity is generated when piezoelectric materials suffer major stress … yes, exactly like what a tiny thing would suffer inside the turbulent blood flow. If you’ve ever kayaked downstream in rough waters, you’ll know what I mean. Current piezoelectric nanomotors still need some battery support to do their thing, but researchers are -as usual- optimistic to this respect.
In the meantime, Sylvain Martel has managed to command a legion of bacteria to carry his nanobots around. No, I’m not joking, he published it at the IEEE 2008 Biorobotics Conference and even filmed it in video. Behold, ye biological slaves!!