Bacteria-sized medical robots inside our bodies?

April 24, 2009

What if doctors could inject robots the size of microorganisms into our bloodstreams and send them to attack individual cancer cells, remove plaque deposits from the walls of our arteries, fix damaged kidneys, deliver drug treatments and perform various bodily repairs from the inside on a scale too tiny for regular-sized human surgeons to attempt?

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The benefits of medical micro-robots could be enormous. Some types of operations, such as coronary bypass surgery, would no longer be necessary at all, while others, such as repair of damaged heart valves, conceivably might be transformed into outpatient procedures.

Patients might be spared the potential risks that now accompany invasive surgeries, and they’d conceivably be less vulnerable to “superbug” infections contracted in the hospital, which kill thousands of patients every year.

The downsides, caveats and complications? For one, obviously, we can expect that people who get nervous about going to the doctor are going to be considerably more squeamish about having tiny robots set loose to roam their insides. And unless we also develop bacteria-sized video cams, doctors aren’t going to be able to guide them by sight, so controlling them and tracking what they’re doing inside people is going to be a considerable technical challenge. Additionally, medical micro-robot manufacturers will have to be extremely careful to use only biocompatible materials, or else the little surgeons themselves might only do more damage to the patient’s body, or worse yet, trigger a fierce counterattack by his or her immune system. 

And no, this topic wasn’t inspired by the upcoming remake of the classic 1966 sci-fi flick Fantastic Voyage, which tells the story of the micro-submarine Proteus and its intrepid “four men, one girl” crew, who are somehow shrunk to microscopic size and injected into the body of the miniaturization process’s ailing inventor to fix a blood clot in his brain. (Though I must confess that it’s one of my faves, especially the scene in which the Proteus and Donald Pleasence, as the treacherous Dr. Michaels, start to de-miniaturize and are devoured by white blood cells.) I actually got the idea for this week's story from the recent revelation that  scientists at the Swiss Federal Institute of Technology Zurich have created tiny replicas of bacteria called Artificial Bacterial Flagella, which are capable of swimming by whipping their tails, just like the real thing. 

    An article on the institute’s Web site provides more detail:

    Artificial bacterial flagella are about half as long as the thickness of a human hair. They can swim at a speed of up to one body length per second. This means that they already resemble their natural role models very closely. 

They look like spirals with tiny heads, and screw through the liquid like miniature corkscrews. When moving, they resemble rather ungainly bacteria with long whip-like tails. They can only be observed under a microscope because, at a total length of 25 to 60 micrometers, they are almost as small as natural flagellated bacteria. Most are between 5 and 15 micrometers long, a few are more than 20 micrometers.

From YouTube, here’s an institute video of how an ABF looks under a microscope. It sure does a pretty good imitation of an actual bacterium, that’s for sure.

Unlike a garden variety E. coli, though, an ABF is fabricated by putting ultra-thin layers of indium, gallium, arsenic and chromium onto a surface, and then patterning those substances with lithography and etching to create a microbe-like flagellum, or spiral tail. (It sounds a lot like the process for making a computer chip.) A tiny magnetic head made of chromium-nickel-gold tri-layer film is then attached to the tail. By tuning the strength and direction of a rotating magnetic field, scientists can steer the fake microbe in whatever direction they want. The current generation of ABFs can swim slightly slower than E. coli, but scientists envision making ones that thrash along several times faster. (They’re also hoping to make ABFs that are even smaller.)

    While lead researcher Brad Nelson cautions that the faux germs are still in the early stages of development, the goal is to turn them into medical micro-robots. Already, the researchers have been able to get ABFs to carry around tiny polystyrene spheres. Someday, that payload could be a dose of medication or a surgical tool.

    So what do you think? Are bacteria-sized micro-robots the wave of the future? Or is the whole idea too buggy? Express your opinion below.

Comments

[Astroboy]

I want little robots crawling around inside my brain

[Caffeine Driven Stress Magnet]

These devices actually are somewhat larger than bacteria. I'm wondering if they have a risk of causing dangerous infections.

[uzy]

maybe that is a bad idea, because if the micro robot is under control, it may cause some risk in our body.

[Dr. Strange]

If they're made out of bio-compatible materials, there shouldn't be any risk of infection, any more than you would get from an artificial knee or hip.

[Raffa]

Israeli scientists are hoping to build a microscopic medical submarine in the next three years...
http://www.sciencedaily.com/releases/2009/01/090115164623.htm

[Jared McManis]

How would you get rid of the robots after they've performed whatever medical procedure they're sent to do? Would there be any hazard to having them floating around in your body afterward?

[Natural Man]

Sounds dangerous to me.

[Common Sense]

I think the idea is plausable for applications to attack deadly diseases that our own immune system cannont see or destroy. But if the robots were ever created to replace our own anti-bodies then that would only significantly weaken our natural immune system. Therefore if we were to ever to be infected by something as faint as the common cold, it could, if not definitily, be fatal.

[Zack]

Trying to replace the immune system would be a bad idea. But I think the real benefit of the micro-robots would be the ability to perform medical procedures from the inside, without invasive surgery.

[Mr. Manhattan age: (AC) Code Obvious]

Well, in my view of this technology, I'll make it simple for a comment.

Good Part: It can save your life! Just like all the new technology that we're studying.

Bad Part: Since they're machines, I'd expect them to have at least some kind of microchip in them, and so can be effected by something. E.M.P., electrical interference, anything of that sort. Also things like rejection of the body, but unable to kill things like this, always having it in your body, and maybe even allergies.

So, ya even though the bad part looks a lot bigger, saving lives... Always today's goal.

[Patrick Kiger]

The ABFs don't have computer chips in them, but I would imagine that future generations of microscopic robots will. (Scientists have created a computer chip the size of a white blood cell, capable of storing 160 kb of data. http://edition.cnn.com/2007/BUSINESS/02/05/technology.smallestchip/index.html)

Btw, here's something even more amazing--synthetic biologists, as they're called, actually have found a way to program a single-celled organism to function as a simple computer. (http://www.sciencedaily.com/releases/2005/04/050427201634.htm)

[Mothra]

Great. They can give medicines concentrated on an area of the body, so it has more of an effect. Plus they could see what is really going on inside you. But how would they get out of you?

[Dr. Strange]

Im wondering if they eventually would be filtered from the bloodstream and eliminated as waste.

[Larry Kovacs]

I don't think it would matter if they stayed in your body, as long as they're made from biocompatible materials that won't trigger an immune system response.

[Natural Man]

indium, gallium, arsenic and chromium...aren't they toxic?

[Beasley]

Ah, a little arsenic is good for you.

[Teresa Byrtus]

I think this sounds a little scary. What if htey malfunction?

[Michael]

Nano bots could remain in your body performing a wide range of renewal & repair process, cleaning plaque from blood vessels, removing defective cells (like cancer) and even supporting extensions to the immune system (like hunting and killing virus cells such as HIV) and even repairing damage to the brain (like alzheimer's). They could even reallocate nerves to repair damage (perhaps even carrying new neurons into position). Consider the ability to prevent fat from accumulating, or maintaining skin & its supporting layers to keep us looking youthful.

[dearslayer46]

can a nano bot be light enough to travel on or in a lazer light projected from point to point,and if it could be done
can a lot of bots be sent to a point in the galxy& assemble
themselfs into a prope and send a signal back to earth

[Ajlouny]

I think that it's a great idea. Imagine a surgeon not cutting into you to have to do heart surgery. If they can perfect it to the point of no error, it would be amazing.