Carbon Nanotubes Can Exist Safely Inside the Body, Help Treat Cancer

iandoh writes "A team of scientists at Stanford University has tracked the movement of carbon nanotubes through the digestive systems of mice. They've determined that the nanotubes do not exhibit any toxicity in the mice, and are safely expelled after delivering their payload. As a result, the study paves the way toward future applications of nanotubes in the treatment of illnesses. Previous research by the same team demonstrated that nanotubes can be used to fight cancer. The nanotubes do this in two ways. One method involves shining laser light on the nanotubes, which generates heat to destroy cancer cells. Another method involves attaching medicine to the nanotubes, which are able to accurately 'find' cancerous cells without impacting healthy cells."

Comments

Commie Plot

[repapetilto]

Though they may sound less than gorgeous visually, the feathery nanotubes turned in a beautiful performance in practical terms, Dai said. The coating of PEG made the nanotubes highly water soluble, which helped them to stay in the blood instead of being absorbed.

I'd prefer to keep my precious bodily fluids pure and unsapped thank you very much.

Re:How common do you see this being?

[snl2587]

Every technology has to start somewhere. How many people 100 years ago would have thought it possible that the people of the future would have magic electric devices that allowed them to communicate through the air and all the way across the world? Small steps, small steps...

As a side note, the cancers that aren't curable aren't curable yet. I welcome anything that helps to move humanity free of cancer.

oh really?

[Goldsmith]

Another paper out this week seems to directly contradict that headline.

What Dai (the Stanford professor) is actually claiming is that specially functionalized nanotubes gather at the back end of the digestive tract, and seem to dissapear. Pure nanotubes cause all sorts of problems. There's an important distinction there, but this is still good news for nanotube (and cancer) research.

Heat is versatile

[bornwaysouth]

The technology does seem useful. At present, all they are doing is cooking the cells. But if you can coat a nanotube with various compounds, you can coat it with toxins tied by a heat labile bond. Cook to release, and poison the cancer cell.

Type of nanotubes

[H0D_G]

From TFA, it appears these are single wall nanotubes, which are a lot more expensive and difficult to produce than multiple wall nanotubes. i'd be interested to see if these could pass through the mouse, as they are more reactive than the single walled variety

You're kidding me right?

[Plazmid]

SINGLE WALL nanotubes do no harm? That is really surprised me because single wall nanotubes are a lot thinner than multiwall and most of the worries have been about them acting like tiny katanas and slicing up cell membranes. A while back someone made an antiseptic coating using carbon nanotube set up like a tiny sharp as hell bed of nails. Another worry was that biomolecules, DNA, RNA, proteins, etc might wrap around single wall nanotubes and gum up cellular machinery. In fact someone used this property to make a nifty little mercury sensor. See more here http://www.news.uiuc.edu/NEWS/06/0126nanotubes.html Of course the nanotubes were coated with polyethylene glycol to prevent stuff like this from happening, so nanotubes might still be toxic uncoated. There definitely needs to be another study done on nanotube toxicity to confirm the results.

Effects on lungs will be interesting

[DrYak]

The gut is rather an easy situation :

Normally, things go through the gut from one end (mouth) to the other (toilet seet) without much hassle, unless there's either a specific receptor or transporter for it (sugar), or it's chemical properties facilitates cross the gut wall (mainly : water can go around cell and hyrdophobic substance (fat) can go through the cell walls).

Nano tube aren't by definition neither water nor small fatty molecule, and as they're synthetic, the probability that some receptor will recognize and bind them is rather low.
Thus TFA seems plausible. But as you point out, not everyone agrees with those results. More research might be needed.

With lung, the situation is different :
Above a given threshold size (sorry, I did have to memorise it exactly for my medical studies but have since then forgotten), the respiratory tract function as some kind of "filter" and is able to stop them and reject them either back outside (by coughing) or to the gut (by swalloing), thank to the ciliated cells on the tract walls and associated mucus movement (which acts as some minature conveyor belt). (Except in smokers where the ciliated cells are paralyzed).

Under some threshold, smaller enough particles may manage to reach the end of the tract to the alveolar sacs.
Normally, specialised dust cells (some lung-specific kind of marcophage) will eat and digest them to destroy them.
Now the problems with nano tube is that they're not your usual microparticles : they're engineered to be indestructible, so the macrophage will have a hard time trying to destroy them.

This is what happens with asbestos, for exemple. Asbestos reaches the alveolar sas. Macrophage "eat it" but fail to digest it (asbestos fiber were made to be used as fire-resistant). Macrophage end up over-eating and exploding. Which releases the asbestos back and causes inflammation (both because the asbestos it self is irritant, and because of the macrophage breakage) in the lungs (asbestosis).

That's something we need to closely test with nanotube :
- are the size of most common nanotube construct under the threshold to reach the alveolar sacs ? (or will we, one day, mostly use nano technology to build huge nanobot - huge on the scale of dust particle, of course - that won't be able to reach the end of the respiratory tract).
- do animal studies show that dust cell somewhat manage to get rid of the tubes ? or do the tube accumulate and cause inflammation just like