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."

oh really?

[Goldsmith]

Another paper out this week [acs.org] seems to directly contradict that headline.

What Dai (the Stanford professor) is actually claiming [pnas.org] 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.

Re:Bizarre overstatement: A *CURE* for Cancer?

[Anonymous Coward]

You're confusing a vaccine and a cure, as well as universal and specific cures. You seem to find cure and vaccine synonymous, which they are not. A vaccine will prevent the formation of a disease state and a cure will... cure it. A cure is not effective until the disease state is reached. And in both cases medical technology generally does not have a one-off of either of them. An easy example would be the flu vaccine. It only contains the top percentage of the previous year's bugs (i.e. the most prevalent last year). Getting the flu vaccine still leaves you with a measurable chance of catching a flu if you get one that is a) heavily mutated or b) is from a few years back and is not represented in the current sample.

Treatments are different and can be more universal because they focus on ameliorating the disease state rather than curing. Chemotherapy, for instance, would be considered a more universal treatment because it is good against a number of different cancers. It is not much of a cure since the success rate isn't too high, as far as I know. Treatments are often hammers that are aimed at identifying most of the nail-looking-things and making them go away a little bit.

Also, just because a cancer may have a number of different causes that does not imply that the underlying pathology is different. If you look at a number of different research paths into cancer physiology and development, there are findings that many cancers exhibit specific morphologies and surface markers. Of course the research is difficult and there are always people who get a different answer from you. If carbon nano-tubes do exhibit the capability to make ion-channels and we can get them to target cancerous surface markers, it's clear we've made a way to destroy target cells without releasing a toxin which would be dangerous to otherwise healthy cells. Unfortunately biomedical engineering is easy to say what needs/should be done (I should know, it's my major) but alot harder to actually do.

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

Re:What the hell happened to conjunctives?

[Bryansix]

This has been standard form for newspaper headlines for as long as I can remember.

Exactly. It's used to save space.