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Monday, 21 July 2008

The danger in Nanotechnologies

Recently I read in NY Times and New Scientist 2 similar articles on a research showing nanotubes can have same effect as asbestos on lungs-that is to cause lesions and ultimately very deadly cancer.
Because I often read about the worries of European Commission over the unknown dangers in nanotechnologies, I'm going to put an article here, just to have it in mind. To me, that study is not very definitive, it still has to tell what are the odds of inhaling such materials or of other kind of penetration in our body and as well, what is the quantity that is toxic. And maybe the measures that can keep us safe from those troubles, because obviously for the moment, the lab workers are in greatest danger.
But definitive or not the alarm is set off, so a further investigation ought to be done. Because obviously it's needed. And now, EC has a really good reason to fund that study and make a decent risk-assessment of those technologies.

Nanotubes' toxic effects 'similar to asbestos'

  • 18:00 20 May 2008

Injecting carbon nanotubes into mice shows they can trigger similar toxic responses to asbestos fibres, causing a strong immune response and possibly cancer in the abdominal cavity, researchers say.

But another recent study suggests the tiny tubes, which are increasingly appearing in commercial and industrial products, are not dangerous when inhaled, probably because they do not persist in the body as asbestos fibres do.

Carbon nanotubes (CNTs) first came to the attention of researchers in the early 1990s. Incredibly strong for their size and able to function as both conductors and semiconductors, the tiny structures are thought to be ideal for applications that range from drug delivery to space elevators.

But under a microscope, some CNTs look identical to asbestos fibres, leading to concerns that they could cause similar health problems. Occupational exposure to asbestos led to widespread lung disease, and cancers known as mesothelioma, in the 20th century.

Deadly lookalike

Asbestosis research revealed a checklist of features that makes the fibres dangerous, says Ken Donaldson at the University of Edinburgh, UK.

Ever since, it was presumed that any needle-like fibres around 20 micrometers long with an ability to persist in the body could have similarly dangerous effects. Donaldson and colleagues have now shown this holds true for carbon nanotubes.

When they injected multi-walled carbon nanotubes – composed of a hierarchy of tubes within tubes – into the abdominal cavity of mice, they saw a strong immune reaction within seven days to tubes longer than 20 micrometers. Lesions known as granulomas had developed in the tissue surrounding the abdominal organs.

The granulomas form when the macrophage immune cells that usually swallow and neutralise foreign particles take on the tubes. The cells get ruptured and die when they try to swallow fibres longer than 20 micrometers.

Highly charged

But Donaldson points out that his study does not reveal whether nanotubes are able to persist in the body long enough to reach the areas he directly injected them into. "We need to show this result in an inhalation study," he says.

James Bonner at the North Carolina State University, Raleigh, US, will shortly publish one of the first such studies.

In his experiments, mice breathed air containing 40-micrometer-long multi-walled nanotubes. "Very little inflammatory or fibrogenic effect was observed," he says.

Donaldson notes that determining the true risks of nanotubes will involve measuring the ways in which people will be exposed to them, something studies on toxicity cannot judge.

There is little evidence about exposure so far, says Donaldson. "But the good news is that nanotubes are probably not very 'dirty'," he says. "They are quite highly charged and stick together, so they don't seem to get airborne easily."

Journal reference: Nature Nanotechnology (DOI: 10.1038/nnano.2008.111) source

Link to NY Times article

6 comments:

The Pagan Temple said...

Research has indicated that metallic nano-particles injected directly into a cancer cell, and then heated with electricity, will destroy the cancer cell. So far this has only been demonstrated in lab animals. The next step is to use human antibodies as a carrier of nano-particles to cancer cells that have spread throughout the body via metastasis.

Once the particles are heated, the cancer cells is destroyed, and disintegrates. Are you aware of these studies?

Denitsa said...

No, I'm not. Or maybe I am, because it sounds familiar, but I can't remember from where.

Anyway, do you know to what temperature should the nanoparticle be heated? Because heating it to more than 40oC isn't really an option. At least if it's not the very particle that burn.

Here, I googled it and that's what I found for you:
http://scitizen.com/screens/blogPage/viewBlog/sw_viewBlog.php?idTheme=5&idContribution=1169
The next link I think refers to precisely what you talk about:
http://www.smalltimes.com/articles/article_display.cfm?Section=ARCHI&C=Envir&ARTICLE_ID=268967&p=109.
But the very fact this site is from 2003 and we don't have that treatment now means that they run into some problem with it.

Here is something more recent (2007) and I think it's promising:
HST researchers have experimented with polymer-coated iron oxide nanoparticles held together by DNA tethers to help them create a visual image of a tumor through magnetic resonance imaging. To test the particles, the researchers implanted mice with a tumorlike gel saturated with nanoparticles and placed those mice into the wells of cup-shaped electrical coils, which activated the nanoparticles via magnetic pulses.

The researchers subjected the metallic iron oxide particles to radiation until the DNA bonds holding them together broke, releasing fluorescent materials.

The researchers are studying DNA sequences to gauge the point at which heat activates the nanoparticles after they have reached tumors in the body. One advantage of a DNA tether, the HST team members say, is that its melting point is tunable—scientists would be able to control when the bonds between the nanoparticles break by creating links of varying lengths with different DNA sequences.

Exposing the nanoparticles to a low-frequency electromagnetic field causes them to radiate heat that, in turn, erases the tethers and releases the drugs. The waves in the magnetic field used by the HST researchers have the same frequency range as radio waves (between 350 and 400 kilohertz). These waves pass harmlessly through the body and heat only the nanoparticles.

Von Maltzahn and six other researchers, including Bhatia, wrapped up their initial study about a year ago and are now planning to replace the original fluorescent payload with a more therapeutic one, such as an enzyme that could be injected directly into the tumor to attack it from the inside out. Their goal is to eventually be able to release nanoparticles intravenously into the bloodstream and activate those particles by heat or magnetism as needed.
http://www.sciam.com/article.cfm?id=nanoparticles-nanotech-cancer-tumor


The problem with nanoparticles is that even if you use them successfully to kill the cancer, you still don't know where they'd go and what they'd do in the body. You must be sure you won't cause more harm than good before creating a good treatment. And another problem is that there are some many types of cancer and you obviously have to either create a nanoparticle for EACH cancerous cell and then burn them (which I guess it's hard) or to make a coating of the particles that would stick to that type of cancer. Obviously that's not that straight-forward, because we still don't have a serious cancer nano-treatment.

The Pagan Temple said...

I think they have been using either gold or iron, or possibly both. The human body contains so much iron anyway, so that shouldn't be a problem. The regulatory agencies in the US makes researchers jump through hoops before they allow them to proceed even with volunteer human testing. They then make them spend so much time studying the results and any potential side-effects, etc.

They are nuts. These people aren't human, as far as I'm concerned. They deprive people who are terminally ill of treatment that might save their lives on the grounds it might kill them-or on the grounds they don't know what the side-effects will be.

That's the kind of thinking you get when you are dealing with a bureaucracy, which is why I tell you, and any who will listen, to drive a stake through the heart of the EU before you find out the monster ain't quite as lovable as Count Chocula.

Yay Ireland.

Denitsa said...

If I understood the "drive a stake" correctly, then you know very well I won't ever agree to such statement.
And I think it absolute hypocrisy to talk against the EU knowing just how much Ireland benefited from its money. It's easy to be brave when you're an economic miracle, huh? So easy to forget the helping hand!

I won't argue with you here, one that, it's your business what you think of Europe. But when you say something so negative, just think of the closed borders, no euro, hating neighbours always ready for war (because nations either work with each other or against each other),no free medical attention abroad, no European money, no cheap flights, no cheap roaming, no GSM ,by the way, since that is an European standard . All those are due to the existence of the EU and probably won't be there if everyone start hating EU and it just falls apart. That's all I can say. I don't want to convince you in anything. The monster doesn't have to be lovable, it should serve its purpose.USA isn't particularly lovable to its citizens but it's working well for them.

As for the nanoparticles- they don't deny the people a possible treatment!
Yes, it is iron, but it is in a form that's not to be found in the body-nano particles are not quite the same as a normal elements. So, it's in no way clear what would happen if they get in our body in great numbers. I wrote already an article on that in After the Pink Goat. There was a problem in a meat factory from pulverising swine brain that the workers inhaled. And guess what, though normal swine brain isn't toxic to our body, since the body has a mechanism to keep the pathogens out of it-but that way doesn't work for nanoparticles, since they get directly into the blood and cells. So, workers had many problems that were directly connected with their work-some of them couldn't even stand on their feet!

So, bottom line, 1) the treatment isn't ready yet, since it's one to know the principle, and another, to make it doable, practical and safe. There are many questions that are unclear-how to direct the nanoparticles, where to take them, how to bond in a best way with the cancer cells, what to do once they are there-burn, let out a medicament, emit something.Yes, it's clear you can do all of those, but which one would work best and be safest? And also it is not known how to make them get out of the body once they're done.

2) Testing has a sense-it might sound like a great treatment, but if you don't test it properly and you apply the treatment to ALL cancer sick people that qualify and then 80% of them die from it, even though many of them could have lived if treated in another way, that sounds to me like a crime against humanity.
It's easy for you, from home, to say it's bureaucracy to do testing, but as a matter of fact, the responsibility if for the scientists and approval authorities to make sure they are safe. Because if it turns out it's not, guess who'd be guilty. Well, obviously not FDA since that's the most corrupted organisation ever and it already obtained a law that limited its responsibility (and that of the companies-producers), so it won't be them. But the scientists that said it's safe would be guilty, they would have killed all those people with their irresponsibility. Not to mention that in case something goes wrong, science would be in a very nasty place in popular mind.
That's a lot of responsibility!

The Pagan Temple said...

Oh come on Dani, I wasn't talking about testing anybody that has cancer, I'm talking about people that are already on their death beds, who have a very limited time left to live, and whom no other known or available treatment will help.

The whole idea behind testing is that it hasn't been proven yet. The test subjects would have to know that going into it, and would have to willingly sign papers to that affect.

Letting them die without giving them that one shot-now THAT would be a crime against humanity, in more ways than one. Not only are you depriving those individuals of a potential cure, but you are holding back the prospect of proving that it is safe for general use-or not.

Denitsa said...

First, I'm Deni, not Dani :) Deni comes from Denitsa, Dani comes from Daniela for example.

And second-well, what you're saying depends from the right of Euthanasia and Suicide. Because strictly speaking allowing someone to take a treatment with questionable safety could be dangerous for the doctor/scientist. It's obvious that you can make such decision for yourself, but your relatives can always call it assisted-suicide and sue the guy that injected you with the stuff. And since the patient is already death, it would be hard to prove, he was informed, he was sane, he understood what was being done to him and agreed.

I'm just randomising, I guess they do that with patients in lethal phase but again under strict rules. I'm not good at ethics, so I have no idea what they are or should be. If you ask me, under informed agreement, you should be allowed to do with your body whatever you like.

But from scientific point of view, dying patients in final stage are not the perfect patients, since the body tends to kill itself in random patterns once the moment comes. Thus, you can't be sure what exactly are the results from your experiment.

Anyway, I'm sure that they are either doing already tests with such patients or simply the article isn't realistic and there are problems they are not mentioning. Because you know, theory is good, but doing it in reality requires much more luck and effort.