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Nanotech Paint To Kill Bacteria
Posted by
kdawson
on Sun Sep 14, 2008 02:57 PM
from the any-color-as-long-as-it's-white dept.
from the any-color-as-long-as-it's-white dept.
ColGraff points out reporting at Science News about the possibility of killing bacteria with paint. Scientists in the UK have found that high concentrations of titanium oxide nanoparticles in paint can kill bacteria by creating hydroxyl radicals when exposed to ordinary fluorescent light. Titanium dioxide is present in most white paint at concentrations of 30% or so, but not always at nanoparticle scale. The researchers found that an 80% concentration of TiO2 nanoparticles worked well to kill E. Coli bacteria. There is hope that the technique could be used against "superbugs," which are resistant to multiple antibiotics. A researcher not associated with the UK team pointed out the problem with developing products based on this idea: "[A]nything that survives and sticks around grows greater resistance... ultimately [antibiotic paint] will be its own worst enemy and the bacteria could grow to be even stronger."
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A researcher says what? (Score:5, Interesting)
What a crazy thing to say. It's true, for sure, but has always been the case in the arms race against bacteria. It's what natural selection does...
What could possibly be the researcher's motivation to say such a strange thing?
*cough*She's the founder of a rival nanotech firm*cough*
A coincidence, or fear mongering unscientific FUD? You decide!
Re:A researcher says what? (Score:5, Interesting)
Actually that was the very forst thing I thought of. Basically the paint is harnessing photon energy to increase the availability of an energetic and highly reactive compound. It also kills bacteria. If some bacteria figures out how to live in the environment --- alkyline loving bacteria exist-- then it will have free food and no competition.
Unlike anti-bacterial soaps, this food source is persistent so the bacteria can more quickly adapt.
Parent
Re: (Score:2, Insightful)
Also, there are enviroments that no bacteria can evolve to survive in, at least from their current state, either because it is just too hostile to life, or because it is too different from their usual environment that they can't adapt quickly enough, because it requires changing too many genes.
The hostile environment option is probably not so nice for us either, you wouldn't want to heat your kitchen top to 3000 degrees to sterilize it, because that would be unpractical and dangerous. But no organism could
Re:A researcher says what? (Score:5, Insightful)
So we get bacteria who adapt to live in conditions that are totally unlike the conditions inside a human body.
Was this supposed to be a bad thing?
(Captcha: fitness. I swear, the thing has a mind of its own.)
Parent
Wrong kind of logic (Score:4, Interesting)
So we get bacteria who adapt to live in conditions that are totally unlike the conditions inside a human body.
It's really not a matter of what "conditions inside the human body" are like. Conditions inside the human body don't normally include the presence of vast amounts of amoxicillin, for example. And yet, when you have a bacterial infection, taking amoxicillin tablets will get rid of them for you.
Bacteria that aren't "adapted to the conditions inside the human body" aren't a threat to begin with, so they're irrelevant. The problem with antibiotic resistance is that, if you wipe out 99% of bacteria, leaving only the 1% that are resistant to that antibiotic, when those multiply to fill the space left by the ones you killed, you have as many bacteria as you started with, but now your antibiotic is useless.
Not that the arguments in TFA make much sense, mind you, but saying that bacterial resistance is only an issue if they're "adapting to conditions inside the human body" is missing the point. Normal conditions inside the human body don't include antibiotic drugs.
Parent
Re:A researcher says what? (Score:4, Insightful)
That would mean (by definition) that they have evolved into a new species. More than likely, they wouldn't be able to live inside the body anymore.
I am working on developing a similar technology in my lab, one that I would argue is better, because it doesn't require light or UV.
Parent
Re:A researcher says what? (Score:4, Informative)
I think evolution finds creative and interesting solutions to problems that we wouldn't think of.
I wouldn't underestimate their ability to "dramatically change their membrane" (if there is no clever way to avoid it), while also being able to live in a human body.
Parent
Re:A researcher says what? (Score:5, Informative)
Its all about resources.
Having resistance to something takes up resources. So this bacteria might need x food, whereas its paint-resistant form might need x+3 food. If there's only x+3 food available to the bacteria, that's all it can do. It can't even reproduce because x+3 isn't enough for the cells to divide. Now, what if you slathered the wall with antibacterial soap? The bacteria would need to have soap-resistance at another +2 food, which isn't there.
It would likely die out.
The point isn't making the wall completely sterile, but is just making it a hostile environment for bacteria. The more a bacteria has to invest to protect itself, the less it can invest in its other traits, given a limited amount of food.
Parent
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What a crazy thing to say. It's true, for sure, but has always been the case in the arms race against bacteria. It's what natural selection does...
It's not crazy at all, nor is it FUD. What is crazy is ignoring antibacterial resistance. As TFA says, almost 100,000 become infected with antibiotic-resistant Staphylococcus aureus in hospitals alone. And that's not a competitor saying that.
Falcon
Re:A researcher says what? (Score:5, Interesting)
And yet the response is always "just use soap and water".
So why aren't we getting soap-and-water-resistant bacteria? Presumably because such an evolved trait is too "expensive".
A genetics professor of mine once explained that when I asked if bacteria can become resistant to alcohol. (As he was wiping his hands with Purell.) He said, yes, you can induce bacteria to evolve alcohol-resistance in a lab environment, but it's such an expensive adaptation that as soon as the alcohol exposure is reduced, the trait rapidly disappears again.
So the real question would be, is any resistance encouraged by this nano-particle approach an expensive trait or not?
Parent
Nanotech is coming along... (Score:4, Funny)
Re: (Score:2)
It's a good thing I did a search for "paint the bacteria" to avoid the -1 Redundant for the obvious joke... although bacteria look really good with a nice coat of white semi-gloss paint.
Let's hope they keep it controller (Score:4, Insightful)
Tetrasodium-including soaps have already given a free boot camp for bacterias at home when folks have been buying the stuff thinking it somehow makes places healthier. There's a difference between clean and sterile environments, and clean is really all that you need.
Re:Let's hope they keep it controller (Score:5, Interesting)
The problem here is British, a historical lack of hygiene.
The paint proposed could be a solution but I doubt whether they'll ever be able to recuperate the investments by lack of an export market...
Another issue is that by now it's known nano particles are potentially in the same league as Asbestos fibres and spreading them on large surfaces might introduces other problems.
Parent
Re: (Score:3, Insightful)
Tetrasodium-including soaps have already given a free boot camp for bacterias at home when folks have been buying the stuff thinking it somehow makes places healthier. There's a difference between clean and sterile environments, and clean is really all that you need.
Unfortunately as the products in the market that has, and is labeled as having, antibiotic properties shows most people don't think clean is enough. When I clean I use baking soda, a citrus cleaner, and vinegar. I try to stay away from antibio
Allergies (Score:3, Interesting)
Not only that but there is some evidence that children need some exposure to germs for their immune system to develop properly. Without this exposure their immune systems start to react to normal items that are a part of their environment. Allergies for short. In extreme cases it can actually develop into an autoimmune disorder. I'm not saying that it is healthy to live in a pig sty.
Aristotle said it best when he thought up the "Golden Mean".
Who needs grey goo? (Score:4, Funny)
So much for grey goo [wikipedia.org].
Now we can have eggshell goo, sky blue goo, burnt sienna goo... the mind boggles.
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Well.. (Score:3, Interesting)
Lets give people lead in small dosages from age of a baby to 18.
Whoever we dont kill will make the rest of them immune.
Or shall we say that boric acid with cockroaches will make boric acid resistant cockroaches? I think not.
Some things in biology are terminal, regardless of dose
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Lets give people lead in small dosages from age of a baby to 18. Whoever we dont kill will make the rest of them immune.
No, but over a 600 year period, humans will have a greater resistance to lead.
Re: (Score:2)
Are you really sure about that?
Why hasnt this been true in the case of boric acid vs cockroaches? We've used boric acid over 100 years, and no resistances as of yet.
There's just certain chemicals that directly affect the chemistry of a biological critter that I dont think we could ever adapt to.
Well, I was going to say that an example would be sodium cyanide... but this [thenakedscientists.com], specifically
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Re: (Score:3, Informative)
Also, it's not clear that cockroaches could evolve immunity to boric acid while still remaining cockroaches. In other words, the biological changes required to make them resistant to the stuff could be so severe that we might not recognize the result as a cockroach.
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It might not. Instead it could wipe out humans completely, to be replaced with another species that is more resistant to lead.
Unfortunately... (Score:3)
Oops (Score:2)
Re: (Score:2)
So is pretty much every other drug. They are dose-dependent poisons with useful side effects (paraphrased from the first sentence of the first lecture in my med school pharmacology course).
That said, I'm not sure I want to welcome our new 'brighter-than white' overlords. As a previous poster has mentioned things generally need to be clean, not sterile.
Re: (Score:2)
DISCLAIMER:It is advised that you don't lick the paint.
That should solve the issues ;)
Titanium dioxide toxicity (Score:2)
How do they break DNA if they're outside the cell nucleus?
Does the titanium dioxide in your sunscreen get taken up by skin cells? Does it even make it past the epidermis? (Not rhetorical questions, asking because I don't know).
Getting really weird, does this mean that if you're stuck without a first aid kit at the beach that you could substitute sunscreen for antibiotic ointment?
UV light triggered mechanism -- good and bad (Score:5, Informative)
I found an article that has much more information about the actual mechanism of the TiO2 anti-bacterial effect [nrel.gov].
The nice thing is that the titanium acts as a catalyst, so ideally it isn't consumed in the reaction.
The bad thing is that this requires UV light (below 385nm), which is really only present from "ordinary fluorescent lights" because they have bad phosphor coatings. All fluorescent lights really generate tons of UV, which is downconverted to visible via that white phosphor coating on the glass. But some UV escapes, and that's the stuff that triggers this anti-bacterial reaction. So good for anti-bacterial, but bad for skin cancer.
In any case, maybe this is the kind of thing where some dedicated UV lights could turn on when no people were in a given room, and that would make for the best of both worlds?
--
Hey code monkey... learn electronics! Powerful microcontroller kits for the digital generation. [nerdkits.com]
Re: (Score:2)
Do Compact Fluorescent Light Bulbs (CFLs) produce a hazardous amount of UV light?
Regular fluorescent light bulbs used in your home and office, including CFLs, do not produce a hazardous amount of ultraviolet light (UV). Ultraviolet light rays are the light wavelengths that can cause sunburn and skin damage. Most light sources, including fluorescent bulbs, emit a small amount of UV light, but the UV light produced by fluorescent light bulbs is far less than the amount produced by natural daylight. The amount of UV given off by regular fluorescent light bulbs used in your home and office are not hazardous. A recent report from E Source indicates a level of UV radiation from CFLs at a range of 50-140 microwatts/lumen. In comparison, this report also sites that some incandescent products have been found to have UV levels exceeding 100 microwatts/ lumen.
Old news (Score:4, Interesting)
So you can use this new nano-titanium paint with a UV light and kill bacteria within 96 hours... or you can use the nano-silver paint [e-spaces.com] to kill them with no light needed in 2 hours. And it's been around for around 4 years.
Operating Theatres (Score:2)
Needs more research (Score:5, Insightful)
A researcher [...] pointed out the problem [...]: "[A]nything that survives and sticks around grows greater resistance"
If those were his words, then I guess this "researcher" needs to do a bit more research, perhaps starting with a book written by a certain "Charles Darwin".
If the bacteria "stick around" it's because they are already resistant. Meaning they get to multiply, not to "grow greater resistance" (if they survived, their resistance is as "great" as it needs to be).
All that antibiotics do (in the long run) is change the relative populations of different kinds of bacteria (eliminating the ones that aren't resistant, leaving more room and resources for the resistant ones to grow). They don't actively make bacteria "get stronger", as the quote suggests. It's not as if the bacteria send a sample of the antibiotic to their underground lab where bacterial boffins come up with an antidote. They don't even have proper immune systems.
It's annoying when even "scientists" attribute some sort of "guiding intelligence" to the process of natural selection (or to individual bacteria, for that matter).
P.S. - And yes, I'm aware of plasmids, but bacteria can't suddenly rush out to buy some when they need them [ * ], so it's still a matter of selection, not "self-improvement".
[ * ] Unless they're playing Bioshock.
Interesting fact... (Score:2)
Re: (Score:3, Funny)
Stronger? Or just different? (Score:4, Interesting)
I realize that we face a pretty tough battle with certain "superbugs", but wouldn't one expect that as these bacteria adapt immunity to current antibiotics that they'll open up a weakness to something else? I suppose it's _possible_ that they're evolving to be stronger in a general sense, but usually I think of evolution as becoming more fit for one's environment -- which usually makes one less fit for another environment. Engineering is all about tradeoffs -- whether via intelligent design (our designs) or evolution (natures "design"). We created a new environment for them by introducing antibiotics, which they've adapted to. So we'll change the environment again.
I understand this is not simple or straightforward, but I think the idea of "superbugs" is a bit of misnomer -- they're only super until we find the next weakness, and I imagine they'll always be one, even if it takes us a while to find it.
Cheers.
Re: (Score:3, Interesting)
Who can say for sure what will happen? This brings to mind what happened to a strain of E. Coli. They were experimenting on a streptomycin resistant strain and they noticed something strange. Some colonies actually needed streptomycin to live! Evolution can do some really strange and unpredictable things.
Re: (Score:3, Insightful)
This paint attacks them via a much different mechanism than antibiotics do. When the TiO2 nanoparticles are moist and exposed to ultraviolet light it breaks down the water into hydrogen gas and a Hydroxide ion, The hydroxide ion is the same that is generated when lye or sodium hydroxide is added to water and it chemically burns the bacteria to death. I suspect this paint will not last very long because it will decompose on exposure to moisture and ultraviolet light, just like the bacteria it is killing.
What could possibly go... ? (Score:2)
"ultimately [antibiotic paint] will be its own worst enemy and the bacteria could grow to be even stronger."
Oh wait. Already in the summary. No need to tag it. No need to even read TFA.
Well done, sir. I'm impressed. ;^)
--
Toro
Antiseptic Antibiotic (Score:3, Interesting)
The reason antibiotic resistance develops is because antibiotics are highly targeted to a certain bacterial mechanism, usually one enzyme or protein, or a complex of enzymes working together. For obvious reasons, these have to be enzymatic mechanisms and proteins unique to bacteria, and not found in humans, primates, mammals, etc.
On the other hand, chlorine kills everything, regardless of details of underlying biology. Presumably, this paint would do the same, unless they evolve some complex way of dealing with titanium dioxide, which is highly unlikely IMHO.
Re:Just what we need, more toxins in environment (Score:5, Informative)
Titanium dioxide accounts for 70% of the total production volume of pigments worldwide. It is widely used to provide whiteness and opacity to products such as paints, plastics, papers, inks, foods, and toothpastes. It is also used in cosmetic and skin care products, and it is present in almost every sunblock, where it helps protect the skin from ultraviolet light.
Parent
Re:Just what we need, more toxins in environment (Score:5, Informative)
Actually i think i heard of evidence that the titanium dioxide particles in sunscreens, especially nano particles are harmful.
http://www.ccohs.ca/headlines/text186.html [ccohs.ca]
"With such widespread use of titanium dioxide, it is important to understand that the IARC conclusions are based on very specific evidence. This evidence showed that high concentrations of pigment-grade (powdered) and ultrafine titanium dioxide dust caused respiratory tract cancer in rats exposed by inhalation and intratracheal instillation*"
http://www.consumerreports.org/cro/health-fitness/nanotechnology-7-07/nanoparticles-in-sunscreens/0707_nano_sunscreen_1.htm [consumerreports.org]
Lab studies indicate that both of those nano-ingredients create free radicals that damage the DNA of cells and possibly cause other harm as well. And even low exposure to nanoparticles of titanium dioxide can damage the lungs of animals if inhaled
http://locokazoo.com/2008/08/05/the-sun-screen-health-disaster/ [locokazoo.com]
http://www.nanowerk.com/spotlight/spotid=6838.php [nanowerk.com]
Parent
Re: (Score:2)
I wish I had mod points for you. I have heard reporting on the possible hazards of nano particles in sunscreens. They are small enough to pass right through the skin into the blood stream. And then what happens? We don't really know. But if there's a chance they could behave like, say, asbestos, why rush into it? You know, asbestos was used on movie sets to simulate snow before we found out how harmful it was. Just one classic example of assuming cool new stuff is safe.
Re:Just what we need, more toxins in environment (Score:5, Informative)
A) and B) have been known for a long time. C) is still being studied, but the results I have seen so far in peer-reviewed journals (not random health websites) show that nanoparticle sunscreens are not harmful in any real-life circumstance, and looking at your locokazoo link, the zinc oxide sunscreens are the only ones I would even consider putting on my skin. The rest are organic photo-sensitizer molecules that are more harmful than zinc oxide even without light shining on them.
None of your links contain any scientific evidence saying nanoparticle sunscreens are harmful. Yes, titanium dioxide powder is bad for your lungs, but the titanium dioxide or zinc oxide suspended in sunscreen or mixed into paint is not particulate, and therefore has more chance of being eaten than breathed, and it is non-toxic in the digestive system. Again, no evidence has shown that the small concentration of "free" hydroxyl radicals formed when light shines on the titanium dioxide in sunscreen has any effect on exposed human surfaces.
Parent
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Then why don't we just use food coloring to kill bacteria?
Re: (Score:3, Insightful)
In a hospital, yes. Because you are more likely to find people who don't have a working immune system, and, already being ill with something else, they are more likely to catch other things.