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Nanotech Paint To Kill Bacteria
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."
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.
I found an article that has much more information about the actual mechanism of the TiO2 anti-bacterial effect.
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?
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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
"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
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/
http://www.nanowerk.com/spotlight/spotid=6838.php
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.
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.
Job? I don't have time to get a job! Who will sit around and bitch about being broke and unemployed then?
Reading into some of your links, and being a researcher into titanium dioxide chemistry, I will tell you that the toxicity of titanium dioxide is a) nil for actual ingestion, b) high for your lungs like any small particulates, and c) unknown for sunscreen use.
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.
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.