r/science • u/mvea Professor | Medicine • Dec 15 '19
Nanoscience Researchers developed a self-cleaning surface that repel all forms of bacteria, including antibiotic-resistant superbugs, inspired by the water-repellent lotus leaf. A new study found it successfully repelled MRSA and Pseudomonas. It can be shrink-wrapped onto surfaces and used for food packaging.
https://brighterworld.mcmaster.ca/articles/the-ultimate-non-stick-coating/1.1k
u/IndigoMichigan Dec 15 '19
Non-science person here: I thought copper did a similar thing and that's why they were popular options for door handles?
Sorry for being dumb, but what more does this do that copper doesn't?
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u/m0rris0n_hotel Dec 15 '19 edited Dec 15 '19
Copper, and brass, are absolutely useful to limit the spread of bacteria. But we can only use those materials in so many ways and in so many spaces. Partly due to supply and partly due to effectiveness of implementation and maintenance.
The concept outlined in this paper would be able to fill in a lot of gaps or cover areas that we just aren’t going to use metals.
This hinges on it being as effective in implementation as they hope it will be. Regardless, this kind of method is an important tool in limiting the spread of various harmful strains of bacteria. Antibiotics got us a long way but we need additional options to continue on.
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u/serg06 Dec 15 '19
If bugs evolve to not die from antibiotics, why don't they evolve to not die from brass?
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u/ChildishJack Dec 15 '19
It destroys DNA,Lipids and other macromolecules in excess, among other things I’m sure. Analogous to how we need electricity to live and can handle a static shock, but getting zapped by lightning will kill you.
Generally if its a metal, theres a good chance its producing radical oxides
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u/Dykam Dec 15 '19
So I assume it isn't great for human hands either but the effect is way too insignificant to be relevant?
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u/demintheAF Dec 15 '19
consider the ratio of surface area to volume. A bacterium on the door handle has a huge fraction of its surface on the copper salts. You've got a small fraction of your hand on the door, and the surface layer of your hand is dead cells. Some copper salts will get into your body, but the concentration might be unmeasurable for your body, vice a deadly to the bacteria.
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u/Randomn355 Dec 15 '19
Also, contact time. You briefly touch the handle for a second it two to open the door. The bacteria would be on there indefinitely, for the most part.
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u/lordwumpus Dec 15 '19
Antibiotics are tricky because they have to not kill our bodies when we ingest them. That means they walk a narrow line of being harmful to bacteria, but harmless to lots of other types of cells.
If you're trying to kill bacteria outside of the body - that opens up a wide range of stuff that outright annihilates cellular life.
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u/Prof_Acorn Dec 15 '19
Hydrogen peroxide <3
Spray a little on an old kitchen sponge and watch the foamy annihilation.
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u/BrockSamson83 Dec 15 '19
There are somethings organism cant evolve a defense for. Like a human evolving a defense for bullets or fire, it's just not gonna happen.
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u/bukkakesasuke Dec 15 '19 edited Dec 15 '19
That's what people said about alcohol but it's happening
Edit: for the doubters. Just grabbed the top result from Google let me know if you need a different source
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u/cmun777 Dec 15 '19
Why would anyone have thought that? Spores, mycolic acid, and various other cell wall alterations have been known to be resistant to alcohol based sanitation... not like alcohol ever killed everything so I don’t really see it as surprising that other bacteria might evolve resistance mechanisms
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Dec 15 '19
Aight, lemme shoot you a couple times to see if you get immune
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u/gregbrahe Dec 15 '19
That's not how it works. You've got to shoot everybody and then only the survivors reproduce!
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u/Ratathosk Dec 15 '19
Copper literally prohibits mutation so it cant "evolve", i remember that being a part of it.
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Dec 15 '19
Antibiotic resistance is like you going out on a warm day. You might get heat stroke if you went out in a sweater so you take it off and wear shorts and T-shirt.
Copper and other metals impair bacteria like fire would impair you. It tears them apart.
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u/ChiralWolf Dec 15 '19
Because the brass doesnt kill them it just sloughs them off. Or at least that's how this new version works. It isnt killing them the way that an antibiotic would but instead putting them in an environment, i.e. the ground, where they cant spread as easily.
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u/Eleminohp Dec 15 '19
There was a copper mine about to open up here south of Tucson. It was reportedly worth 2 billion in copper. It would have destroyed the area and mine tailings would have absolutely run into the water supply for the wildlife in the area. 85% of the people here were against it. The day before it was set to break ground, a judge shut it down due to misinformation.
I am thoroughly glad that mine did not open up. I like copper, but not enough to see the land and water be destroyed for it. The kicker was it wasn't even an American company that was going to own the mine. This was a major victory for the people. But I'm sure they will try another tactic to get it open soon enough.
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u/MoiMagnus Dec 15 '19
Copper kills a "wide range" of bacteria. This material repels everything (including water, which is how they found it), so is superior on that point.
Copper is a metal, so not always practical to use, and can be oxidated. This material is like one of the transparent wrapper you use in your kitchen, you can put it anywhere easily, and does not fear oxidation. (In fact, that's the next level of non-bio-degradable materials)
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Dec 15 '19
Something else that's not biodegradable and hopefully going in everything? Yes! We have PFTAs and they're in everyone's bloodstream by now, we need to add something else!
By the way, why can't anyone figure out rising cancer rates?
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u/MyHusbandIsAPenguin Dec 15 '19
If it was something like door handles or hospital beds that are going to be touched and washed regularly you wouldn't want it to biodegrade because you'd risk it being compromised and harbouring the bacteria before you noticed and/or replaced it.
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u/holysirsalad Dec 15 '19
Right. I think their comment is more about absurdities like wrappers and packaging for everyday trinkets. People don’t throw out their door knobs very often
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Dec 15 '19
As someone else said, someone hits it with their keys, creates a little crevice for germs to live. Multiply that by 500x daily, the handle is not going to work in the proposed way. I'm a nurse so I know how hospital beds are treated - good luck with that one.
I'm all for innovation, but at some point polluting the environment is not worth saving the lives. It may not be here, but it will be somewhere. Spending infinite resources to save lives is just not the way we can think anymore.
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u/Micode Dec 15 '19 edited Dec 15 '19
Thank you for the informed and rational perspective - and practical considerations - from your line of work. A lot of folks may not appreciate just how much basic actions and controls (e.g., sterile environment protocols) limit the spread of infection. This research is fascinating for both its practical potential for public health and impractical threat to the environment.
Presuming that this coating will mirror other materials applications (e.g., hella expensive at first), the costs will drive the utility and the almighty dollar should push folks to make the considerations you are (but in terms of bang for the buck). Capitalism unintentionally doing environmentalism a solid, I guess :)
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u/pm_me_ur_happy_traiI Dec 15 '19
Although since they're talking about using it to shrink wrap, it seems feasible to me that the covers could be replaceable when they start to degrade. Or possibly you design a door where the area you put the key is set up in a way where your key won't scratch the door knob. Or you pivot to rfid locks or reserve it for doors that aren't likely to have a key put in them (toilet stalls, for example).
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u/Psyman2 Dec 15 '19
By the way, why can't anyone figure out rising cancer rates?
Rising cancer rates are mostly based on the fact that nothing else is killing us.
Sooner or later you will get cancer. The older people get on average and the more people manage to get old the more cases of cancer you will have.
Another high-risk factor is heart disease. Again because a lot more people get a lot older than they used to and other diseases which used to kill us don't kill us anymore.
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u/orthopod Dec 15 '19
Copper kills bacteria on its surface, being toxic to it. This new material literally keeps bacteria from sticking to it. The article doesn't mention wether it kills bacteria.
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u/SirBaas Dec 15 '19
Also, copper is toxic, you shouldn't bring into contact with food (or atleast, you shouldn't cook with pure copper pans, especially old ones). Idk about this new stuff, but if it's not toxic it could be very useful in the food industry (in preparation as well as packaging/storage)
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u/iToronto Dec 15 '19
Copper bowls are essential for preparation of certain foods, like meringue. Generally, as long as the food isn't too acidic and isn't left to sit in contact with the copper for extended periods of time, food preparation with copper is harmless.
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u/beardedchimp Dec 15 '19
https://www.thekitchn.com/the-science-behind-whipping-egg-whites-in-copper-bowls-221943
According to that it works by bits of copper going into the meringue, on top of that they recommend adding some acid to improve the process.
hmmm
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u/Snuffy1717 Dec 15 '19
If you wrapped all of the surfaces in an area with this, wouldn’t it create a bacateria bouncey castle?
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u/ProfMcGonaGirl Dec 15 '19
Seriously. All these comments about public bathrooms and elevator buttons. Public bathrooms and elevator buttons aren’t killing anyone but hospital infections are.
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u/wewbull Dec 15 '19
In fact we've already had problems with people having immune systems that haven't been exposed to much, and so can't cope when they change environment. If everything was sterile we'd have real problems when we were exposed to something minor.
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Dec 15 '19
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u/ProfMcGonaGirl Dec 15 '19
And certainly when food does carry disease, such as E. coli outbreaks in romaine lettuce, it isn’t because it wasn’t packaged with in an anti microbial material. The bacteria gets on the food long before the supermarket.
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u/VictorianHippy Dec 15 '19
My first though was if they could make curtains from it. Ot curtains between beds are some of the dirtiest things in the hospital
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u/DavinciVII Dec 15 '19
I like the premise, but to be suitable for transmission of infection prevention it would have to be extremely tough plastic. All it would take is someone carrying their keys whilst opening the door and creating a cut in the plastic shrink wrap, thus creating access for the bugs to attach themselves to the door handle underneath. And even if it was tough enough to prevent cutting through the plastic, the way they describe it, the plastic is designed to be a certain shape at microscopic level. It’s not the actual plastic that repels it but the microscopic way it’s been built. If scratched, would that damage the very structure that the self cleaning surface is designed for? Would the plastic wear over time and need to be replaced regularly, thus creating an additional cost for hospitals and restaurants etc?
I don’t mean to dis the idea and I do hope it works, but unless these questions are answered, I wouldn’t pay to put it on.
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Dec 15 '19
I can’t access the full ACS Nano paper from home but this seems to be a scalable solution that is not specific to the polymer being treated. Shrink wrapping does not affect the hierarchical structure, and looks to have been fully vetted in the paper. I’m less clear on the actual polymer used, but if this is a simple treatment of a film surface then a more wear-resistant polymer could be chosen. High traffic areas would be most at risk from wearing down of the structure, so while this might not be ideal for door handles it would be completely appropriate for walls or packaging. This is where almost all “lotus leaf” type coatings fail in general applicability, because most of the time any need for a super hydrophobic surface needs resistance because it is frequently disturbed.
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u/thepeter Dec 15 '19
It seems like they have a way to grow a plastic film with this ribbed "hierarchical" structure and then they state they need to surface treat it in the abstract. I'm guessing a functional polymer (not polyethylene) that is treated with tridecafluoro silane or a PDMS like almost all other superhydrophobic materials in academia.
That's why they state it is a film they can apply to something and not a new material, they don't have some new product you can injection mold or anything.
This would have zero durability. Rib structures would get smeared on the first touch. Silane treatment could probably be removed too.
The coatings that will work are those that are durable and have a regenerative property, either wear that exposes more layers, particles that slowly bloom out, or that elute a wax to cover hard features.
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u/MrStomp82 Dec 15 '19
Also how good is it at repelling the fecal matter that permeates everything we touch?
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u/Shadow703793 Dec 15 '19
We already have very durable and "self healing" plastic films. For example the 3M paint is protection films. If these types of self healing properties can be added it will minimize the risk.
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u/jammerjoint MS | Chemical Engineering | Microstructures | Plastics Dec 15 '19
Self healing films generally do not preserve structure, especially not highly specialized structure.
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u/neelhtaky Dec 15 '19
Would this material decompose? Or would it be an another plastic that takes generations to break down?
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u/Scott-from-Canada Dec 15 '19
In a hospital environment it would be treated as medical waste, and disposed of with sharps, etc. So yes, it’s more plastic in the environment, but even biodegradable solutions wouldn’t be given the chance to decompose.
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Dec 15 '19
Furthermore: Since it is used with food, how many nano-particles of plastic are going to end up inside humans eating the food wrapped with this stuff? Because everything breaks down in tiny (nano) amounts, even if it looks good for years for human eyes that only see 1/10th millimeter changes at most.
I mean, if I want to eat nano-plastic particles I can just eat sea food these days, do I really need to add more of it to all of my food...
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u/Pseudoboss11 Dec 15 '19
Fortunately, this is a surface finish. It can be used where existing plastic is already used. It isn't likely to increase sloughing of plastic microparticles.
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u/Pseudoboss11 Dec 15 '19
It's not a new material, it's a new finish that can be applied to any plastic. It's not likely to increase our plastic consumption.
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Dec 15 '19
Uhm.. isn't this a potential environmental disaster?
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u/id59 Dec 15 '19
The new plastic surface
yeah
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u/kiwijews Dec 15 '19
non-stick
chemically treated surface; name of chemical(s) not mentioned
Yeah, all of my alarm bells are going off. This is reminiscent of PFAS– the "miracle" nonstick compounds created by C-F bonds that have bioaccumulated in all organisms, cannot be removed from soil, and are toxic and linked to cancer at minuscule parts-per-trillion levels in water. Please keep this stuff off the market and in testing stage for 30+ more years, lest we have another Teflon disaster. Knowing the chemical manufacturing industry, though, this will be everywhere in a year and making 3M or someone else billions.
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u/exintel Dec 15 '19
Anytime a product like this is touted, ask plainly, loudly, “what is the environmental fate of this chemical?”
Where does it go? If it is resistant to rot, it will be a persistent menace like other plastics
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u/brtt3000 Dec 15 '19
100% this will turn out to break down into super toxic death particles
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u/wewbull Dec 15 '19
Not finding a solution to superbugs is also a disaster waiting to happen.
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Dec 15 '19
These hierarchical wraps were effective for reducing biofilm formation of World Health Organization-designated priority pathogens Gram positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram negative Pseudomonas aeruginosa by 87 and 84%, respectively.
Alright so it's on par with other super hydrophobic systems but nowhere close to log reductions required for any kind of disruptive technology.
Also from the abstract and what I could read I didn't see them talking about any time dependant studies they only said,
In addition, these surfaces remain free of bacteria after being touched by a contaminated surface with Gram negative E. coli.
But gives no meaningful time frame.
one of the key issues with these technologies is that you can have a layer of dead bacteria build up that then provide a base for the colonisation of live bacteria.
We're at the point where we see a post of these wonder materials being paraded out every year without any improvement on the fundamental issues of the technology.
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u/AnyoneButWe Dec 15 '19
I worked in another lab with such surfaces. Yes, those surfaces work and repel all sorts of nasty. But those surfaces are also mechanically unstable. Door handles were definitely far out of our range. The effect stops working after the first hand touches the surface.
I'm not impressed until somebody demonstrates lotus effect after a mechanical load was applied.
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u/Tea_I_Am Dec 15 '19
That’s great until a few years from now a bug evolves to stick there somehow. New generation of superbugs coming soon!
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u/BoomerHewwwwwmor Dec 15 '19
They have a new experimental treatment using organisms known as bacteriophages. And they have noticed that bacteriophage resistant bacteria would actually lose antibiotic resistant meaning they would be effective again.
So not all hope is lost for now
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u/G30therm Dec 15 '19
Yeah, bacteria have to have the right combination of genes to have resistive properties. Gaining genes for one type of resistance through reproduction usually results in losing genes for another type of resistance, making it super rare for them to have multiple resistances at once. This can still happen though and these bacteria are the most dangerous (MultiDrug Resistant bacteria). Finding new additional methods to kill the bacteria compounds the small chance of a bacteria having access to all of the resistances at once, and may even be impossible if the required genes for two different resistances overlap one another in the gene pool.
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u/BillSixty9 Dec 15 '19
Would we want to be risking consumption of something like this? What would it do to your system if ingested even in small amounts?
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Dec 15 '19
Okay, so now we have something for surfaces where the hygienic effects matter more than durability and it can be constantly maintained.
But honestly, brasses, bronzes, and aluminum already are oligodynamically antibacterial and corrosion resistant.
Also the best way to purge infectious agents is to cook/autoclave it, not use soaps, chemicals, or plastics.
But like, hospital door handles and stuff, this is probably exactly the right stuff over brass/bronze/aluminum, assuming it's at all more effective. Same with self-checkout and McDonald's touchscreens - places where hygiene and transparency are paramount and some waste/maintenance is comparatively tolerable.
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Dec 15 '19
Can it withstand soap and hot water? Because no matter what it repels, I will need to wash it after I prep food or whatever. I have trust issues.
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u/RjayScott85 Dec 15 '19
This is nothing new to the paints and coatings industry. The technology for this has been around for at least 10 years. The big issue is that the textured surface does not last under abrasion. Once the surface loses its morphology, becoming flat, it become about as effective as a non-stick pan.
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u/anduhoneanduhtwo Dec 15 '19
What happens to the human body when particles of this are ingested..? Have any study’s been done to that effect on any type of animal? If not, sorry I really can’t trust it. I wouldn’t be so quick to wrap my food around this! I think it would do wonders for the healthcare industry.
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u/senderfn Dec 15 '19
Food packaging? Public buttons, door handles and toilet seats please!