How Tiny Nanoparticles Are Transforming Technology
IRA FLATOW, host:
Switching tracks, so to speak: Picture a glass skyscraper. Let's say it's 50 or 60 stories high and it's completely covered with windows. Now imagine that those hundreds of crystal-clear windows are actually solar panels, generating electricity to run the building's air-conditioning, the elevators, the computers.
Some scientists think nanotechnology may make this picture a reality. And nanotech isn't inspiring just renewable energy research. Medical researchers are working on targeting cancer treatments, sending tiny nanomessengers to tumors to destroy them. Maybe you've heard of the nanobees research that was out this week. Others imagine new more efficient computer components, much smaller than the ones we have today.
But despite all these tantalizing possibilities, there's always the question: Is this new nanotechnology safe? Because nano-sized particles have physical properties that allow them to do these amazing things, but they are also the same properties that can affect the body in unexpected ways. They're very small. They're too small to be caught by the body's natural defenses. They can enter the lungs and the bloodstream and individual cells. So while all of this is good stuff, this nanotechnology news, how can we protect ourselves against these risks?
Our next guests are here to talk about the promises and also some of the pitfalls about the research in nanotechnology. Give us a little update on some of that really interesting stuff that's happening in nanotechnology. James Gimzewski is a professor of chemistry, University of California, Los Angeles. Also, director of the Nano & Pico Characterization Core Utility - say that quickly - at UCLA's California NanoSystems Institute. Welcome back to SCIENCE FRIDAY.
Dr. JAMES GIMZEWSKI (Chemistry, UCLA; Director, Nano & Pico Characterization Core Facility, UCLA's California NanoSystems Institute): Hi. Pleasure to be here.
FLATOW: You're welcome. Mark Ratner is professor of chemistry and director of the Initiative for Sustainability and Energy at Northwestern University in Evaston, Illinois. Welcome to SCIENCE FRIDAY, Dr. Ratner.
Dr. MARK RATNER (Chemistry; Director, Initiative for Sustainability and Energy, Northwestern University): Thanks, Ira. How are you?
FLATOW: How are we doing, Jim, with new ideas about nanotechnology?
Dr. GIMZEWSKI: At UCLA, at the California NanoSystems Institute, one of the big interests we have is in what you would call nanomedicine. And at the moment, there are already some nanotechnology products that are used in pharmaceuticals. But the field is growing rapidly, particularly in new ways to battle cancer and also detect cancer. And that type of area is one particular focus that I'm interested in at the moment.
FLATOW: Then you must know about these nanobees that were talked about this week.
Dr. GIMZEWSKI: Yeah. Nanobees, carbon nanotubes. There are also things like carbon nanoshells, very small nanoparticles that when you stimulate them with light, they have this ability to destroy tumors. And they have another possibility that they can be functionalized in such a way that they actually directly bind to cancer cells selectively.
FLATOW: And the research was saying that they've attached bee venom to these nanoparticles…
Dr. GIMZEWSKI: Yeah, bee…
FLATOW: …and they're targeted right to the tumor.
Dr. GIMZEWSKI: Mm-hmm. Bee venom is one approach already on the market. There is a company called Abraxane, which is a way to introduce Taxol which is used for breast cancer. And that already involves the use of nanoparticles that are coated. There are about 130 nanometers in diameter. So, there are so many approaches at the moment that the field is really - is very exciting.
FLATOW: 1-800-989-8255 is our number. Talking about nanotechnology. And if you'd like to call us and tell us something that you know about, we'd love to hear from you. Also you can tweet us @scifri, @-S-C-I-F-R-I.
We did a story, Mark Ratner, a few weeks ago about taking chicken feathers and carbonizing them into tiny little pieces and carrying - storing energy in them. And nanotechnology seems like the perfect way to store energy.
Dr. RATNER: It is a perfect way to store energy. There are lots of others, but the advantage in nanoscience is that you get a lot of surface area. And if you want to bind something and store it while the surface area is good - in the old days, you know, people used to swallow little carbon pills to grab some nasties in your tummy after you drank too much. Same idea. It's a lot of surface area. Nanoparticles are really small, so they have a lot of surface compared to volume. So we can bind things to them. So you can store hydrogen on them, you can store electricity in them, and there are a lot of new battery companies based on nanostructure. So it is a very good way to think about that storage problem.
FLATOW: I talked about nanotechnology solar panelled windows before. Is that a reality? Is it…
Dr. RATNER: Not yet…
FLATOW: Not yet.
Dr. RATNER: …but it's very close. I mean, the entire photovoltaic area, which is light turning into electricity, has been around for a very long time. But there are several new ideas in this area. It's not just the wonderful sort of purple panels that we see on all the blinks that have current photovoltaics. Those are very wonderful, but they are not super efficient, they're about 15 percent efficient. And they're not super cheap and they're not super flexible. And what people are thinking about is trying to make them by printing presses. So you could basically get an old printing press that was used to make magazines and print out photovoltaics with it using nanostructures.
FLATOW: I've read about a company called Nanosolar.
Dr. RATNER: Yes, there is a company called Nanosolar. There are a number of nano entities that are trying to get into this sort of material/energy interface which is after all one of the social things we're trying to deal with at the moment.
FLATOW: Can we store - we're talking a little bit about hydrogen. Could you store hydrogen on nanoparticles?
Dr. RATNER: Yes, you can because hydrogen can bind to the surface of - the simplest way to think about it is there's a molecule which is hydrogen. It has a weak binding strength to this particle, and it just sits there. And when you warm the particle up, it comes off. And when you cool a particle down, it stays on. And so, you can use it as kind of a sponge.
FLATOW: Wow. Wow. Lots more to talk about in nanotechnology. We're going to take a short break, come back and talk much more with Mark Ratner and Jim - James Gimzewski and your questions. Our number, 1-800-989-8255. Have you got questions about nanotechnology? Give us a call. Also send us a tweet @scifri. We'll also get into talking a bit about the possible perils of dealing with such tiny particles like these, and where they go, what they do, and what the long-term effects might be for this. They haven't been around that long, so. We'll be back with all of this. Stay with us.
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FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR News.
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FLATOW: You're listening to SCIENCE FRIDAY from NPR News. I'm Ira Flatow. We're talking about advances in nanotechnology this hour with my guests James Gimzewski who is professor of chemistry in University of California, Los Angeles, director of the Nano & Pico Characterization Core Facility. Mark Ratner, professor of chemistry and director of the Initiative for Sustainability and Energy at Northwestern University. Our number: 1-800-989-8255.
Let me just follow up a question with Mark Ratner. Is there any possibility that we could make totally new fuels with nanotechnology, not just to find ways to store what we have better, but all kinds of new fuels?
Dr. RATNER: The densest way to store energy, the most effective way to store energy that we know of other than nuclear is actually in chemical fuels. In other words, when you fill your car up with gas, you're putting material in there that has an enormously high energy density. You were talking to your previous guest about hydrogen. Hydrogen, again, it burns, it makes water, and it gives off a huge amount of energy. So, the density of energy that you get in a gas tank is remarkable. So, if you want to store energy long term, it's a little hard to really think of something that's going to be better than chemical fuels. And so, there are a lot of effort in trying to turn the sun into chemical fuels. And that was mentioned a little bit but there's a lot more to be done on that.
FLATOW: What do you - give us a little bit more detail on how that would work.
Dr. RATNER: Well, suppose that you take carbon dioxide, which is the global warming gas and something we don't much like, and suppose that you put it into a chamber along with nanoscale titanium dioxide and sunlight. Well, it turns out that if you get to the right conditions, you can actually take the carbon dioxide, the carbon monoxide. That's poisonous. But if you keep it in the box, you can burn that back to carbon dioxide. So, think of this box as a place where sunlight comes in and either heat or electricity comes off.
FLATOW: It almost sounds like artificial photosynthesis.
Dr. RATNER: It is a lot like artificial photosynthesis. In photosynthesis, you're making, well, you're making green plants and you're making leaves and you're making oxygen, and here you'd be making chemical fuels. But it's very similar.
FLATOW: And how close are we to doing that? So, you could actually suck the CO2 out of the air.
Dr. RATNER: Well, you have to suck it out of the air first and then you have to react it.
FLATOW: Yeah, yeah.
Dr. RATNER: And, in fact, the sucking is actually pretty expensive. That's part of the problem with CO2 sequestration. You know, you have to separate the CO2 from the effluent gas. But, in a sense, you start with the CO2, you start with that and sunlight and out you get energy. And it's pretty promising, pretty interesting actually.
FLATOW: Hmm. But what about all of these nanoparticles that are out there now?
Dr. RATNER: Yes.
FLATOW: They're out there everywhere, aren't they?
Dr. RATNER: Yes, they are.
FLATOW: Should we not be concerned that, you know, we once thought for example - first of all, let me just put the caveat in that no one has shown them to be harmful yet, but when we first started fooling around with little fibers, we didn't think that, you know, we were going to get asbestos either years back.
Dr. RATNER: Exactly. There's a lot of scary stuff out there. There are, you know, these little reports from various places around the world about this person, you know, getting really ill or that person dying. And as you said, silicosis, black lung disease, all of those came from entities that are not produced, you know, within the human body, coming into the human body in large amounts. If you - instead of having a glass of Coke, you took pure carbon dioxide in. You wouldn't last very long.
So, I think there's a serious issue actually for toxicology at the nanoscale. And there is research on this subject. But it's going to be a big deal.
FLATOW: Yeah. Jim Gimzewski?
Dr. GIMZEWSKI: Yeah. I think one of the things one has to remember is that your body is producing nanoparticles at this very moment. In your mouth, you have things called the exosomes. There - in very cell, there are 17 nanometer structures that are called vaults. These are a part of your life. So, nanotechnology is around you. If you look at a blue butterfly, that surface is structured on the nanoscale to make a beautiful blue iridescent pattern, same with beetles and so on.
So, the idea that nanoparticles are something that we have invented is not completely true. And the second point is that, for instance, at UCLA, we have a large nanotoxicology center that actually looks into these properties. And I think, compared with things like GM and so on that was brought into the public without any debate, what we see with nanotechnology is that there is a debate, there is a research going on and people are aware of it. And I think that is very positive.
And finally, let me just say that if we look at the stuff, the technology, the heat, beat and treat - the industrial revolution that we, you know, we still use burning oil, we look at the effects of those and agrochemicals on our health, that is, to me, a bigger concern. And that is the type of thing that nanoparticles, in principle, and nanotechnology can help to reduce. It can make us a better environment. So there are two sides to the argument but, certainly, we should be cognizant of it. And I think we are, in general, being very responsible.
FLATOW: Question from second life (unintelligible) who wants to know what is it that makes the nanotubes target the tumor cells? Do they work only on solid tumors or how do they know to get there, I guess?
Dr. GIMZEWSKI: Well, they don't actually know how to get there, so they have to be given something that directs them there. And it could be, for instance, a thing called a peptide or some type of antibody that specifically would target the tumor cell. So that is the first thing. You give it some kind of information system that it can bind to a tumor cell. And the second part is nanotubes or other types of things like nanoshells. Naomi Halas at Rice has done this a long time ago. There is this ability to cause selective heating of these nanoparticles, which then kills the cells. So it's actually the case where the nanoparticle has to be given multiple functions, and that is one of the beautiful things about it. And, of course, the nanoparticle, depending on the type you use, has also the ability to enter the cell and it does not necessarily disturb the immune system.
FLATOW: Do they - do nanoparticles cross the blood-brain barrier?
Dr. GIMZEWSKI: Nanoparticles can cross the blood-brain barrier if they're less than approximately four nanometers in size. And there is one good case where people have used - they used gadolinium for MRI imaging, about 30 percent of the MRI imaging is - involves some type of contrast agent. Gadolinium in the brain, extremely toxic, and researchers have found that if they encapsulate about nine gadolinium atoms into a very ultra short nanotube, then they get a signal that's 50 times larger, that mean less toxicity. And because it's encapsulated in the nanotube, it can then be expelled through the body.
And so, you see, we have to consider the toxic effects of what we do now, such as in chemotherapy and imaging, versus what nanotechnology can offer. And certainly targeting, as in the case of these, you know, the nano bee venom and so on, is one example of that approach.
FLATOW: It's illustrative to say - to talk and give an illustration of how small a nanoparticle can be and that you can put nine atoms of something in it.
Dr. GIMZEWSKI: Yeah.
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Dr. GIMZEWSKI: They're actually called nano-peapods because it's a tube about a nanometer or so in diameter, and the atoms look like, you know, peas in the pod actually.
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FLATOW: You have any good nanotube jokes we could tell at a party? How many nano-peapods does it take - never mind.
1-800-989-8255. Anthony(ph) in Cincinnati. Welcome to SCIENCE FRIDAY.
ANTHONY (Caller): Hi. Thanks for taking my call.
FLATOW: You're welcome.
ANTHONY: My question was in regards to nanotechnology in being used as a biological type of weapon. What is the likelihood that these kind of things will be adopted by terrorists and turned into things that are meant to harm people on a large scale because they're so small that they can't be eradicated by our bodies themselves? And I guess just the likelihood and is it something that is being thought about right now? And I'll take my answer off the air. Thanks.
FLATOW: All right. Thank you, Anthony. Some people call it the grey-goose scenario.
Dr. GIMZEWSKI: Yeah.
FLATOW: Well, what about that? James or Mark?
Dr. GIMZEWSKI: Yeah. I could maybe step in there and say that, you know, as we guard some terrorism, if you look at 9/11, it was knife, okay? If you take a knife in the hands of surgeon, it's a fantastic thing. If you take the knife in the hands of chef, it's also a fantastic thing. You give a knife to a terrorist, there's problems. So nanotechnology in the hands of terrorists, like anything in this planet Earth, possibly could be used in a negative way. But, typically, we tend to be technologically much more advanced in the States than - and that is an important thing that we maintain in this country.
Dr. RATNER: But you want to think about weaponizing things, kind of difficult to weaponize a small particle. I mean, how do you get it to somebody and how do you disperse it around? And I think if you are really a terrorist, there are more conventional ways that would be probably much more effective.
FLATOW: Mark, there was a study recently that show that salt can actually stretch like taffy on the nanoscale.
Dr. RATNER: Yes.
Dr. RATNER: Yes. Yes, yes. So we've talked about the two important applications areas, which are medicine and materials. But the third part of nanoscience is that it's a science. It's an entirely new way of looking at things. And, for example, as you said, there's this salt that becomes essentially super plastic, meaning it's almost like silly putty. You can draw it out. You don't think of a salt crystal as doing that, but when you get down to this scale where the structures are only a few atoms across, then it's much easier to bend them and it's much easier to stretch them.
FLATOW: Why? Why?
Dr. RATNER: Because you don't have to pull across what are called grain boundaries. It's not held together in the same sense that a solid is. And instead of each atom being surrounded by a whole bunch of other atoms, some of the atoms are on the surface. In fact, the smaller they get, the more surface there is. In that particular experiment actually, they're also blasting the thing with electrons at the same time. And so they think that these electrons are sort of stabilizing all these intermediate states.
But it is pretty neat that even something as simple as stretching is different at the nanoscale than it is at the macroscale. We know that the colors are different. We know that melting points are different. But even something like stretching is different.
FLATOW: Does it retain that stretch after you let go of it, if you stretch it on a nanoscale? So then you make something new, you know, that's now stretchy where it was just salty before?
Dr. RATNER: Good point. You know, what I saw in that article is that, basically, they pull them out and let them go and they come back.
Dr. RATNER: And that's generally going to be true. But certainly there are, you know, if you take silly putty and you pull it out too far, it will break. And these will also break if you pull them out too far.
FLATOW: Hmm. And as far as any - as we've talked a lot in other programs about combining organic or almost living things, like viruses or DNA or something with nanoparticles, that seems to be a whole interesting, unexplored area.
Dr. RATNER: Jim talked about these so-called smart nanoparticles, the things that run round in your bloodstream and do things for you. The nanobees are one but there are lots and lots and lots of others one. They're smart nanoparticles. The nanobees actually start with Teflon basically. The nanoparticles have Teflon onto which they glue melittin and the melittin comes around it and does its thing.
Some of the cancer targets, as Jim indicated, there are two or three things on the nanoparticles. There's an anchor that seeks out, say, a malignant cell and binds to it. And then there's a toxic load that destroys that cell. So you can actually imagine one of these things as, you know, almost like a car that you can decorate with various things.
FLATOW: We're talking about nanotechnology this hour on SCIENCE FRIDAY from NPR News.
It's almost like a robot when you think of it. It's got an anchor and then a destroying part.
Dr. RATNER: Except the robot, you can control. I mean, once you put this thing into the body, it has to have all of its own codes because it's a little bit difficult to do much with it once it's in there. If it's near the surface, you can shine a light on it. And if you're willing to settle for infrared light, you can get light on it when it's farther into the body. But really, there really needs to be most of the chemistry to do what it wants to do in the parent particle.
FLATOW: Jim, what's this thing, this new form of carbon called graphene? What is that?
Dr. GIMZEWSKI: Well, graphene is, you know, graphite is the material you find in a pencil. And it's made of sheets essentially of carbon hexagons. And if you take one such sheet of that, one atomically thick sheet, you have a material called graphene.
Graphene has attracted terrific interest recently because if you look at the electronic properties of graphene in comparison with silicon, it is very attractive. And so the idea to make ultra-fast super nanoelectronic devices, graphene is, at the moment, let's say, you know, just like in the top 10 of the music charts on the nanoscientist list, I would say.
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FLATOW: There is an interesting question from a tweet that came in from Cara Beyak(ph) who says: why isn't matter at the nanoscale said to be in another state since the properties are so different? Liquid, solid, gas, nano.
Dr. GIMZEWSKI: Nano. Well, I think Mark's talked about surface area, okay?
Dr. GIMZEWSKI: You get to the point where there are more surface atoms than atoms inside. But if you take a black material, an inorganic material that's black and you shrink it down to the nanoscale, then you can make that material blue. You can make it yellow. You can make it red. This is something called the quantum dot. And so, it's possible to take a material that's fairly inert and convert it into a colorful material. And this could be used in medical diagnosis. It could also be used as a replacement for regular paints, you know, that contain toxic chemicals, heavy metals and so on.
So the reason for that really is, sort of, quantum mechanical and, you know, basically the smaller it gets, the more it sort of changes all its optical and, you know, electronic properties.
FLATOW: Mark, we only have about a minute left, I want you to tell me about a new study that uses nanoparticles to help fight cholesterol.
Dr. RATNER: Yeah.
FLATOW: Is that right?
Dr. RATNER: Yes, it is. This again uses gold nanoparticles. This is some really recent work from Chad Mirkin's operation. And what they do is use this gold nanoparticle coded with HDLs. It runs around the body. It binds to LDLs which are the ones you don't want. And it carries them away until it gets them to the liver where they're dealt with, meaning they're separated. And then this thing circles around the body again. Eventually, it's eliminated.
Now, this is still way in laboratory. I think there's a little startup that's going to do this. But, again, it's using nanoparticles to do what Jim has indicated they're so good at, which is on their surfaces doing things. There's a lot of surface in a nanoparticle and so there's a great, big chemistry laboratory on this very small particle. Gold nanoparticles go back at least as far as the middle ages in stained glass windows. But they are powerful, powerful things.
FLATOW: Well, there's a lot more, I'm sure we could talk about. We'll have to just - can I have you folks - fellows back for a follow up because we just scratched the surface. It's just like - it's like people are going nutty just trying to think of things they can do with nanoparticles, right?
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Dr. GIMZEWSKI: Big surface.
FLATOW: You guys in your basements working on good stuff. Thank you for both -for taking time to be with me today.
James Gimzewski is a professor of chemistry, University of California at the Los Angeles, also director of the Nano & Pico Characterization Core Facility at UCLA's California NanoSystems Institute.
Mark Ratner, professor of chemistry, director of the Initiative for Sustainability and Energy at - that's at Northwestern University in Evanston, Illinois. Thanks again. For taking time to…
Dr. GIMZEWSKI: Thank you.
Dr. RATNER: Thank you.
FLATOW: And have a good holiday weekend.
Dr. GIMZEWSKI: Thank you.
FLATOW: You're welcome.
We've got Flora's Sci-fri pick of the week up there. It's a lot of fun. It's playing mini golf with a rocketry theme. It's over at the Rocket Park at the New York Hall of Science playing mini golf. It's a lot of fun. And you may want to head over to there on the holiday weekend. Also, we're going to be tweetering all week, as we usually we do. You can still send us some tweets. We'd like to get your tweets and hear what you have to say. Also our podcasts are up there. Go over to iTunes and download our podcasts. And our video podcast - Flora's video pick of the week - you can also have as a video podcast. Have a great and safe holiday weekend. We'll see you next week.
I'm Ira Flatow in New York.
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