Building Synthetic Tissues from Water Droplets?
Reporting in Science, Gabriel Villar and colleagues have turned tiny water droplets into cooperating networks that can pass electrical signals and do mechanical work. Villar says that in theory, water droplet networks could be used as artificial tissues.
IRA FLATOW, HOST:
That flute can only mean that Flora Lichtman is here. Hi, Flora.
FLORA LICHTMAN, BYLINE: Hi, Ira.
FLATOW: Flora is our correspondent and managing editor for video. And we've got our Video Pick of the Week.
LICHTMAN: This week, it's some far out science this week. The researchers reporting in the journal, Science say that they can turn tiny, little water balls into a cooperating network that act sort of like the tissues in your body. And you can see them, in all their very multicolored glory, on our website. It looks sort of like the tapioca balls in a bubble tea.
FLATOW: Oh, bubble tea. Sure.
LICHTMAN: Or, you know, caviar to whatever your reference is, high or low. Bubble tea was what came to me.
FLATOW: We know your salary level, so it's going to be bubble tea.
LICHTMAN: Yeah. Right. So the- but they're micro-scaled.
LICHTMAN: And they stick together because the way that they're made, and the technique was invented by Gabriel Villar while he was getting his Ph.D. at Oxford, is that they're shot out of these little - it's sort of like a 3-D printer and the water is shot out of these very thin tubes. And as soon as it hits - as soon as it leaved the tube, it's in a van of oil. And the oil covers each little droplet and the oil is what causes these little balls of water to stick together. And what Villar and colleagues showed in this paper is that they don't just stick together, they can move together.
LICHTMAN: They can transmit electrical signals through certain pathways, if you tweak what's inside the little balls. And the idea is that, you know, he said in his wildest scientific fantasies, you know, this might be the tissue transplant of the future. We're not there yet.
FLATOW: We're not there yet.
LICHTMAN: But that's the idea.
FLATOW: So far, on your video, you show that you can make something that looks like Band-Aid, like cover a cut.
LICHTMAN: It's like a blob. But it's a really beautiful blob.
FLATOW: It's beautiful. I think it reminded me of flower petals, you know, opening and closing.
LICHTMAN: Yes. Yes. So this is one of the neat things. They figured out how to make these little balls move in concert. And the idea is to use osmosis. So in some of the balls, they have a higher salt concentration than the other ones, and water can pass through this oily membrane. And so, the water travels from the less salty balls to the more salty balls. And because they're stuck together, you get this unfolding and these, sort of, complicated geometries playing out in real time just through the salt. And so they've actually gotten these little water networks to mechanical work, even.
FLATOW: So they think that there might be some medicinal benefits to this - drug delivery?
LICHTMAN: Drug delivery was another idea. And it depends on what you can put in the balls and get them to do. So, you know, with the osmosis, you can't get them to unfold, after they've folded up.
LICHTMAN: But they think there may be other ways to induce this movement. And they said that, you know, if they can transmit electrical signals, via ions, through these balls, maybe you could get them to act like a nerve; where you would stimulate them and they would produce their own, sort of, current. So that's what they're thinking in far-out terms. But you can - they really are pretty to look at.
FLATOW: They're gorgeous.
FLATOW: It's gorgeous. It's our Video Pick of the Week. It's up there on our website at sciencefriday.com. When you look at it, first when you see the process of how this - looks like these little tight paths, the balls are dropping out. They're dropping on a couple of colors and they get, just like you say, they get to be built into something like a 3-D printer.
LICHTMAN: Yeah. And...
FLATOW: It's the first thing that struck me. Hey, we got a 3-D printer with these little...
LICHTMAN: It is. So it's a watery 3-D printer, and it's mostly automated. But if you - there are some techniques that require some manual manipulation. And Gabriel Villar said to me that he built it so that you can actually control with your keyboard and it's like playing "Tetris."
LICHTMAN: So it's like - if you look in the video, you'll see some sort of weird - he's totally had a little bit of fun making some of these blogs...
LICHTMAN: ...with the different colors and building squares inside circles, inside squares.
FLATOW: There's no end to what you can do with this kind of stuff.
LICHTMAN: He said, you know, I think he had to do a lot of it. So it's good for entertaining.
FLATOW: Yeah. It would have to be entertaining.
FLATOW: A lot of Twinkies maybe. All right.
FLATOW: Thank you, Flora.
LICHTMAN: Thanks, Ira.
FLATOW: That's our Video Pick of the Week. It's up there on our website at sciencefriday.com, where all our other videos are up there for all our weeks. Transcript provided by NPR, Copyright NPR.