Part 3 of the TED Radio Hour episode Revitalize
An ear made from an apple, a spinal cord rebuilt using asparagus ... it sounds like bizarre science fiction. But Andrew Pelling is working on a way to revive human tissue with a trip to the supermarket.
About Andrew Pelling
Andrew Pelling is a biophysicist and professor at the University of Ottawa's Department of Physics. He is the co-founder of biomedical research at the Pelling Lab for Augmented Biology, known for its discovery that plant tissues can be harnessed to regenerate human cells.
He also serves as co-founder and chief scientific officer of Spiderwort, a company that produces plant-based biomaterials.
Pelling received a B.S. in Biological Chemistry from University of Toronto, and Ph.D. in Physical Chemistry from University of California, Los Angeles.
MANOUSH ZOMORODI, HOST:
On the show today - ideas about revitalizing and rebuilding. And what if all we need to revitalize parts of our bodies is the right tool?
ANDREW PELLING: Could we think about biology kind of like hardware? Could I take the pieces I'm interested in and sort of rewire them and put them together physically in different ways?
ZOMORODI: This is Andrew Pelling. He's a biophysicist at the University of Ottawa.
PELLING: And I run a research lab that creates augmented living biological systems.
ZOMORODI: OK, augmented living biological systems - what the heck is that? Can you explain, please?
PELLING: (Laughter) So we're really kind of interested in creating living tissues that might not normally be found in nature. We've also discovered ways to heal and regenerate living tissues in the human body. And what my lab has become very well-known for is creating an apple ear. And it's essentially an apple that we carved into the shape of a human ear. We processed it, decellularized it, pulled out all the plant cells and then repopulated it with human cells.
ZOMORODI: OK. Wait a minute. Hold up. I just want you to say that one more time. You made an ear that has human cells out of an apple.
PELLING: Mmm hmm.
ZOMORODI: Can you just back up and explain this to me?
PELLING: Yeah. It's a long story. But a lot of us have heard of approaches to biomedicine right now that might involve something called CRISPR or DNA technologies that you might engineer or change our DNA. And that's all really fascinating and very hard work. But my response to that type of effort has always been like, well, can we actually control our cells and tissues without even touching the DNA? So what we needed was a sort of scaffold, sort of a three-dimensional architecture we could grow our cells into.
And we had found a way to take plant tissues we find in the grocery store. We can strip out all the plant cells. And all you're left with is this fibrous material, the stuff that gets stuck in your teeth when you're eating a salad or whatever. And that material, cellulose, was the three-dimensional scaffolding we were looking for. And it was really cheap. We could get it in the grocery store, and our cells could grow inside of it.
ZOMORODI: OK. Wait, though. So you get an apple, but then how do you make an ear out of it?
PELLING: So what we did (laughter) - we had been doing a lot of work with apples. And if you've ever cut an apple in half and looked at it, it does kind of look like two ears side by side, at least to me. And the only person in our orbit that we knew who could carve anything was actually my wife. She's a violin maker. And so I asked her, you know, could you carve me an ear from this piece of apple? And...
ZOMORODI: So great.
PELLING: I have a very loving and patient wife and...
PELLING: She's kind of used to me at this point, so...
ZOMORODI: Sure, honey.
PELLING: ...She got to it. I was modeling, and she carved us several ears. And I took them back to the lab. And so now I've got this, like, Tupperware container full of these pieces of apple that look like human ears. And what we do with them is we essentially put them into a large beaker. And inside of the beaker is the solution that we used to pull out all the plant cells. It's like a soap or detergent. And it slowly sort of shakes and spins over several days.
It's a slow process to remove all of the cells. But at the end, what you get is - it's almost completely white, and it still holds its shape. It looks like an ear. And this scaffold or this implant, we can then put in a petri dish. We can put cells onto it, and we let them grow. And over time, they'll start to invade inside of the scaffold and fill it up with - as they replicate, and what you end up with is a really nice proof of concept of a plant-based human implant.
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ZOMORODI: What kind of cells do you put into the scaffolding?
PELLING: So we can actually put all sorts of cells. We've done work with muscle cells and sort of vascular cells and neurons, and you name it. Over the years, it's become fairly straightforward. You can grow almost anything in there. That's how generalizable it is.
ZOMORODI: So you said it's a proof of concept. So tell me what you learned from being able to grow cells like this and why it's not being used to help people yet.
PELLING: Well, I hope it will be helping people soon, and that's what we're working on now. That ear was the first proof of concept. It really convinced me and the whole team that what we had wasn't just some goofy, funny discovery but was something that could actually be quite impactful in terms of human health and well-being. And so what has happened since that time is now translating these materials into the clinical space. And we've actually, since that year, been able to demonstrate that not only can we make three-dimensional structural objects but, at least in the case of spinal cord, actually repair spinal cords in small animals. And this is really, really exciting and potentially revolutionary.
ZOMORODI: And that brings us to what you're working on right now - right? - to repair spinal cord tissue using not an apple, but another food.
PELLING: Yeah. We - it's funny. I was - in the early days, literally, we would go to the grocery store, just buy everything you could see. The lab would look like a farmer's market - like, just bags and bags of produce, and we just - decellularizing everything and throwing cells on them. And in the midst of all this, one day I was at home, and I was cooking asparagus for dinner. I had cut the ends of the asparagus off, and I was sort of looking at the sort of stalk and noticing all of those long capillaries, those little tubes inside the stalk. I started to wonder, you know, could we actually use those conduits as a way to guide neurons back together in the case of spinal cord injury?
ZOMORODI: In a minute, more from Andrew Pelling on the extraordinary possibilities of rebuilding the body with produce. On the show today - ideas about revitalization. I'm Manoush Zomorodi, and you're listening to the TED Radio Hour from NPR.
It's the TED Radio Hour from NPR. I'm Manoush Zomorodi. On the show today, ideas about revitalization. And before the break, we were talking to Andrew Pelling about his mind-boggling experiments, including a new idea to rebuild human spinal cords with asparagus.
PELLING: And this wasn't a totally original idea or anything like that. There's been plenty of work on synthetic materials with tunnels and conduits and all that sort of thing. But again, I was wondering, you know, could it be this simple? Could I just go to the grocery store and find my scaffolding there? And the interesting thing about plant-based biomaterials is they don't break down. They're actually quite stable, long-lasting. So we, again, stripped out all the cells and made some asparagus scaffolds.
And then I thought, well, I got to talk to an expert at this point because I'm so far out of my sort of comfort zone at this stage. So I looked around. And one of the top neurosurgeons in Canada happened to be right here in my own city, in Ottawa, and we brought her some scaffolds. And she spent time thinking about this and looking at them. And her first question to me was, can I take these today and use them in a patient?
PELLING: (Laughter) Yeah. I was like, you neuro people are crazier than me, man. Like, this is...
ZOMORODI: Wow. Yeah.
PELLING: One of the problems that she had seen and experienced was that scaffolding that she had used previously had always broken down. And this is what really excited her about what we were proposing, was a scaffold that was long-lasting and stable. And so thankfully, she was willing to collaborate and helped us sort of design some preliminary animal studies to first look at, you know, the efficacy of this scaffold in repairing a severe spinal cord injury.
ZOMORODI: And so you basically started a study where you put this asparagus implant in some animals with spinal cord injuries, right? And what happened?
PELLING: One of the most fascinating things I've ever witnessed in my life started to happen a few weeks after this, about two weeks. The animals that received the implants, they started - they looked like they were having sort of pins and needles in their legs. They were sort of scratching at their rear legs and biting at them. It was like they were gaining some feeling back.
And over the course of the next - over the course of about 12 weeks, we watched these animals go from being paralyzed from the waist down to starting to move their legs - so left, right, left, right - and then starting to lift themselves up on their back legs and lift their bellies off the ground. This is a really important step in recovery. And this is also showing that those core muscles are getting activated, the legs are getting activated, healthy cells migrate inside of the scaffold and it really just becomes a living tissue within the body. It becomes something that's kept alive by the heart.
And by no means were the animals perfectly walking or anything like that, but this for us was an incredible moment because what seemed like such a far-fetched, you know, idea appeared to actually have legs to it and potentially could impact tens of thousands, if not millions of lives on the planet. And I've never, never expected as a scientist to be involved in something that important. And late last year, we announced that this technology was just designated a breakthrough medical device by the FDA. This is going to dramatically speed up the timeline between when - you know, from going from the bench to eventually to the patient.
ZOMORODI: So how do you get to the point where asparagus can actually be a potentially viable therapy for someone who has a spinal cord injury? Like what - walk - like, what does that look like? Is - are we talking five years, 50 years?
PELLING: That is a good question. I mean, you know, it's interesting. As I've met and spoken with many people who live with spinal cord injury, you know, walking, of course, is sort of held out as that holy grail. But there are these really just - these things that we take for granted that you lose - you know, the ability to control your bladder, you know, sexual function, scratching an itch, feeling an itch, you know? There are these dramatic - these things that seem small but can have dramatic impacts on human life.
Now, the timeline, that's - I think it's difficult for me to give you an answer on that. I mean, we've heard timelines before and been disappointed. So I think we need to be realistic here. But those human trials are about two years down the road from now, but we've got - we still have to meet certain milestones and prove to the FDA that we're ready for that. And that's part of what we're working on every single day now, and it's what keeps me up pretty much all the time, so (laughter)...
ZOMORODI: That's biophysicist Andrew Pelling. You can check out his talks at ted.com.
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