Constructing 3D Meat on Decellularized Spinach

July 7, 2020

We are excited to partner with the Cultured Meat and Future Food podcast for a multi-part series highlighting the research being conducted by New Harvest research fellows. In this episode, Alex Shirazi interviews New Harvest Fellow Jordan Jones about how to construct 3D meat on decellularized spinach leaves. Transcript is below. 

Transcript

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Alex (00:04):

Thanks for joining us on the Cultured Meat and Future Food show. This episode is part of the New Harvest Fellowship series. We’re excited to be chatting with Jordan Jones. Jordan Jones grew up in Memphis, Tennessee. He graduated as valedictorian from Memphis Academy of Science and Engineering. His interests in biomedical engineering began in high school through an internship at Memphis Bioworks. While there he was able to study cartilage regeneration using human stem cells. Jordan then began pursuing a Bachelor’s Degree of Science in Biomedical Engineering at WPI or Worcester Polytechnic Institute. He received several merit scholarships, including the Marshall/Chavez/Means award. Jordan was research assistant in Dr. Glenn Gaudette’s laboratory from 2014 to 2016. He worked on numerous research projects focused on cardiac regeneration, decellularization, and designed bioreactor systems. For his senior thesis, Jordan designed a system that utilized decellularized plant vasculature as a model for medical diagnostics and drug testing.

Alex (01:11):

After graduating from WPI, Jordan worked in the medical device industry from 2016 to 2018. He then returned to WPI to pursue a PhD in Biomedical Engineering. In 2018, Jordan’s research was displayed at The Centre Pompidou in Paris, France, in the exhibit “La Fabrique Du Vivant”. Shortly after returning to WPI, Jordan became a New Harvest Research Fellow. He’s currently working on developing lab grown meat. Jordan uses decellularized plant tissues to form a vascularized scaffold suitable for 3D bioengineered tissues, including structured meats such as steak. Let’s jump right in. Jordan, I’m excited to welcome you to the Cultured Meat and Future Food show.

Jordan (01:56):

Yep. Thanks for having me.

Alex (01:58):

Jordan, tell us a little bit about your academic background.

Jordan (02:01):

Well, I’ve always wanted to be an engineer when I was a kid. Wasn’t quite sure what kind of engineer I wanted to be. So my parents asked me to go to a Memphis Academy of Science and Engineering. It’s a charter school in Memphis, Tennessee, and there, I got involved in robotics. And then I later on did an internship at a local company, and I really fell in love with biomedical engineering. So from there I went on to WPI and got a Bachelor’s Degree in Biomedical Engineering. I also got pretty involved in a lot of the research at WPI, mainly with professor Gaudette, who at the time did a lot of research with fiber and micro threads. And those fiber micro threads are made of proteins that are found in blood clots. And they were used to help injuries heal, particularly with the skin. They were used to make sutures, but he also thought that those things could be useful for helping patients recover from heart attacks.

Jordan (02:55):

So our research surrounded using those micro threads as actual ways to transplant stem cells into myocardial infarctions, which is the term used to describe the dead area of the heart that happens as a result of the heart attack. That’s pretty much how I got started in biomedical research. After leaving there, I went to work for a couple of years for various medical device companies. I realized that that wasn’t really what I wanted to do. So I ended up going back to school to get a Master’s and then shortly after starting my Master’s, I converted over to a PhD student.

Alex (03:28):

Cool. And that company that you did the internship with, what kind of things were they doing?

Jordan (03:33):

Right. So that company, I don’t remember a lot about what their primary products were because, you know, as an intern, you don’t really have access to all the information. But what we were actually doing, at least what I was involved in, was using stem cells to regenerate cartilage. That was my first opportunity to actually work in the laboratory, my first opportunity to get involved with learning the different procedures that people do in the laboratory.

Alex (03:58):

Cool. And so when did you first hear about cultured meat and how did that lead to your current project?

Jordan (04:05):

Right. So I first heard about cultured meat actually looking at suggestions that people were making about our technology in the laboratory. So I guess there’s a little bit of background that needs to be given here. So like I said, we used to work with these micro threads are made out of fibrinogen and thrombin. We ended up using these cellularized heart tissue as a model to test those sutures. And decellularization is removing all the cellular material from a particular tissue. So we would take rat hearts and we would remove all the cells from the rat hearts and we used that as a model to test these micro threads. And then one day Professor Gaudette got the idea to actually decellularize plants. And the reason why we wanted to decellularize plants was because plants have a native vasculature, that’s hard to replicate synthetically. So essentially we would take the plant, remove all the cells from it and then use the plant itself as a scaffold that comes prepacked with vasculature required to grow cells in three dimensions. So online, people would come up with all kinds of ideas of how to use this technology and one of them was you should grow meat with this stuff and we thought that idea was awesome. So that was the first time I actually thought about it and I looked into it a little bit more. Then I ran into Mark Post’s research where he developed like ground beef using cells. So I thought that was pretty awesome.

Alex (05:25):

Cool. And so you mentioned micro threads. Can you tell me a little bit about it, like super high level, explain it like I’m five, what are micro threads in this type of scenario?

Jordan (05:36):

Alright, so the way it works is you take two proteins that are typically found in blood clots fibrinogen and thrombin. And when you mix them together, they kind of coagulate into a transparent gel and that gel can be stretched out and dried to form like a thread, a little tiny thread. When you break those threads together, you can form a suture. That’s what we were doing at the time.

Alex (05:58):

I see. Okay. And you were doing this at the Gaudette lab before you even started working on cultured meat?

Jordan (06:04):

Exactly.

Alex (06:05):

Okay, cool. And so in terms of the work that you were doing there that was mostly related to the heart muscle, or does it have a lot of other applications?

Jordan (06:16):

We were using it in respect to primarily heart muscle, but you know, we have collaborators, for instance, George Pins, who’s at WPI as well, he uses it for skin to help wounds heal.

Alex (06:27):

And so from the research that you’re conducting, where could this lead from a cellular agriculture perspective?

Jordan (06:35):

So right now there are several labs and even startups working to develop culture meat. But at the moment, there’s no definitive way to create three dimensional tissues. So they’re kind of limited to developing things like ground beef, ground chicken, just amorphous meats, that’s the term they would like to use. But my technology focuses on addressing the problem of growing cells in three dimensions, by providing it with a vasculature network that can provide nutrients to the cells as they grow in three dimensions. So this kind of technology will lead the way to producing what I like to call structured meats, like steak or whole chicken that can kind of replicate the texture that most people associate with eating meat.

Alex (07:18):

Okay, cool. And so when we’re thinking about decellularizing, like let’s say a spinach leaf, and growing cells there, is this only to be used in the research phases, or do you think that that decellularized plant will ever make it to the production phases?

Jordan (07:36):

My professor, Professor Gaudette, that always taught me that you want to create value. You want to do something that people will actually find use for. So we are always looking to create something that will actually be used, something that would actually make it out to the market. So of course I believe that decellularized plants will have some kind of use and I hope that that’s in cultured meat. So yeah, I would hope that it would go on to actually make it into grocery stores actually make it into restaurants.

Alex (08:04):

Then would we have like a spinach leaf shaped steak potentially?

Jordan (08:11):

I don’t think it will be shaped quite like a spinach leaf. The idea for, I guess production scale, will be to use something a bit larger than spinach and then cut out the appropriate shape from that. So just to clarify it, the concept is to grow cells on both sides of the spinach leaf and then layer. So one unit of meat would be a spinach leaf or cells on the top and cells on the bottom. And then we would then stack multiple of these units together to make something a bit thicker than a spinach leaf. And then from there you could cut it down to size or cut it into the shape you want.

Alex (08:46):

Cool. And in your research, how much of the cells that you’re, I guess for lack of a better term, putting into this decellularized spinach leaf, how much of the cells are muscles versus fat?

Jordan (08:57):

Right. So at the moment we’re using only muscle. I guess to be more explicit, what we’re using is our satellite cells, which are the progenitor cells or pre-muscle cells. We use those to differentiate into muscle. And at the moment we are only using muscle on our scaffold. Now we understand that that isn’t a good representation of meat, because different cuts of meat have different fat contents, but that’s a good place for us to start. In the future, we’d want to incorporate fat tissue into it, to kind of start playing around with the texture and the taste.

Alex (09:30):

Okay. So this is all super cool. At what point did New Harvest get involved?

Jordan (09:35):

Right. So going back to, when I first heard about, or first seriously thought about cultured meat, this all happened relatively quickly. So it all started when Professor Gaudette gave a presentation at the 2018 New harvest conference and he came to me shortly afterwards and he was like, ‘Hey, do you think you can do this? Is this something you want to work on?’ And I was like, ‘yeah, that sounds great’. I thought it was genius to be honest. So that’s when I seriously considered working on it. That’s when I really started working on it.

Alex (10:05):

Great. And so then did you approach New Harvest for the fellowship or did New Harvest approach the lab? How did that work?

Jordan (10:12):

I’m not exactly sure in the background, but I applied for the New Harvest Fellowship program. They were already familiar with Professor Gaudette, seeing that he recently gave a presentation. I’m not sure if they reached out to him or if he reached out to them to do the presentation, but certainly after accepting the project I applied. I first did some preliminary research. So we started working pretty fast to actually verify that this kind of research is actually possible. So a lot of the stuff that we did and we actually did it right before I applied for the Fellowship. So we had already isolated cells from a cow, we’d already tested whether or not it was possible for those cells to attach to the scaffold. And then I applied for the Fellowship and I got to know all the other Fellows, I got to know the administrators within New Harvest and they’re all just fantastic people. So yeah, we really got along.

Alex (11:04):

Cool. And so when we’re thinking about the research that you’re doing, and you mentioned you’re using beef cells, is that right?

Jordan (11:11):

Yes.

Alex (11:11):

And maybe to step back, can I call it beef cells? Is it not considered beef at that point? What do you call it at that stage?

Jordan (11:19):

I don’t actually know. I call it beef because I just associate beef with cow. I don’t know if there is a technical term or a technical way to describe beef in the meat industry. I’m not exactly sure about that part. I call it beef

Alex (11:33):

Beef. Okay. And so if you were to take one of these finished leaves with beef cells on one side and the other side, not only is it going to be very thin because it’s a spinach leaf, but maybe it even gets a little bit thinner once you decellularize. It is that right?

Jordan (11:48):

It was as far as the leaf, whether or not the leaf gets a bit thinner, that’s possible, but the dimensions don’t change very much from before it’s decellularized. It gets a little thicker after we add cells to it. So I think the thickness of the spinach leaf is between 400 and 800 microns, we’re adding essentially another 400 microns to it after we add the cells,

Alex (12:11):

I see, 400 microns together, including both sides.

Jordan (12:15):

Both sides, yep.

Alex (12:15):

And if we were to take this and throw it in a frying pan, would we taste any part of that spinach leaf scaffold?

Jordan (12:23):

No, I don’t think we would taste anything at that point. It’s all cellulose. There are no plant components left other than the cellulose backbone.

Alex (12:32):

Interesting. Okay. One of the huge benefits that you had mentioned of using a spinach leaf is because of the vascularization network, is that right?

Jordan (12:41):

Yeah. The vascular network.

Alex (12:42):

The vascular network. And so what benefits are there to have a kind of good vascular network? Is it in terms of cell growth or what are the benefits?

Jordan (12:52):

Okay, so let’s imagine that we are creating a ball of cells. And let’s say that this ball of cells is suspended in a bath of all the nutrients that the cells need, including oxygen. So we have oxygen dissolved in the cell media that’s supplying nutrients to the cells. As this ball grows, eventually the oxygen won’t be able to diffuse or to seep into the center of this ball and that limit is about 200 microns. So once the radius of this circle exceeds 200 microns, then the cells in the middle would begin to lose access to the oxygen and they’ll begin to die and form what’s called a necrotic core. And this problem isn’t just a theoretical one in the laboratory. This is a problem that exists in nature. And almost every organism on this planet has evolved to solve it. So humans, for instance, have arteries and veins. They exist to address this problem. Every single cell in your body is within 200 microns of some sort of vein or artery. And that’s where they get their oxygen from. Now, plants have had to solve that same problem instead of arteries and veins. They have xylem and phloem and the xylem exists to pull water from the roots up to the rest of the plant. And the phloem exists to take the nutrients from the leaves and take it to the rest of the plant. So essentially what we have is a baked in vascular system that we don’t have to create on our own because creating such a system on our own brings up a number of engineering challenges that we have yet to solve.

Alex (14:23):

Interesting. Okay. And since plants are cheap and easy to grow, they make a really good way to kind of get this very quickly.

Jordan (14:32):

Yeah, exactly. If we can actually exploit this characteristic of the plants, it can be very cheap and efficient to use plant leaves instead of synthesizing our own scaffolds or even using technology such as 3D printing. I believe this is more accessible than even 3D printing.

Alex (14:49):

And so what other, I guess, vegetables, or what other plants have you experimented with or is it just spinach for the R&D phases?

Jordan (14:58):

We’ve actually tried a number of plants. We’ve done green onion, we’ve done broccoli, we’ve done parsley stems, literally anything we can find at the grocery store we’ve probably tried to decellularize it at one point. We use spinach in a lot of our research because we find it convenient. If you take a look at a spinach stem, there’s a big hole in the middle of the stem. That hole actually connects to the whole vasculature network of the leaf. So we use it to access that vascular network. So we take a needle and we use a needle to actually cannulate the stem and then we can perfuse media or blood or anything else that we want through that stem into the vascular network

Alex (15:41):

In terms of taking this to the next step in terms of scaling and production, a lot of times we refer to as like a huge bioreactor, similar to like a brewing beer in a tank, what kind of bio-reactors system would we be using to make large amounts of meat in these types of either spinach leaves or just plant scaffold?

Jordan (16:06):

Yeah. So, yeah, you were using it correctly. And I guess our research in particular, we would need a couple of bioreactors and one would be to decellularize the spinach leaves or whatever plant we choose to use during the scale up. We would have to be able to decellularize them at mass. We’ve actually started working on that already in our lab. We’d have some sort of vat. In that vat there would be all the detergents used for the desalinization process. And we would actually kind of stir the leaves around in there with the detergents to really mix it in and decellularize them. But you would also need another bioreactor to actually expand your cells. So that’s called proliferation. So we’d actually need a bioreactor to do that and of course you would have to provide all the new chance that the cells need. You’d also have to provide some sort of scaffold or surface for them to grow on in that proliferation bioreactor. So this is totally different. This is not using the spinach leaves. I suppose it could, but that would be another story altogether. But then you would also have to differentiate the cells. So once you proliferate the cells and we have an adequate number of cells, now you have to differentiate them or turn them into muscle. That’s what it would look like to have bioreactors, at least in the process that we use.

Alex (17:23):

Right. And so let’s say we could manipulate broccoli to take the shape of a T-bone steak. That would be, for example, an ideal system for something like this, or is that too much of a Frankenstein question?

Jordan (17:39):

I don’t know if broccoli would be the best for something like a T-bone steak, but what makes a T-bone steak a T-bone steak. If you wanted to replicate the bone in the middle of a T-bone steak, you could use something like bamboo. We’ve had some collaborators decellularize, bamboo to kind of replicate bone. So, I mean, I guess if you’re trying to make a T-bone steak, you would have to incorporate that somehow. Is your question specifically on how to use broccoli?

Alex (18:05):

Oh, no, not related to broccoli in particular, just kind of manipulating an existing plant-based structured to make that more like meat we eat today.

Jordan (18:15):

Oh, I see. We haven’t yet made it to the point of trying to replicate individual cuts of meat or trying to replicate any particular item in the store, as much as we’re trying to replicate the structure of muscle or meat just as a whole, as it is. So right now we’re using a spinach and things of that sort. Mostly leafy plants because we’ve tried it with green lettuce also. Very leafy plants that have a dicot vascular network, which is weblike, to try to replicate just the structure of meat in general before we can try to imitate different cuts of meat or different types of steak.

Alex (18:51):

Cool. And so I’m totally thinking of a green onion and cell cultured beef jerky. We’ll leave that and move on to the next question.

Jordan (19:01):

Well, I can talk about the green onion, if you’d like.

Alex (19:03):

Yeah, let’s hear about it.

Jordan (19:03):

If you look at the green onion, it’s very tubular and when we saw that we saw a tissue engineered blood vessel, that’s what we saw. So you would coat the inside with cells and then have smooth muscle on the outside and there go, you have a tissue engineered blood vessel. Now we haven’t actually tried to do that or seriously considered it just yet. But that’s what we saw when we decellularized green onion.

Alex (19:28):

I know there’s a lot of other research going on in the lab that is for medical purposes, but could it also be that some of your research on cultured meat also leads to advancements on the medical side of things?

Jordan (19:40):

Most definitely. The only difference between meat and other muscles are the species. I’ve had a lot of people ask me about growing human cells on the spinach leaves and that would be very useful for doing things like having a tissue engineered muscle graft, for instance, for patients who have volumetric muscle loss. Maybe they’ve had an accident or something that has caused them to lose a big chunk of muscle. We could actually use this to the same exact techniques to grow muscle, to replace the muscle that was lost.

Alex (20:12):

Wow. Yeah, no, that’s cool. Awesome. So when we last spoke, we talked about the opportunities of potentially creating a new startup in the cell ag field. So what would a startup like this look like if you were to start a company in cellular agriculture?

Jordan (20:28):

It can come in several forms. It could be a company that sells meat out of a grocery store, just like many people are familiar with. It can also sell meat directly to restaurants. And there’s numerous restaurants now where you can go and get like the Impossible Burger, I believe. There’ll be a similar thing where you would go into a restaurant and you would order the, let’s see, slaughter free meat, I think is a good way to call it. And then also, because there are other companies that are currently working on the same thing, and in our case, let’s just mention Mosa Meats or Memphis Meats, either or, that are currently working on the technology to grow meat in the lab. We actually had the scaffold technology to grow 3D tissues. There exists a potential partnership there where Mosa Meats or Memphis Meats could grow the cells and then we could provide the scaffold, and then from there, you can have a slaughter free steak come about.

Alex (21:19):

For someone that is growing meat cells, or as we discussed, beef cells, in your day to day research, what are some of the challenges that maybe you’re not working on specifically, but you see may apply to the rest of the industry?

Jordan (21:35):

There are numerous challenges. Most of them are involved in the scaling process. How do you go from laboratory to dinner plate? And a lot of them are surrounding the cell media. There are a lot of components of the cell media that are expensive, such as the serums and the growth factors that are required to grow the cells and differentiate them. That’s a really big problem because when you scale it, it ends up making the final product ridiculously expensive, so much so that it’s still considered fantasy by some people. I mean, it’s not considered a fantasy to me, but many people consider it just unfeasible because of the sheer price. So one challenge is actually bringing that price down. The second challenge is actually the one that I’m currently working on, is how do you provide a scaffold that will allow them to grow in three dimensions?

Alex (22:20):

I see. Okay. For other researchers that are interested in getting into the field, what advice do you have for them?

Jordan (22:27):

I guess it depends on what stage of their career they’re in. If they’re a college student, I would tell them to look around and find someone who’s working on research that you’re interested in. Read some of their papers if they have any, look at their projects and think, ‘How can I help further this project? Do I have any ideas to contribute? Do I having any useful skills that I’ve learned that I think would be very helpful?’ And reach out to them, actually start a conversation with that person and get to know them a little bit. You’d be surprised at how open people are to communicate with you and talk and consider collaborations or working with you. There are also REU’s that different schools have that actually pay a stipend for students to come out and work in the laboratories. I knew WPI has an REU program, so that can also be a good option. And I guess that also applies to graduate. Students who want to get involved. The process is very similar to what I said at first about essentially doing your homework and reaching out to the PI of the lab. Or even the graduate students in some cases, and seeing how you can get involved.

Alex (23:31):

We have a question from one of our listeners. Keeley asks, if we were to walk into your lab, what kind of things would we see across your bench?

Jordan (23:41):

If you were to walk in my lab, let’s see, what would you see? Of course you would see the microscopes that we have in there. You would also see it’s been a while since I’ve been at my bench. So I have to remember because of COVID, but essentially you would see all of my papers and note books, not the most organized person in the world. So you’d see all my notebooks. You would also see next to me is actually one of the other students in the lab, Rick. Rick is always doing some kind of crazy experiment. So there are a lot of things sitting around that I wouldn’t be able to explain to anyone who walked in without consulting Rick first, because there’s no telling what’s going on in there.

Alex (24:22):

Oh, interesting.

Jordan (24:33):

There’s no telling what’s going on. You know, a lot of times we have guests come over and they ask me, ‘Hey, what’s going on in that beaker right there?’ And I said, ‘I have no idea. Got to ask Rick’. So, yeah. I mean, other than that, it’s pretty normal. We have lab equipment out there. Notebooks. I might have samples out that I might be getting ready to stain. But what I will say is that we have the decellularization apparatus. At least that’s what I’m going to call it. The name changes frequently, but right now I’m going to call it the decellularization apparatus. And it’s like several bottles in an array. And inside of each bottle is a spinach leaf. And the top of these bottles have tubes that come out and they go to a big reservoir at the top of the shelf that has inside of it, all the detergents for decellularization. So that’s interesting. I think that’s one of the most eye catching things in our lab that people see when they show up.

Jordan (25:19):

Another interesting thing that we have is our other decellularization station. We have two. So the first one is for a perfusion where we actually forcefully push the detergents through the leaf to decellularize it. The other one is more passive, where we put the spinach leaves into tubes and the tubes themselves are full of the detergent. And we actually have, they’re rollers, but they look kind of like hot dog rollers, and they spin around. And as the tubes spin the leaves decellularize.

Alex (25:50):

Oh, interesting, like hot dog rollers that you would see at like at a gas station.

Jordan (25:54):

Right. They look just like that. Yeah. We have basically hot dog rollers that have tubes with leaves in them. And over time, you’ll see the leaves turn from a bright green to a clear translucent colour.

Alex (26:06):

That was a cool answer. Now I really want to know what Rick is up to.

Jordan (26:10):

There’s no telling, all sorts of stuff.

Alex (26:13):

You can get in touch with Jordan on LinkedIn and learn more about New Harvest at www.new-harvest.org. Jordan, is there a website for the Gaudette lab?

Jordan (26:24):

There is, it’s not really up to date, so I wouldn’t necessarily send people there, but you can get to it by navigating or even searching Gaudette lab at WPI and it should lead you there.

Alex (26:36):

Okay. Awesome. And do you have any last insights for our listeners today? Any last thoughts?

Jordan (26:41):

I guess the only thought I have is, you know, I’m happy that people are becoming more interested in cellular agriculture and other technologists like it, because I feel like people it’s time that we start thinking about not only how can we make things better for ourselves as far as our technology, but how can we make our technology kind of cooperate more with nature itself. So I’m very happy to see people more interested in cellular agriculture because this is kind of a step towards being able to, I guess, cooperate with nature, to live at peace with nature, instead of destroying it and making it better for ourselves, but not necessarily making the earth a better place as a whole. So that’s about it.

Alex (27:22):

That’s great. Yeah. And thank you so much for being with us today on the Future Food show.

Jordan (27:27):

No problem. Thank you. It was a pleasure.

Alex (27:29):

This is your host Alex, and we look forward to being with you on our next episode.

 

Transcribed by New Harvest volunteer Bianca Le. 

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