To Save Lives, This Scientist Is Trying to Grow Human Organs Inside of Sheep
More than 114,000 men, women, and children are awaiting organ transplants in the United States. Each day, 22 of them die waiting. To address this shortage, researchers are working hard to grow organs on-demand, using the patient's own cells, to eliminate the need to find a perfectly matched donor.
"The next step is to transplant these cells into a larger animal that will produce an organ that is the right size for a human."
But creating full-size replacement organs in a lab is still decades away. So some scientists are experimenting with the boundaries of nature and life itself: using other mammals to grow human cells. Earlier this year, this line of investigation took a big step forward when scientists announced they had grown sheep embryos that contained human cells.
Dr. Pablo Ross, an associate professor at the University of California, Davis, along with a team of colleagues, introduced human stem cells into the sheep embryos at a very early stage of their development and found that one in every 10,000 cells in the embryo were human. It was an improvement over their prior experiment, using a pig embryo, when they found that one in every 100,000 cells in the pig were human. The resulting chimera, as the embryo is called, is only allowed to develop for 28 days. Leapsmag contributor Caren Chesler recently spoke with Ross about his research. Their interview has been edited and condensed for clarity.
Your goal is to one day grow human organs in animals, for organ transplantation. What does your research entail?
We're transplanting stem cells from a person into an animal embryo, at about day three to five of embryo development.
This concept has already been shown to work between mice and rats. You can grow a mouse pancreas inside a rat, or you can grow a rat pancreas inside a mouse.
For this approach to work for humans, the next step is to transplant these cells into a larger animal that will produce an organ that is the right size for a human. That's why we chose to start some of this preliminary work using pigs and sheep. Adult pigs and adult sheep have organs that are of similar size to an adult human. Pigs and sheep also grow really fast, so they can grow from a single cell at the time of fertilization to human adult size -- about 200 pounds -- in only nine to 10 months. That's better than the average waiting time for an organ transplant.
"You don't want the cells to confer any human characteristics in the animal....Too many cells, that may be a problem, because we do not know what that threshold is."
So how do you get the animal to grow the human organ you want?
First, we need to generate the animal without its own organ. We can generate sheep or pigs that will not grow their own pancreases. Those animals can then be used as hosts for human pancreas generation.
For the approach to work, we need the human stem cells to be able to integrate into the embryo and to contribute to its tissues. What we've been doing with pigs, and more recently, in sheep, is testing different types of stem cells, and introducing them into an early embryo between three to five days of development. We then transfer that embryo to a surrogate female and then harvest the embryos back at day 28 of development, at which point most of the organs are pre-formed.
The human cells will contribute to every organ. But in trying to do that, they will compete with the host organism. Since this is happening inside a pig embryo, which is inside a pig foster mother, the pig cells will win that competition for every organ.
Because you're not putting in enough human cells?
No, because it's a pig environment. Everything is pig. The host, basically, is in control. That's what we see when we do rat mice, or mouse rat: the host always wins the battle.
But we need human cells in the early development -- a few, but not too few -- so that when an organ needs to form, like a pancreas (which develops at around day 25), the pig cells will not respond to that, but if there are human cells in that location, [those human cells] can respond to pancreas formation.
From the work in mice and rats, we know we need some kind of global contribution across multiple tissues -- even a 1% contribution will be sufficient. But if the cells are not there, then they're not going to contribute to that organ. The way we target the specific organ is by removing the competition for that organ.
So if you want it to grow a pancreas, you use an embryo that is not going to grow a pancreas of its own. But you can't control where the other cells go. For instance, you don't want them going to the animal's brain – or its gonads –right?
You don't want the cells to confer any human characteristics in the animal. But even if cells go to the brain, it's not going to confer on the animal human characteristics. A few human cells, even if they're in the brain, won't make it a human brain. Too many cells, that may be a problem, because we do not know what that threshold is.
The objective of our research right now is to look at just 28 days of embryonic development and evaluate what's going on: Are the human cells there? How many? Do they go to the brain? If so, how many? Is this a problem, or is it not a problem? If we find that too many human cells go to the brain, that will probably mean that we wouldn't continue with this approach. At this point, we're not controlling it; we're analyzing it.
"By keeping our research in a very early stage of development, we're not creating a human or a humanoid or anything in between."
What other ethical concerns have arisen?
Conferring human properties to the organism, that is a major concern. I wouldn't like to be involved in that, and so that's what we're trying to assess. By keeping our research in a very early stage of development, we're not creating a human or a humanoid or anything in between.
What specifically sets off the ethical alarms? An animal developing human traits?
Animals developing human characteristics goes beyond what would be considered acceptable. I share that concern. But so far, what we have observed, primarily in rats and mice, is that the host animal dictates development. When you put mouse cells into a rat -- and they're so closely related, sometimes the mouse cells contribute to about 30 percent of the cells in the animal -- the outcome is still a rat. It's the size of a rat. It's the shape of the rat. It has the organ sizes of a rat. Even when the pancreas is fully made out of mouse cells, the pancreas is rat-sized because it grew inside the rat.
This happens even with an organ that is not shared, like a gallbladder, which mice have but rats do not. If you put cells from a mouse into a rat, it never grows a gallbladder. And if you put rat cells into the mouse, the rat cells can end up in the gallbladder even though those rat cells would never have made a gallbladder in a rat.
That means the cell structure is following the directions of the embryo, in terms of how they're going to form and what they're going to make. Based on those observations, if you put human cells into a sheep, we are going to get a sheep with human cells. The organs, the pancreas, in our case, will be the size and shape of the sheep pancreas, but it will be loaded with human cells identical to those of the patient that provided the cells used to generate the stem cells.
But, yeah, if by doing this, the animal acquires the functional or anatomical characteristics associated with a human, it would not be acceptable for me.
So you think these concerns are justified?
Absolutely. They need to be considered. But sometimes by raising these concerns, we prevent technologies from being developed. We need to consider the concerns, but we must evaluate them fully, to determine if they are scientifically justified. Because while we must consider the ethics of doing this, we also need to consider the ethics of not doing it. Every day, 22 people in the US die because they don't receive the organ they need to survive. This shortage is not going to be solved by donations, alone. That's clear. And when people die of old age, their organs are not good anymore.
Since organ transplantation has been so successful, the number of people needing organs has just been growing. The number of organs available has also grown but at a much slower pace. We need to find an alternative, and I think growing the organs in animals is one of those alternatives.
Right now, there's a moratorium on National Institutes of Health funding?
Yes. It's only one agency, but it happens to be the largest biomedical funding source. We have public funding for this work from the California Institute for Regenerative Medicine, and one of my colleagues has funding from the Department of Defense.
"I can say, without NIH funding, it's not going to happen here. It may happen in other places, like China."
Can we put the moratorium in context? How much research in the U.S. is funded by the NIH?
Probably more than 75 percent.
So what kind of impact would lifting that ban have on speeding up possible treatments for those who need a new organ?
Oh, I think it would have a huge impact. The moratorium not only prevents people from seeking funding to advance this area of research, it influences other sources of funding, who think, well, if the NIH isn't doing it, why are we going to do it? It hinders progress.
So with the ban, how long until we can really have organs growing in animals? I've heard five or 10 years.
With or without the ban, I don't think I can give you an accurate estimate.
What we know so far is that human cells don't contribute a lot to the animal embryo. We don't know exactly why. We have a lot of good ideas about things we can test, but we can't move forward right now because we don't have funding -- or we're moving forward but very slowly. We're really just scratching the surface in terms of developing these technologies.
We still need that one major leap in our understanding of how different species interact, and how human cells participate in the development of other species. I cannot predict when we're going to reach that point. I can say, without NIH funding, it's not going to happen here. It may happen in other places, like China, but without NIH funding, it's not going to happen in the U.S.
I think it's important to mention that this is in a very early stage of development and it should not be presented to people who need an organ as something that is possible right now. It's not fair to give false hope to people who are desperate.
So the five to 10 year figure is not realistic.
I think it will take longer than that. If we had a drug right now that we knew could stop heart attacks, it could take five to 10 years just to get it to market. With this, you're talking about a much more complex system. I would say 20 to 25 years. Maybe.
Niklas Anzinger is the founder of Infinita VC based in the charter city of Prospera in Honduras. Infinita focuses on a new trend of charter cities and other forms of alternative jurisdictions. Healso hosts a podcast about how to accelerate the future by unblocking “stranded technologies”.This spring he was a part of the network city experiment Zuzalu spearheaded by Ethereum founder Vitalik Buterin where a few hundred invited guests from the spheres of longevity, biotechnology, crypto, artificial intelligence and investment came together to form a two-monthlong community. It has been described as the world’s first pop-up city. Every morning Vitalians would descend on a long breakfast—the menu had been carefully designed by famed radical longevity self-experimenter Bryan Johnson—and there is where I first met Anzinger who told me about Prospera. Intrigued to say the least, I caught up with him later the same week and the following is a record of our conversation.
Q. We are sitting here in the so-called pop-up network state Zuzalu temporarily realized in the village of Lusticia Bay by the beautiful Mediterranean Sea. To me this is an entirely new concept: What is a network state?
A. A network state is a highly aligned online community that has a level of in-person civility; it crowd-funds territory, and it eventually seeks diplomatic recognition. In a way it's about starting a new country. The term was coined by the crypto influencer and former CTO of Coinbase Balaji Srinivasan in a book by the same title last year [2022]. What many people don't know is that it is a more recent addition or innovation in a space called competitive governance. The idea is that you have multiple jurisdictions competing to provide you services as a customer. When you have competition among governments or government service providers, these entities are forced to provide you with a better service instead of the often worse service at higher prices or higher taxes that we're currently getting. The idea went from seasteading, which was hardly feasible because of costs, to charter cities getting public/private partnerships with existing governments and a level of legal autonomy, to special economic zones, to now network states.
Q. How do network states compare to charter cities and similar jurisdictions?
A. Charter cities and special economic zones were legal forks from other existing states. Dubai, Shenzhen in China, to some degree Hong Kong, to some degree Singapore are some examples. There's a host of other charter cities, one of which I'm based in myself, which is Prospera located in Honduras on the island Roatán. Charter cities provide the full stack of governance; they provide new laws and regulations, business registration, tax codes and governance services, Estonia style: you log on to the government platform and you get services as a citizen.
When conceptualizing network states, Balagi Srinivasan turns the idea of a charter city a bit on its head: he doesn't want to start with this full stack because it's still very hard to get these kinds of partnerships with government. It's very expensive and requires lots of experience and lots of social capital. He is saying that network states could instead start as an online community. They could have a level of alignment where they trade with each other; they have their own economy; they meet in person in regular gatherings like we're doing here in Zuzulu for two months, and then they negotiate with existing governments or host cities to get a certain degree of legal autonomy that is centered around a moral innovation. So, his idea is: don't focus on building a completely new country or city; focus on a moral innovation.
Q. What would be an example of such a moral innovation?
A. An example would be longevity—life is good; death is bad—let's see what we can do to foster progress around that moral innovation and see how we can get legal forks from the existing system that allow us to accelerate progress in that area. There is an increasing realization in the science that there are hallmarks of aging and that aging is a cause of other diseases like cancer, ALS or Alzheimer's. But aging is not recognized as a disease by the FDA in the United States and in most countries around the world, so it's very hard to get scientific funding for biotechnology that would attack the hallmarks of aging and allow us potentially to reverse aging and extend life. This is a significant shortcoming of existing government systems that groups such as the ones that have come together here in Montenegro are now seeking alternatives too. Charter cities and now network states are such alternatives.
Q. Would it not be better to work within the current systems, and try to improve them, rather than abandon them for new experimental jurisdictions?
A. There are numerous failures of public policies. These failures are hard, if not impossible, to reverse, because as soon as you have these policies, you have entrenched interests who benefit from the regulations. The only way to disrupt incumbent industries is with start-ups, but the way the system is set up makes it excessively hard for such start-ups to become big companies. In fact, larger companies are weaponizing the legal system against small companies, because they can afford the lawyers and the fixed cost of compliance.
I don't believe that our institutions in many developed countries are beyond hope. I just think it's easier to change them if you could point at successful examples. ‘Hey, this country or this zone is already doing it very successfully’; if they can extend people’s lifespan by 10 years, if they can reduce maternal mortality, and if they have a massive medical tourism where people come back healthier, then that is just very embarrassing for the FDA.
Q. Perhaps a comparison here would be the relationship between Hong Kong and China?
A. Correct, so having Hong Kong right in front of your door … ‘Hey, this capitalism thing seems to work, why don't we try it here?’ It was due to the very bold leadership by Deng Xiaoping that they experimented with it in the development zone of Shenzhen. It worked really well and then they expanded with more special economic zones that also worked.
Próspera is a private city and special economic zone on the island of Roatán in the Central American state of Honduras.
Q. Tell us about Prospera, the charter city in Honduras, that you are intimately connected with.
A. Honduras is a very poor country. It has a lot of crime, never had a single VC investment, and has a GDP per capita of 2,000 per year. Honduras has suffered tremendously. The goal of these special economic zones is to bring in economic development. That's their sole purpose. It's a homegrown innovation from Honduras that started in 2009 with a very forward-thinking statesman, Octavio Sanchez, who was the chief of staff to the president of Honduras, and then president. He had his own ideas about making Honduras a more decentralized system, where more of the power lies in the municipalities.
Inspired by the ideas of Nobel laureate economist Paul Romer, who gave a famous Ted Talk in 2009 about charter cities, Sanchez initiated a process that lasted for years and eventually led to the creation of a special economic zone legal regime that’s anchored in the Hunduran constitution that provides the highest legal autonomy in the world to these zones. There are today three special economic zones approved by the Honduran government: Prospera, Ciudad Morazan and Orchidea.
Q. How did you become interested and then involved in Prospera?
A. I read about it first in an article by Scott Alexander, a famous rationalist blogger, who wrote a very long article about Prospera, and I thought, this is amazing! Then I came to Prospera and I found it to be one of the most if not the most exciting project in the world going on right now and that it also opened my heart to the country and its people. Most of my friends there are Honduran, they have been working on this for 10 or more years. They want to remake Honduras and put it on the map as the place in the world where this legal and governance innovation started.
Q. To what extent is Prospera autonomous relative to the Honduran government?
A. What's interesting about the Honduran model is that it's anchored within the Honduran constitution, and it has a very clear framework for what's possible and what's not possible, and what's possible ensures the highest degree of legal autonomy anywhere seen in the world. Prospera has really pushed the model furthest in creating a common law-based polycentric legal system. The idea is that you don't have a legislature, instead you have common law and it's based on the best practice common law principles that a legal scholar named Tom W. Bell created.
One of the core ideas is that as a business you're not obligated to follow one regulatory monopoly like the FDA. You have regulatory flexibility so you can choose what you're regulated under. So, you can say: ‘if I do a medical clinic, I do it under Norwegian law here’. And you even have the possibility to amend it a bit. You're still required to have liability insurance, and have to agree to binding arbitration in case there's a legal dispute. And your insurance has to approve you. So, under that model the insurance becomes the regulator and they regulate through prices. The limiting factor is criminal law; Honduran criminal law fully applies. So does immigration law. And we pay taxes.
Q. Is there also an idea of creating a kind of healthy living there, and encourage medical tourism?
A. Yes, we specifically look for legal advantages in autonomy around creating new drugs, doing clinical trials, doing self-medication and experimentation. There is a stem cell clinic here and they're doing clinical trials. The island of Roatán is very easily accessible for American tourists. It's a beautiful island, and it's for regulatory reasons hard to do stem cell therapies in the United States, so they're flying in patients from the United States. Most of them are very savvy and often have PhDs in biotech and are able to assess the risk for themselves of taking drugs and doing clinical trials. We're also going to get a wellness center, and there have been ideas around establishing a peptide clinic and a compound pharmacy and things like that. We are developing a healthcare ecosystem.
Q. This kind of experimental tourism raises some ethical issues. What happens if patients are harmed? And what are the moral implications for society of these new treatments?
A. As a moral principle we believe in medical freedom: people have rights over their bodies, even at the (informed) risk of harm to themselves if no unconsenting third-parties are harmed; this is a fundamental right currently not protected effectively.
What we do differently is not changing ethical norms around safety and efficacy, we’re just changing the institutional setup. Instead of one centralized bureaucracy, like the FDA, we have regulatory pluralism that allows different providers of safety and efficacy to compete under market rules. Like under any legal system, common law in Prospera punishes malpractice, fraud, murder etc. This system will still produce safe and effective drugs, and it will still work with common sense legal notions like informed consent and liability for harm. There are regulations for medical practice, there is liability insurance and things like that. It will just do so more efficiently than the current way of doing things (unless it won’t, in which case it will change and evolve – or fail).
A direct moral benefit ´to what we do is that we increase accessibility. Typical gene therapies on the market cost $1 million dollars in the US. The gene therapy developed in Prospera costs $25,000. As to concern about whether such treatments are problematic, we do not share this perspective. We are for advancing science responsibly and we believe that both individuals and society stand to gain from improving the resiliency of the human body through advanced biotechnology.
Q. How does Prospera relate to the local Honduran population?
A. I think it's very important that our projects deliver local benefits and that they're well anchored in local communities. Because when you go to a new place, you're seen as a foreigner, and you're seen as potentially a danger or a threat. The most important thing for Prospera and Ciudad Morazan is to show we're creating jobs; we're creating employment; we're improving people's lives on the ground. Prospera is directly and indirectly employing 1,100 people. More than 2/3 of the people who are working for Prospera are Honduran. It has a lot of local service workers from the island, and it has educated Hondurans from the mainland for whom it's an alternative to going to the United States.
Q. What makes a good Prosperian citizen?
A. People in Prospera are very entrepreneurial. They're opening companies on a small scale. For example, Vehinia, who is the cook in the kitchen at Prospera, she's from the neighboring village and she started an NGO that is now funding a school where children from the local village can go to instead of a school that's 45 minutes away. There's very much a spirit of ‘let's exchange and trade with each other’. Some people might see that as a bit too commercial, but that's something about the culture that people accept and that people see as a good thing.
Q. Five years from now, if everything goes well, what do we see in Prospera?
A. I think Prospera will have at least 10,000 residents and I think Honduras hopefully will have more zones. There could be zones with a thriving industrial sector and sort of a labor-intensive economy and some that are very strong in pharmaceuticals, there could also be other zones for synthetic biology, and other zones focused on agriculture. The zones of Prospera, Ciudad Morazan and Orchidea are already showing the results we want to see, the results that we will eventually be measured by, and I'm tremendously excited about Honduras.
How to Measure Your Stress, with Dr. Rosalind Picard
Today’s podcast guest is Rosalind Picard, a researcher, inventor named on over 100 patents, entrepreneur, author, professor and engineer. When it comes to the science related to endowing computer software with emotional intelligence, she wrote the book. It’s published by MIT Press and called Affective Computing.
Dr. Picard is founder and director of the MIT Media Lab’s Affective Computing Research Group. Her research and engineering contributions have been recognized internationally. For example, she received the 2022 International Lombardy Prize for Computer Science Research, considered by many to be the Nobel prize in computer science.
Through her research and companies, Dr. Picard has developed wearable sensors, algorithms and systems for sensing, recognizing and responding to information about human emotion. Her products are focused on using fitness trackers to advance clinical quality treatments for a range of conditions.
Meanwhile, in just the past few years, numerous fitness tracking companies have released products with their own stress sensors and systems. You may have heard about Fitbit’s Stress Management Score, or Whoop’s Stress Monitor – these features and apps measure things like your heart rhythm and a certain type of invisible sweat to identify stress. They’re designed to raise awareness about forms of stress such as anxieties and anger, and suggest strategies like meditation to relax in real time when stress occurs.
But how well do these off-the-shelf gadgets work? There’s no one more knowledgeable and experienced than Rosalind Picard to explain the science behind these stress features, what they do exactly, how they might be able to help us, and their current shortcomings.
Dr. Picard is a member of the National Academy of Engineering and a Fellow of the National Academy of Inventors, and a popular speaker who’s given over a hundred invited keynote talks and a TED talk with over 2 million views. She holds a Bachelors in Electrical Engineering from Georgia Tech, and Masters and Doctorate degrees in Electrical Engineering and Computer Science from MIT. She lives in Newton, Massachusetts with her husband, where they’ve raised three sons.
In our conversation, we discuss stress scores on fitness trackers to improve well-being. She describes the difference between commercial products that might help people become more mindful of their health and products that are FDA approved and really capable of advancing the science. We also talk about several fascinating findings and concepts discovered in Dr. Picard’s lab including the multiple arousal theory, a phenomenon you’ll want to hear about. And we explore the complexity of stress, one reason it’s so tough to measure. For example, many forms of stress are actually good for us. Can fitness trackers tell the difference between stress that’s healthy and unhealthy?
Show links:
- Dr. Picard’s book, Affective Computing
- Dr. Picard’s bio
- Dr. Picard on Twitter
- Dr. Picard’s company, Empatica - https://www.empatica.com/ - The FDA-cleared Empatica Health Monitoring Platform provides accurate, continuous health insights for researchers and clinicians, collected in the real world
- Empatica Twitter
- Dr. Picard and her team have published hundreds of peer-reviewed articles across AI, Machine Learning, Affective Computing, Digital Health, and Human-computer interaction.
- Dr. Picard’s TED talk
Rosalind Picard