The Superposition of Chickens: How Tissue Engineering Could Impact Your Pantry
Meet Ian. He is the chicken chilling in the top left corner.
In the top right corner, you can see meat from Ian turned into chicken nuggets.
Before you get too bummed, check out the last bottom picture. Those people eating those Ian nuggets are looking at Ian. Fully healthy and intact, clucking away on the grass.
All three of these photos were taken at the exact same time in the same backyard.
Trippy right?
What you're seeing here is an example of the implications of cultured meat or growing meat without growing entire animals.
How the hell do you G R O W meat without an animal?’
It all starts with a technology called tissue engineering. Tissue engineering is the science of growing organs and tissues to replace damaged or diseased parts of your body.
An idea inspired by a WW2 Japanese prisoner of war camp (a story for another time) was to use this same technology to grow meat. This means 90+% less resource use with NO animal cruelty involved AND you still get to chow down on some fire chicken wings. Using tissue engineering to make animal products, not just meat, is called Cellular Agriculture.
First, before we get into the nitty-gritty of cultured meat, we have to understand the problem: the meat industry.
Listen, I’m not here to try to deny that meat is delicious. Hit me up with chicken tenders, filet mignon, or buffalo wings any time.
However, I think that it is very important to be mindful that the way we produce meat is very much not good [even as an avid meat lover myself].
You can take a moral argument and look at animal cruelty and mistreatment. [You can check out all the PETA videos for that one.]
As for me, I’m going to talk about how our carnivorous cravings are effecting us AND good ole’ mother nature.
How much meat do we REALLY eat, though?
Answer: too much.
Every year we raise tens of BILLIONS of chickens, BILLIONS of pigs, and hundreds of millions of cattle, sheep, and goat.
We also harvest around 800 million tons of milk each year AND fish over 155 million tons of seafood EVERY YEAR.
And those numbers are only rising. The amount of meat we eat increases as the world gets richer and more families can afford it. By 2050 meat consumption could increase by as much as 160 percent.
Ok, so what? Why should I care?
Well, this increase would put enormous pressure on our water resources AND crop resources. And we are ALREADY pretty deep in the dog house with those.
Producing a SINGLE POUND of beef uses 1,799 gallons of water (this taking into account drinking water and water to grow the crops they eat).
This issue doesn’t end at how much goes into making meat. We also have to look at what’s coming out alongside our hamburgers.
14.5 percent of all greenhouse emissions that are caused by human activity originates from global livestock.
Cattle (cows, for those of us who are not the most ranch-savy) make up 65 percent of the emission caused by livestock.
Meat is just plain inefficient. What I mean by that is THINK about how much food you have to feed a cow vs. how many pounds of food you get out of said cow. Just to help you conceptualize, a cow eats around 24 pounds of food
E V E R Y S I N G L E D A Y).
But hey, lets lay off the lands for a bit. How about we dive into how our fishy friends are affected by our meal preferences.
The ocean is really, really… really big. But we have gotten really-really-REALLY good at catching fish. We reel in these fishies at such a high rate that we eat them faster than the fish can reproduce.
This is called overexploitation, and an estimated 33% of global fish stocks are overexploited. Overexploitation is one of the biggest threats to biodiversity, meaning it can disrupt entire ecosystems.
Okay yeah, all this sounds like it sucks. But how does it really affect me?
Eating mass-produced meats isn’t just bad for the animals AND the environment, it can ALSO be bad for the people that consume it.
Many diseases can be transferred from meat to meat-eater. Dementia-inducing mad cow disease (BSE), parasitic trichinosis and bathroom destroying E. coli are just a few that can make that steak seem a hell of a lot less appetizing.
On top of all that stuff, animals are often over-medicated with antibiotics to compensate for their unsanitary and stressful living conditions. This can lead to the development of antimicrobial resistance. That means the diseases can mutate to become stronger than the medication.
TLDR:
- meat produces a significant amount of carbon emissions
- meat uses up an incredible about of resources
- meat production only has around 3% ROI [return on investment]
- meat can give transmit diseases
- meat production can create stronger diseases
Yikes.
Turns out, a lot of super-smart people realized just how bad meat is for our planet. And, turns out everyone with a pulse knows that most people aren’t going to just up and toss away the bacon because some guys in lab coats said to.
And that leads us into a bit of a pickle.
People want meat. Making meat is no Bueno.
So, one of those things we really can’t change. But what if we thought of a way to make meat that DOES NOT involve killing animals.
… huh?
The meat-formula isn’t perfect, which is why you can’t go out and buy cruelty-free filet mignon for dinner tonight. We got the basics, but fine-tuning is essential to making a ‘scaleable’ production line (meaning that it can be massed-produced).
If any of you saw the 2013 “$330,000 Lab-Grown Burger”, that was the first public tasting of cultured meat. It was an on-air tasting of a completely Lab-Grown Burger. The single burger took three lab techs three months to put together. This process? Not scalable.
Every Cultured Meat company has their own lil’ Krabby-Patty-Secret-Formula spin on how they grow meat to try and make this stuff scaleable.
But, the fundamentals remain. The proverbial meat-cheese-bun of the Cultured Meat recipe:
1. Cells
Surprised? Cellular Agriculture all starts with cells!
There are two main ways to procure the cells needed. Either through Cell Lines/Immortalized Cell Lines or Primary Cells.
Cell Lines you can buy from vendors. They are essentially a lineage of reliable cells that are supposed to live and divide for a long time.
Primary Cells are cells that you get directly from a tissue source. So, you get to choose your coolest cow.
Types of Cells Used
Embryonic Stem Cells
Embryonic stem cells are stem cells taken from embryos [a bit obvious but still].
Stem cells are undifferentiated, meaning they haven’t chosen what cell they want to be yet. They are also pluripotent, meaning they can turn into almost any type of cell.
Embryonic stem cells are regarded as a potentially promising cell candidate. They are known for their unlimited regeneration potential, meaning they may have the capacity to generate an endless amount of other cells.
However, embryonic stem cells can be a lil’ tricky. They have the risk of genetically mutating over time. This potentially limits their reliability and the number of times they can replicate.
Adult Stem Cells
Adult stem cells are different from embryonic stem cells. Adult stem cells have fewer options for cells that they can become. It is thought that adult stem cells can only become the different types of cells of the place they came from.
They also have a limited number of potential divisions, this is called the ‘Hayflick limit”. These cell types can only replicate around 40- 60 times and varies depending on how old the animal they harvest the cells from is.
Myosatellite cells
[Also known as just Satellite cells, but Myosatellite just sounds cooler]
Myosatellite cells are a type of skeletal muscle stem cell.
Skeletal muscle is the type of muscle you’d be flexing in a gym mirror. Its the type of muscle you think of when you hear the word muscle. The ones that you can control, contract, grow, and workout.
[The other types of muscle are cardiac and smooth. Cardiac muscle is found in your heart. Smooth muscle is found in your organs. Both are involuntary, meaning you can’t control them. But we like to eat skeletal muscle]
So, a Myosatellite cell is an undifferentiated cell that is going to become a skeletal muscle cell.
The issue with these bad boys is that they are hard to keep alive and growing in a lab. They usually only differentiate around 20 times. It’s possible but a real pain.
Induced Pluripotent Stem Cells [IPSCs]
IPSCs are cells that have been re-winded into pluripotent stem cells.
If you take adult cells and add just 4 chemicals to them, they reverse into pluripotent cells and have the capacity to replicate indefinitely.
IPSCs are cheaper to make and extensive amounts of research done on them. This means that they are easier to use to make cell lines. The downside is they can require genetic editing and can behave differently than a cell directly harvested from an animal. So far have experienced low success since they are new to the field and hard to control, but they still have a promising future.
2. Cell Culture Media
Cell culture media is essentially the food you give those cells so that they grow and divide.
Its a mix of different nutrients like glucose, salts, vitamins, and amino acids. The balance of nutrients has to be essentially perfect.
Too much or too little of any given substance can significantly impact the cells’ growth rate. That makes it very hard to get right. It’s been coined as one of the biggest obstacles on the was of market-ready cultured meat.
A serum can be added as a type of supplement. A serum is like a pre-mix of all of those nutrients.
It’s a fluid that is separated from coagulated blood that is super rich in proteins. The issue is that the serum used in Cellular Agriculture is animal-derived.
Its a by-product of the meat industry and is the most cost-effective for experimentation, but obviously cannot be used for any market-ready product. This further complicates creating the serum.
Companies like Ultroser G make serum substitutes in order to produce animal cruelty-free serum for media.
Other factors that are especially important in media:
Another important factor of cell media is the pH. The pH level has to be 7.2–7.4 for optimal growth and is controlled by a buffering system. A natural buffering system balances 5–10% CO2 with CO3/HCO3 by controlling the atmosphere to maintain the correct pH. A chemical like Phenol red or HEPES [not herpes, although you might've read it like that] could be added for the same balancing effect.
Vitamins are essential for the growth of the cells. These are hard to get without employing the use of serum. Serum-free methods for providing adequate vitamin amounts use B vitamins as supplements. B vitamins assist cells in turning their other foods into energy.
Amino acids are the building blocks of proteins, making them a cell media necessity. Cells cant grow without them. One of the most important amino acids is L-glutamine, which is another way that cells produce energy. They also add a lot of non-essential amino acids to media in order to replace the ones used most during cell growth. This helps lengthens the amount of time the cells can divide.
Carbohydrates are ANOTHER source of energy for the cell. Damn, can someone just give these guys a Red Bull? Anyway, they come in the form of sugars like glucose and galactose to get those cells buzzin’.
Proteins and peptides are added and are especially important because they help bind together nutrients and transport them throughout the cells and even tissues.
Inorganic salts are added to balance the amount of water that goes in and out of the cells and helps the membrane of the cell. The cell membrane is a layer around a cell that regulates what goes in and out of the cell. The inorganic salts help the membrane by providing sodium, potassium, and calcium. They improve the membrane’s regulating abilities.
There are also sometimes antibiotics to stop any unwanted fungal growth. These aren't necessary for growing the cells but are useful for keeping everything sanitary. But they can impact more sensitive cells, which is one of the reasons it is not universally used.
3. Scaffolds
Just like scaffolding in construction, scaffolds provide structure and support as something is being ‘built’ [in this case grown].
Scaffolds are complicated for a few reasons. They have the task of making the texture and shape right for whatever type of product you are growing.
First off, the scaffold has to be biocompatible. Biocompatible means that the material can interact with living tissue without having any negative effects on the tissue or growth of the cells. This makes the material that the scaffolding is built with is vital. There are all sorts of things that can be used for scaffolds, from mushroom foam to gelatin to collagen bead mesh. The best material is yet to be determined.
The architecture of the scaffold is also vital. Think of a steak. It has all sorts of different types of connective tissues, fats, and muscles all jumbled up in really intricate ways. All of these different requirements add difficulty to scaffold design.
Scaffolding is a highly-complex, design-oriented task. That’s why the first products you will probably see will be things like burgers and meatballs. Those require way more basic scaffolding or even no scaffolding to produce.
4. Bioreactors
One of the hardest parts of growing cells is in vivo homeostatic regulation. What that means is that when cells grow within a body, there are a lot of systems in the body that the cells depend on.
Think of it as living in a city. When you live in a city or just any developed area you have a lot of systems around you that provide for you: plumbing, air conditioning, highways, water, garbage trucks, etc. Now imagine getting thrown onto an island in the middle of nowhere. You have to start from scratch.
In a body there are the different bodily systems that cells depend on for survival, nutrients are circulated, blood vessels circulate nutrients, metabolic waste is disposed of, the temperature is regulated.
A bioreactor’s job is to recreate all of these functions, almost like mimicking a human body. Similarly to how an egg incubator mimics the environment, an egg is hatched in.
This makes bioreactors another major hurdle and a vital aspect of cultured meat production.
None have been made to scale yet, but prototypes have been made.
Culture Meat is a product that has the potential to impact every one of us. Imagine if we worked out all the aforementioned kinks? If we had a reliable production line?
Having control of meat at a cellular level means that we can make meat more nutritious AND delicious.
We could make every hamburger healthier than a salad. We could make novel shaped and flavors of meat. We could make this process crazy efficient and drive down the costs cheaper than traditional meat could ever be. We could make this nutritious new food so cheap that low-income household could easily provide their families with proper nutrition.
There are so many CRAZY implications for this tech aside from just helping our environment. This was just a simplified overview of the components to know in the field, there is so much more awesome stuff to learn!
Keep checking out my Medium page, there is certainly more Cell Ag content coming soon!
