Written by TKS Ottawa student, Avery Parkinson (email: averyparkinson23@gmail.com)

It’s old news — our current methods of farming meat are insufficient. Not only do they frequently involve the inhumane treatment of animals, but they are also energy intensive, resource inefficient and emit a staggering 18% of our total global greenhouse gas emissions.

This is crazy — how have we come to tolerate a world where the simple and necessary act of eating is literally destroying our planet? One might contemplate veganism, but honestly, for most, meat just tastes too good.

Clearly, we need a solution — one that enables us to eat meat while also reducing the ecological drain producing it puts on the environment and does not involve unethical treatment of animals.

Enter, cellular agriculture: the solution to all our problems.

Cellular agriculture is based on the idea of producing animal products with out the animal. It is typically done in three main steps:

  1. Adult Stem Cells (cells which have the potential to become almost any type of specialized cell) are extracted from an animal through a painless biopsy.
  2. They are immersed in a culture medium — basically a large power smoothie — which gives the cells all the essential nutrients, carbohydrates, proteins and fats they need to grow and multiply.
  3. They are put in a bioreactor which exercises and introduces the cells to growth factors and encourages them to differentiate into the many different kinds of specialized cells we find in meat.

And bam, we have a steak!

Well, not quite.

This process would be just about where everything ends for unstructured meat, but not for structured meat. Unstructured meat is, as it sounds, meat that doesn’t have a real structure (like ground beef). Structured meat, on the other hand, is meat that has a specific composition of cells — it’s not just the type of cells that characterize it, but the arrangement too (like steak).

Getting a particular arrangement is not reliable by just allowing the cells to float around in the bioreactor and crossing our fingers. So, we need something called a scaffold. A scaffold is a mold which the cells grow in and around to form the specific shape and structure of the meat. The scaffold is usually placed inside the bioreactor so that the cells can get organized while they get specialized.

Scaffolds for Structured Meat Products

Ah, so there — problem solved.

Well, not quite.

We may have a nicely structured cut of meat, but now we have a scaffold in it. Scientists have proposed using edible scaffolds, but since the whole idea behind the cultured meat is to perfectly replicate meat, scientists are leaning towards figuring out a way to make biodegradable scaffolds.

However, this in itself introduces some new issues, most notably the rate of decay. If our scaffold literally disappears while the meat is growing on it, it kind of defeats the purpose.

In recent years, scaffolds made of decellularized plant tissue, chitosan or recombinant collagen have been studied. Researchers at the University of Ottawa and University of Western Australia have been looking into the benefits and downsides of each type, and found the following.

Decellularized Plant Tissue

Decellularized plant tissue is abundant and has a great structure and texture. However, it lacks many of the growth cues deemed vital for growing mammalian cells.

Chitosan

Chitosan is abundant, and has antibacterial properties. It can also be blended easily with other polymers which suggests that it could easily be tailored to what a scientist is trying to grow. However, in the presence of lysozymes (a naturally occurring enzyme), chitosan will start to break down in unpredictable ways.

Recombinant collagen is highly biocompatible but is hard to produce and source.

All of these potential scaffolds have some kind of shortcoming, so instead of looking for a natural material which fits all the characteristics of an ideal scaffold, what if we just design our own?

Designing the Perfect Scaffold

In a real animal, cells rely on something called the Extracellular Matrix (ECM) to transfer environmental cues and signal different growth patterns. The ECM is perfectly suited to the cells which surround it in that it is biocompatible, has a variety of topography, and is non degrading. On top of that, through small veins, the ECM is able to deliver nutrients to the inner cells rather than those that are exclusively on the surface (as they are in our current scaffolds).

Nanobots?

What if we use nanobots to mimic the extra cellular matrix?