Lab-grown meat causes heated debates. Proponents see benefits for the climate and animal welfare. Opponents worry about a Frankenstein food they regard as risky and unnatural. Whatever your opinion, the technology underpinning cultivated meat is moving fast to create large pieces of muscle tissue.
Author
- James Hague
Senior Lecturer (in Theoretical Condensed Matter Physics and Biophysics), The Open University
The fact that artificial meat starts as a living tissue means that, as it gets bigger and better, the technologies involved could have a huge impact on medical research.
Lab-grown meat is a sort of engineered tissue. It aims to replicate the meat grown in an animal by dividing a small number of animal cells to create muscle. Meat is mostly made up of muscle cells (myocytes), plus a mix of fat cells (adipocytes) and cells that add structure through materials such as collagen (known as fibroblasts).
The arrangements and proportions of these cells give meat its overall taste and texture. We call the meat grown in a bioreactor "cultivated meat". Other common terms are "cultured meat", "lab-grown meat" and "artificial meat", and the production process is also called "cellular agriculture".
Cultivated meat is real meat grown in bioreactors rather than animals (it's very different to plant-based products such as soya burgers). Some companies are also trying to grow other animal tissues, such as liver to replace foie gras . Key benefits of cultivated meat include avoiding animal slaughter and lower greenhouse gas emissions.
The technologies for making cultivated meat were originally designed for growing engineered tissue for applications like organ transplant, regenerative medicine and pharmaceutical testing.
One day, engineered tissue could be used to give us new livers, help to rebuild tissues damaged in accidents and select personalised treatments for cancers.
Shared challenges
Just like muscle, other tissues in the body such as organs also contain cells and things like collagen that give them structure.
The cells in tissues are carefully organised according to their function. For example, in muscle, the cells are all lined up so they contract in the same direction during movement.
A big difference between tissues cultivated for meat and those grown for medical applications is this tissue functionality. Cultivated meat does not need to be able to contract like muscle and, once grown, does not need to be kept alive. Meanwhile, engineered tissue for medical applications needs to work just like its counterpart in the body.
Despite this, some of the lessons learned from cultivated meat growth could be applied to regenerative medicine. Fibroblasts, the "structure" cells, are important during wound healing . Techniques to cultivate muscles and liver could be modified to grow working tissue.
A shared design challenge when growing cultivated meat and engineered tissue is to control tissue organisation, which is essential to grow large cuts of meat such as steaks, but also for replacement tissue and organs for the body. Possibilities include holding the tissue under tension using tethers, adding scaffolds, and using 3D printing.
The process of designing ways to control a tissue can take months or years of careful trial and error. Recent computer simulations of tissue growth, including those carried out by myself and colleagues , can help with the difficult task of controlling cell organisation to improve things like texture and production efficiency.
Developing this control can help to engineer body tissues used in early pharmaceutical testing, which could improve success rates in clinical trials while reducing animal testing. This would be better for trial participants and could help to reduce drug development costs.
Another major unsolved problem for both cultivated meat and regenerative medicine is how to supply larger tissues as they grow . Smaller tissues can get the oxygen they need from the atmosphere, or grow in a nutrient bath. Steaks are too large for this and would need to be kept alive with vessels similar to arteries to deliver oxygen and nutrients.
Natural blood vessels form branching networks to supply tissue. Computational techniques can predict this style of network and 3D bioprinting could be used to create similar vessels. Lessons learned by growing networks of vessels in steaks could be directly applied to tissues for regenerative medicine (and vice versa).
I expect pressure for cheap, cultivated meat will decrease the price of currently expensive technologies, such as 3D bioprinting and bioreactors. This will ultimately benefit medical applications.
Coming to a shop near you
As these issues are solved, cultivated meat will become widely available and more like farmed meat. Since cultivated meat will ultimately be indistinguishable from farmed meat, there's no reason to believe that one should be more or less healthy than the other. Currently, many products are undergoing regulatory processes.
So far, a few countries have approved cultivated meat products for human consumption, and approval applications are being submitted worldwide. UK regulators recently announced a two-year timeline to approve (or not) cultivated meat for human consumption. Lab-grown meat is already approved for consumption by dogs .
Overall, there are important links between cultivated meat and cultured tissue applications in medicine. Both applications have similar challenges, and the technologies developed for one field can push forward the other.
Both fields can benefit animal welfare, removing the need for animal slaughter and reducing the need for animal testing.
I expect cultivated meat will come to a supermarket near you within the next few years. Whether you want to buy it or not, think about how the technology used to create it could be a step towards better medicines and lab-grown organs for transplant.
James Hague receives funding from STFC and EPSRC.
