Bioprocess development for production of 3D tissues to underpin creation of engineered meat

The way we feed ourselves is becoming a growing problem, growing population and income growth in many developing countries is fueling an increase in global meat demand. Animal agriculture has been responsible for around 14.5% of total man-made greenhouse gas emissions, takes up 70% of arable land and 27% of fresh water usage for maintaining livestock and feed production1.

Traditional meat production and its role in perpetuating the climate crisis is a clear problem which is currently affecting the climate and is set to get worse.

Cultured meat represents a solution to this problem, by producing laboratory grown animal tissue from a small cell sample using laboratory techniques rather than livestock rearing and slaughtering. This technology has many benefits over livestock farming with drastic reductions in land and fresh water requirements as well as greenhouse gas emissions.

Further, being manufactured under controlled conditions, the meat can be produced free from bacteria and viruses which could infect consumers. This is achieved without the excessive antibiotic usage that occurs in livestock farming which perpetuates the rise of antibiotic resistant diseases. Controlled manufacturing conditions also support customisable nutrient profiles which can be enriched in desired nutrients to eliminate deficiencies and have reduced levels of certain compounds such as cholesterol which are potentially harmful.

Cultured meat has come a long way since the first 250,000 Euro burger in 2013 with a recent Good Food Institute report depicting a growing industry with 366 million dollars of investment in 2020 alone. With the company Good Meat selling cultured chicken in a Singapore restaurant the race to bring commercially viable large scale cultured meat to consumers is under way.

Despite the GFI reports encouraging statement that there are no more fundamental technological breakthroughs required for commercially viable large scale cultured meat, there is still much research needed to tackle the biochemical and engineering challenges of increasing affordability, scaling up production and mimicking the texture and nutritional profile of slaughtered meat.

This project aims to produce cultured meat tissues by engineering hydrogel capsules that will act as a 3D scaffold on which cells can grow into a 3D network. These encapsulated cells can be cultured within a bioreactor and the co-culture of different cell types can help replicate the complexity of meat tissue. In order to imitate livestock meat, cultivated meat will need a complex structure consisting of muscle, fat and connective cells which together provide the taste and nutritional value of meat.

Bovine mesenchymal stem cells (bMSCs) will therefore be used in this project as not only are they easy and cheap to grow and easy to isolate but they also have the ability to differentiate into both muscle and fat cells, both of which are necessary for the co-culture of a complex meat-mimicking tissue2.

The hydrogel capsules on which these bMSCs will be grown will need to fit a range of parameters. They will need to be edible and provide a 3D structure suitable to allow adhered cell growth, these characteristics will be defined by the hydrogels biochemical make up and to thoroughly investigate ideal growth conditions a range of hydrogels and capsule sizes will be explored.

Capsule size can be altered through fine tuning of production parameters, such as hydrogel injection rate and shearing force, and specific size ranges can be selected using membrane extrusion techniques.

This project aims to define an optimized process by which complex bovine tissue can be cultured using 3D hydrogel capsules, grown within a bioreactor for the scalable production of cultured meat. 1Stephens, N. et al. (2018) Trends in Food Science & Tech 2Hanga MP et al (2020) Biotech Bioeng; 117(10):3029-3039.