Angelina Woychosky
There is no sweeter, more refreshing experience than eating a freshly picked, homegrown cherry tomato under the sun. Now, imagine enjoying freshly grown beef or pork at the family BBQ. As Science-Fiction as it seems, cultured meat has been a reality since 2013, when Dr. Mark Post produced the first-ever cultured meat prototype to explore if a more sustainable way of consuming animal meat was possible. Since then, numerous challenges to the production and commercialization of culture meat have been identified. There are many difficulties with the mass production of functional stem cells in vitro – outside the living organism – especially in maintaining the function of stem cells after long-term cultures. After being isolated, muscle stem cells need to be able to differentiate into myoblasts, which are precursors to the cells that make up muscle tissue. Stem cells have the potential to become many different kinds of cells before undergoing differentiation. To create more muscle tissue, the muscle stem cells need to differentiate into these muscle cell precursors. Creating large pieces of muscle tissue is another challenge. For cultured meat to possibly be sold in stores, researchers must find a way to produce enough product for it to be accessible and affordable.
Researchers at Nanjing Agricultural University seek to optimize the number of muscle stem cells that can be isolated and grown from 1 gram (g) of pig muscle tissue (Zhu et al., 2022). After isolating muscle stem cells from pigs and allowing them to culture and differentiate, they used a cell sorting strategy to calculate the number of stem cells obtained, and then performed various analyses of the cells, including gene expression and ATP production. ATP is the chemical energy converted from food that fuels all activities and work within cells, which is especially important in muscle tissue to power movement. These analyses are important in the process of developing a cultured meat that shares the qualities, taste, and nutrition of traditional meat.
The researchers were able to isolate 53,000 muscle stem cells from 1g of tissue from newborn pigs. They found that producing 100g of cultured meat from this 1g of tissue would require one million times amplification. Although, during the amplification process, the stem cells gradually lose their function. In their analyses, they also found DNA damage and metabolic impairment which they associated with oxidative stress, but they have yet to understand the exact mechanism.
The current rates and methods of animal meat production and consumption pose ethical and environmental issues. Animals face inhuman treatment in slaughterhouses, and the amount and density of animals used for agriculture increases greenhouse gas in the atmosphere and the warming of the Earth. Cultured meat grown in laboratories could be a more sustainable solution to these issues, but this solution is not without its own difficulties and ethical questions. Producing enough cultured meat to feed populations could require an immense number of resources and have its own negative consequences, and whether consuming cultured meat defies what is natural introduces more philosophical and cultural debates.
References
Post, M. J. (2014). Cultured beef: Medical technology to produce food. Journal of the Science of Food and Agriculture, 94(6), 1039–1041. https://doi.org/10.1002/jsfa.6474
Zhu, H., Wu, Z., Ding, X., Post, M. J., Guo, R., Wang, J., Wu, J., Tang, W., Ding, S., & Zhou, G. (2022). Production of cultured meat from pig muscle stem cells. Biomaterials, 287, 121650. https://doi.org/10.1016/j.biomaterials.2022.121650