Tissue Engineering for Clean Meat Production

Abstract

Increasing public awareness of foodborne illnesses, factory farming, and the ecological footprint of the meat industry, has generated the need for animal-free meat alternatives. In the last decade, scientists have begun to leverage the knowledge and tools accumulated in the fields of stem cells and tissue engineering toward the development of cell-based meat (i.e., clean meat). In tissue engineering, the physical and biochemical features of the native tissue can be mimicked; cells and biomaterials are integrated under suitable culture conditions to form mature tissues. More specifically, in skeletal muscle tissue engineering, a plurality of cell types can be co-cultured on a 3D scaffold to generate muscle fibers, blood vessels and a dense extracellular matrix (ECM). This review focuses on tissue engineering of skeletal muscle and the adjustments needed for clean meat development. We discuss the skeletal muscle structure and composition, and elaborate on cell types from farm animals that have the potential to recapitulate the muscle ECM, blood vessels, muscle fibers and fat deposits. We also review relevant biomaterials, primarily for fabricating scaffolds that can mimic the intramuscular connective tissues, as well as gene expression studies on the biological pathways that influence meat quality.

The Myth of Cultured Meat: A Review

“…The best medium is known to contain fetal bovine serum (FBS), a serum made from the blood of a dead calf, which is going to be rate-limiting, and not acceptable for vegetarians nor vegans. More than one trillion cells can be grown, and these cells naturally merge to form myotubes which are no longer than 0.3 mm; the myotubes are then placed in a ring growing into a small piece of muscle tissue as described in different reviews (17,18). This piece of muscle can multiply up to more than a trillion strands (13).…”

“…This piece of muscle can multiply up to more than a trillion strands (13). These fibers are attached to a sponge-like scaffold that floods the fibers with nutrients and mechanically stretches them, "exercising" the muscle cells to increase their size and protein content (17,18). Based on this process, fewer animals will be necessary to produce huge amounts of meat due to cell proliferation, thereby avoiding killing as too many animals but potentially lots of calves if FBS is still used.…”

“…Throughout this process, the cells are kept in a monitored environment that replicates the temperature inside the body of a cow, for example, to speed up the development of the lab-grown meat (17,18).…”

A 2020 synopsis of the cell-cultured animal industry

“…The production of cell-cultured protein products is the scaling up of the cell culture meat production process used in biological research since the 1970s ( Ben-Arye and Levenberg, 2019 ). A simplified schematic of cell-cultured protein production is provided in Figure 1 .…”

“…Aleph Farms are using technology developed at the Israel Institute of Technology to scale up the production of whole muscle beef where stroma cells, adipocytes, and muscle fibers grown in concert similar to living tissue. Ben-Arye and Levenberg (2019) discuss how multiple cell types can be co-cultured on a 3D scaffold that will generate muscle fibers, blood vessels, and a dense extracelluar matrix or connective tissue. Aleph Farms defined this uniques approach to cell-cultured product as alternative meats ( Figure 5 ).…”