Morphology and functionality in biomimetic cultured meat produced from various cellular origins.

Alternative meat production technologies offer the potential to alleviate many of the ethical, environmental, and public health concerns associated with conventional meat production. Cultured meat produced using cell culture technology promises to become a viable alternative to animal-raised meat for the future of the food industry. The process of cultured meat production relies on cell sources harvested from livestock such as bovine, swine, and chicken. Previously, we have developed a primary culture method allowing the efficient collection of myogenic cells from bovine cheek meat. Although the myogenic cells were used as a cell source to produce bovine muscle tissues with biomimetic morphological and functional characteristics in a "biomimetic cultured beef" product, it is not certain that the cells harvested from cheek meat are the best choice as a cell source for cultured meat. Moreover, there are no previous studies investigating the appropriate selection of cell sources for producing cultured meat on demand. In this study, myogenic cells were harvested from three different cuts of swine muscle (cheek, loin, and ham) to assess the impact of each cell type and understand how to best select from the various cuts of muscle. Although it was expected that the three types of swine myogenic cells have different characteristics based on each meat cut, they all proliferated similarly while maintaining the expression of myogenic markers (MyoD, Myf5) during repeated passages. They also had differentiation ability at the same level in the first step of differentiation (fusion of myogenic cells to form myotube) in vitro. Therefore, the myogenic cells from different cuts of muscle fundamentally expressed the same characteristics in normal 2D culture. On the other hand, since our tissue engineering method allowed us to produce morphologically and functionally biomimetic muscle tissues, we successfully produced contractile muscle tissues with native-like aligned structures from all types of the swine myogenic cells. Through the tissue maturation process, the three types of myogenic cells also showed site-specificity in the further differentiation step (maturation into contractile myofibers). The myogenic cells harvested from ham formed significantly thicker myofibers in "ham muscle tissues", compared with that in "cheek muscle tissues" and "loin muscle tissues". This suggested that swine myogenic cells have some unique characteristics depending on the different cuts of muscle. On the other hand, there was no significant difference in contractile functionality between the three types of muscle tissues. Although further experiments will be required to deepen our understanding of the similarities and differences of site-specific myogenic cells, we believe that the results of this study are important to selectively produce various types of cultured meat and ultimately become the conventional meat in the future.