Milk-derived extract for skeletal muscle cell cultivation

Recently skeletal muscle cell culture has been applied to construct large three-dimensional tissues such as cultivated meat. For this purpose, it is necessary to establish a safe and inexpensive mass cell culture method. While fetal bovine serum has a high cell proliferation capacity and is essential for cell culture, it raises ethical concerns and may not be considered a food-grade ingredient. To overcome this issue, we explore the potential of using bovine milk-derived extract for skeletal muscle cell culture. Milk is produced and supplied on a large scale as a safe food product and known to contain various physiologically active substances. Here, we prepared two kinds of milk-derived extract by ultrafiltration of raw milk using two different molecular weight cut-off membranes (100 kDa or 1000 kDa). The proteins contained in these extracts were different from fetal bovine serum but promoted survival and proliferation of mouse myoblast C2C12 cells and primary bovine myoblasts compared to basal media-only conditions. In addition, the cells gradually increased and underwent myogenic differentiation when cultured with those extracts for a long period. Therefore, we believe that the current milk-derived extract would be effective in cell culture for producing cultivated meat.