Evaluation systems of generated forces of skeletal muscle cell-based bio-actuators

Skeletal muscle is the most abundant tissue in the body, and its capability of generating an active force is one of the most significant features. In order to study the physiology and disorders related to the skeletal muscle using cells in vitro, the active force should be evaluated, in addition to molecular and cell biological experiments performed. This article reviews an evaluation system for the active tension generated by cultured skeletal muscle cells or tissue-engineered skeletal muscles. First, we focused on experimental models involving a single or several myotubes. Then, we focused on the systems for tissue-engineered skeletal muscles consisting of much larger numbers of myotubes. Such systems can be used to study the physiology of the skeletal muscle, screen drug candidates for skeletal muscle-related disorders, and improve the function of tissue-engineered skeletal muscle.