Skeletal muscle is one of the most abundant tissues in the human body, representing approximately 40% of body weight. Under certain circumstances, skeletal muscle can be regenerated through satellite cells, a reservoir of quiescent muscle stem cells, that can be activated with injury or in certain diseases and give rise to newly formed multi-nucleated myotubes and myofibers. However, the regenerative potential of muscle is diminished or is completely absent in the course of normal aging, certain diseases, and space travel. For example, time spent in microgravity can have a profound impact on human physiology, especially the muscular system, as astronauts lose up to 20% of their lean muscle mass and up to half of their strength.  

The identification of countermeasures against the effects of muscle regeneration, including microgravity, is an increasing priority for an aging population and continued space travel. Experiments in microgravity, conducted on the International Space Station, offer a unique opportunity to understand muscle regeneration and the effects of microgravity. Our guests today will discuss muscle regeneration, their muscle-on-a-chip platform that mimics salient aspects of impaired muscle regeneration, and the feasibility of drug screening in microgravity.