Subcutaneous Muscle Patch Mimics Exercise Benefits in Mice

A team led by Ng Shyh‑Chang at the Beijing Institute for Stem Cell and Regenerative Medicine has shown that injecting mature muscle cells beneath the skin of mice creates a patch that contracts continuously, delivering exercise‑like benefits without physical exertion. The patch, formed from about six million myocytes, develops its own micro‑vascular network and pulses even while the mice sleep. Mice receiving the grafts exhibited increased whole‑body muscle mass, improved immune function, higher bone density, greater physical strength and endurance, and reduced liver inflammation. Older and obese mice also benefited, showing better maze navigation and reversal of liver damage. Imaging confirmed the grafts survived at least 81 days, with no tumor growth observed. Researchers plan to initiate clinical trials in patients with limited mobility within a year, aiming to provide an exercise surrogate for those unable to move.