Scientists have created tiny living muscle implants that may reproduce some of the health benefits associated with exercise. Early animal experiments suggest that the implants could eventually inspire treatments for people who cannot exercise because of illness or disability.
Exercise protects far more than the muscles used during movement. Active muscle tissue releases chemical signals that influence inflammation, metabolism, bones and other organs throughout the body.
Researchers wanted to see whether small pieces of living muscle could provide some of those signals without requiring a person to perform physical activity. They developed muscle tissue from cells grown in the laboratory and placed it beneath the skin of experimental animals.
A major challenge with earlier muscle transplants was keeping the cells alive. Without a reliable blood supply, transplanted cells can quickly die because they cannot obtain enough oxygen and nutrients.
The new approach allowed the implanted cells to develop their own blood vessels. The resulting muscle grafts survived for at least 81 days and continued to contract spontaneously without outside stimulation.
When tested in older and obese animal...