Stimulating muscle fibers with magnets causes them to grow in the same direction, aligning muscle cells within tissue, Massachusetts Institute of Technology (MIT) and Boston University investigators report October 20 in the journal Device. The findings offer a simpler, less time-consuming way for medical researchers to program muscle cell alignment, which is strongly tied to healthy muscle function.
In a previous investigation, Raman and colleagues found that “exercising” muscle fibers by making them contract in response to electrical stimulation for 30 minutes a day over the course of 10 days made the fibers stronger. This time, the researchers wanted to explore whether mechanically stimulating the muscle fibers over the same time frame (rather than letting them respond on their own) would have the same result. To investigate, they developed a method to mechanically stimulate muscle tissue that differs from typical lab techniques.
To stimulate the muscle cells in a more true-to-life way, Raman and her team grew cells in a Petri dish on a soft gel that contained magnetic particles. When they would move a magnet back and forth under the gel, the particles moved back and forth, too, which “flexed” the cells.
The researchers could precisely control the way the gel moved, and, in turn, the magnitude and direction of the forces the cells within experienced, by changing the strength and orientation of the magnet. To measure the alignment of the muscle fibers within the tissues and whether they contracted in synchrony, the team’s collaborators at Boston University developed a custom software that automatically tracked videos of the muscle and generated graphs of its movement.
While mechanically stimulating the muscle fibers over the 10-day period did not seem to make them any stronger, it did cause them all to grow in the same direction.
Raman and colleagues plan to take the study further by investigating how different mechanical stimulation regimens impact both healthy and diseased muscle fibers. Additionally, they plan to study how mechanical stimulation affects other types of cells.