Revealing the Potential of Lab-Grown Muscles with Magnets

Wednesday - October 25 2023, 13:48 UTC - 1 year ago

In a groundbreaking new study, scientists from MIT have developed a magnetic hydrogel 'sandwich' that controls muscle cell orientation in a lab dish. This model provides insight on the intricate communications between muscle cells that allows them to self-organize and adapt to mechanical forces, with potential applications in muscle-grafting for humans, or in robotic technology.

As I’m typing these words, I don’t think about the synchronized muscle contractions that allow my fingers to dance across the keyboard. Or the back muscles that unconsciously tighten to hold myself upright while sitting on a spongy cushion.

It’s easy to take our muscles for granted. But under the hood, muscle cells perfectly align to build fibers—interwoven with blood vessels and nerves—into a biological machine that lets us move about in our daily lives without a second thought.

Unfortunately, these precise cell arrangements are also why artificial muscles are difficult to recreate in the lab. Despite being soft, squishy, and easily damaged, our muscles can perform incredible feats—adapt to heavy loads, sense the outside world, and rebuild after injury. A main reason for these superpowers is alignment—that is, how muscle cells orient to form stretchy fibers.

Now, a new study suggests that the solution to growing better lab-grown muscles may be magnets. Led by Dr. Ritu Raman at the Massachusetts Institute of Technology (MIT), scientists developed a magnetic hydrogel "sandwich" that controls muscle cell orientation in a lab dish. By changing the position of the magnets, the muscle cells aligned into fibers that contracted in synchrony as if they were inside a body.

The whole endeavor sounds rather Frankenstein. But lab-grown tissues could one day be grafted into people with heavily damaged muscles—either from inherited diseases or traumatic injuries—and restore their ability to navigate the world freely. Synthetic muscles could also coat robots, providing them with human-like senses, flexible motor control, and the ability to heal after inevitable scratches and scrapes.

Raman’s work takes a step in that direction. Her team built a biomanufacturing platform focused on replicating the mechanical forces between muscle cells and their environment, a relationship essential for the cells to organize into tissues. But it’s not just about mimicking physical forces—stretching, pulling, or twisting. Rather, the platform also takes into account how mechanical movements alter communications between cells directing them to align.

Along with a custom algorithm, the platform essentially turned cells into a living, functional biomaterial that self-organizes and responds to pushes and pulls. In turn, the system could also shed light on muscle cells’ remarkable ability to adapt, align, and regenerate.

"The ability to make aligned muscle in a lab setting means that we can develop model tissues for understanding muscle in healthy and diseased states and for developing and testing new therapies that combat muscle injury or disease," Raman said in a press briefing.

Muscling Through .

Raman has long sought to use living cells as an adaptive biomanufacturing material.

Over a half decade ago, she engineered tiny 3D-printed cyborg bots with genetically-altered muscle cells that responded to light. Like moths to a flame, the bio-bots followed beams of light. Surprisingly, like well-trained athletes, the bots’ engineered muscles became more flexible as they exercised, allowing them to steer and rotate through different challenges.