This small spring in soft robotics could make it possible to fight against muscular atrophy. A hope for patients suffering from multiple sclerosis.
Today themuscle atrophy is often unavoidable when one cannot move due to a serious injury, advanced age or illness such as amyotrophic lateral sclerosis (ALS) or multiple sclerosis (MS). However, Harvard researchers see hope in soft robotics. The latter could help stimulate the muscles of patients unable to do so on their own.
This small spring in soft robotics could help fight muscle atrophy
Harvard engineers have tested a new mechanostimulation system on mice, managing to prevent or help their recovery from muscle atrophy. The team implanted their “soft robotics device” into a mouse’s hind limb, which they immobilized for about two weeks. If the test group at muscles untreated had great difficulty, muscles actively stimulated by the device experienced significantly reduced degradation. The researchers believe their system could lead to implants that help humans with atrophy.
The idea is as follows: it is a question of triggering a small mechanical muscle which reproduces the natural stimulation during exercise. Moreover, by helping to ward off atrophy, the device did not cause any severe inflammation or other tissue damage.
“There is a great chance that diverse soft robotic approaches, with their unique effects on muscle tissue, could open avenues in the mechano-therapeutic treatments of specific diseases or injuries,” explained David Mooney, Ph.HD, senior author and fellow of the Wyss Institute at Harvard.
Hope for multiple sclerosis patients
Baptized MAGENTA, for “mechanically active gel-elastomer-nitinol tissue adhesive“, this anti-atrophy system includes a spring made of nitinol (nickel-titanium), a shape-memory alloy (SMA) that can quickly activate when heated. The researchers control the spring via a wired microprocessor unit that determines the frequency and duration of muscle contractions and stretches.
The system also includes an elastomeric matrix forming the body of the device and providing the insulation of the alloy. Additionally, a layer of “tough adhesive” helps keep MAGENTA aligned with the muscles natural axis of motion while delivering stimulation deep into muscle tissue.
“Although untreated muscles and muscles treated with the device but not significantly stimulated were greatly degraded during this period, actively stimulated muscles showed greatly reduced muscle loss,” said first author Sungmin Nam, Ph.D. “Our approach could also aid the recovery of muscle mass that has already been lost over a three-week period of immobilization, and cause the activation of biochemical mechanotransduction pathways known to trigger protein synthesis and muscle growth .”
The team also experimented with a wireless version, via a laser light rather than an electrical wire to activate the SMA spring. Although this approach has shown reduced effectiveness due to fatty tissue absorbing some of the lasers, the researchers believe this approach has great potential and requires further research.