An experimental graphene-infused mesh has been designed that could help prevent a recurrence of a rotator cuff injury. The University of Connecticut’s Dr. Cato Laurencin says that surgical repairs are often only a short-term solution.
“The real problem is that the muscle degenerates and accumulates fat,” he says. “With a tear, the muscle shrinks, and the body grows fat in that area instead. When the tendon and muscle are finally reattached surgically to the shoulder bone, the weakened muscle can’t handle normal stresses and the area can be injured again.”
Laurencin collaborated with grad student Nikoo Shemshaki and colleagues to create a therapeutic mesh that could be surgically embedded in the affected shoulder muscle after the injury has occurred. The resulting electroconductive mesh is composed of aligned poly(l-lactic acid) (PLLA) nanofibers, infused with graphene nanoplatelets. PLLA is a biocompatible, biodegradable polymer already used in medical applications, while graphene is an ultra-thin, highly conductive material consisting of one-atom-thick sheets of linked carbon atoms.
When the researchers attempted to grow muscle tissue on samples of the mesh in a petri dish, the mesh appeared to encourage the growth of myotubes (precursors to muscle fibers) and to discourage fat formation. More importantly, when the mesh was placed in the atrophied shoulder muscles of rats with chronic rotator cuff injuries, the muscles grew back instead of being replaced with fat.
Dr. Laurencin says the graphene nanoplatelets were responsible for these responses, as they were found to increase intracellular calcium content (which plays a key role in boosting muscle cell growth) within the myotubes, and they decreased adipogenesis (the generation of fat) in the stem cells which were used to grow the myotubes.
Trials on larger animal models are now being planned. The research has been published Proceedings of the National Academy of Sciences.
Source: University of Connecticut as reported in www.newatlas.com.