Biomedical engineers have found a critical component for growing self-healing muscle tissues from adult muscle the immune system. The discovery in mice is expected to play an important role in studying degenerative muscle diseases and enhancing the survival of engineered tissue grafts in future cell therapy applications. The study was published in Nature Biomedical Engineering.
In 2014, the group led by Nenad Bursac, professor of biomedical engineering at Duke, debuted the world's first self-healing, lab-grown skeletal muscle. It contracted powerfully, integrated into mice quickly and demonstrated the ability to heal itself both inside the laboratory and inside an animal.
The milestone was achieved by taking samples of muscle from rats just two days old, removing the cells, and "planting" them into a lab-made environment perfectly tailored to help them grow.
Besides a three-dimensional scaffolding and plenty of nutrients, this environment supported the formation of niches for muscle stem cells, known as satellite cells, that activate upon injury and aid the regeneration process.
For potential applications with human cells, however, muscle samples would be mostly taken from adult donors rather than newborns. Many degenerative muscle diseases do not appear until adulthood, and growing the muscle in the lab to test drug responses for these patients would benefit from the use of the patient's own adult cells.
There's just one problem lab-made adult muscle tissues do not have the same regenerative potential as newborn tissue. Moreover, bone-marrow-derived macrophages within engineered tissues implanted in a mouse dorsal window-chamber model augmented blood vessel ingrowth, cell survival, muscle regeneration, and contractile function.