A team of biomedical engineers from Duke University have created muscle from non-muscle.
They’ve engineered the first functioning human skeletal muscle from pluripotent stem cells (self-replicating cells, derived from the human embryos and fetal tissue).
With more testing and research, scientists may discover how to grow an entire muscle starting from a single cell.
THE ORIGIN STORY
Duke’s team made its first breakthrough in 2015, growing working, human muscle tissue from cells extracted during muscle biopsies.
It began with a sample of human cells that progressed beyond stem cells, but still weren’t muscle tissues. Engineers Nenad Bursac and Lauran Madden expanded these myogenic precursors by more than a 1000-fold, and then placed them into a 3D scaffolding.
They filled the scaffolding with a nourishing gel, allowing them to form functioning muscle fibers.
Madden put the new muscle through multiple tests, determining how closely it resembled native tissue (used in repairing anterior vaginal prolapse surgery). The muscles contracted in response to electrical stimuli; the signaling pathways allowing nerves to activate the muscle were also fully functional.
The engineers strived to create personalized medicine by taking a biopsy from each patient, then growing new muscles as test samples to experiment and explore which drug works best.
THE CURRENT STORY ARC
Pluripotent cells aren’t muscle cells but can become any type of existing cell in our body, meaning we can grow an unlimited number of myogenic progenitor cells.
Myogenic progenitor cells, or satellite cells, are precursors to skeletal muscle cells, giving rise to differentiated skeletal muscle cells. In undamaged muscle, the majority of satellite cells are quiescentmeaning they don’t differentiate or undergo cell division.
After facilitating a muscle response to stimuli like electric shock, or chemicals similar to neuronal signals, the research team implanted the stem-cell-grown tissue into mice. The engineers discovered that the muscle survived and functioned for at least three weeks, and integrated into the mice’s native tissue.
THE STORY BEHIND THE SCENES
To construct functioning muscle tissue, human pluripotent stem cells were taken from adult non-muscle tissues such as skin and blood.
Researchers “reprogrammed” these cells into a simpler and undefined state. They overwhelmed the cells with Pax7 a molecule and transcription factor that plays a role in myogenesis, through regulation of a muscle precursor cells’ proliferation.
The process triggered the cells, so they turned into muscle as they grew. The cells developed faster and longer within the confines of unique cell culture conditions and 3D matrix, differing from the less effective 2D cultures typically used.
THE STORY BEYOND THE STUDY
While the results are promising and potentially offer a deeper understanding through models of rare diseases and muscle damage treatments, the research is still in its infancy. The stem cell-derived muscle tissue contains more of the satellite cells that repair damage, but native muscle, or muscle grown from biopsies, are currently stronger.
Researchers’ long-term aim is to use the stem cell-derived tissue for regenerative therapies, in combination with genetic therapy. Together, they could fix issues in a patient’s stem cells, then grow new patches of completely healthy muscle.
RegenerVate fully supports this kind of stem cell research, even if there’s tremendous work ahead.
We may not be able to create muscles from non-muscle, but we offer various stem cell and PRP injection therapies, that can treat chronic pain hampering your muscles and joints, such as osteoarthritis, plantar fasciitis, and tendonitis.