Lead researcher Dr. Shulamit Levenberg of the Technion-Israel Institute of Technology, along with scientists from the Massachusetts Institute of Technology, grew the muscle from scratch by seeding a sponge-like, three-dimensional plastic scaffold with myoblasts and endothelial cells, which are the precursors to mature skeletal muscle and blood vessel cells.
The researchers also added fibroblasts to the mix as a crucial third ingredient. "The idea is that this hopefully will be used to repair or replace damaged muscle tissue when needed," Levenberg says.
In the near future, Levenberg explains, a simple muscle biopsy might provide the seed cells for a person's own engineered replacement muscle. For example, the lab-grown muscles could replace tissue lost to severe trauma or build up muscle that has weakened.
By adding fibroblast cells to the scaffold, the researchers were able to significantly boost the growth of the blood vessel network forming within the muscle tissue. Thanks in part to the stabilising influence of the fibroblasts, the surface area covered by vessel cells and the percentage of vessel-like structures in the tissue doubled within two weeks.
The endothelial cells and the vessel networks that they provide may also be useful in coaxing the muscle cells to differentiate and organise themselves in a mature, three-dimensional tissue, the researchers suggest.
To test the new muscles' therapeutic potential, the researchers implanted them within three groups of living mice. The new muscle was placed under the skin of the back and within a thigh muscle, and used to completely replace an abdominal muscle segment. The transplanted muscle continued to grow and develop within the mice's bodies.
Endowing the muscle tissue with its own blood supply boosted the new tissue's chance of survival and of connecting seamlessly with the mice's own blood vessel networks, they concluded.
MEDICA.de; Source: American Technion Society