Muscles can be restored
Mammalian skeletal muscles are capable of repairing minor injuries by mobilizing muscle stem cells into the injured area. However, with major injuries, the main task of the body is to stop bleeding, which leads to the rapid formation of a scar that prevents the restoration of lost muscle tissue.
Scientists at Worcester Polytechnic Institute and CellThera have developed an approach to solve this problem. They used mature human myocytes returned to the state of stem cells using a safe technique developed earlier and tested on fibroblasts, without the use of genetically modified viruses or the introduction of "pure" genes. After that, the cells were cultured on the surface of polymer microfibers made of fibrin, a protein involved in the formation of blood clots. Fiber bundles covered with cells were placed in a wound on the mouse leg created by surgical removal of a large fragment of the anterior muscle of the lower leg. This muscle was chosen because its injuries lead to significant restrictions on the mobility of the foot, but do not deprive animals of the ability to move.
10 weeks after the procedure, the functioning of the damaged muscles was almost completely restored in the mice of the experimental group, while the formation of scar tissue and the absence of muscle regeneration were observed in the animals of the control group.
The control group mice formed at the site of injury
scar tissue (on the right, blue).
Implantation of cell-coated microfibres from fibrin
minimized scarring and promoted the formation of
functional muscle tissue (left).
The researchers expected that most of the new tissue would consist of human cells.
However, to their surprise, it turned out that almost all newly formed muscle fibers were represented by mouse myocytes.
Based on this, it was suggested that fibrin microfibers, the shape of which is similar to the shape of muscle fibers, stimulate the migration of resting mouse progenitor cells into the area of damage and tissue repair. Moreover, they can prevent the development of a natural inflammatory reaction that promotes scarring of injury sites.
This unexpected discovery indicates the possibility of using only fibrin microfibers as a tool for healing major injuries of muscle tissue. The researchers plan to study the effectiveness of a separate application of fibrin fibers and determine the degree of damage that requires the addition of a cellular component to this therapeutic approach.
Article by Raymond L. Page et al. Restoration of Skeletal Muscle Defects with Adult Human Cells Delivered on Fibrin Microthreads is published in the journal Tissue Engineering.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Worcester Polytechnic Institute: Body Rebuilding: Scientists Regenerate Muscle in Mice.
02.12.2011