Wound healing involves a series of complex biological processes whereby injured tissue is repaired, specialized tissue is regenerated, and new tissue is reorganized. The healing of wounds is generally divided into three phases: the inflammatory phase, the proliferative phase, and maturation and remodeling phase.
In the inflammatory phase, the clotting cascade is initiated in order to stop blood loss. In addition, various factors, such as chemokines, cytokines, and growth factors, are released to attract and activate cells that phagocytize debris, bacteria, and damaged tissue.
The proliferative phase is characterized by angiogenesis and rebuilding of the extracellular matrix architecture which includes collagen deposition, granulation tissue formation, and epithelialization. The formation of new blood vessels, such as capillaries, and the formation of extracellular matrix enable activated satellite cell to proliferate, differentiate, and fuse into new muscle fibers.
Typically, the maturation and remodeling phase of wound healing is said to begin when the levels of collagen production and degradation equalize. During maturation, type III collagen, which is prevalent during proliferation, is gradually degraded and the stronger type I collagen is laid down in its place. The originally disorganized collagen fibers are rearranged, cross-linked, and aligned. In addition, the newly regenerated muscle matures and contracts with the reorganization of the scar tissue.
An impairment in any of these complex phases leads to complications in wound healing. Therefore, it would be beneficial to provide methods for promoting wound healing and/or muscle regeneration.