Depending on extent of injury, bone marrow derived stem cells are known to mobilize and migrate in order to accelerate healing. This has been demonstrated in conditions such as heart attack, stroke, and in critical limb ischemia after administration of exogenous stem cells.
Various parts of the body also have tissue resident stem cells. For example, in the heart there exists a population of c-kit positive cardiac-specific stem cells that multiply and generate functional progeny after injury. Also in the dentate gyrus and subventricular zone of the brain endogenous stem cells have been identified. The argument has been made that the ex vivo expansion and re-introduction of adult tissue specific stem cells is more physiologically feasible as opposed to systemic delivery of undifferentiated cells. Although it sounds difficult to get a heart biopsy of a patient after infarct or during heart failure, this procedure is actually in clinical trials.
The current patent teaches expansion of muscle specific stem cells using modulators of wnt-signaling. Unfortunately the patent is limited to in vitro expansion. However, the claims are very broad, which one can get a feel for after reading the first independent claim:
"An in-vitro method of promoting or inhibiting proliferation, differentiation or both proliferation and differentiation of a population of CD45+: Sca 1+ muscle stem cells comprising, administering a composition comprising one or more activators or inhibitors of wnt-signaling to said stem cells to promote proliferation or differentiation thereof"