Project Summary Abstract The long term objective of the proposed research is to use cellular therapy to advance regenerative medicine. In particular, we wish to help amputees who have lost a limb. While major improvements have been made to prosthetics, the skin side of the interface at the stump site was not evolved to bear weight. The stump does not normally have the pressure adaptive abilities of the soles of the foot for example. The present grant proposes to biopsy, purify and expand fibroblasts from an existing palm or sole and inject them into the stump site of an amputee to improve their use of prosthetics. We also propose to study the basic biology behind cell therapy to understand how the injected cells change the native cells, and in turn how those native cells affect the injected cells. The results of this grant will hopefully lead to a new therapy to help not only amputees, but potentially prevent pressure ulcers and provide a platform for future cell therapies.