Differentiation of adipose-derived stem cells for tendon repair.

The goal of primary tendon repair is to increase tensile strength at the time of mobilization. Tendon repair and regeneration using mesenchymal stem cells have been described in several studies; however, the use of adipose derived stem cells (ASCs) for tendon repair has only recently been considered. In order to establish a suitable experimental model for the primary tendon repair using ASCs, this chapter describes the detailed methods for: (1) isolating stem cells from adipose tissue, (2) generation of a primary tendon injury and repair model, (3) evaluating functional restoration by measuring tensile strength, and (4) investigating the mechanisms involved in ASC-mediated tendon healing by histological and immunohistochemical analyses. Topical administration of ASCs to the site of injury accelerates tendon repair, as exhibited by a significant increase in tensile strength, direct differentiation of ASCs toward tenocytes and endothelial cells, and increases in angiogenic growth factors. These findings suggest that ASCs may have a positive effect on primary tendon repair and may be useful for future cell-based therapy.