The use of mesenchymal stem cells in collagen-based scaffolds for tissue-engineered repair of tendons.

Tendon and ligament injuries are significant contributors to musculoskeletal injuries. Unfortunately, traditional methods of repair are not uniformly successful and can require revision surgery. Our research is focused on identifying appropriate animal injury models and using tissue-engineered constructs (TECs) from bone-marrow-derived mesenchymal stem cells and collagen scaffolds. Critical to this effort has been the development of functional tissue engineering (FTE). We first determine the in vivo mechanical environment acting on the tissue and then precondition the TECs in culture with aspects of these mechanical signals to improve repair outcome significantly. We describe here a detailed protocol for conducting several complete iterations around our FTE 'road map.' The in vitro portion, from bone marrow harvest to TEC collection, takes 54 d. The in vivo portion, from TEC implantation to limb harvest, takes 84 d. One complete loop around the tissue engineering road map, as presented here, takes 138 d to complete.