The results show that all tissue bioengineering treatments and advanced cell therapy with autologous and allogeneic mesenchymal stem cells expanded ex vivo are safe at experimental level. The treatments stimulated a bone regeneration response in all injured animals. None of the analytical parameters indicated an anomalous immune response or any systemic damage in the treated animals. In all cases, the formation of new bone was observed on existing trabeculae that had varying degrees of necrosis. Consequently, a second phase of clinical trial can be undertaken to assess the efficacy and safety of the new tissue engineering product. This trial will be undertaken at the Hospital Universitari Vall d’Hebron, an entity that collaborated in this project.