Strategies for regeneration of the bone using porcine adult adipose-derived mesenchymal stem cells

Bone is a plastic tissue with a large healing capability. However, extensive bone loss due to disease or trauma requires tissue-engineering applications. Presently, bone grafting is the gold standard for bone repair, but presents serious limitations including donor site morbidity, rejection, and limited tissue regeneration. The use of stem cells appears to be a means to overcome such limitations. Bone marrow mesenchymal stem cells (BMSC) have been the choice, thus far, for stem cell therapy for bone regeneration. However, it has been shown that adipose-derived stem cells (ASC) have similar immunophenotype, morphology, multilineage potential, and transcriptome compared to BMSC. Moreover, ASC are much more abundant, more accessible and have lower donor morbidity, which combined may make ASC a better alternative to BMSC. ASC are also able to migrate to the site of injury and have immunosuppressive abilities similar to BMSC. Further, ASC have demonstrated extensive osteogenic capacity both in vitro and in vivo in several species, greatly enhancing the healing of critical size defects. The use of scaffolds in combination with ASC and growth factors provides a valuable tool for guided bone regeneration, especially for complex anatomic defects. Some critical elements include ASC-scaffold interactions and appropriate three-dimensional design of the porous osteoinductive structures. This review examines data that provides strong support for the clinical translation of ASC for bone regeneration.