Amniotic Fluid Mesenchymal Stromal Cells as Innovative and Advantageous Resource for Bone Regeneration

Tissue engineering approaches based on stem cells are a promising line of treatment for patients with bone defects. In orthopedics, mesenchymal stromal cells of various origins have been extensively studied and opinions are still conflicting. Although mesenchymal stromal cells from bone marrow are already clinically applied, recent evidence suggests advantages of using mesenchymal stromal cells from extra-embryonic tissues, such as amniotic fluid, as an innovative and advantageous resource for bone regeneration. The application of cells from amniotic fluid does not raise ethical problems and provides plenty cells without invasive procedures. Furthermore, they do not develop into teratomas when transplanted, a consequence observed with pluripotent stem cells. Their multipotent differentiation ability, low immunogenicity, and anti-inflammatory properties make them ideal candidates for bone regenerative medicine. Here, we give an overview of the current state-of-the-art of the osteogenic ability of amniotic fluid-derived cells and different approaches available to improve bone regeneration. We have highlighted the current progress in this field , focusing on the strategies applied to improve in vitro osteogenesis. Importantly, a detailed understanding of the behavior of amniotic fluid mesenchymal stromal cells and their osteogenic ability is desirable considering a feasible application in bone regenerative medicine.