Osteogenic differentiation of amniotic fluid mesenchymal stromal cells and their bone regeneration potential

Abstract

In orthopedics, tissue engineering approach using stem cells is a valid line of treatment for patients with bone defects. In this context, mesenchymal stromal cells of various origins have been extensively studied and continue to be a matter of debate. Although mesenchymal stromal cells from bone marrow are already clinically applied, recent evidence suggests that one may use mesenchymal stromal cells from extra-embryonic tissues, such as amniotic fluid, as an innovative and advantageous resource for bone regeneration. The use of cells from amniotic fluid does not raise ethical problems and provides a sufficient number of cells without invasive procedures. Furthermore, they do not develop into teratomas when transplanted, a consequence observed with pluripotent stem cells. In addition, their multipotent differentiation ability, low immunogenicity, and anti-inflammatory properties make them ideal candidates for bone regenerative medicine. We here present an overview of the features of amniotic fluid mesenchymal stromal cells and their potential in the osteogenic differentiation process. We have examined the papers actually available on this regard, with particular interest in 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.

Keywords: Mesenchymal stromal cells; Amniotic fluid; Amniotic fluid mesenchymal stromal cells; Amniotic fluid stem cells; Osteogenesis; Bone regeneration

Core tip: Several papers regarding the osteogenic differentiation potential of cells isolated from amniotic fluid have been published so far with particular attention to various feasible approaches to improving differentiation both in vitro and in vivo. Hence, an overview is necessary on the data reported up to now in order to understand the potential of amniotic fluid-derived cells in bone regenerative medicine. This review takes a general look at the current state-of-the-art of the osteogenic ability of amniotic fluid-derived cells and the different strategies available to improve bone regeneration.