Amniotic Mesenchymal Stem Cells (AMSCs)

Amniotic mesenchymal stem cells (AMSCs) are highly abundant in the amniotic fluid and several techniques have been described for their isolation. They usually involve the removal of amniotic fluid by amniocentesis and their distinction from other cells may be based on their morphology or other characteristics. Human leukocyte antigen testing has been utilised to confirm that the AMSCs stem from the fetus and not from the mother. Originally it was proposed that the MSCs were discarded from the embryo at the end of their life cycle but since the cells remained viable in the amniotic fluid and were able to proliferate in culture this hypothesis was overturned. Comparison of amniotic fluid-derived MSCs to bone-marrow-derived ones showed that the former has a higher expansion potential in culture. However, the AMSCs have a similar phenotype to both adult bone-marrow-derived MSCs and MSCs originating from second trimester fetal tissue.