Placental stem cells

• The placenta is a reservoir of stem cells with minimal ethical concerns.
• The placenta is a source of haematopoietic stem cells during fetal development.
• The establishment of placental cell biobanks will enable their use in regenerative medicine.

The placenta represents a reservoir of progenitor, stem cells and epithelial cells that have been shown to differentiate into various types, including adipogenic, osteogenic, myogenic, hepatogenic, cardiac, pancreatic, endothelial, pulmonary and neurogenic lineages. This review focuses on the properties of placenta-derived cells, and it evaluates their current therapeutic applications in regenerative medicine and cell transplantations. Ongoing clinical and preclinical studies are investigating the safety and efficacy of the human amniotic epithelial cells (hAECs), human amniotic mesenchymal stromal cells (hAMSCs) and chorionic mesenchymal stromal cells (hCMSCs). The establishment of biobanks for placental stem cells will enable the translation of scientific research into the clinic. The advantage of the placenta as a cellular source is that it contains different cell lineages, such as the haematopoietic lineage that originates from the chorion, allantois and yolk sac, and the mesenchymal lineage that originates from the chorion and amnion. In this review, we address advances in placental stem cell characterization, and we explore their possible uses in cell therapy.