Stem cells from amniotic fluid – Potential for regenerative medicine

• Regenerative medicine focusses on replacement, repair and regeneration of cells, tissues and organs.
• Amniotic fluid stem cells (AFSCs) are broadly multipotent, that is, they can differentiate into all embryonic germ lineages, but they do not form tumours.
• Amniotic fluid mesenchymal stem cells (AFMSCs) are multipotent cells with mesodermal potential, that is, they can only differentiate towards fat, cartilage and bone.
• AFSCs and AFMSCs can be expanded, differentiated and used together with scaffolds for engineering of tissues and organs.
• AFSCs and AFMSCs home to sites of tissue injury and have paracrine effects that stimulate host repair/regeneration processes.

Regenerative medicine has recently been established as an emerging field focussing on repair, replacement or regeneration of cells, tissues and whole organs. The significant recent advances in the field have intensified the search for novel sources of stem cells with potential for therapy. Recently, researchers have identified the amniotic fluid as an untapped source of stem cells that are multipotent, possess immunomodulatory properties and do not have the ethical and legal limitations of embryonic stem cells. Stem cells from the amniotic fluid have been shown to differentiate into cell lineages representing all three embryonic germ layers without generating tumours, which make them an ideal candidate for tissue engineering applications. In addition, their ability to engraft in injured organs and modulate immune and repair responses of host tissues suggest that transplantation of such cells may be useful for the treatment of various degenerative and inflammatory diseases affecting major tissues/organs. This review summarises the evidence on amniotic fluid cells over the past 15 years and explores the potential therapeutic applications of amniotic fluid stem cells and amniotic fluid mesenchymal stem cells.