Transamniotic stem cell therapy (TRASCET).

Transamniotic stem cell therapy (TRASCET) constitutes the least invasive approach to prenatal stem cell delivery described to date. This strategy is largely based on the recently discovered active transport of donor cells from the amniotic fluid to the placenta directly through the amnio-placental interface. From a simple amniocentesis, via the placenta, donor cells of different phenotypes can reach the fetal circulation and virtually any fetal anatomical site, including, and particularly, the fetal bone marrow. As a result, TRASCET has shown broad therapeutic potential in an assortment of animal models. First reported experimentally only a little over a decade ago, it has yet to be attempted clinically, though clinical translation may be imminent. Much of TRASCET's appeal lies in the fact that, in large part, it constitutes a form of replenishment therapy based on the magnification of naturally occurring processes in the distinctive environment of the maternal-fetal unit. Despite significant experimental advances, much promise and perhaps excessive publicity, most cell-based therapies have yet to deliver meaningful large-scale impact to patient care. The few exceptions have been therapies based on the amplification of the normal biological role played by donor cells in their natural environment. TRASCET falls in that category. Further, while fetal stem cells possess unique characteristics when compared with postnatal stem cells, so does the fetus when compared with any other age group, converging into a scenario that enables therapeutic paradigms exclusive to prenatal life. This review summarizes the biological basis, diversity of applications and operability of the TRASCET principle.