Amniotic membrane mapping discloses novel promising features of amniotic membrane epithelial cells for regenerative medicine purposes

The amniotic membrane (AM) is the innermost part of the placenta, in direct contact with the amniotic fluid. In recent years the interest toward placenta stem cells has been increasingly growing, due in part to the absence of any ethical issues concerning their isolation. At present, two main stem cells populations have been identified in AM: amniotic epithelial cells (AECs) and amniotic mesenchymal stromal cells (AMSCs). Albeit AM is an excellent source of cells for regenerative medicine, additionally due to its immune-modulatory properties and low immunogenicity, only a few papers have studied its sub-regions. Thus, our focus was to map the human AM under physiological conditions to identify possible differences in morpho-functional features and regenerative capacity of its components. Human term placentas were amassed from salubrious women after vaginal distribution or caesarean section at Fondazione Poliambulanza-Istituto Ospedaliero of Brescia, University Hospital of Cagliari and SS. Annunziata Hospital of Chieti. Samples of AM were isolated from four different regions according to their position relative to umbilical cord (central, intermediate, peripheral, reflected). By designates of immunohistochemistry, morphometry, flow cytometry, electron microscopy, CFU assays, RT-PCR and AECs in vitro differentiation we demonstrated the esse of different morpho-functional features in the different regions of AM, highlighting that AECs are a heterogeneous cell population. This should be considered to increment efficiency of amniotic membrane application within a therapeutic context.