Amniotic Membrane and Amniotic Epithelial Cell Culture

Amniotic membrane (AM) is considered an important medical device for applications in regenerative medicine. The therapeutic properties of AM are due to its resistant extracellular matrix and to the large number of bioactive molecules released by its cells. To this regard, ovine amniotic epithelial cells (AECs) are a subset of placental stem cells with great regenerative and immunomodulatory properties. Indeed, either oAEC or AM have been object of intense study for regenerative medicine, thanks to several advantages in developing preclinical studies on a high value translational animal model, such as sheep. For this reason, a critical standardization of cultural practices is fundamental in order to maintain, on one hand, AM integrity and structure and, on the other hand, oAEC native properties, thus improving their in vivo therapeutic potential and clinical outcomes.In addition, freshly isolated AECs or AM can be exploited to produce enriched immunomodulatory secretomes that had been used with success into cell-free regenerative medicine procedures.To this aim, here is described an improved oAEC cultural protocol able to preserve their native epithelial phenotype also after the in vitro amplification and an innovative AM in vitro cultural protocol design to prolong the integrity and the biological properties of this tissue in order to collect stable conditioned media enriched with immunomodulatory factors.

Graphene oxide accelerates TGFβ-mediated epithelial-mesenchymal transition and stimulates pro-inflammatory immune response in amniotic epithelial cells

The application of biomaterials on immune regenerative strategies to deal with unsolved pathologies is getting attention in the field of tissue engineering. In this context, graphene oxide (GO) has been proposed as an immune-mimetic material largely used for developing stem cell-based regenerative therapies, since it has shown to influence stem cell behavior and modulate their immune response. Similarly, amniotic epithelial stem cells (AECs) are getting an increasing clinical interest as source of stem cells due to their great plasticity and immunomodulatory paracrine activities, even though GO bio-mimetic effects still remain unknown. To this aim, GO-functionalized glass coverslips have been used for AECs culture. The results demonstrated how GO-coating is able to induce and accelerate the Epithelial-Mesenchymal Transition (EMT), in a process mediated by the intracellular activation of TGFβ1-SMAD2/3 signaling pathway. The trans-differentiation towards mesenchymal phenotype provides AECs of migratory ability and substantially changes the pattern of cytokines secretion upon inflammatory stimulus. Indeed, GO-exposed AECs enhance their pro-inflammatory interleukins production thus inducing a more efficient activation of macrophages and, at the same time, by slightly reducing their inhibitory action on peripheral blood mononuclear cells proliferation. Therefore, the adhesion of AECs on GO-functionalized surfaces might contribute to the generation of a tailored microenvironment useful to face both the phases of the inflammation, thereby fostering the regenerative process.