The Potential of Amniotic Membrane/Amnion-Derived Cells for Regeneration of Various Tissues

Abstract

Abstract. Regenerative medicine is a new field based on the use of stem cells to generate biological substitutes and improve tissue functions, restoring damaged tissue with high proliferability and differentiability. It is of interest as a potential alternative to complicated tissue / organ transplantation. Recently, amnion-derived cells have been reported to have multipotent differentiation ability, and these cells have attracted attention as a cell source for cell-transplantation therapy. The amnion possesses considerable advantageous characteristics: the isolated cells can differentiate into all three germ layers; they have low immunogenicity and anti-inflammatory functions; and they do not require the sacrifice of human embryos for their isolation, thus avoiding the current controversies associated with the use of human embryonic stem cells. Moreover, we developed human amniotic cell-sheets using a novel culture surface coated with a noncytotoxic, temperature-responsive elastic protein-based polymer. We also generated a "hyperdry-amnion", which has already been applied clinically in the ophthalmological field. Compared to cryopreserved fresh amnion, "hyper-dry-amnion" is easy to handle and has started to bring good results to patients. These materials from the amnion are also expected to open a new field in tissue engineering. Thus, amnion, which had been discarded after parturition, has started to be appreciated as an attractive material in the field of regenerative medicine. In this review, the most recent and relevant clinical and experimental data about the use of amniotic membrane and cells derived from it are described.

Isolation, characterization, and in vitro differentiation of ovine amniotic stem cells

“…These preclinical studies are needed to increase the safety of new regenerative therapeutic approaches. The relevance of the preclinical studies in medicine is also greater when the experimental species have a comparable size and physiology to humans (In 't Anker et al 2003;Toda et al 2007). We must also consider the applicative advantage that can be offered, even in veterinary medicine, by the characterization of pluripotent stem cells.…”

“…In particular, their low immunogenicity, low tumorigenicity upon transplantation, widespread availability, and lack of ethical problems associated with their use, suggest they are ideal for wide use in regenerative medicine (Toda et al 2007). However, despite their high potential, their use in the clinical field is still subject to finalization of important aspects such as: a) identification of protocols for in vitro amplification; b) molecular characterization by identification of specific markers that will allow monitoring of their in vitro performance during different processes starting from isolation to differentiation; c) definition of their in vitro cell plasticity; and d) in vivo analysis of their regenerative tissue capacity in preclinical models transferable to humans (Toda et al 2007). On this basis, the purpose of this research was to develop a suitable and reproducible experimental protocol to isolate, culture, and amplify in vitro AMSCs and AFSCs derived from sheep fetuses.…”

“…The sheep, in fact, represents a good animal model because its size and physiological conditions of development are very similar to those of humans. On the isolated and in vitro cultured cells, we also evaluated the expression of pluripotent stem cell-specific markers such as Oct-4 and TERT (In 't Anker et al 2003;Toda et al 2007). This characterization of their phenotype has allowed us to observe, during culture, the different behaviors of AMSCs and AFSCs, and to document their abilities to differentiate into osteogenic and smooth muscle lineages.…”

The transplantation of mesenchymal stem cells derived from unconventional sources: an innovative approach to multiple sclerosis therapy

“…Fetal annexesderived MSCs (FA-MSCs) including umbilical cord blood, term placenta, villi, and amniotic fluid represent an easily accessible and abundant font of progenitors (Chan et al 2007;Toda et al 2007;Di Trapani et al 2013). Moreover, these kind of cells are preferable to embryonic cells obtained from a direct biopsy of the fetus during gestation, as the collection technique is associated with a defined morbidity/mortality and ethical issues (Bollini et al 2013).…”

Amniotic stem cells repair ureteric defect: a study to evaluate the feasibility of amniotic membrane as a graft in surgical reconstruction

“…The amniotic cavity also develops in the inner cell mass and together with amnion forming cells (which are derived from the epiblast) constitutes a thin membrane; the amnion. The extra embryonic mesoderm, derived from the yolk sac, surrounds the amnion and lines the inner surface of the cytotrophoblast, giving rise to the amniotic and chorionic mesoderm [1].…”