How do we know the power
of Placental tissue as a
potent promoter of
regenerative powers?
Continued from previous issue
It’s long been possible to identify certain defects in a developing fetus and surgically repair them. The surgery itself requires incision into mothers abdomen. Yet, after further development in the womb, the baby is born with no scar, while mother still has scar. Why is that?
Lets look at its background, a commonly used phrase in the field of chronic wound management, is the “process of replacing or regenerating human cells, tissues, or organs to restore or establish normal function” (1). The term also refers to a group of biomedical approaches to clinical therapies that involve the use of stem cells. Tissue-engineered skin and platelet-derived growth factors represent substantial advancements in wound healing, because they stimulate the delivery of certain factors considered important to regenerative medicine, including growth factors, fibroblasts, collagen, and a physical scaffold on which wound repair and regeneration can occur.
The amniotic membrane (AM) or amnion is a tissue of particular interest because it can provide cells with multi-potency. Amnion is easily obtained after Cesarean delivery, because the placenta and associated fluid and membrane are typically discarded after childbirth. The cells have been shown to have extremely low immunogenicity, and their procurement avoids the controversies associated with obtaining human embryonic stem cells. Thus, the use of AM and amniotic fluid (AF) has been proposed as a potentially useful allograft cell therapy in regenerative medicine (2).
The AM is the innermost layer of the placenta and consists of a thin epithelial layer, a thick basement membrane, and an avascular stroma. It contains collagen types III, IV, V, and VII and fibronectin and laminin (3–5). It also contains fibroblasts and growth factors, modulates cytokine and growth factor levels.
It has also been shown to have unique properties, including the ability to suppress pain, fibrosis, and bacteria, and to promote wound healing (6–10). The AM contains 2 cell types of different embryologic origin; specifically, amnion epithelial cells, derived from the embryonic ectoderm, and amnion mesenchymal cells, derived from embryonic mesoderm (2). The recommendation of the International Society for Cellular Therapy has been that mesen-chymal cells derived from amnion be referred to as amniotic membrane-human mesenchymal stromal cells (AM-hMSCs) (3).
AF contains nutrients and growth factors that facilitate fetal growth and provides mechanical cushioning and antimicrobial properties that protect the fetus. The human amnion is a single layer of epithelial cells separating the amniotic cavity from the vascularized chorion. Early in gestation these amniocytes are flattened; however, as pregnancy progresses, they become cuboidal and have increasing numbers of microvilli on their apical surface. Tortuous intercellular channels exist between the tight junctions of amniocytes. Vascular endothelial growth factor (VEGF) in the fetal membranes appears to be a mediator of this process. VEGF promotes blood vessel development within the amnion and influences the permeability of the microvessels, which perfuse the fetal and placental surfaces (11).