Inducing of Angiogenesis is the Net Effect of the Amniotic Membrane Without Epithelial Cells

Amniotic membrane (AM), the nearest layer of placenta to the fetus, has some biological properties important for the experimental and clinical applications including anti-microbial, anti-fibrosis, anti-scarring, as well as low immunogenicity. The basement membrane of the AM contains several extracellular matrix components such as types , III, IV, V collagen, laminin, fibronectin and perlecan which can induce proliferation of endothelial cells. The stormal side of the AM consists of mesenchymal cells which have capability to differentiate into endothelial cells. Moreover, several angiogenic factors such as interleukin (IL)-6, IL-8, growth-related oncogene (GRO), monocyte chemoattractant protein-1 (MCP-1) and intravascular adhesion molecule (ICAM) are secreted by the amniotic mesenchymal cells. Since the majority of anti-angiogenic factors are released by amniotic epithelial cells and due to the advantages of basement membrane and stromal side for inducing of angiogenesis, we have suggested here that the AM without epithelial layer would promote angiogenesis, an effect that would be a beneficial therapeutic approach for ischemic vascular diseases. To evaluate the hypothesis, the AM with or without epithelial cells will be implanted onto the striated muscle tissue of rats. The dorsal skinfold chamber model will be employed for intravital microscopic observation of the angiogenic host tissue response to implanted biomaterials throughout a time period of 7-14 days.