Background and purpose: Amniotic membrane (AM) is a proper candidate for vascular tissue engineering. The aim of this study was to evaluate the hemocompatibility of the epithelial surface of the AM.

Materials and methods: In this study, we assessed the effects of the epithelial surface of
the AM on blood coagulation system by measuring activated partial thromboplastin time (aPTT), prothrombin time (PT), clotting time (CT), hemolysis and platelet aggregation compared with expanded Polytetrafluoroethylene (ePTFE). The amount of P-selectin was measured to test the platelet activation using ELISA. Adhesion and morphological changes of platelets were analyzed by scanning electron microscopy. 

Results: The results of aPTT, PT and CT tests showed that the epithelial surface of the AM activated the external coagulation pathway less than ePTFE and had same effects as this synthetic material on the internal coagulation pathway. Furthermore, the epithelial surface of the AM suppressed aggregation, activation and adhesion of the platelets and in turn inhibited initiation of clot formation. In contrast, more number of platelets were adhered and activated on the surface of ePTFE.  

Conclusion: Based on suitable features of the AM and hemocompatibility results of amniotic epithelial cells which have stem cell characteristics, the AM could be a good candidate for vascular tissue engineering.