RESUMEN
BACKGROUND: In the development of new biomaterials for pericardium substitute, acellular amniotic membrane (AAM) presents potential for new applications in regenerative medicine. We studied an AAM as a pericardial substitute to achieve a suitable, cost effective, abundant matrix for the purpose of using it as graft for tissue repair. METHODS: Twenty Wistar rats were randomly divided into 2 groups (n = 10/group) and had their pericardiums excised. In the experimental group, the excised pericardium segment was substituted by a 7-mm-diameter patch of decellularized AAM sutured to the lesion area. After 4 weeks, the heart's outer layer of both groups was evaluated. The structure and component characteristics of the scaffold were determined with the use of hematoxylin and eosi, Alizarin Red S, and immumohistochemical staining and scanning electron microscopy. RESULTS: Histopathologic examination of the AAM patches revealed that the integrity of the AAM was preserved, and no calcification was observed on the surface of the myocardium. We also observed thicker pericardium repair tissue in the AAM group compared with the control group. AAM patches, by virtue of their low immunogenicity, evoked minimal host-versus-graft reaction. CONCLUSIONS: We conclude that AAM appears to be an ideal substitute for pericardium lesions, because it is integrated into the biologic tissue owing to its low immunogenicity and its ability to diminish the occurrence of adhesions and scarring, increasing the pericardium thickness.