Surface-immobilized biomolecules on albumin modified porcine pericardium for preventing thrombosis and calcification

The search for a noncalcifying tissue material to be used for valve replace ment application continues to be a field of extensive investigation. A seri es of porcine pericardial membranes was prepared by modifying the glutarald ehyde - treated tissues with albumin and subsequently immobilizing bioactiv e molecules like PGE(1), PGI(2) or heparin via the carbodiimide functionali ties, The in vitro calcification and collagenase degradation of these modif ied tissues were studied as a function of exposure time. Furthermore, the b iocompatibility aspects of such novel interfaces were established by platel et adhesion and fibrinogen adsorption. The results reported in this article propose that the treatment with antipl atelet agents such as albumin, heparin and prostaglandins (PGE(1) or PGI(2) ) change the surface conditioning of pericardial tissues, suggesting a poss ible role of deposited serum components in affecting mineralization process on bioprosthesis. Therefore, if is worthy to hypothesize that besides inhi biting the accumulation of calcium in the devitalized cells, the early form ation of a conditioning layer on the bioprosthesis surface may affect salt precipitations, determining the propensity of the implant to calcify. More detailed studies are needed to understand the involvement of plasma protein s and cellular components of the recipient blood in tissue-associated calci fication.