Surface-Immobilized Biomolecules on Albumin Modified Porcine Pericardium for Preventing Thrombosis and Calcification

Abstract

The search for a noncalcifying tissue material to be used for valve replacement application continues to be a field of extensive investigation. A series of porcine pericardial membranes was prepared by modifying the glutaraldehyde--treated tissues with albumin and subsequently immobilizing bioactive molecules like PGE1, PGI2 or heparin via the carbodiimide functionalities. The in vitro calcification and collagenase degradation of these modified tissues were studied as a function of exposure time. Furthermore, the biocompatibility aspects of such novel interfaces were established by platelet adhesion and fibrinogen adsorption. The results reported in this article propose that the treatment with antiplatelet agents such as albumin, heparin and prostaglandins (PGE1 or PGI2) change the surface conditioning of pericardial tissues, suggesting a possible role of deposited serum components in affecting mineralization process on bioprosthesis. Therefore, it is worthy to hypothesize that besides inhibiting the accumulation of calcium in the devitalized cells, the early formation 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 proteins and cellular components of the recipient blood in tissue-associated calcification.

Protein adsorption under electrical stimulation of neural probe coated with polyaniline

“…Protein adsorption to a biomaterial is one of the first events following implantation, and subsequent cellular events occur through a mediating layer of adsorbed proteins. The accumulation of proteins on biomaterial surfaces plays a critical role in determining the biocompatibility of tissue-implant interface [26]. Thus, study on possible changes in protein adsorption when an electrical current was applied to PANI films is valuable.…”

Plasma-surface modification of biomaterials

“…The results show that the modified PLLA and fibronectin (Fn)-coated modified PLLA exhibit significant improvement in human vascular endothelial cell (HUVEC) and rabbit microvascular endothelial cell (RbMVEC) growth when compared to PLLA and Fn-coated PLLA, and that the ammonia plasma treatment provides the unique capability of modifying prosthetic biomaterials of various constructs with the eventual transplantation of mammalian cells to be used in tissue engineering or as biological implants. Sharma et al [216] and Chandy et al [217] have developed a method to immobilize phospholipids on polyether urethane urea (PEUU) using nitrogen plasma treatment. Free radicals are generated on PEUU to which phospholipids are attached.…”

Delivery of LMW Heparin via Surface Coated Chitosan/peg-Alginate Microspheres Prevents Thrombosis

“…Heparin and LMW Hep loaded or encapsulated Alg/chit/PEG beads also were surface coated with chitosan and CAP via carbodiimide functionalities (26,27). For that, 450 mgs of heparin loaded or encapsulated Alg/chit/PEG beads were exposed to 1.0% carbodiimide in 0.05M Tris-HCl buffer, pH 7.4, for 15 minutes at room temperature and the excess diimide washed.…”