Cardiac tissue engineering aims to regenerate damaged myocardial tissues by applying heart patches created in vitro. The present study was undertaken to explore the possible role of matrix-attached RGD peptide in the engineering of cardiac tissue within macroporous scaffolds. Neonatal rat cardiac cells were seeded into RGD-immobilized or unmodified alginate scaffolds. The immobilized RGD peptide promoted cell adherence to the matrix, prevented cell apoptosis and accelerated cardiac tissue regeneration. Within 6 days, the cardiomyocytes reorganized their myofibrils and reconstructed myofibers composed of multiple cardiomyocytes in a typical myofiber bundle. The nonmyocyte cell population, mainly cardiofibroblasts, benefited greatly from adhering to the RGD-alginate matrix and consequently supported the cardiomyocytes. They often surrounded bundles of cardiac myofibers in a manner similar to that of native cardiac tissue. The benefits of culturing the cardiac cells in RGD-immobilized alginate scaffolds were further substantiated by Western blotting, revealing that the relative expression levels of α-actinin, N-cadherin and connexin-43 were better maintained in cells cultured within these scaffolds. Collectively, the immobilization of RGD peptide into macroporous alginate scaffolds proved to be a key parameter in cardiac tissue engineering, contributing to the formation of functional cardiac muscle tissue and to a better preservation of the regenerated tissue in culture.
Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.