Characterization of Decellularized Porcine Hearts as Scaffolds for Tissue-Engineering

Abstract

Purpose Biological scaffolds are widely used in the process of cardiac tissue engineering. Here, we have successfully decellularized (DC) whole intact porcine hearts and characterized the resultant matrix for morphological and biometric properties. Methods and Materials Serial perfusion and agitation with a hypotonic, an ionic detergent and a nonionic detergent with hypotonic rinses was used to systematically decellularize porcine hearts (n=5). The degree of decellularization and morphological integrity of the treated hearts was analyzed with DAPI, Masson’s Trichome staining, electron microscopy, and DNA assay. Residual growth factors were detected using luminex. The conservation of extracellular matrix (ECM) proteins was evaluated by immunohistochemical staining and electron microscopy. The biomechanical properties of the obtained scaffolds were evaluated using uniaxial tension tests. Innate non-decellularized grafts served as controls. Results The protocol used resulted in extensive decellularization of the cardiac tissue but the cytoskeletal elements (contractile apparatus) of cardiomyocytes was largely unaffected by the procedure although their membraneous organelles were completely absent. Further, several residual angiogenic growth factors such as angiopoietin-2, G-CSF, endothelin, VEGF, follistatin were found to be present in the DC tissue. The resultant cardiac ECM retained collagen, elastin, and glycosaminoglycans, and mechanical integrity. Wall biomechanical parameters (stiffness, elasticity, ultimate force) were relatively similar to the native tissue even after decellularization. Conclusions The decellularization protocol used successfully preserved the morphological properties of the scaffold. The intact decellularized porcine heart provides a tissue engineering template that may be beneficial for future preclinical studies and eventual clinical applications.