Structural and biomechanical characterizations of porcine myocardial extracellular matrix

Abstract

Extracellular matrix (ECM) of myocardium plays an important role to maintain a multilayered helical architecture of cardiomyocytes. In this study, we have characterized the structural and biomechanical properties of porcine myocardial ECM. Fresh myocardium were decellularized in a rotating bioreactor using 0.1 % sodium dodecyl sulfate solution. Masson’s trichrome staining and SEM demonstrated the removal of cells and preservation of the interconnected 3D cardiomyocyte lacunae. Movat’s pentachrome staining showed the preservation of cardiac elastin ultrastructure and vascular elastin distribution/alignment. DNA assay result confirmed a 98.59 % reduction in DNA content; the acellular myocardial scaffolds were found completely lack of staining for the porcine α-Gal antigen; and the accelerating enzymatic degradation assessment showed a constant degradation rate. Tensile and shear properties of the acellular myocardial scaffolds were also evaluated. Our observations showed that the acellular myocardial ECM possessed important traits of biodegradable scaffolds, indicating the potentials in cardiac regeneration and whole heart tissue engineering.

Myocardial Scaffold-Based Cardiac Tissue Engineering: Application of Coordinated Mechanical and Electrical Stimulations

“…41 . As shown in our previous publications, 38, 39 we have developed an optimal decellularization protocol to generate 3D porcine acellular myocardial scaffolds, in which 3D cardiomyocyte lacunae and ECM networks were well preserved along with mechanical anisotropy and vasculature templates; 38, 39 the acellular myocardial scaffolds also showed good stem cell recellularization and differentiation potential and experienced positive tissue remodeling manifested by a recovering trend in tissue mechanical properties. 38 …”

“…39 Forty fresh pig hearts were harvested from ∼6-month old pigs and transported from the local slaughter house to our laboratory in phosphate Buffered Saline at 4 °C. From the middle region of the anterior left ventricular wall, we were able to trim square-shaped myocardium samples (20 × 20 × ∼3 mm), of which one edge aligned along the muscle fiber preferred direction (PD) and the other edge aligned along the cross-fiber preferred direction (XD); note that the PD direction was determined based on overall muscle fiber texture and heart anatomy.…”

“…and Taylor et al 36, 37 Our group, however, has undertaken an effort to harness the potential of decellularized porcine myocardium as a scaffold material (e.g., for making cardiac patch). 38, 39 Up to now, studies have emerged not only on acellular porcine and rat myocardial scaffolds, 38-40 but also on acellular human myocardial scaffolds. 41 .…”

Building a better infarct: Modulation of collagen cross-linking to increase infarct stiffness and reduce left ventricular dilation post-myocardial infarction

“…While the properties of the normal myocardium are dominated by the structure and orientation of the myocytes, the properties of the infarct region are primarily governed by the network of newly deposited collagen fibers [3, 8]. Biaxial mechanical testing is the gold standard for testing planar anisotropic materials, making this method ideal for studying how variations in the properties of the collagen network alter scar mechanics in a mouse MI model [7, 9, 10]. Biomechanical analysis of infarct tissue, therefore, provides a critical understanding of the complex interactions between ECM structure, LV function, and patient outcome.…”

Establishing Early Functional Perfusion and Structure in Tissue Engineered Cardiac Constructs

“…They found that the engineered construct improved the infarcted tissue regeneration, evidenced by vascularization and cardiomyocytes differentiation in the implanted region. 124 Wang et al 76,125 and Godier-Furnemont et al 126 decellularized porcine (Figure 2A) and human myocardium and recellularized these acellular scaffolds with stem cells. Both studies found that the preservation of myocardial 3D ECM architecture and mechanical cues benefit cell proliferation, ingrowth, differentiation, tissue remodeling, and angiogenesis.…”