Optimization of Pericardium Decellularization Method for Tissue Engineering Applications

Abstract

Background: The pericardium is a double layered transparent membrane that encloses the heart and provides friction free environment. The pericardium also helps in maintaining the hydrostatic pressure and heart volume and protects the heart from injury. The collagen rich outer fibrous pericardium is connected to the diaphragm, mediastinal pleura and sternum. The inner serous pericardium consists of two layers- parietal layer and visceral layer. The visceral layer that lines the outer surface of the heart is composed of a single layer of mesothelial cell resting on a thin fibrous basement membrane. The multilayered architecture along with the collagen and elastin extracellular matrix proteins and mesodermal epithelial cells determines the nonlinear mechanical properties of pericardium. Pericardium tissue obtained from the caprine can be used as biomaterials for making pericardial patches, and bioprosthetic heart valves. The purpose of this study is to determine the best method for decellularization of caprine pericardium preserving the ECM. Methods: In this study, two different decellularization procedures was designed, first based on anionic detergent and the second with combinations of both anionic and non-ionic agents, to achieve acellular caprine pericardium. In protocol A, the tissue samples were treated with various concentrations of anionic detergent and protocol B has combination of both anionic and non-ionic detergent in different ratios. The effectiveness of decellularization procedure is assessed by histological micro-structural analysis, and protein estimation. To study the impact of chemicals on the pericardium tissue uniaxial experiments were performed on the decellularized tissue and compared the response with the native tissue.

Analysis: Histological images indicate both the protocols A and B removes the mesothelial cells from the pericardium tissue. Treatment with anionic agent alone results in significant swelling and stiffening of the pericardium tissue. Protein eluted out from the ECM was quantified and it was found high elution of crude protein with protocol B.

Result and Conclusion:This study shows that the treatment of caprine pericardium tissue with combination of anionic and non-ionic agent is superior to the anionic agent and thus it helps us to obtain decellularized tissue with intact ECM. This method can be further used for the development of tissue engineered pericardium scaffold for the construction of bioprosthetic heart valves and other biomedical application.