Supramolecular structure of human aortic valve and pericardial xenograft material: atomic force microscopy study
Pericardial tissue (bovine or porcine), chemically stabilized with glutaraldehyde (GA), is widely used in cardiovascular surgery in the form of bioprosthetic valves. GA reacts with tissue proteins and creates inter- and intra-molecular cross-links, resulting in improved durability. However, tissue calcification and mechanical damage are still unresolved problems. The purpose of this study was to examine the surface topography of normal human aortic valve and GA-stabilized porcine pericardium tissue in order to gain comparative insight into supramolecular structure of both tissues. The analysis was focused on morphologic evaluation of collagen constituents of the tissues. Atomic force microscopy working in the contact mode in air was employed in the study. Considerable diversity in the spatial orientation of collagen fibrils for the human aortic valve and pericardial tissue were observed. It was found that different forms of collagen fibril packing, i.e. dense and “in phase” or loose, could have an impact on the collagen D-banding pattern. Stabilization with GA introduced significant changes in the surface topography of collagen fibrils and in their spatial organization on the tissue surface. Strong disturbance in the fibril’s D-spacing was observed. It was also suggested, that the observed structural changes at the supramolecular level might make an important contribution to the progressive damage and calcification of the tissue. The presented results demonstrate that the AFM method can be useful for non-destructive structural characterization of heart valves and bioprosthetic heart valve material.
KeywordsAtomic Force Microscopy Fibril Aortic Valve Heart Valve Collagen Fibril
The authors wish to thank Dr. J. Nozynski from the Department of Histology and Embryology of the Medical University of Silesia, Poland, for the preparation of human aortic valve and helpful discussion.
This work was supported by the State Committee for Scientific Research (KBN, Poland) under Project No. NN-2-365/05.
- 4.E. JORGE-HERRERO, J. M. GARCIA PAEZ, DEL CASTILLO-OLIVARES RAMOS, J. Applied Biomater. Biomech. 3 (2005) 67Google Scholar
- 7.M. MIRZAIE, T. MEYER, P. SCHWARTZ, S. LOTFI, A. RASTAN and F. SCHÖNDUBE, Ann. Thorac. Cardiovasc. Surg. 8 (2002) 24Google Scholar
- 8.M. MIRZAIE, M. SCHULTZ, P. SCHWARTZ, M. COULIBALY and F. SCHÖNDUBE, Ann. Thorac. Cardiovasc. Surg. 9 (2003) 163Google Scholar
- 11.B. P. JENA and J. K. H. HÖRBER, 2002, in “Atomic force microscopy in cell biology. Methods in cell biology” (Amsterdam, London, New York: Academic Press) p. 1–64. Google Scholar
- 16.W. A. NAIMARK, J. M. LEE, H. LIMEBACK and D. T. CHEUNG, Am. J. Physiol. 263 (HEART CIRC. PHYSIOL. 32) (1992) H1095Google Scholar
- 21.A. STEVENS and J. LOWE, 1997, in “Human histology” (Amsterdam, London, New York: Mosby) p. 147Google Scholar
- 27.M. E. NIMNI and R. D. HARKNES, 1998, in “Collagen:biochemistry Vol.1” (Boca Raton, FL: CRC Press) p. 1–7Google Scholar
- 28.B.B. TOMAZIC, Zeitschrift fur Kardiologie, Band 90, suppl. 3 (2001) III68Google Scholar
- 29.J. M. CONNOLLY, I. ALFERIEV, J. N. CLARK-GRUEL, N. EIDELMAN, M. SACKS, E. PALMATORY, A. KRONSTEINER, S. DEFELICE, J. XU, R. OHRI, N. NARULA, N. VYAVAHARE and R. J. LEVY, Am. J. Pathol. 166 (2005) 1Google Scholar