TISSUE ENGINEERING OF HEART-VALVES - HUMAN ENDOTHELIAL-CELL SEEDING OF DETERGENT ACELLULARIZED PORCINE VALVES

Objective: Tissue engineering of heart valves represents a new experim ental concept to improve current modes of therapy in valvular heart di sease. Drawbacks of glutaraldehyde fixed tissue valves or mechanical v alves include the short durability or the need for life-long anticoagu lation, respectively. Both have in common the inability to grow, which makes valvular heart disease especially problematic in children. The aim of this study was to develop a new methodology for a tissue engine ered heart valve combining human cells and a xenogenic acellularized m atrix. Methods: Porcine aortic valves were acellularized by deterging cell extraction using Triton(R) without tanning. Endothelial cells wer e isolated in parallel from human saphenous veins and expanded in vitr o. Specimens of the surface of the acellular matrix were seeded with e ndothelial cells. Analysis of acellularity was performed by light micr oscopy and scanning electron microscopy, Cell viability following seed ing was assayed by fluorescence staining of viable cells. Results: The acellularization procedure resulted in an almost complete removal of the original cells while the 3D matrix was loosened at interfibrillar zones. However the 3D arrangement of the matrix fibers was grossly mai ntained. The porcine matrix could be seeded with in vitro expanded hum an endothelial cells and was maintained in culture for up to 3 days to document the formation of confluent cultures. Conclusions: Porcine ao rtic valves can be almost completely acellularized by a non-tanning de tergent extraction procedure. The xenogenic matrix was reseeded with h uman endothelial cells. This approach may eventually lead to the engin eering of tissue heart valves repopulated with the patients own autolo gous cells. (C) 1998 Elsevier Science B.V. All rights reserved.