IN-VITRO ENDOTHELIALIZATION OF COMMERCIALLY AVAILABLE HEART-VALVE BIOPROSTHESES WITH CULTURED ADULT HUMAN-CELLS

The possibility of improving the performance of heart valve bioprosthe ses by preendothelialization with autologous cells has been suggested. In this study we used cultured adult human vein endothelial cells to endothelialize cusps isolated from commercially available porcine valv e bioprostheses. We also describe a method for primary endothelializat ion of the intact heart valve bioprosthesis. After detoxification of t he glutaraldehyde, the cusps or valves were seeded at high density wit h cultured cells. To obtain an even distribution on the intact valve b ioprosthesis, a device was designed which permits application of cells from different directions during rotation. Evaluation was performed b y hematoxylin-eosin staining, scanning electron microscopy and immunoh istochemistry of the von Willebrand factor and the human basement memb rane constituent collagen IV. The endothelial cells were vital-stained during culture by the addition to the culture medium of carbocyanine dye. This made it possible to verify that the endothelium was derived from culture. A confluent lining of cultured endothelial cells in clos e proximity to a de novo formed basement membrane was observed on the isolated cusps 7 days after seeding. The intact heart valve bioprosthe sis showed an even distribution of seeded cells with areas of cells sp reading to confluency as evaluated after 24 h. However, 7 days after s eeding only unspread and probably dead cells were observed.