Résumé
Objective Using a bioreactor to culture reendothelializing homograft bioprosthetic valve (HBV) in order to ultimately form viable tissue in vitro, so as to provide basic material for animal experiment and clinical application. Methods The reendothelializign HBV was placed in a pulse duplicator system (“bioreactor”), designed and fabricated by us. These grown under gradually increasing nutrient media flow and pressure for additional 14 days: 125 ml/min at 30 mm Hg (days 1-4), 250 ml/min at 40 mm?Hg (days 5-7), 500 ml/min at 50 mm Hg (days 8-10), 750 ml/min at 75 mm Hg (days 11 to 14). Throughout the studies, the flow device was placed in an incubator with 95% humidity and 5% carbon dioxide. The morphologic structure was observed and photographed by stereomicroscope with 0.5% silver nitrate (AgNO_3)staining and SEM on the 7th, 10th and 14th day. The retention rate of the ECs overlaid onto the HBV was evaluated with the percentage (%). Results The reendothelization level on the surface of the leaflets was 92% before pulsatile-flow-cultivation. But the rate of ECs retention on the scaffold exposured to pulsatile flow was only 36%, 23% and 11% on the 7th, 10th and 14th day, respectively. Conclusion The retention rate of ECs on the scaffold was low for pulsatile-flow-cultivation in vitro. Problems, including deficiency of mature stress fibers in the endothelial cells from MSCs deficiency of the adherence and growth factors still need improvement.