The effect of dynamic culture conditions on endothelial cell seeding and retention on small diameter polyurethane vascular grafts

Due to the limited number of cells available in endothelial cell (EC) seeding of small diameter vascular grafts, high seeding rate and ideal proliferation are normally required and can be achieved by optimizing the EC seeding and culture procedures. In this study, by using rotational seeding at 0.16 rpm for 12 h in an incubator, 90% cells were successfully seeded on the polyurethane vascular grafts. Following a period of 72 h of static culture, the cell retention after 6 h of flushing could reach 90%. The retention was further enhanced after perfuse culture (9 cm/s). The optimal procedures to prepare a polyurethane vascular graft (4-mm i.d., 4 cm long) populated with firmly attached EC were therefore: (1) seeding the graft with 0.5 ml of cell suspension containing ∼105 cells rotated at 0.16 rpm for 12 h; (2) culturing the seeded graft in static for 72 h; and (3) culturing the graft by perfusion (9 cm/s) for another 72 h to 7 days. These procedures consistently resulted in a graft covered with confluent vein EC that fully retained on the surface after 6 h of in vitro flushing.