A new semi-automatic endothelial cell seeding technique for biological prosthetic heart valves

Background: Until today, tissue heart valve prostheses have been made with biological dead porcine or bovine tissue. However, the durability of this t issue is limited due to degeneration and calcification. Surface seeding wit h vital human endothelial cells (EC) could improve valve durability and bio -compatibility. A new seeding technique that includes a newly developed spe cial seeding device is presented here. Methods: The aortic valve, including a cylinder of the aortic root, was pre pared from a fresh porcine heart taken from the slaughterhouse. Porcine end othelial cells were removed by surface treatment with chemical detergent so lutions. A new seeding device with an integrated CO2-incubator was designed . The device is composed of: the seeding chamber (SC), the rotation unit (R U), and the Control Unit (CU). The porcine aortic root cylinder with the va lve leaflets is placed into the SC. A matrix of fibronectin is applied to t he acellular valve. The SC is then filled with the endothelial cells suspen ded in modified Dulbecco's eagle medium (DMEM). Under cell culture conditio ns, the endothelial cell seeding of the tissue valve is established by rota ting the valve around two orthogonal axes simultaneously and independently. This is done following the software controlled preset parameters. Results: Using initial endothelial cell seeding concentrations of 6x10(6) e ndothelial cells/ml DMEM, it was possible to achieve a seeding efficiency o f 80-85% within 3-4 hrs. Cell viability tests proved that 90-95% of the see ded endothelial cells are vital after the seeding procedure. Conclusions: This new seeding technique allows the complex warped surface o f a tissue heart valve to be covered with vital endothelial cells to form a confluent endothelial cell monolayer.