Development of a Small Diameter Vascular Graft Using the Human Amniotic Membrane

Although there have been significant advances in the development of fully functional vascular grafts suitable for coronary artery bypass graft surgery, so far no technology has been developed that meets all of the requirements suitable for clinical use. Here we present an approach using a decellularized biological membrane, seeded with smooth muscle cells (SMCs) and rolled into a tubular construct. We show that the human amniotic membrane provides a thin and strong biological extracellular matrix that supports the attachment and proliferation of both rat aortic SMCs and of human myofibroblasts. The results show that after 1 week in static culture, the rolled construct develops an elastic modulus higher than that of native tissue. The elastic modulus decreases with time in culture, suggesting that cells actively remodel the matrix. Cells continue to proliferate in the rolled state and histology images show that some cells attach to the neighboring membrane in the construct. The burst pressure of the construct remains below physiological levels. A bioreactor system was used to deliver flow to both the lumen and the ablumenal spaces through two separate flow circuits but resulting burst pressures of this treatment still remain below physiological values. Our study demonstrates that the human amniotic membrane is a cell biocompatible biological membrane that has the potential to be useful in a vascular application.