In a first-of-its-kind operation in the US, a team of doctors at Duke University Hospital, Durham, NC, helped create a bioengineered blood vessel and transplanted it into the arm of a patient with end-stage kidney disease. The procedure was the first US clinical trial to test the safety and effectiveness of the bioengineered blood vessel, and considered a milestone in the field of tissue engineering since it is an off-the-shelf, human cell-based product with no biological properties that could cause organ rejection.
Using technology developed at Duke and at a spin-off company it started called Humacyte, the vein was engineered by cultivating donated human cells on a tubular scaffold to form a vessel. The vessel was cleansed of qualities that might trigger an immune response. In pre-clinical tests, the veins performed better than synthetic and animal-based implants. The initial trial focuses on implanting the vessels in an easily accessible site in the arms of kidney hemodialysis patients.
Starting with a biodegradable mesh as the scaffolding for the veins, the mesh is formed into a blood vessel of varying lengths and widths and then seeded with smooth muscle cells. The mesh gradually dissolves as the cells grow in a special medium of amino acids, vitamins, and other nutrients. A pulsing force is introduced during the growth process, in which the nutrients are pumped through the tube in a heartbeat rhythm to build the physical properties that are similar to native blood vessels, which strengthens the bioengineered tissue. Within a couple of months, a life-like vein results.
If bioengineered veins prove beneficial for hemodialysis patients, the researchers aim to develop a durable graft for heart bypass surgeries.
