Biomedical team reports bio-engineered blood vessels.

 Biomedical team reports bio-engineered blood vessels.
 

The creation of blood vessels:

The team grew the “TEVG” blood vessels from human cadaver cells and dog cells, stored them for a year.

Heart surgery patients may someday receive ready-made blood vessel replacements, a biomedical team reports.

In the Science Translational Medicine journal, a team led by Shannon Dahl of Humacyte Inc., in Durham, N.C., reports the creation of blood vessel, “grafts using human allogeneic or canine smooth muscle cells grown on a tubular polyglycolic acid scaffold.” In other words, they have grown bypass artery grafts on biodegradable plastic scaffolding tubes, pre-made for quick surgical use.
Says the study:

There is a considerable need for readily available vascular grafts when a patient’s own vasculature cannot be used for grafting because it is diseased or because suitable vascular tissue has already been harvested. Instances when a vascular graft might be needed include peripheral arterial disease, coronary artery disease, or to provide arteriovenous access for hemodialysis in patients with kidney failure. To date, the most successful vascular conduits for coronary or peripheral vascular surgery are the patient’s own blood vessels, often the greater saphenous vein in the leg.

The team grew the “TEVG” blood vessels from human cadaver cells and dog cells, stored them for a year, and then tested a random selection of them on baboons, large grafts, and dogs, thinner ones. None of the vessels exhibited calcium deposits or immune system rejection, and more than 80% avoided signs of clotting, or thrombosis.

Our approach of using allogeneic human cells to produce TEVGs allows one human donor to provide grafts for dozens of patients. This approach differs significantly from the one-donor-to-one-recipient model, which pertains to autologous tissue engineering and to cadaveric human or animal blood vessels. One human donor provides a cell bank large enough to produce 37 large-diameter [6-mm internal diameter (ID)] TEVGs or 74 small-diameter (3-mm ID) TEVGs. Pooling cells from multiple donors allows for the generation of large cell banks, which in turnmakes possible themanufacture ofmany TEVGs per cell bank (that is, 200 to 500 TEVGs). This offers greater economies of scale than completely autologous tissue engineering approaches. Further, use of allogeneic cells, combined with decellularization and simple storage methods, allows the culture period for graft production to be moved “off-line.” Therefore, patients have no waiting period for graft production, because the grafts have already been created and stored. The ability to store grafts is an important step in making TEVGs available to the patient immediately at their time of need, as opposed to custom-made grafts for each patient that involve a lengthy waiting time. This is an important departure from cellular products,which generally cannot be stored long-term without specialized cryopreservation equipment and laborious thawing procedures

The purpose of the study was to test whether the grafts could withstand the force of blood pumping through the vessels. They will need much more testing before undergoing human experimentation, but the researchers are hopeful that future bypass patients will benefit from such ready-made grafts.

Biomedical team reports bio-engineered blood vessels.