Australian Researchers Create Technique for Engineering Blood Vessels Using Natural Tissue

Daniel Heath and Andrea O’Connor are research professors at Australia’s University of Melbourne. They head up a team focused on tissue engineering of small blood vessels that could be used in the treatment of cardiovascular disease. Their latest results were published last month in the academic journal, ACS Applied Materials and Interfaces.

Why engineer blood vessels? Blocked blood vessels, particularly coronary arteries, are responsible for cardiovascular and cerebrovascular diseases that lead to heart attacks and strokes. One-third of those under the age of 70 suffering from cardiovascular or cerebrovascular disease die prematurely.

When I first came across this research I was reminded of my own recent experience after a cardiac catheter punctured the wall of my femoral artery during an ablation procedure. I needed a vascular repair to stop the shunting of blood from the artery to the femoral vein which caused swelling in my lower extremities. If the condition had persisted I could have experienced clotting or other complications. Fortunately, the surgical repair worked.

The Highways of Our Bodies Are Blood Vessels

Blood vessels form the transportation network within our bodies. They are streets where red and white blood cells drive. They are the delivery system to oxygenate our brain and other vital organs and muscles. There are other highways in our bodies such as our nervous and lymphatic systems, but blood vessels are the ones that are central to healthy heart function and keeping our brain supplied with oxygen. When blood vessels are compromised we can suffer a stroke, heart attack, aneurysm or die.

When usual causes of heart attacks are blocked coronary arteries. The coronary arteries supply blood and oxygen to the heart. When partially blocked people experience symptoms like angina. When blocked they can suffer a myocardial infarction, the fancy name for a heart attack.

Today, harvested blood vessel grafts from human donors or the patient are used for bypassing coronary blood vessel blockages. But researchers at the University of Melbourne believe that fabricated blood vessel tissue that can be shaped to any need would be an effective substitute for existing grafts. The team in its search for a graft alternative has combined a variety of materials and living tissue with a fabrication technique to create complex blood vessels that can serve multiple purposes.

States Daniel Heath: “Current methods are slow, require specialized and expensive equipment like bioreactors, and are low throughput – meaning it’s difficult to provide the needed supply of engineered vessels…By combining multiple materials and fabrication technologies, our method brings us closer to a future where engineered blood vessels will become a transformative solution for cardiovascular disease, especially for those patients who lack suitable donor vessels.”

The fabrication technique produces tissue-engineered vascular grafts (TEVGs) as opposed to harvested grafts from human donors. The inventors claim that their TEVGs are low-cost and use electrospun polycaprolactone (PCL) that can be conformed to any required shape to fit surgical requirements. The technology fabricates a custom graft in hours. They are not synthetic and will not cause blood clotting or obstructions. They are made from human cells and tissues, and although not yet ready for prime time, the advancements being made here in tissue engineering should allow for the rapid and cheap manufacture of living tissue with appropriate properties soon, to become a life-saving alternative for replacing severely damaged arteries and veins.