Blood vessels that have been tissue-engineered from bone marrow adult stem cells may serve as a patient's source of new blood vessels following a coronary bypass or other procedures that require vessel replacement. A team of researchers from the University at Buffalo Department of Chemical and Biological Engineering have demonstrated the potential for eventually growing tissue-engineered vessels out of stem cells harvested from patients, providing an alternative to grafts now done in patients undergoing coronary bypass operations.
Vein grafts cause pain and discomfort at the donor sight, have a high failure rate of 10 years, and there is limited availability of vessels. The UB team developed a method for isolating functional smooth muscle cells from bone marrow by using a fluorescent marker protein and a tissue-specific promoter for alpha-actin, a protein found in muscles that is responsible for their ability to contract and relax.
The tissue-engineered vessels (TEVs) performed similarly to native tissue in their morphology, their expression of several smooth muscle cell proteins, the ability to proliferate, and the ability to contract in response to vasoconstrictors, one of the most important properties of blood vessels. The TEVs also produced both collagen and elastin, which give connective tissue their strength and elasticity, and are critical to the functioning of artificial blood vessels.