AHA: Fat-Derived Stem Cells Can Be Used to Create Blood Vessels
Tissue-engineered blood vessels fabricated using human amniotic membrane as a substrate
THURSDAY, July 26 (HealthDay News) -- Fat stem cells can be used to engineer new small-diameter blood vessels, according to a study presented at the American Heart Association's Basic Cardiovascular Sciences 2012 Scientific Sessions, held from July 23 to 26 in New Orleans.
Jaclyn A. Brennan, from the University of Oklahoma in Norman, and colleagues used human amniotic membrane as a biological substrate to fabricate a small-diameter tissue-engineered blood vessel (TEBV). They differentiated adipose-derived stem cells into smooth muscle cells (SMCs) and seeded them onto a flat sheet of the amniotic membrane. To develop a tubular construct similar to that of a muscular artery's tunica media layer, the cell-seeded sheet was wrapped around a 3 mm O.D. removable mandrel with six to seven revolutions. The TEBV was assessed for biochemical and mechanical properties after a two-week static culture period. Contraction of the vessel in response to carbachol, a specific agonist for SMCs, was examined and compared to the contraction of porcine coronary arteries. Burst pressure and elastic modulus tests were also conducted.
The researchers found that the mechanical integrity of this construct could be further improved by exposure to appropriate physiological conditions in a perfusion bioreactor. Adipose-derived endothelial cells could be also be seeded into the lumen of the construct to prevent platelet adhesion.
"Our engineered blood vessels have good mechanical properties and we believe they will contract normally when exposed to hormones. They also appear to prevent the accumulation of blood platelets -- a component in blood that causes arteries to narrow," a coauthor said in a statement.