TISSUE ENGINEERING LAMB HEART-VALVE LEAFLETS

Tissue engineered lamb heart valve leaflets (N - 3) were constructed b y repeatedly seeding a concentrated suspension of autologous myofibrob lasts onto a biodegradable synthetic polymeric scaffold composed of fi bers made from polyglycolic acid and polylactic acid. Over a 2-week pe riod the cells attached to the polymer fibers, multiplied, and formed a tissue core in the shape of the matrix. The tissue core was seeded w ith autologous large-vessel endothelial cells that formed a monolayer which coated the outer surface of the leaflet. The tissue engineered l eaflets were surgically implanted in place of the right posterior pulm onary valve leaflet of the donor lamb while on cardiopulmonary bypass. Pulmonary valve function was evaluated by two-dimensional echocardiog raphy with color Doppler which demonstrated valve function without evi dence of stenosis and with only trivial regurgitation under normal phy siologic conditions. Histologically, the tissue engineered heart valve leaflets resembled native valve leaflet tissue. (C) 1996 John Wiley & Sons, Inc.