BACKGROUND:Ideal tissue-engineered urinary tract should have good mechanical properties to bear long-term attack of urine and excretion. Muscular conduit of urinary tract in static culture exerts poor strength. It is reported that mechanical stimuli promote cellular growth and secretion of extracellular matrix. OBJECTIVE:To investigate the feasibility of constructing tissue-engineered muscular conduit of urinary tract in bioreactor. METHODS:Adipose-derived stem cells were harvested by col agen enzyme method. After series culture and expansion in vitro, flow cytometric analysis was carried out to detect the immunophenotypes of adipose-derived stem cells. Then the cel-polyglycolic acid complex was constructed by seeding adipose-derived stem cells on polyglycolic acid fibers. After 1 week of in vitro culture, cel-polyglycolic acid complex was cultured in a bioreactor. The experimental group was subjected to pulsatile stimuli, while the control group was cultured in static state. After 3 weeks of in vitro culture in basic medium, the cel-polyglycolic acid complex was induced in the induced culture medium for 4 weeks, and then engineered tissue was examined both grossly and histological y. RESULTS AND CONCLUSION:Flow cytometry demonstrated that the adipose-derived stem cells expressed CD90 (99.42%), CD44 (98.12%) and CD105 (93.27%), but not CD34 (4.92%) or CD45 (0.38%). In the experimental group, tissue-engineered muscular conduit of urinary tract appeared bright color with a round lumen. Immunohistochemical staining showed that after cel-polyglycolic acid complex was induced for 4 weeks, the cells expressed desmin and α-smooth muscle actin. More col agen was found in the complex. In contrast, the control group appeared pale surface and its lumen col apsed slightly. Less col agen was in the complex. Tissue-engineered muscular conduit of urinary tract with good structure can be constructed in a bioreactor.