摘要Objective: Unlike other tissues, myocardium has not substitute whick can be used to repair damaged cardiac tissue. This paper proposes engineering 3-D myocardium-like tissue constructs in vitro with bone mesenchymal stem cells (BMSCs)of infant and poly-lactic-co-glycolic acid (PLGA) in vitro. Methods: Bone marrow was obtained from the sternal marrow cavum outflow of infant with congenital heart disease (CHD) undergoing cardiac operation. BMSCs were obtained by density gradient centrifugation. The cells in passages two were induced in DMED with 10 umol/L 5-Azacytidine(5-Aza) for 24 h. When the induced BMSCS were cultured nearly into filled, the cells were planted in the scaffold of PLGA in 5.5×106 cells/cm2. The cell-scaffold complex has been cultured in the shake cultivation for 1 week, then the complex has been planted in the dorse of the nude mouse. When the experiment had been finished, the histology, immunology, real time PCR and so on were done. Results: The BMSCs of infant with congenital heart disease have the properties of the stable growth and the rapid proliferation. The immunohistochemistry showed that tissue engineered myocardium constructed in vitro expressed some cardiac related proteins such as α-actin,Cx-43, Desmine,cTNI and so on. The transparent myofilaments, gap junctions and intercalated disk-like structure formation could be observed in the 3D tissue-like constructs by transmission electron microscope (TEM). The engineered myocardium-like tissue had the auto-myocardial property as assessed by real time-PCR and so on. Conclusion:The engineered myocardial tissue-like constructs could be built with infant BMSCs and PLGA in vitro. Our results may provide the first step on the long road toward engineering myocardial material for repairing the defect or augmenting the tract in CHD, such as ventricular septal defect, tetralogy of Fallot and so on.