Abstract:

BACKGROUND: Previous research has demonstrated that bone marrow mesenchymal stem cells (BMSCs) differentiate into varying mesoderm-derived mesenchymal cells, such as myocardial cells.
OBJECTIVE: To investigate the feasibility of construction of engineered myocardial tissues with polylactic-co-glycolic acid (PLGA) polymer and cardiomyocyte-like cells derived from BMSCs in vitro.
METHODS: BMSCs were isolated from bone marrow of SD rats by density gradient centrifugation. The third passage cells were induced with the culture medium including 5-aza for 4 weeks. After successful induction, the cells were trypsinized and suspended, then the cell suspension was added to the polylactic-co-glycolic acid square slowly and cultured in the incubator for 14 days. The morphological changes were observed before and after induction under phase contrast microscope. The cardiomyocyte-like cells were identified by immunofluorescence staining. The naked eyes were used to observe the morphology of engineered myocardial tissues. The ultrastructures of the engineered myocardial tissues were viewed with a transmission electron microscope.
RESULTS AND CONCLUSION: BMSCs of primary culture formed cell colonies at 14 days. The passaged cells were larger than those of primary culture. After induction by 5-aza, the cells presented long spindle and aligned in parallel. The expression of specific proteins of cardiac troponin I (cTnI) in induced BMSCs was positive. Transmission electron microscopy showed that the engineered myocardial tissues had myofilaments, Z line-like substances. With PLGA and cardiomyocyte-like cells derived from BMSCs, the engineered myocardial tissues which resemble native cardiac tissues can be successfully constructed in vitro.