In vitro construction of tissue-engineered cardiac tissue sheet by small intestinal submucosa with bone mesenchymal stem cells

Abstract

Objective To explore the feasibility of in vitro construction of tissue-engineered cardiac sheet by small intestinal submucosa(SIS) with bone mesenchymal stem cells(BMSCs). Methods BMSCs separated from rat bone marrow were induced by 5-azacytidine(5-Aza) for 3 weeks,and were seeded on the serosal side of acellular SIS scaffold.The tissue-engineered cardiac tissue sheet was established in vitro after co-culture in dynamic culture system for 2 weeks,and its properties were evaluated by histological,ultrastructural and immunohistochemical examinations. Results After co-culture for 2 weeks,HE staining revealed that the seeded cells were not restricted in the upper area of SIS,forming multiple uniform layers on SIS,and some cells penetrated and migrated into the porous matrix.Scanning electronic microscopy revealed that BMSCs adhered,proliferated and migrated well on SIS,and secreted a large amount of extracellular matrix.Immunohistochemical staining demonstrated that the cells on SIS were cardiomyocyte-like cells with the expression of α-actin,cTnⅠ and connexin-43. Conclusion The engineered cardiac tissue sheet has been successfully constructed by SIS with 5-Aza-induced BMSCs in vitro,and SIS is an ideal bio-scaffold material for cardiac tissue engineering.