Abstract 13559: Engineered Three-dimensional Cardiac Tissues Maturated by Dynamic Culture in a Rotating Wall Vessel Bioreactor Remodel the Diseased Heart in the Rat Infarction Model

Abstract

Introduction: To completely repair the distressed heart with few myocytes it may be crucial how to construct massive engineered three-dimensional cardiac tissues (E3DCTs) and integrate them to myocardium after transplant. We hypothesized that E3DCTs maturated by dynamic culture could enhance to remodel diseased left ventricle (LV) in the distressed rat heart. Methods: We made E3DCT by seeding 2.0 х 10 6 human induced pluripotent stem cell derived cardiomyocytes on the 6mm х 6mm PLGA fiber sheet. It was cultured in a rotating wall vessel bioreactor for seven days (RWV group) or culture dishes for the control. After in vitro assessment, these tissues were transplanted to myocardial infarction model nude rats, and 4 weeks after transplantation, we evaluated functional recovery and histology. Results: In the RWV group, thickness of E3DCTs were around 400μm, and cardiomyocytes showed mature phenotype evidenced by significantly higher expression of Troponin T (TnT), sarcomeric α actinin (SAA), connexin 43 (Cx43) and myosin heavy chain 7 (MYH7) with upregulation of mammalian target of rapamycin by Western blots (TnT; 2.1±0.2 vs. 1.0±0.2, SAA; 2.0±0.2 vs. 1.0±0.2, Cx 43; 2.0±0.3 vs. 1.0±0.1, MYH7; 2.0±0.2 vs. 1.0±0.2, p<0.05, respectively) (Figure 1A). Moreover, the concentration of angiogenic cytokines was significantly higher in the RWV group. Four weeks after transplantation, the LV ejection fraction was significantly improved in the RWV group than in the control (47±4.9 vs. 38±6.9%, p<0.01). On histological analysis, transplanted E3DCT reached a thickness of 1mm and vascular-like structures were partially observed inside (Figure 1B). In the RWV group, LV remodeling was significantly attenuated and neovascularization was significantly noted (Figure 1C, 1D). Conclusions: E3DCTs maturated by dynamic culture in a RWV bioreactor could remodel the diseased LV in rat infarction model, proposing potent armamentarium for cardiomyogenesis therapy in failed heart.