Pulsatile flow conditioning of three-dimensional bioengineered cardiac ventricle.

Current physical stimuli mechanical stretch bioreactor studies focus on conditioning planar and/or tubular engineered cardiac constructs. The current 3D bioreactor models in cardiac tissue engineering use differential pressure loading for structural support as opposed to conditioning. The development of the pulsatile flow conditioned ventricle (PFCV) provides a 3D mechanical stretch conditioning method to generate pump function in the engineered cardiac left ventricle. The study utilizes a chitosan bioengineered open ventricle scaffold, to produce the in vitro PFCV model. PFCV were fabricated by wrapping the outer scaffold surface with a 3D fibrin gel artificial heart muscle patch, followed by pulsatile flow conditioning for 20 h. The average contractile frequency was 57 bpm. The average pressure generated, under maintained flow, post-conditioning, was 3.1633 mmHg. The average biopotential output was 0.4881 mV. Histologically, the PFCV displayed a more disseminated presence of intercellular interactions and sarcomeric organization. The results of this study clearly demonstrate the effectiveness of pulsatile flow conditioning to improve the function of our engineered left ventricle.