Abstract 13027: Ex Vivo Induction of Microvascular Network Within the Engineered Three Dimensional Cardiac Tissues Using a Novel Bioreactor System
Background: In tissue engineering, current methods are limited by the restrictions of passive diffusion, preventing the creation of thick and viable tissues. Therefore, new technologies for making functional tissues with a well-organized vasculature are required. In this study, we hypothesized that it may be possible to overcome these diffusion limits by employing ex vivo microvascular bed and bioreactor system that allowed for sufficient vascular network within engineered cardiac tissues created by our cell sheet-based tissue engineering approach (Fig. A).
Methods: Neonatal rat cardiac cells with endothelial cells were harvested as cell sheets from temperature-responsive culture dishes. Three cell sheets were layered and transplanted over the microvascular bed with an artery and a vein ex vivo. Layered cardiac cell sheets were maintained in original tissue bioreactor with culture medium. Three days after transplantation, the perfused engineered cardiac tissues were histologically analyzed.
Results: Three days after the transplantation, 3D tissue-engineered cardiac tissues had survived and could maintain their pulsation (Fig. B, C). Immunostaining of the blood cell perfused cardiac tissues demonstrated that the entire CD31 positive microvasculature within the cardiac tissues were stained around the blood cells, indicating that vascularization was induced from the microvascular bed and that the tissues were supplied with culture medium from the underlying branch of the artery (Fig. D).
Conclusion: Vascularized 3D cardiac tissues were successfully fabricated by transplanting the constructs over the microvascular bed using the novel tissue bioreactor system ex vivo. The present methods demonstrate the possibility for further development of engineered thick tissues with the ability for well-organized microvessels in vitro.
- © 2011 by American Heart Association, Inc.