Vascularization and perfusion remain as long-standing challenges in engineering thick cardiac tissue con- structs and enabling efficient host integration once implanted. In this proposal, we form an interdisciplinary team that brings complementary expertise from different scientific fields to build cardiac tissue integrated with a hierarchical vascular system, all derived from a single stem cell source, and develop new imaging tools to measure tissue perfusion dynamics in vitro and in vivo. The overall hypothesis is that a hierarchical vasculature with perfusion will enable engineering of thick and functional human myocardium in vitro and improve vascular and cardiac integration in vivo. We will use human pluripotent stem cells (hPSCs) to generate all cellular com- ponents, namely cardiomyocytes, epicardial cells, endothelial cells, smooth muscle cells, and cardiac fibro- blasts, in the engineered cardiac constructs.
In Specific Aim 1, we will combine three of our recently developed techniques (lithography, self-assembly and direct photopatterning) to fabricate vessel trees with diameter rang- ing from large arterioles to capillaries, and assess their pressure- and flow-based remodeling under perfusion in vitro.
In Specific Aim 2, we will test the role of perfusion on cardiomyocyte survival, maturation and contrac- tile function in hPSC derived cardiac constructs. We will build large scale three millimeter thick vascularized cardiac constructs that allow for long term remodeling.
In Specific Aim 3, we will assess the effect of perfusion and vascular architecture on vascular and cardiac integration in vivo. We will improve our prototype optical mi- croangiography (OMAG) system to assess perfusion dynamics in the graft and host over time after implanta- tion. This project merges new vascular engineering technology, stem cell biology, and imaging tools and ap- plies them towards engineering an improved cardiac tissue. The success of the project will provide important information in designing principles and optimization process in vascularization, perfusion, and cardiac function towards future cardiac tissue engineering and regenerative approaches.
Vascularization remains as one key challenge towards engineering thick cardiac tissue. In this grant, we will develop engineering tools to generate three-dimensional hierarchical vasculature and thick cardiac constructs in vitro and study the impact of perfusion on cardiac survival and function, and will exploit novel optical imaging techniques to evaluate perfusion dynamics during vascular remodeling in these constructs in vitro and in vivo. These experiments are directly relevant to public health, because they will allow us to more effectively repair the injured heart and to build human heart tissue outside the body for drug discovery and disease modeling.
