Abstract 213: Evolving Challenges in Promoting Stem Cell Based Cardiovascular Repair and Regeneration

Abstract

Introduction: Use of adult stem cells in the stimulation of mammalian cardiac muscle regeneration is in its infancy, and to date, it has been difficult to determine the efficacy of the procedures that have been employed. The outstanding question remains whether stem cells derived from the bone-marrow or some other location within or outside of the heart can populate a region of myocardial damage and transform into tissue-specific cells, and also exhibit functional synchronization. As a result, this necessitates the development of an appropriate in vitro three-dimensional (3-D) model of cardiomyogenesis and prompts the development of a 3-D cardiac muscle construct for tissue engineering purposes, especially using the adult stem cells. Hypothesis: Functioning vascularized cardiac tissue can be generated by the interaction of human induced pluripotent stem cell-derived embryonic cardiac myocytes (hiPSC-ECMs) and human multipotent mesenchymal stem cells (hMSCs) on a 3-D prevascularized collagen cell carrier (CCC) scaffold. Methods and Results: In order to achieve the above aim, we have developed an in vitro 3-D functioning vascularized cardiac muscle construct using hiPSC-ECMs and hMSCs. First, to generate the prevascularized scaffold, human cardiac microvascular endothelial cells (hCMVECs) and hMSCs were co-cultured on 3-D CCCs for 7 days under vasculogenic culture conditions, hCMVECs/hMSCs underwent maturation, differentiation, and morphogenesis characteristic of micro vessels, and formed extensive plexuses of vascular networks. Next, the hiPSC-ECMs and hMSCs were co-cultured onto this generated prevascularized CCCs for further 7 or 14 days in myogenic culture conditions. Finally, the vascular and cardiac phenotypic inductions were analyzed at the morphological, immunological, biochemical, molecular, and functional levels. Expression and functional analyses of the differentiated cells revealed dramatic neo-angiogenesis and neo-cardiomyogenesis. Conclusions: Thus, our unique 3-D co-culture system provided us the apt in vitro functioning prevascularized 3-D cardiac patch that can be utilized for cellular cardiomyoplasty.