Abstract 199: A 3-D Prevascularized Cardiac Muscle Construct for Analyzing hMSCs Engraftment and Differentiation Potential in vitro

Abstract

Introduction: The most fundamental problem facing cardiac therapy, unlike vascular grafts and heart valves, is to repair and/or regenerate the damaged myocardium. Restricted myocardial regeneration after tissue damage and shortage of donor organs for cardiac transplantation are the major constraints of conventional therapies. The most daunting task in the field of cardiovascular tissue engineering is the creation and/or regeneration of an in vitro engineered cardiac muscle; tissue engineering is associated with two common underlying concerns for clinical applicability, viz., contractility and thickness. However, both the thickness and the contractility of the derived cardiac tissue are dependent on the vascularity of the construct. Hypothesis: Whether functioning vascularized cardiac tissue can be generated by the simultaneous interaction of cardiac myocytes, endothelial cells, and somatic stem cells, as would expect to occur during myocardial reparative/regenerative processes; by utilizing, viz., the embryo-derived embryonic cardiac myocytes (eCMs) and the human adipose-derived multipotent mesenchymal stem cells (hMSCs) on a three-dimensional (3-D) prevascularized collagen cell carrier (CCC) scaffold. Methods and Results: First, to generate the prevascularized scaffold, human cardiac microvascular endothelial cells (hCMVECs) and hMSCs were co-cultured onto a 3-D CCC for 7 days under vasculogenic culture conditions, hCMVECs/hMSCs underwent maturation, differentiation, and morphogenesis characteristic of microvessels, and formed dense vascular networks. Next, the eCMs and hMSCs were co-cultured onto this generated prevascularized CCCs for further 7 or 14 days in myogenic culture conditions. Lastly, expression and functional analyses of the differentiated progenies revealed neo-cardiomyogenesis and neo-vasculogenesis. In this milieu, not only were hMSCs able to couple electromechanically with developing eCMs, but also able to contribute to the developing vasculature as mural cells, respectively. Conclusions: Hence, our unique 3-D co-culture system provides us a reproducible and quintessential in vitro 3-D model of cardiomyogenesis, and a functional cardiac graft that can be utilized for personalized medicine.