Background: Cells capable of self-renewal and bearing the plasticity potential have recently been proven to reside in the myocardium. These specific Cardiac Stem/Progenitor Cells (CSCs/CPCs) are multipotent and clonogenic, giving rise to cardiomyocytes, smooth muscle cells and endothelial cells both in vivo and in vitro. The micromechanical environment of extracellular matrix (ECM) plays an important role in cell behaviour - migration, proliferation and differentiation of the stem cells. The aim of this study was to compare the effects of different micromechanical stimulations on the CSCs/CPCs differentiation and morphology.
Material/Methods: Myocardial tissue samples were taken from the explanted hearts under sterile conditions. Tissue samples were then minced and cultured in IMDM medium. After the cells had grown to confluence, they were detached by gentle enzymatic digestion divided in to two groups: a) reseeded for expansions on fibronectin b) PoliD-lisyne coated dishes. After the expansion, the cells were cultured in cardiosphere-forming medium. Flow cytometry and fluorescent microscopic techniques were used to verify the presence of specific markers (c-kit, CD105, CD 166, CD31 and CD166) and morphology of the cells.
Results: After 14-22 days of culture a monolayer of fibroblast-like cells was generated from the adherent explants, over which small phase-bright cells migrated. After expansion of the primary culture, the cells reseeded on the poliD-lisyne coated dishes formed cardiospheres and the capillary like structure. No cardiosphere and capillary structure were observed in the fibronectin coated dishes. The percentage of c-kit, CD105 and CD166, were significantly higher in the Poli-D lisyne group compared with the fibronectin group. Moreover cells were negative for hematopoietic, endothelial and smooth muscle cell markers.
Conclusions: The micromechanical environment can infl uence the differentiation and morphology of CSCs/CPCs. Understanding the role of micromechanical stimuli on the CSCs/CPCs can be important for the successful cell transplantation.

Keywords: Heart Transplantation, Stem Cell Transplantation