Controlling hESC-CM Cell Morphology on Patterned Substrates Over a Range of Stiffness

There is a consensus in the cardiac stem cell biology field that human embryonic stem cell derived–cardiomyocytes (hESC-CMs) are immature and do not resemble human adult cardiomyocytes, either phenotypically or transcriptionally. One striking difference between hESC-CMs and mature adult cardiomyocytes is their morphology. hESC-CMs grown in vitro are pleomorphic in shape and have no clear sarcomere organization; conversely, adult cardiomyocytes are rod-shaped with an average length-to-width (aspect) ratio of 7:1 and display a highly organized internal cytoskeletal structure. By combining multiple cues, i.e. substrate stiffness and topographical features, it may be possible to create a more physiologically-relevant model that better recapitulates the architecture of the native human heart which will aid in regenerative medicine therapies, disease modeling, drug testing, developmental and cardiotoxicity studies. Prior work in our lab used microcontact printing on glass slides to control the cell shape to improve the maturation of hESC-CMs. Since then, new work has focused on patterning methods on more compliant substrates using both microcontact printing, as well as a sacrificial polyvinyl alcohol (PVA) film. In this proceeding, the advantages and disadvantages of the above methods will be discussed in relationship to hESC-CM maturation.