| CPC C12N 5/0657 (2013.01) [G01N 33/5061 (2013.01); C12N 2503/02 (2013.01); C12N 2506/45 (2013.01); C12N 2533/52 (2013.01); C12N 2533/54 (2013.01); C12N 2533/90 (2013.01)] | 19 Claims | 

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               1. A method for determining the cardiotoxicity or proarrhythmic effect of a drug compound in vitro, the method comprising: 
            (i) obtaining immature cardiomyocytes derived from human induced pluripotent stem cells, wherein the immature cardiomyocytes exhibit a single nucleus; 
                (ii) contacting the immature cardiomyocytes with an extracellular matrix obtained from culturing isolated cells from amniotic fluid obtained from a human at greater than 37 weeks of gestational age (AFC-ECM), wherein the AFC-ECM comprises laminin, collagen alpha-1 (XVIII), basement membrane-specific heparan sulfate proteoglycan core protein, agrin, vimentin, and collagen alpha-2 (IV), or isoforms thereof; 
                (iii) culturing the immature cardiomyocytes with the AFC-ECM in a culture media to form a layer of mature cardiomyocytes on the AFC-ECM, wherein the mature cardiomyocytes exhibit two nuclei; and 
                (iv) contacting the drug compound with mature cardiomyocytes and observing for a change in the electrophysiology of the mature cardiomyocytes to confirm whether the drug compound has a cardiotoxic or proarrhythmic effect on the mature cardiomyocytes. 
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