The present disclosure provides compositions and methods for the reprogramming of cells such as fibroblasts into cardiomyocytes. The invention provided herein features a chemically defined media and methods of reprogramming cells to increase cardiac gene and protein expression in cardiac fibroblasts and other fibroblasts, e.g. dermal fibroblasts. The media and methods also enhance miR-combo mediated cardiac reprogramming of fibroblasts to cardiomyocytes. Thus, the invention encompasses a chemically defined reprogramming media comprising a base tissue culture media, insulin-transferrin-selenium (ITS) or ascorbic acid in a somatic cell-reprogramming, e.g., fibroblast-to-cardiomyocyte-reprogramming, amount.
