Chemically defined generation of human cardiomyocytes

Cardiac differentiation strategy using a chemically defined medium consisting of just three components: the basal medium RPMI1640, l-ascorbic acid 2-phosphate and rice-derived recombinant human albumin. This protocol produced contractile sheets of up to 95% TNNT2+ cardiomyocytes at a yield of up to 100 cardiomyocytes for every input pluripotent cell. They first assessed chemically defined pluripotent culture on other defined matrices: rh E-cadherin, rh vitronectin, laminin-521, iMatrix-511, human fibronectin and a fibronectin mimetic. Laminin-based matrices resulted in higher growth rates com­pared to the vitronectin peptide. Fibronectin-based matrices did not support pluripotent growth. All five suitable matrices supported efficient differentiation in CDM3 but only the laminin-based matrices main­tained long-term adhesion (>15 d) during CDM3 cardiac dif­ferentiation. The authors state that laminin-521 is an optimal matrix for chemically defined differentiation of human iPSC to cardiomyocytes but they still performed all subsequent characterization on the vitronectin peptide due to cost awareness.