Following a myocardial infarction (heart attack), cardiac muscle tissue is permanently damaged because mature cardiomyocytes have extremely limited regenerative capacity. A promising therapeutic approach involves transplanting functional cardiomyocytes grown in a laboratory.

What type of unspecialised cells, characterized by their ability to differentiate into any cell type of the three embryonic germ layers but not extraembryonic tissues (such as the placenta), are used to generate these replacement cardiomyocytes?