Scalable generation of cardiomyocytes from mouse embryonic stem cells

Summary form only given. Cardiomyocyte transplantation could offer a new approach to replace scarred, nonfunctional myocardium in a diseased heart. The present work describes a bioprocess for the generation of cardiomyocytes from differentiating mouse embryonic stem (ES) cells. ES cells transfected with a fusion gene consisting of the alpha-cardiac myosin heavy chain (MHC) promoter driving the aminoglycoside phosphotransferase (neomycin resistance) gene were inoculated into bioreactors, differentiated for 11 days, and selected using G418 for 8 days. The resulting embryoid bodies (EBs) were enzymatically dissociated, and cellular expression of sarcomeric MHC was assessed by flow cytometry using a monoclonal antibody. The fraction of MHC positive cells increased from <1% at culture initiation to ∼80% by day 19, which represented a yield of cardiomyocyte per input ES cell of ∼30%. These findings demonstrate the feasibility of large-scale production of viable, ES cell-derived cardiomyocytes for tissue engineering and/or implantation.