Cell Transplantation—A Potential Therapy for Cardiac Repair in the Future?

Adult human myocardium lacks the possibility of regeneration because cardiac muscle cells do not reenter the cell cycle. Transplantation of myoblasts, cardiomyocytes, and stem-cell-derived cardiomyocytes has been done in experimental settings to replace lost myocardial tissue. This paper reviews the experimental data about cell transfer into myocardium and highlights the advantages of the particular cell types used. Transplantation of myoblast would enable an autologous transfer. They can be easily obtained and expanded in culture. Gene transfer is possible, and there exist no ethical reservations against a myoblast transfer. However, their integration in the heart tissue and final differentiation is not clear yet. Fetal cardiomyocytes are integrated in the myocardial tissue, improve cardiac function, and can be expanded in culture. However, their transfer would be allogenic, making immunosuppression necessary. Stem-cell-derived cardiomyocytes could be used to replace all three types of cardiac muscle cells. They can be expanded in culture. The possibility of teratoma formation makes a 100% selection mandatory. At present, there exist ethical concerns against working with human embryonic stem cells. Cell transfer therapy has been shown to improve myocardial function in animal experiments. This indicates that a reduced myocardial function could be improved by a cell transfer therapy. Especially stem cell-derived cardiomyocytes would allow for selective replacement of pacemaker cells or atrial or ventricular cardiomyocytes.