The study, led by Dr. Kenji Miki, a cardiovascular surgeon at Osaka University Graduate School of Medicine, appears in the May issue of STEM CELLS Translational Medicine.
Miki's team removed adult stem cells from 30 female mice and genetically modified them to mimic embryonic stem cells. They then used the modified stem cells to grow sheets of healthy heart muscle tissue and implanted them into rats with damaged heart muscle.
The implanted tissue sheets survived for four weeks and the damaged hearts of the rats that received them began to heal, they found.
"The tissue we developed not only survived but improved heart function," Dr. Miki said. "We believe this study could lead to a very real procedure to regenerate the heart."
Implanting the new cells in sheet form appeared to improve their ability to transfer to the damaged host cells, he added.