Cardiac spheroids boost early survival after heart attack in mice
Danish biologists from Professor Ditte Caroline Andersen’s lab at the University of Southern Denmark transplanted mice with induced heart attacks and weakened immunity with cardiomyocytes derived from stem cells — either as loose single cells or as dense spheres of 250 cells. In the first two days, 92% of mice receiving spheres survived, compared with 36% receiving single cells and 50% receiving no cells. The results were posted as a preprint on bioRxiv on 11 September.
After a heart attack the heart can lose up to a billion cardiomyocytes and cannot replace them; the adult heart lacks resident stem cells. Regenerative medicine produces such cells from induced pluripotent stem cells (iPSC) and transplants them — worldwide 12 clinical trials have been registered. Single cells wash out of the injection site and die without neighbor contact, while engineered patches persist longer but integrate poorly with cardiac tissue. Spheres represent a compromise: aggregates of several hundred cells delivered through the same thin needle, with preserved intercellular contacts that aid survival during injection.
To eliminate immune confounding, the authors used the new mouse line NXG B2m, which lacks B and T lymphocytes, natural killer cells, and the gene that normally displays the “self” marker for immune surveillance. The procedure itself was nearly lethal: of 49 mice, only 50% survived the first two days with the vehicle
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bioRxiv
Poor survival after myocardial infarction in immune deficient NXG B2m mice is alleviated by transplantation of induced pluripotent…
The human heart lacks cardiac stem cells and the ability to reestablish the loss of ventricular cardiomyocytes (vCMs) after myocardial infarction (MI) resulting in heart dysfunction. vCM replacement using intracardiac transplantation of human induced pluripotent…
September 18, 2026 11
