Double the chromosomes, stronger the heartbeat: Japan's lab-grown heart cells grow up

Most adult heart-muscle cells carry double the usual chromosomes — and scientists in Tokyo wondered whether that is part of what makes them strong. A team led by Yuichiro Miyaoka at the Tokyo Metropolitan Institute of Medical Science fused stem cells to create doubled-chromosome (tetraploid) versions, then grew them into heart cells. The doubled cells came out larger, richer in mitochondria — the cell's power stations — and contracted more strongly and rapidly than ordinary ones, with a more mature, adult-like profile. Published in Communications Biology, the work could make lab-grown heart cells better tools for testing medicines and, one day, for repairing failing hearts.

SDG 3 · Good health and well-being — Mechanism: tech innovation