Scientists at University of California at Berkeley have induced pluripotent stem cells to form miniature hearts by using special scaffolds. Induced pluripotent stem cells are adult cells that have been genetically reprogrammed to be like embryonic cells that are capable of producing nearly any other cell.

Stem cells don’t just spontaneously form into us. The structure of the womb helps determine how the cells organize themselves. Designing the right biophysical scaffold is important, so they end up in the correct shape. The scientists have found a specific cell-patterning method to direct stem cells to form not only microchambers, but beating ones.

Ma, Z. et al. Self-organizing human cardiac microchambers mediated by geometric confinement, Supplementary Movie 1. Nat. Commun. 6:7413 doi: 10.1038/ncomms8413 (2015)
. Image 1.Ma, Z. et al. Self-organizing human cardiac microchambers mediated by geometric confinement, Supplementary Movie 1. Nat. Commun. 6:7413 doi: 10.1038/ncomms8413 (2015)

This could be a very important step on the way to growing new organs via your already existing cells. Even as microhearts, they’re already useful as they can be used to test the safety of drugs on a pregnant woman’s embryo’s organs, without a human trial.