Celprogen, it would seem, is ahead of many research labs worldwide---and probably the envy of many---as they have produced a 3D printed heart created with a PLA scaffolding that holds adult cardiac stem cells. This technology may indeed one day pave the way for 3D printed organs that can actually be used in transplants. Working toward this cause, the Celprogen team is also in the process of making their own 3D printer so that they will have full control over the cells and resulting bioprints. Read more at 3DPrint.com: https://3dprint.com/149998/celprogen-3d-printed-heart/