Researchers have managed to turn a spinach leaf into working heart tissue and are on the way to solving the problem of recreating the tiny, branching networks of blood vessels in human tissue.

Until now, scientists have unsuccessfully tried to use 3D printing to recreate these intricate networks.

Now, with this breakthrough, it seems turning plants with their delicate veins into human tissue could be the key to delivering blood via a vascular system into the new tissue.

Scientists have managed in the past to create small-scale artificial samples of human tissue, but they have struggled to create it on a large scale, which is what would be needed to treat injury.

Researchers have suggested that eventually this technique could be used to grow layers of healthy heart muscle to treat patients who have suffered a heart attack.