According to the British Heart Foundation, over a quarter of all deaths in the UK are caused by heart and circulatory diseases. One study from the University of Minnesota, published in July, gives hope that this number may soon decline. It reports the successful creation of a functioning scaled-down human heart pump using a 3D printer. High densities of human stem cells were printed onto an extracellular matrix and then reprogrammed to create muscle tissue. This 1.5cm long piece of muscle was able to beat just like a human heart.