Researchers have moved a step closer to creating a synthetic liver, after a US team created a template for blood vessels to grow into, using sugar. Scientists have long been experimenting with the 3D printing of cells and blood vessels, building up tissue structure layer by layer with artificial cells. But the synthetically engineered cells often die before the tissue is formed.
The technology, in which a 3D printer uses sugar as its building material, could one day be used for transplants. So far, it's been difficult to make organs big enough so that they could provide useful function - and if you implant any tissue thicker than about a millimetre, we can't provide it enough nutrients without also engineering blood vessels into the tissue. Sugar is a very nice material that can be dissolved away in the presence of living tissue, it's very friendly to biological tissue and a 3D matrix out of sugar can be easily printed. You can use these types of biomaterials, cells or a combination of them, and a group of scientists has now correctly identified that the sticking point in all this is going to be vascularity - blood vessels - making sure that you've got sufficient nutrients going in and waste coming out of something that otherwise is going to be a solid block of tissue that cannot be maintained inside a living organism.