Jul 03, 2012 5:24 PM GMT
Growing artificial organs takes another big step.
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.
The study appears in the journal Nature Materials.
Dr Jordan Miller from the lab of the lead scientist, Dr Christopher Chen, at the University of Pennsylvania, told BBC News: "The big challenge in understanding how to grow large artificial tissue is how to keep all the cells alive in these engineered tissues, because when you put a lot of cells together, they end up taking nutrients and oxygen from neighbouring cells and end up suffocating and dying."
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Sugar is a very nice material that can be dissolved away in the presence of living tissue, it's very friendly to biological tissue ”
Prof Sangeeta Bhatia
The body's cardiovascular system - blood vessels - solves this issue with natural cells and tissues.
So a group of scientists from the University of Pennsylvania and the Massachusetts Institute of Technology (MIT) decided to build a synthetic vascular system that would serve the same purpose - by creating a place where the future artificial blood vessels would be located.
Dr Miller's colleague Prof Sangeeta Bhatia, from MIT, said that the technique was similar to creating the shape of a vase in wax, surrounding it with molten metal and then melting the wax away.
But instead of wax, the team used sugar.
"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," said Prof Bhatia.