3D printing using sugar could help to grow artificial livers for transplants

Researchers in the United States say that they are close to creating a synthetic liver after making a template for blood vessels to grow into using sugar.
 
For several years boffins have been attempting to create tissue structures of cells and blood vessels using 3D printing methods to build up layers of artificial cells but each time the cells have died before the project can be completed.

The experts believe that the 3D printing which uses sugar to build materials could one day come in handy for transplant procedures.

"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," Dr Jordan Miller from the lab of the lead scientist, Dr Christopher Chen, at the University of Pennsylvania, told BBC News.

Experts from the University of Pennsylvania and the Massachusetts Institute of Technology (MIT) decided to construct an artificial vascular system that would serve the purpose that blood cells normally do with tissue.

Prof Sangeeta Bhatia, from MIT, said: “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.

"We created a network of places that we wish vessels to grow into, so they would become piping into the tissue, and we printed those in 3D out of sugar.

"Sugar is a very nice material that can be dissolved away in the presence of living tissue, it's very friendly to biological tissue.

"We then surrounded the network with the cells that we would like to be fed by the blood vessels when the tissue is implanted - and once we have this structure of pipes-to-be and tissue, we dissolve away the sugar using water."

Prof Martin Birchall, a surgeon scientist at University College London, said that he is fascinated by the research but believes “they're quite a way from clinic yet”.