Almost 100,000 people languish on organ-transplant waiting lists. But new tissue-fabrication techniques should make swapping in a man-made liver as easy as snapping Lego bricks into place.
Method: 3-D printer
When: 5 years
Gabor Forgacs, a tissue engineer at the University of Missouri, is making blood-vessel networks by culturing three types of vessel cells and loading them into a fridge-size bioprinter. This machine prints out the cells to build capillaries in preprogrammed patterns.