Fit to print

摘要

The climax of "Sleeper", a futuristic fantasy from the 1970s that was directed by, and starred, Woody Allen, has Mr Allen's character throw the preserved, disembodied nose of a dictator beneath a steamroller. In a movie filled with orgasmatrons and car-sized bananas, it is a last absurd gesture that vanquishes the villains. If the film were made today, though, those villains might simply print another nose. The idea of printing organs has moved beyond the realm of fantasy, as the technology of three-dimensional printing (in which layers of material are laid down one at a time to create a solid object) has improved. Though implantable organs are still beyond reach, researchers have used the technique to build layers of cells into living tissues.