From Singularity Hub: "Wake Forest's Institute for Regenerative Medicine (WFIRM) and the Armed Forces Institute for Regenerative Medicine (AFIRM) have developed a skin printer that can deposit cells directly onto a wound to help it heal faster. They recently presented the results of their latest experiments at the American College of Surgeons Clinical Congress (ACSCC) in Washington DC. Mice given topical wounds were able to heal in just three weeks when a new skin was printed onto the damaged area (compared to 5-6 with control groups). WFIRM and AFIRM also stated that the skin printer had been tested to see if it could print human cells, but that the next step forward would be experiments on pigs. If ultimately successful, skin printers could revolutionize the way we treat injuries - making serious wounds less fatal and rapidly speeding the healing of other injuries. ... the recent conference [gives] some valuable insights into how the skin printer actually works. Two different printing heads are used - one with skin cells, a coagulant, and collagen; the other with a different kind of coagulant. Keeping these substances separate allows them to be deposited easily (like ink) but then quickly bond together and form a solid skin covering with fibrin."

Link: http://singularityhub.com/2010/11/04/wake-forest-could-print-you-some-new-skin/