Organovo and Bioprinting

Bioprinting is printing cells on "biopaper" made of collagen. The cells come out in a matrix of gel that protects them as they print. The bioink (cells) are printed in groups of thousands of cells

Diagram from ExplainingTheFuture.com

Eventually, we will be able to print organs that won't be rejected by bodies, because they will be made of the same cells as the rest of the body. This would be a huge development for medicine because huge numbers of people  are on waiting lists for organs without enough donors.

An Interview with Mike Renard of Organovo ( A 3D printing company) on Bioprinting

 - blog post by starspatteredsky

UPDATE:  An excellent, comprehensive article on this subject was (2D!) printed in the August 2013 issue of Popular Science.  Read more here.