Medical 3D Printing & Bioprinting
Researchers at Lawrence Livermore,California , have successfully 3D printed live blood vessels from cells and organic material. These vessels are capable of self-assembling and delivering nutrients, but are being worked on for further organization before they can be used in real transplants.
Source: http://www.engadget.com/2015/12/06/scientists-3d-print-live-blood-vessels/