Science : Scientists are attempting to build a human heart with a 3D printer

Ultimately, the goal is to create a new heart for a patient with their own cells that could be transplanted. It is an ambitious project to first, make a heart and then get it to work in a patient, and it could be years -- perhaps decades -- before a 3D printed heart would ever be put in a person.

So far, the University of Louisville team has printed human heart valves and small veins with cells, and they can construct some other parts with other methods, said Stuart Williams, a cell biologist leading the project. They have also successfully tested the tiny blood vessels in mice and other small animals, he said.
The 3D printer works in much the same way an inkjet printer does, with a needle that squirts material in a predetermined pattern.

The cells would be purified in a machine, and then printing would begin in sections, using a computer model to build the heart layer by layer. Williams' printer uses a mixture of a gel and living cells to gradually build the shape. Eventually, the cells would grow together to form the tissue.

Williams believes they can print parts and assemble an entire heart in three to five years.
The finished product would be called the "bioficial heart" -- a blend of natural and artificial.