The emerging process of 3D printing, which uses computer-created digital models to create real-world objects, has produced everything from toys to jewelry to food. Soon, however, 3D printers may be spitting out something far more complex, and controversial: human organs.

 

Researchers are working diligently to create human organs and body parts through the use of a 3D printer. The 3D printer works in much the same way an inkjet printer does - with a needle that squirts material in a predetermined pattern. Instead of ink, the printer uses cells or human tissue. 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

 

Bioprinting works like this: scientists harvest human cells from biopsies or stem cells, then allow them to multiply in a petri dish. The resulting mixture, a sort of biological ink, is fed into a 3D printer, which is programmed to arrange different cell types, along with other materials, into a precise three-dimensional shape.

 

Doctors hope that when placed in the body, these 3D-printed cells will integrate with existing tissues.

 

For years, researchers have been printing skin, blood vessels, and other biologic structures. Now, efforts are underway to construct complete organs - this is much more difficult to do. Last year a 2-year-old girl in Illinois, born without a trachea, received a windpipe built with her own stem cells.

 

At the University of Louisville researchers are making progress - although it may be years before the first 3D printed organ is transplanted into a human.

 

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.

 

Ultimately, we are probably five years away from actually being able to transplant a human heart that has been printed in this way.

 

An organ built from a patient's cells could solve the rejection problem some patients have with donor organs or an artificial heart, and it could eliminate the need for anti-rejection drugs

 

It is many researchers hope that 3D printers could someday produce much-needed organs for transplants. Americans are living longer, and as we get deeper into old age our organs are failing more. Some 18 people die in the United States each day waiting in vain for transplants because of a shortage of donated organs.

 

Approximately 3,000 people in the United States are on the waiting list for a heart transplant on any given day. About 2,000 donor hearts are available each year. Wait times vary from days to several months and will depend on a recipient's blood type and condition.

 

But plenty of difficulties remain, including understanding how to keep manufactured tissue alive after it is printed. With complex organs such as the kidney and heart, a major challenge is being able to provide the structure with enough oxygen to survive until it can integrate with the body.

 

The first patients would most likely be those with failing hearts who are not candidates for artificial hearts, including children whose chests are too small to for an artificial heart.