Three-dimensional printing has been used to make everything from pizza to prostheses, and now researchers are working on using the emerging technology to fabricate hearts, kidneys, and other vital human organs.
That would be very big news, as the number of people who desperately need an organ transplant far outstrips the number of donor organs available. On average, about 21 Americans die every day because a needed organ was unavailable.
What exactly is the promise of 3D printing organs and tissues, or "bioprinting?" How does the technology work, and when might it start saving lives?
For answers to these and other questions, HuffPost Science reached out to Dr. Anthony Atala (right), director of the Wake Forest Institute for Regenerative Medicine and a world-renowned expert in the field, to find out.
See below for a lightly edited version of the Q & A.
Can 3D printing end the shortage of organs?
3D printing is not magic. It is simply a way to scale up the current processes we use to engineer organs in the laboratory. Our team has successfully engineered bladders, cartilage, skin, urine tubes and vaginas that have been implanted in patients. Our goal is produce organ structures such as these with 3D printing to make the engineering process more precise and reproducible. The ultimate goal of regenerative medicine -– regardless of the way the organs are engineered -- is to help solve the shortage of donor organs.
How might 3D-printed organs compare to donor organs?
Our goal is to engineer organs using a patient’s own cells. With this approach, there would be no issues with rejection, and patients wouldn’t have to take the powerful anti-rejection drugs that are now required. This is certainly one advantage of customized organs.
What's the actual process by which organs would be "printed?"
A first step in organ engineering –- whether it involves 3D printing or other methods –- is to get a biopsy of the organ that needs to be replaced. From this biopsy, certain cells with regenerative potential are isolated and multiplied. These cells are then mixed with a liquid material that provides oxygen and other nutrients to keep them alive. This mixture is placed in a printer cartridge. A separate printer cartridge is filled with a biomaterial that will be printed into the organ- or tissue-shaped structure. The structure is designed on a computer using a patient’s medical scans.
When happens when you press the "print" button?
When the “print” button is pushed, the printer builds the structure layer by layer and embeds cells into each layer. When cells are provided the right mixture of nutrients and growth factors –- and placed in the right environment -- they know what to do and perform their functions. For some structures, two or more types of cells may be required.
(Story continues below image.) A 3-D printer at Wake Forest Institute for Regenerative Medicine at work on a kidney prototype.
What challenges are you facing?
Scientists have successfully engineered three categories of organs: flat structures such as skin; tubular structures such as urine tubes and blood vessels; and hollow structures such as the bladder. The most complex organs are solid structures such as the kidney, liver, and pancreas. Some of the challenges we face with these organs are learning to grow the billions of cells required for these organs, as well as learning how to best supply the new organs with oxygen until they integrate with the body.
We are exploring a variety of options that include printing oxygen-generating materials into the structures; printing micro-channels that can maximize the diffusion of nutrients and oxygen from nearby tissues; and printing blood vessels into the structures.
How many years away are we from printing complex organs like the heart and kidney?
Science is unpredictable, so it is impossible to make predictions. But I think we can safely say that the timeframe required to routinely print and implant complex organs is decades, rather than years.
What are some recent breakthroughs that have brought us closer to making 3D printed organs a reality?
We are continuing to refine our printers to increase printing resolution and learning how to keep the printing process from damaging cells. In addition, we are making advances in identifying which biomaterials work best for specific structures. And, we are great making strides printing with multiple cells types and controlling placement of cells.
What are the next steps?
One relatively new bioprinting project, funded by the Defense Threat Reduction Agency, aims to print mini hearts, livers, blood vessels, and lung on a chip system. Called a “Body on a Chip,” this project has the potential to test new drugs more accurately and perhaps eliminate the need for testing in animals. The immediate goal is to test effects on the body of biological weapons and to develop antidotes.
To learn more about regenerative medicine and Dr. Atala's vision for 3D printing organs, check out his 2011 TEDTalk below.