If you’re on the waiting list for a life-saving organ transplant today–along with 122,596 other Americans–there’s a fairly good chance you won’t ever have the operation you need. An average of 22 people die in the U.S. each day waiting for a transplant.
But in the not-so-distant future, patients may no longer have to rely on organ donors and chance. Researchers at Carnegie Mellon University have pioneered new technology that could eventually be used to 3-D print a heart or liver.
A fake heart might even work better than a real one. “We can actually base the organ on your own anatomy,” says Adam Feinberg, an associate professor of materials science and engineering and biomedical engineering at Carnegie Mellon University, who leads a group that developed the new bioprinting method. “We can essentially take a medical scan, an MRI or CT of your body, and make something that fits you perfectly.”
The technology could also potentially be used with a patient’s own cells, eliminating the chance that the organ will be rejected, or the need for immuno-suppressing drugs that can cause more problems. A 3-D printed organ could also be healthier than one donated from someone who, say, didn’t exercise or eat well.
“The organ that you have transplanted is going to have a history of whoever donated that organ,” Feinberg says. “Obviously every one of us chooses to live our life differently, so there’s actually pretty wide variability in the quality of organs. But if we’re building it we can essentially ensure a certain level of quality control.”
While the new 3-D printing technology can’t print a full organ yet, it’s a step closer to that possibility. In the past, 3-D printing soft objects–like tissue–didn’t work very well.
“The challenge with soft materials is that they deform under their own weight,” he says. “They’re not rigid enough to support themselves, so once the layers starts to shift its position, anything you try to put on top is no longer going to be in the correct place relative to the layer below it. And then it just kind of gets worse and worse as you build up to a larger object.”
To solve the problem, the researchers took a new approach. “We came up with the idea that maybe we could do something more like a Jello mold, like the dessert,” he says. “Everyone who’s seen a Jello mold realizes that people very often put fruit or other things inside the Jello and they can stay there and not ever move, even though the whole Jello mold is soft.”
Using gelatin–the same thing you’d buy in the baking aisle at the grocery store–they created tiny microparticles and turned them into a squishy support structure. A needle can easily pass through the particles, but anything that comes out of the needle will stay in place. A 3-D printer can shoot delicate living cells through a syringe into the goo. Later, when everything is heated to body temperature, the support structure melts away, but the printed tissue remains.
The technique could also be used to create new tissues for testing drugs. Mice or rats, commonly used in testing today, don’t represent human physiology well, and human trials are extremely expensive–one of the reasons that new pharmaceuticals are also expensive. “We can create models of human tissue and organs in the dish that we can do this development on, and that should make it faster and cheaper to develop drugs,” Feinberg says.
Before the technology can actually be used to print usable tissue and organs, the stem cell community will also have to solve the problem of the cells that will be used in printing–both supplying the stem cells themselves and turning them into the right type of cell, whether it’s a muscle cell or a nerve cell.
“The way I envision it is that people doing stem cell biology are hopefully going to progress the field at the same time that we’re progressing the fabrication technology,” says Feinberg. “And that hopefully in five or 10 years we’ll be a position where we can effectively start to combine these technologies to create usable tissues.”
To make progress happen faster, the researchers made their tech widely accessible. Other bioprinters often cost over $100,000; they hacked a $1,000 MakerBot, and released open-source instructions for how to do it on the NIH website.
“The idea there just to have as many people using this technology as possible,” says Feinberg. “It should be a toolset that the bioengineer has and being able to accelerate the adoption of all of the promises that these technologies hold.”