A huge limitation to the advancement of 3-D printing of organic tissue has been supplying them with blood throughout the process. But enthusiasts have reason to hope.
The evolving 3-D printing process excites people for several reasons. The technology's capable of making complex shapes quickly, and it's a great way to produce parts to test for form and function in early manufacturing stages. However, most operators currently use plastic or light metal alloys for relatively large objects.
But what if the technology could print human organs and microfibers on a large scale?
Scientists are already printing tiny strips of living tissue, and they hope to print entire human organs as the technology grows in sophistication. In a process called "bioprinting," doctors could use isolated organs and tissue to test vaccines and other biological agents without worrying about harming animals or relying on inaccurate modeling programs. And the process, once perfected, could produce entire body parts for patient transplants.
According to CNN, 3-D bioprinting involves harvesting living cells from biopsies or stem cells before allowing them to multiply in a petri dish. Scientists feed this "biological ink" into a 3D printer that converts the cells into a 3-D shape that may integrate with existing tissue when placed inside of or onto a host body.
Gastroenterologist Dr. Jorge Rakela essentially told CNN that the technology could transform medicine. "This is an exciting new area of medicine," he said. "It has the potential for being a very important breakthrough.
The world's zeal for 3-D printing will increase, as will the medical community's involvement. According to Bloomberg, the market for 3-D printing reached $777 million in 2012, and it may grow to $8.4 billion in 2025 as medical applications come into play.
Current applications hold promise, but some incorporate non-organic issue for a cybernetic result. Princeton scientists 3-D printed a bionic ear last year that could hear beyond a regular human's natural ability. They printed human cells and nanoparticles, and bonded them with antenna and cartilage to create the body part. They created an ear that heard radio frequencies a million times higher than human ears can. Princeton researcher Michael McAlpine told Mashable that it was intended for demonstration purposes rather than actual application.
"The idea of this was: Can you take a normal, healthy, average human and give them [a] superpower that they wouldn't normally have?" he said.
Other researchers also are developing the technology to produce microscopic materials. Harvard scientist Jennifer Lewis and her students have printed microscopic components, including electrodes, that could be used to make lithium-ion batteries. This year, they also manufactured a patch of tissue with blood-vessel-like material inside that can carry actual blood.
She's adapted 3-D printing to make it more sophisticated, with "inks" comprising materials that are more diverse than plastic and metal, and also high-precision printing platforms with fine nozzles.
Lewis told the Wyss Institute last year that her team's approach was "distinct from commercially available 3-D printers because of its materials flexibility, precision and high throughput."
3-D printing's evolution will continue for the foreseeable future, especially when it comes to organic tissue. A huge limitation to the advancement of 3-D printing of organic tissue has been supplying them with blood throughout the process. Additionally, living tissue is more complex than anything else that's currently being created. But enthusiasts have reason to hope with developments like Lewis's blood vessel work.
Anthony Vicari, an analyst at Boston-based Lux Research, told Bloomberg that 3-D printed organs are possible, but it will be a while before they become reality.
"Organs are foreseeable, but that's a long-term goal," Vicari said. "That requires not just the better printing technology, but much better understanding of tissue engineering."