Three-dimensional (3D) printing is an emerging technology that will almost certainly revolutionize many aspects of our lives. These new, highly sophisticated printers essentially “print” multiple layers of a compound, such as metal or plastic, to construct 3D objects. New machines are being developed that can print with increasing precision and efficiency, and new materials are being added to the list of “inks” that the machines can print. The technology offers considerable benefits to manufacturers who can “print” components using minimal amounts of material, thereby eliminating the waste associated with conventional manufacturing practices. In fact, the European Space Agency has embraced the technology as a way to print ultra-light metal components for its aircraft and space vehicles. And as the cost of 3D printers declines (some machines now cost only a few hundred dollars), they will become a boon for hobbyists wishing to design and construct novel objects. On a darker note, nefarious uses are also possible, such as the recent construction of a working gun from printed components.
Since the technology is so new, there are likely many possible uses and benefits yet to be discovered. However, one area that is creating a great deal of excitement is the use of the technology in the biomedical field. At the basic research level, scientists have been able to construct 3D structures from protein that contain a series of “rooms” in which individual bacteria can be held. This allows researchers to study communication between bacteria under highly controlled conditions and is advancing our understanding of how bacterial resistance to antibiotics is transferred between individual bacteria.
The technology is also finding a growing role in modern medicine. One company is printing small strips of liver tissue that can be used to test new drugs for efficacy and toxicity. Other advances include the printing of fitted components for hearing aids, hip implant cups and dental crowns and for printed patient-specific surgical guides to assist during surgery. 3D printing has also been used to create surgical splints. For example, a printed splint was used to save the life of a baby born with a condition called tracheobronchomalacia, which results in the lack of support for the trachea. The splint was custom-printed for the baby’s throat and used to guide the development of the baby’s trachea.
Perhaps one of the most exciting promises of 3D printing is the creation of brand new organs for transplant patients. This new technology will allow designer organs to be created using the individual’s own cells, thereby potentially eliminating the need to find a donor match. The basic idea is to print layers of live cells along with a biomatrix that supports the structure. The printer can be programmed to print a variety of cells in each layer, potentially constructing a fully functioning organ. Of course, the architecture of the body’s organs is complex, involving multiple tissues and an intricate network of blood vessels and nerves. But the technology is advancing rapidly, and there is every reason to believe that all of the technical challenges can be met in the future, including the ability to print a 3D vasculature directly into the organ during construction. The current challenge is to prevent “printed” blood vessels from collapsing after printing. One potential solution is to print a supporting material in the blood vessels that can be melted away under the right conditions. Such an approach is currently under development by doctors at Harvard University. It should also be noted that the body has the ability to spontaneously grow new blood vessels into transplanted organs, perhaps reducing the need to print them all that extensively in the first place.
While we are still many years away from truly printing vital internal organs ready for transplantation, there have already been some amazing successes in printing bone- and cartilage-based structures. For example, just this year, researchers in Belgium printed a new jawbone for a woman. And cartilage-based structures, such as ears, have also been successfully printed. For those of you who are fans of the show Star Trek, you may remember the “replicator” that was used to produce all sorts of foods including cooked meals. At the time, the concept seemed ridiculously futuristic. But maybe that future is already upon us. Time to print a Scotch on the rocks.
David L. “Woody” Woodland, Ph.D. is the Chief Scientific Officer of Silverthorne-based Keystone Symposia on Molecular and Cellular Biology, a nonprofit dedicated to accelerating life science discovery by convening internationally renowned research conferences in Summit County and worldwide. Woody can be reached at 970-262-1230 ext. 131 or firstname.lastname@example.org.