Washington , D.C.—Designing organs on a computer and printing them out in a matter of minutes definitely beats growing them in vats. But is it possible? Scientists speaking today at the annual meeting of the American Association for the Advancement of Science (which publishes ScienceNOW) say the technology is closer then you might think, and could revolutionize transplantation and wound repair.
Using skin cells as ink and a human body as paper, James Yoo of Wake Forest University School of Medicine in Winston-Salem, North Carolina, has designed a printer that can analyze a burn. First, it uses a laser scanner to determine the exact size and shape of the lesion. Then it creates a 3D reconstruction. Finally, it prints the layers of different cells needed—all in less than an hour. Yoo, whose work is funded by the U.S. Department of Defense, said that the project was motivated by the fact that 30% of battlefield injuries involve burns. "Using bioprinting, we thought we could address some of the challenges they face in burn care," he said.
Although the bioprinted skin might not be a permanent fix for severe burns, the technology is portable enough to bring to a battlefield and fast enough to prevent the loss of precious bodily fluids. The printer would be stocked with one or more inkjet reservoirs of human skin cells, not the donor's own, sparking an allergenic reaction that would initiate the body's own healing processes. So far, his group has been able to print skin patches as large as a 10 cm x 10 cm patch on a pig. They hope to someday repair scars with the donor's own cells, a slower process but one that will more effectively prevent rejection.
While skin is fairly two-dimensional and can easily be placed on a body, three-dimensional organs present a different challenge. Cornell University engineer Hod Lipson has developed a similar bioprinting technology using a 3D printer to print cells, layer upon layer, into a 3D structure. Printing organs rather than growing them as cells on a scaffold, he says, is a better way to entice blood vessels to grow into the center of an organ, which is one of the major difficulties in current regenerative biology. His bioprinter could print them right in, although integrating the organ into a body is another challenge, he said.
Cell biologist Vladimir Mironov from the Medical University of South Carolina in Charleston listed several applications for bioprinted organs, including using them in labs to do drug discovery and manufacturing organs for transplants. "If you could turn the operating room in a [hospital] building into a plant, it would save money on health care," he said.
Although a liver is far too complex to print at this point, Lipson said, his group has had success with printing cartilage, since the cells are easy to print and have simple connective structure. His group has printed cells directly into the meniscus of an injured knee to reconstruct it, and at the AAAS meeting, he printed an ear out of silicon in about 20 minutes.
The speakers warned that printers will only produce "meat-flavored Jell-O" until the anatomy of different structures is better understood. But Yoo said that he expects skin printing to be ready for use within a few years and to become standard practice for burn repair within 20 years.