In a harshly lit laboratory in Winston-Salem, North Carolina, there sits a machine that is, in many ways, similar to a standard-issue desktop printer. It has ink reservoirs and nozzles, an internal fan to keep it cool, and a set of input jacks that can be used to connect it to a nearby computer. It is subject to the occasional jam. And yet the 800-pound steel and plastic device is unlike anything you’ve ever encountered, because what it prints is alive — millions and millions of living human cells, contained in a viscous gel and woven through delicate biodegradable supports in a quivering simulacrum of human tissue.
It took a decade for numerous scientists and engineers to build and refine the Integrated Tissue and Organ Printing System, or ITOP. Ultimately, though, it’s the brainchild of a single man — a tousle-haired 59-year-old doctor named Anthony Atala. Born in Peru, and raised outside of Miami, Atala — today the director of the Wake Forest Institute for Regenerative Medicine — has spent the past decade attempting to print living organs. “For me, it all started back in Boston, in the early 1990s,” recalls the urologic surgeon and biotechnologist. “Because that’s when I really came face to face with the transplant organ shortage.” At the time, Atala was working his first post-medical school gig, as a research fellow at Harvard Medical School. In 2004, Atala agreed to spearhead such an initiative at Wake Forest, which is not far from North Carolina’s Research Triangle, a biotech hub and home base for a handful of 3D-printing companies. Over the years, Atala and his staff have been able to develop printers capable of printing customised scaffolding of human organs, which could be manually coated with human or animal cells. Then they constructed a printer that could print skin cells directly onto a patient, albeit in extremely small amounts. But printing of tissue turned out to be a big challenge, partly because the expanding tissue also requires a steady flow of blood and nutrients. They could print the cells for an organ, or they could print blood vessels and other supporting tissue, but they couldn’t manage to print both at the same time in such a way that the organ would survive.
Then came the ITOP, with its essential breakthrough technologies. Unique reservoirs keep human and animal cells alive for longer than earlier printer models; and extremely precise needles, or jets, print a latticework of “microchannels,” measuring 200 microns each, into the biomaterial. These vessels allow nutrients to flow through the tissue. In a paper published earlier this year in Nature Biotechnology, Atala and five Wake Forest researchers revealed that cartilage, bone and muscle tissue printed on the ITOP had been successfully implanted in rodents and that, two months later, the tissue had developed a system of blood vessels and nerves. Tests on human patients will likely follow in the next year or so, pending government approval.
(Source: www.smothsonianmag.com)
