The December 2009 press release created quite a stir: Organovo, a San Diego-based company that specializes in regenerative medicine announced a new $200,000 bioprinter that prints artificial organs using inkjet technology. Partner engineering firm Invetech in Melbourne, Australia designed and developed what may well turn out to be the world’s first production model 3D bioprinter:
Yes, artificial organs… kidneys, esophagi, bladders, muscles, cartilage, ureters, glands, trachea, bone, breast lung, uterus, testes, nerves, livers, and even hearts. Need a new retina? Print one. Technovelgy points out that artificial organs have appeared in SF since Philip K. Dick wrote about artiforgs in his 1964 novel Cantata 140 (a.k.a. The Crack in Space) and Larry Niven described artificially-grown organs in his 1968 novel A Gift From Earth. Once again, science fiction is rapidly becoming science fact.
Since the 2009 press release, Invetech has cemented its plans to ship a number of 3D bioprinters to Organovo during 2010 and 2011. Organovo will then distribute them globally to researchers at world-class medical research centers. These initial units will be capable of printing only very basic tissues like blood vessels, not full-blown organs. Nevertheless, this technology has attracted the attention of longevity pioneer Aubrey de Grey and his Methuselah Foundation. What better way to counteract a damaged or aging heart, kidney, or liver than to replace it with a new one? Rather than wait for a donor organ, simply print one. That might just add a few years to your life. Here’s a video on organ printing produced for a Methuselah Foundation newsletter:
Dr. Gabor Forgacs is the Scientific Founder and Chief Scientific Officer of Organovo. Dr. Forgacs ultimately foresees fully implantable organs printed from a patient’s own cells. “You give us your cells: we grow them, we print them, the structure forms and we are ready to go,” he says. “I am pretty sure that full organs will be on the market [one day].” A printed biological heart might not appear exactly like an embryonic heart with a pericardium, two superior atria, and two inferior ventricles. But it will perform the same function: pumping blood throughout the blood vessels.
According to the Methuselah Foundation newsletter, the “ink” in the bioprinting process is composed of spheres packed with tens of thousands of human cells. These spheres are assembled or “printed” on sheets of organic biopaper. The placement of the cells involves computer-aided design, biophysics, and a knowledge of cell biology. Proper placement with the correct precursor cells and growth factors results in self-assembly of functional tissue.
The bioprinter relies on stem cells, extracted from adult bone marrow and fat, as precursors. Using appropriate growth factors, the stem cells can be differentiated into other types of cells. The cells are formed into droplets 100-500 microns in diameter and containing 10,000-30,000 cells each. The droplets retain their shape well and pass easily through a process not that different than the inkjet printer on your desk: propelling variably-sized droplets of liquid onto a page.
A second print head deposits a sugar-based, biofriendly hydrogel scaffold that supports but does not interfere with or stick to the cellular droplets. The hydrogel-droplet structure is left for a day or two, to allow the cellular droplets to fuse together. Once the tissue has formed, the hydrogel is removed. Here’s a video that shows the inkjet process fabricating a 3D biocompatible hydrogel tube in which living cells can be embedded:
Well before Organovo announced their mind-blowing bioprinter, Anthony Atala, M.D. and his team were growing organs successfully from scratch on scaffolds. Dr. Atala is director of the Wake Forest Institute for Regenerative Medicine, and chair of the Department of Urology at the University School of Medicine in North Carolina. He made history when his laboratory-manufactured bladders were the first artificial organs used in human trials. In 1999, several young children began receiving bladders grown from their own cells — in small, medium, and large sizes. According to the Wake Forest website, these patients continue to do well. Wake Forest scientists are now working to grow more than 22 different organs and tissues.
You give us your cells: we grow them, we print them, the structure forms and we are ready to go.
Bioprinters may one day be capable of printing tissues and organs not just for use by surgeons, but directly into the body. Dr. Atala is currently working on the design for a bioprinter that would scan the contours of a body part requiring a skin graft and then print skin onto it. As for bigger body parts, Organovo’s Dr. Forgacs thinks they may ultimately come in different shapes and sizes — designer organs. What this might mean to the sex industry… well, let’s not go there. Organovo is definitely a company to keep an eye on.