Perhaps some day, 3D printers will be spitting out replacement organs made from your own DNA, and like Amazon.com, they will show up in your “mailbox” an hour after you order them.
The science behind this is fascinating, but, despite sexy headlines, this won’t be happening anytime soon. So, we are stuck with essentially the same problem that we had 50 years ago, when Christiaan Barnard, a South African surgeon performed the first “successful” heart transplant. The heart recipient survived only 18 days, dying from pneumonia that was caused by the immunosuppressant drug that was necessary to prevent organ rejection. (The first successful organ transplant was with a kidney in 1953, but this received much less attention.)
In the absence of the holy grail of transplantation — human organs that are derived from the recipient (autologous transplantation) — organs that are derived from donors of the same species (allotransplantation) are currently the best bet. Unfortunately, there is always a shortage.
The shortage problem could evaporate overnight if transplantation from other species (Xenotransplantation) was a more viable option. This is starting to look rather promising.
Writing on the MIT Technology Review site, senior editor Antonio Regalado discusses the rapid progress that is being made in this area. His article, entitled “Surgeons Smash Records with Pig-to-Primate Organ Transplants,” highlights some very exciting developments in the technology of transplantation of non-primate organs (mostly from pigs) into primates.
Better still, these advances are possible because the pigs from which the organs are harvested are genetically modified to be more “human-like.” The pigs are modified such that they contain as many as five human genes, which all but guarantees a better match between the new organ and the primate (soon to be human?) recipient.
Dr. Josh Bloom, the director of chemical and pharmaceutical sciences at the American Council on Science and Health asks, “Dear anti-GM ideologues: When you or a loved one is dying from kidney or liver failure, and can only be saved by an organ transplant, think about what is more important. Saving your mother’s life, or continuing to propagate anti-GM scares because of (fill in blank) reason? Betcha I know the answer.”
Very much behind this movement is Martine Rothblatt, the CEO of the Virginia-based biotech Revivicor. She is nothing if not ambitious: Her goal is to create “an unlimited supply of transplantable organs” and to perform the first successful pig-to-human lung transplant—no small order— within a few years. She also plans on “turning xenotransplantation from what looked like a kind of Apollo-level problem into just an engineering task.” Even more so: “We want to make organs come off the assembly line, a dozen per day.”
Are these predictions reasonable? Maybe, but only because of the GM pigs. The major obstacle in any transplant is, and always has been organ rejection. The human immune system “sees” the new organ as a foreign body, much like a pathogen, and tries to eliminate it.
This is a very big hurdle.
Bruno Reichart, a professor at the University of Munich and transplant expert says, “It’s challenging to insert human genes and difficult to get them to function correctly. You try to put all your genes into one parcel so they go to one place in the genome. It’s very cumbersome. Creating a good pig is really like winning the lottery.”
If this sounds difficult, it may be even more so. Sean Stevens, the head of mammalian synthetic biology program at Synthetic Genomics — a the company that is working to humanize pigs — says “Every time you relieve one rejection issue, another one comes in behind. You peel back one layer and there is another layer underneath. No one is so naïve as to think, ‘Oh, we know all the genes—let’s put them in and we are done.’ It’s an iterative process, and no one that I know can say whether we will do two, or five, or 100 iterations.”
Dr. Bloom comments, “In many ways, this is similar to drug discovery. Just when you think you’ve solved one problem, ten others pop up, almost always unanticipated. The new technology behind xenotransplantation would be an enormous advance in medicine. Revivicor is using very clever, cutting edge technology, but they should be prepared for a bumpy ride. In medical research, almost all rides are bumpy.”
Republished with permission from the American Council on Science and Health. Read the original here.