July 1, 2011 | 2
Instead of waiting around for organs to become available, have shelves of them instantly ready
In "Too Hard for Science?" I interview scientists about ideas they would love to explore that they don’t think could be investigated. For instance, they might involve machines beyond the realm of possibility, such as particle accelerators as big as the sun, or they might be completely unethical, such as lethal experiments involving people. This feature aims to look at the impossible dreams, the seemingly intractable problems in science. However, the question mark at the end of "Too Hard for Science?" suggests that nothing might be impossible.
The scientist: Anthony Atala , director of the Institute for Regenerative Medicine and chair of the department of urology at Wake Forest University.
The idea: Instead of waiting for potentially life-saving donor organs to become available — time that many patients might not have to spare — Atala imagines having storehouses of living organs of all shapes and sizes immediately ready for transplantation. "You can imagine having shelves with small, medium, large, extra-large organs, all at the ready," he says.
Increasingly, tissue engineers are creating more complex body parts. One can then imagine keeping organs alive in " bioreactors " that feed them nutrients and oxygen, all stored at a medical facility that patients can visit for surgery or that can ship them off when needed. "Off-the-shelf organs would be the end goal I’d see — the holy grail," Atala says.
The problem: Although researchers are growing more intricate tissue structures, "creating solid organs with a mix of different cell types is still a major challenge," Atala says. "These cells also need nutrition to survive, which means that you have to provide them with vasculature, with blood vessels. So we are still developing ways to make such complex structures that can function normally."
The greatest problem with the idea of a living off-the-shelf organ, however, is making sure it can match any patient without getting rejected. "Ultimately, you’d want a universal donor organ just like you have universal blood donors, but we don’t know a way to engineer cells to be universal donor cells," Atala says.
The solution? A number of techniques under development suggest it should be possible for tissue engineers to create solid organs. For instance, they might grow such three-dimensionally complex structures by seeding biodegradable scaffolds with cells, or with " bio-printers " that manufacture organs by laying down cells layer by layer in desired patterns. "It’s a tough challenge, but I think it’s doable," Atala says.
However, no one is exploring the idea of a living universal donor organ, as far as Atala knows. "The idea is outlandish, but I’ve been working in the field of regenerative medicine for 20 years, and a lot of things we thought were impossible back then are possible now," he says. "Science is a matter of perseverance."
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About the Author: Charles Q. Choi is a frequent contributor to Scientific American. His work has also appeared in The New York Times, Science, Nature, Wired, and LiveScience, among others. In his spare time he has traveled to all seven continents. Follow him on Twitter @cqchoi.
The views expressed are those of the author and are not necessarily those of Scientific American.