So far this year, 18,048 people (and counting) have received organ transplants. Another 122,586 people are in need of a lifesaving organ transplant, with no choice but to add their name to a waiting list and hope for a donor.
What if, instead of 122,586 people, that number was zero? Thanks to serious advancements in medical technology, that's an increasingly possible scenario. But when? Depends what technology you're referring to, and whom you ask.
Genetically Engineered Pigs
In the late 1980s, Japanese researchers investigating Escherichia coli stumbled across a mysterious patch of repeating DNA that stuck out from its surrounding genetic material. It wasn't until the late 2000s that scientists realized the anomalous DNA had been inserted there by an enzyme identified as "Cas9," and -- critically -- that with a bit of tinkering, humans could use Cas9 to edit other DNA sequences, too.
Researchers have since developed a powerful technique known as "CRISPR" which employs Cas9 to quickly, cheaply and effectively modify DNA in virtually any animal. This month, George Church, a genetics professor at Harvard Medical School, revealed he and his team had successfully used CRISPR to alter 62 genes in a pig cell at once.
Per The New York Times, Church's team specifically targeted a group of viruses in the pig cell's DNA that make them unsuitable for human transplant. Remarkably, CRISPR completed the entire process in all of two weeks.
“This work brings us closer to a realization of a limitless supply of safe, dependable pig organs for transplant,” Dr. David Dunn, a transplantation expert at the State University of New York at Oswego, told The New York Times. “It’s a cruel situation currently, that someone who needs a heart transplant has to pin their chance for a healthy life on the untimely death of another person.”
(Doctors have long used pig and cow valves to replace their leaky equivalents in a human heart.)
So should we expect these breakthroughs before, or after pigs start to fly?
Sooner. Possibly much sooner. Church told The Huffington Post his team hopes to have organs ready for primate testing within a year, and if that goes smoothly, human clinical trials conceivably could start within another year.
The most-needed organ is the kidney, said Church, but there's no reason to stop there. With this technique, he said, "nearly all of the tissues/organs currently transplanted should be possible."
The same basic technology your niece used to print her own custom bobblehead doll could one day fabricate her a new kidney.
Here's how it works: Doctors perform a biopsy of the organ to obtain cells that can be isolated and grown in a lab, grow them, then mix them in an oxygen-rich liquid with other nutrients to keep them alive. That slurry is then printed into the appropriate shape for the patient, along with a biomaterial to provide structure.
"When the 'print' button is pushed, the printer builds the structure layer by layer and embeds cells into each layer," Dr. Anthony Atala, director of the Wake Forest Institute for Regenerative Medicine, told HuffPost. "When cells are provided the right mixture of nutrients and growth factors -- and placed in the right environment -- they know what to do and perform their functions. For some structures, two or more types of cells may be required."
At present, solid organs like kidneys, livers and organs are proving difficult for 3D printers, but other less-complicated tissues are not. Flat structures like skin, tubular structures like veins, and hollow structures like the bladder have all successfully been grown in the lab. (Wake Forest is working on printing skin for burn victims, for instance).
"3D printing is not magic," Atala explained. "It is simply a way to scale up the current processes we use to engineer organs in the laboratory. Our team has successfully engineered bladders, cartilage, skin, urine tubes and vaginas that have been implanted in patients."
So how far away are we from printing and transplanting more complex organs like kidneys? It could take a while.
"Science is unpredictable, so it is impossible to make predictions," said Atala. "But I think we can safely say that the timeframe required to routinely print and implant complex organs is decades, rather than years."
Stem Cells In A Petri Dish
We've already grown -- and eaten -- hamburger in the lab (never mind that it cost $380,000 and was said to taste "not that juicy"), so why not grow organs?
In August, scientists at Ohio State University revealed they'd converted human skin cells into stem cells, then used them to grow the first near-complete human brain in a lab, containing a spinal cord, cortex, midbrain, brain stem, multiple cell types, circuitry and even a retina -- essentially, everything but a vascular system.
How does it work? The process isn't all that different from 3D printing as described above -- and varies from tissue to tissue -- but generally, instead of "printing" the cells into a supportive lattice, researchers assist the more complex organs (think spinal cords, brains, etc.) in growing on their own.
A German team used the technique in 2014 to grow complete spinal cords by embedding stem cells in a three-dimensional, nutrient-rich "gel," then letting them do their thing.
As with simpler 3D printed organs, some of these lab-grown organs have already been used provisionally. One remarkable case: that of Darek Fidyka, a 38-year-old Polish man left paralyzed from the waist down after a knife attack in 2010. Using cells taken from Fidyka's nose, doctors in England grew and implanted a "nerve bridge" in his damaged spinal column. After 19 months of treatment, Fidyka regained some movement and sensation in his legs.
Encouraging as Fidyka's experience has been, however, it's more of an initial step, with plenty more work to be done.
Commenting on the work of another team that successfully grew a functioning thymus in the lab, Chris Mason, a professor of regenerative medicine at the UK's University College London, said we're still at least a decade away from lab-grown organs like the thymus being a "a safe and effective routine therapy."
"The time and resources required ... will be very significant," he told The Guardian, "10 years and tens of millions of [British] pounds at a bare minimum."
Which Leaves Us Where, Exactly?
For now, the simplest, most constructive method to help ease a shortage of organs is to become an organ donor yourself. Yes, there have been some incredible technological advancements in the last decade, but no lab can come close to reproducing the marvel of the human body.
One organ donor can save eight lives. One lab grown organ -- that only exists theoretically -- saves zero.