If you live anywhere near the Gulf of Mexico, earlier this month, while you were sipping your coffee or surfing the web, a plane was zooming 30,000 ft (about 9,100 m) overhead, simulating weightlessness while a 3D bioprinter spit out heart and vascular structures created with human stem cells. The project was a joint effort between several companies experimenting with bioprinting in zero gravity environments – an initiative that could lead to better and more widely available human organs.
The project was led by Techshot, a company that has been involved in creating equipment and experiments for space for years, and is able to commercially operate its equipment aboard the International Space Station (ISS) through a Space Act Agreement with NASA. The 3D printer used was developed by nScrypt and the bioinks came from Bioficial Organs Inc, a company that has sorted out a way to keep adult human stem cells alive and viable for transplantation even after being bioprinted.
The flight took place aboard a Boeing 727 modified by the Zero Gravity Corporation. The plane is designed to induce weightlessness through maneuvers known as parabolas, which are basically bell-shaped arcs that induce weightlessness at the top of the curve. The weightlessness lasts for 20-30 seconds, and during the experiment 25 parabolas were executed. During several of them, the 3D printer went to work printing out cardiac and vascular structures designed to be completed in that short time frame. The tissues were generated from human stem cells.
But why bring bioprinting into a weightless environment in the first place? We asked Techshot's chief scientist, Eugene D. Boland, that very question and here's what he had to say.
From a material standpoint, all the cells, proteins, polymers, growth factors are blended together into into very specific cocktails generally called bioinks. During the printing process, these bioinks have a consistency between honey and gelatin. And like both of those, there are tricks to make it thinner or thicker. Unfortunately most of the 'tricks' to make bioinks thicker on the ground make the material less hospitable for the cells.
The reason you want them thick is to hold the complex geometries the printer is trying to mimic from nature. All this changes in space. Without gravity, complex geometries can be built with bioinks that are optimized for biological activity rather than structural integrity. For the first time, we will be able to let the end tissue dictate the recipe rather than settle for good enough because it's strong enough.
The next step for the group is to create a smaller and robust 3D bioprinter, says Techshot, which it hopes to launch on a commercial space capsule in January. That will be followed by a version for the ISS in 2018 that can print thicker and more complex human tissue.
Boland says that in addition to be able to produce better tissues and organs, bioprinting in the weightlessness of space could also solve an issue with cost and organ shortages.
"While it is true that no one is claiming that manufacturing in low earth orbit is cheap, neither is sitting on the heart transplant list," he told Gizmag. "Most of those patients will be in and out of the hospital, spend time in the ICU, possibly have an assist pump implanted to rescue their failing heart, spend hundreds of thousands of dollars in actual payments and missed income over years waiting for a donor and tragically tens of thousands will still die due to organ shortages.
"Now, what if a patient who reached the point of needing an organ such as a heart, could have a simple procedure to extract some fat, and from that some stem and stromal cells? Those cells could be mixed into a tailored ink, taken to the ISS for about a month to be printed and grown, then returned to the patient for implantation."
Boland says that his company envisions the program being similar to current blood and tissue transplant programs, although it has not yet established pricing or received regulatory approval. That makes sense considering that bioprinting technology still has a ways to go before the scheme envisioned by Boland can become a reality.
Still, it's intriguing to think of a world in which transplant patients will be able to say: "My heart came from outer space."
The following video from Techshot shows the printer in action during one of the weightless periods on the flight.