Brain, Bone and Blood Vessels Coming Hot Off the Press

Could the days of custom clavicles and bespoke bladders produced just in the knick of time for suffering patients be around the corner?

While keeping an eye on tissue engineering studies, we’ve been seeing some significant wins in the lab that are bringing the sci-fi future of on-demand 3-D printed organs, bone and blood vessels closer.

Harvard and Brown bioengineers are taking their own routes to build complex tissues in customized 3-D printers. And just the other week, we reported on newly unveiled work at the University of Florida to print complex soft structures in baths that could one day birth replacement human parts along with soft robots.

Now, Carnegie Mellon engineers reported on Friday that they had successfully printed simplified proof-of-concept anatomical structures like mini femurs, blood vessels and brains suspended in soft gelatin. Learn more and see a video below.

Their work, like that of the University of Florida team, constructs soft tissue that would otherwise collapse under its own weight by depositing drops of natural proteins like collagen or fibrin into a gelatin bath, which suspends and supports them. Printing happens at around 72 degrees Fahrenheit. Going a step further, the CMU process can release the structure from the support gel after it’s done printing by heating the bath to body temperature, which melts the gelatin away. They call their process freeform reversible embedding of suspended hydrogels, or FRESH.

The group’s initial products were printed just to show that the process can work, and are in fact solid structures whose shape mimics the actual biological blood and organ tissue like a femur or brain. After printing a hollow mockup of a coronary artery using 3-D MRI imaging data, however, they were able to push liquid through it in the same way that an actual blood vessel would transport blood. Their work was published in the journal Science Advances.

“We’ve been working on building 3-D printers that can print soft materials and tissues,” said Adam Feinberg, a CMU materials scientist and biomedical engineer who led the research. “Traditional 3-D printers print hard materials and we’re trying to move that into a whole new range of soft materials that will eventually allow us to print living things.”

Perhaps the biggest breakthrough from the work by Feinberg and his colleagues is the fact that they built their FRESH printer with open-source software and a $400 hardware unit. They got the plans for a custom syringe-based extruder from the National Institutes of Health’s 3-D printing online clearinghouse. This approach puts the technology in many more researchers’ hands than the current crop of commercial units, which can cost many thousands of dollars.



“The low cost of FRESH and the ability to 3-D print a range of hydrogels should enable the expansion of bioprinting into many academic and commercial laboratory settings and accelerate important breakthroughs in tissue engineering for a wide range of applications, from pharmaceutical testing to regenerative therapies,” the team concludes in their paper.



All gifs created from videos courtesy of Thomas J. Hinton/Carnegie Mellon University College of Engineering/AAAS.