How to Hack a Normal Printer to 3D Print Coronary Arteries

We’re well on our way to mass-producing functioning bioprinted hearts.

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Oct 24 2015, 9:09pm

Image: Carnegie Mellon

One of the most promising applications of 3D printing is the ability to manufacture custom fit functioning organs for patients in need. While there has been some progress in this direction over the years, it wasn't until last week that this dream began to feel more like reality.

On Friday, Science Advances published research from a team of bioengineers at Carnegie Mellon University who developed a new bioprinting technique which was shown to be capable of printing coronary arteries using store bought printers that were modified and loaded with soft materials such as collagen and other tissue engineering gels.

It's an unprecedented breakthrough. Traditionally, 3D printing has made use of hard materials such as plastic or metal, which were ideal for a manufacturing process that works by depositing super thin layers of the material on top of one another. In the medical field this was great for rapid prototyping and creating prosthetics. But the Holy Grail of applied 3D printing, the bioprinting of patient specific organs, remained elusive.

This is largely because advances in this area would require softer materials, such as collagen and fibrin, common tissue engineering gels. While some minor advances were made in bioprinting soft materials, most structures continued to collapse under their own weight during the printing process. Even when researchers were successful in bioprinting soft materials, it came with a prohibitively expensive price tag: most bioprinters cost somewhere around $100,000, making the technology all but inaccessible to a handful of research institutions with the funds and knowhow to operate these state of the art machines.

The new technique, known as Freeform Reversible Embedding of Suspended Hydrogels (FRESH), may have just eradicated both of these obstacles in a single blow, however.

FRESH works by printing one gel inside of another gel, the outer gel working as a semi-rigid scaffold ensuring that the softer gel on the inside doesn't collapse under its own weight. What's more, the support gel melts away at roughly body temperature, which means that it won't damage the sensitive bio-material that comprises the core structure.

"We've been able to take MRI images of coronary arteries and 3-D images of embryonic hearts and 3-D bioprint them with unprecedented resolution and quality," said Adam Feinberg, an associate professor of Materials Science and Engineering and Biomedical Engineering at Carnegie Mellon who lead the study.

The added bonus to all of this is that the team accomplished this historic first on a modest budget, using an off-the-shelf printer that they modified with open source software and hardware, the entire rig costing under $1,000.

"Not only is the cost low, but by using open-source software, we have access to fine-tune the print parameters, optimize what we're doing and maximize the quality of what we're printing," said Feinberg. "It has really enabled us to accelerate development of new materials and innovate in this space. And we are also contributing back by releasing our 3-D printer designs under an open-source license."

The possibilities opened up by this development are virtually endless and it is undoubtedly welcome news to the over 4,000 people in the US who are biding time they might not have waiting for a heart transplant. Meanwhile, the next step for the researchers is to incorporate real heart cells into these tissue structures which will enable the formation of a contractile muscle, effectively ushering in the age of affordable, functioning 3D printed hearts.

Welcome to the future.