No Plastic Here, CMU Professor Uses Cells And Collagen To 3-D Print Heart Tissue

Feb 28, 2017

In a lab at Carnegie Mellon University, Adam Feinberg is using 3-D printing to create human tissue.

The associate professor of materials science & engineering and biomedical engineering said he often downloads 3-D images to print dollhouse furniture and Pokémon characters out of plastic for his children. He said that led him to ask: why not do that with the images made by an MRI or CT scan?

He said making a computer model from a scan is actually pretty easy.

“That opens up some exciting ideas about how we can leverage this custom, patient-specific information on anatomy and build potentially replacement organs or tissues that are unique to the disease or trauma that affects the person,” Feinberg said.

Feinberg’s lab is working on printing heart muscle that would match the shape of the scar created by a heart attack. 

The process is a little more complicated than using a spool of plastic filament, as with traditional 3-D printing. There’s no spool of heart cells available on Amazon.

“So what we do is we actually combine cells with a collagen solution before it gels and then that goes into a syringe,” Feinberg said.

But that mixture would not hold its shape if it was just 3-D printed onto a petri dish.

“We basically embed what we’re printing inside of another gel,” Feinberg said.

That gel-inside-a-gel model helps the tissue maintain its structure. The outside gel is temperature sensitive, he said, so that the two pieces can be easily separated once ready for use.

“We can print at room temperature and when we’re done, we just raise everything we printed to body temperate and it melts away the support gel, leaving our 3-D printed tissue scaffold behind,” Feinberg said.

After printing, the heart tissue is still immature and too delicate to be implanted into a sick heart. It then has to go through a bio-reactor. Like an athlete hitting the gym, the bio-reactor helps condition and strengthen the newly printed muscle.

“(It’s) basically a box filled with fluid, with some pumps that provides pulsatile flow,” he said, “and it provides mechanical conditioning.”

Over a few weeks or month, the tissue becomes stronger and can eventually match the strength of healthy heart tissue.

Currently, the lab is working with strips of heart muscle a few millimeters wide and about a centimeter in length. That’s about the size of the part that you click on a retractable pen – still much smaller than a heart attack scar, in most cases. Feinberg said those scars are usually the size of a quarter or larger.

Feinberg said he’s still experimenting to find the right “ink” for his printer and how to build larger swatches of tissue.

“The largest expense for 3-D printing right now is really the cells and the materials we’re using,” he said. “So if we’re going to print something big, we have to be pretty confident it’s going to work.”

He said he thinks the technology is still a decade away from being implanted into an actual person. But, he said, a short-term use could be to test new drugs for potential negative side effects on the heart.  

In this week’s Tech Headlines:

  • The National Energy Technology Laboratory, in the South Hills, has been honored for its work in transferring corrosion-protection technology out of the lab and into the real world. The annual Excellence in Technology Transfer Award from the Federal Laboratory Consortium for Technology Transfer calls attention to the cost-effective coating process that creates a protective barrier using aluminum rather than the more typical heavy metals, which are more expensive and environmentally harmful. The new process is expected to positively impact several industries including biomedical, automotive, and aerospace.
  • This week’s Samsung product showcase was most notable for what it was missing. The company opted to not roll out a new flagship phone. Instead, Samsung spotlighted new Android and Windows tablets. The release of the Galaxy S8 smartphone was delayed in part because of the battery problems the company had when it rolled out the Note 7. Samsung said the new tablets will go through extensive safety checks put in place after dozens of Note 7 phone overheated and in some cases exploded.

The Associated Press contributed to this story.