Talk about a potentially nasty printer jam. Researchers at the University of Alabama in Huntsville are working toward, perhaps in a decade, being able to use a patient’s own cells to print a new liver or heart.
While that’s the lofty goal, a UAH sophomore and his collaborator took a step closer to it recently by developing a specialized 3-D printing extruder that could lower the costs of printing cellular structures for use in drug testing.
The CarmAl extruder — shorthand for Carbohydrate Anhydrous Rapid Manufacturing Aluminum extruder — its controlling software and the manufacturing processes being developed by second-year biological sciences student Tanner Carden and collaborator Devon Bane are able to produce a sugar grid that mimics blood vessels.
Normally a UAH mechanical and aerospace engineering undergraduate student, Bane is taking the semester off to catch up with the numerous inventions and commercial projects with which he’s involved.
The CarmAl extruder’s name is a play on words, since the inspiration for the technology came from 3-D printers developed to make specialty candies.
“We’re using the sugar molecules in a form of reverse 3-D printing, ” says Carden. “In this process, we first make the structures we want and then we embed them into a cellular matrix.” After cells held in suspension in an agarose solution are grown around the vascular structure, a solvent can be used to wash the sugar away.
The result is a cell mass that contains vessels like a human organ would. That’s an advantage for drug tests over flat-dish cell cultures currently used, because it more accurately represents living tissue and more of the test cells can be kept alive by vessel-supplied nutrients. “It helps to prevent necrosis in your sample, ” says Carden. For example, if the process were used to create liver cells for a drug test, the resulting product “would actually have vascularization in it that is modeled on how a liver works.”
Further advances to their system could include the addition of 5-D printing capabilities, which would allow the current grid-like vascular structures to flow and branch in a more natural fashion and truly be created in three dimensions.
Text by Dave Helms