Researchers at Harvard 3D-print blood vessel tissues

Image via Lewis Lab

Jennifer Lewis, a member of the Wyss Institute for Biologically Inspired Engineering at Harvard University, directed a team to create 3D-printed blood vessels. The team used a customized 3D printer with “disappearing ink” to generate printed patches of tissues that contained skin cells and material combined with a blood-vessel-like zig-zag formation. This tissue, constructed through a 3D-printing process, could eventually be implanted into patients’ already functioning blood vessels.

Scientists have already made strides toward this level of progress. Previously, researchers have created lab-grown structures, like tissues and organs. Trachea, grown from a patient’s given cells, could also be used to treat patients. These experiments have shown that under very specific conditions, researchers can start to develop stem cells that grow into complex structures resembling a human brain, eyes, or piece of liver. When this regenerative technology is put into place, it requires more blood vessels. That’s where this innovative tech comes into play.

The team at Harvard produced tube-like structures inside a layer of printed cells. The ink used to print liquefies as it cools down, taking on a Jell-O-like consistency. This specialized ink is made from gelatin and acts as an extracellular matrix due to its structural qualities of proteins and molecules that appear within the human body. There are two other inks integrated within the gelatin material that are potent enough to retain structure after they are printed.

The hollow tubes were integrated immediately when researchers realized the untenable properties of the third ink. Ink tracks were printed, left to cool, and then a vacuum was applied to eliminate the ink. The vacuum’s purpose was to leave empty channels in the 3D-printed structure. Normal human cells are then aligned into the channels to promote growth. The smallest channels measured 75 micrometers in diameter, a much larger size than the capillaries responsible for replacing nutrients in the human body.

The ability to create replacement tissues and organs is still a long-term goal for researchers. In regard to 3D-printing blood vessels, Lewis stated her team “views this as a method to print the larger vessels; then we want to harness biology to do the rest of the work.” The team's advancements thus far have definitely expedited the process, and will absolutely be crucial to future developments. 

Story via Technology Review