Bioprinting Takes a Step Forward with Printing of Viable Blood Vessels

In the not so distant future, millions of patients around the world may find themselves the recipients of 3D printed organs. Multiple companies are at work on the problem, but they’ve all shared the same stumbling block. While each company might be able to print viable organ tissue, they’ve lacked a way to incorporate blood vessels into a completed organ.

Researchers at Brigham and Women’s Hospital (BWH) in Boston, MA look to have overcome the problem by developing an additive manufacturing (AM) method that allows for the creation of viable blood vessels. The new process uses agarose (a naturally derived sugar-based molecule) in a manner similar to earlier experiments, but produces a better final product.

The process begins by bioprinting an agarose fiber structure meant to mimic the pattern of naturally occurring blood vessels. Researchers then use that structure like a mold, covering it in hydrogel which is then reinforced via photocrosslinks.

“Our approach involves the printing of agarose fibers that become the blood vessel channels. But what is unique about our approach is that the fiber templates we printed are strong enough that we can physically remove them to make the channels,” said senior study author, Ali Khademhosseini, PhD, biomedical engineer, and director of the BWH Biomaterials Innovation Research Center. “This prevents having to dissolve these template layers, which may not be so good for the cells that are entrapped in the surrounding gel.”

The result of the experiment was a series of microscopic tubes that could be used as functional blood vessels. Khademhosseini’s team was then able to produce the vascular networks in a number of different patterns, demonstrating the potential for changing the architecture for use in different areas of the body. The team also managed to embed the new channels into a number of commonly used hydrogels, such as methacrylated gelatin or  poly(ethylene glycol)-based hydrogels.

Added to the existing work on artificial organs and even 3D printed skin, the future looks brighter for transplants built using a patient’s own blood and organic material, which should seriously cut down on rejection rates. While 3D printed organs aren’t likely to appear overnight, the ability to provide AM-produced tissue that can be properly sustained by this new vascular process will be nearly as invaluable to researchers.

Results of Khademhosseini’s work can be found in the online journal, Lab on a Chip, under the title “Hydrogel bioprinted microchannel networks for vascularization of tissue engineering constructs.” Below you’ll find an older video that discusses the potential offered by 3D printed blood vessels.

Source: Brigham and Women’s Hospital