An international team of researchers has developed a method for creating 3D printed vasularized liver tissue. The bioprinting breakthrough could have important applications for drug toxicity testing and drug screening.

 

In the field of bioprinting, the future looks bright as we expect to one day have access to 3D printed organs and implantable tissues. At the moment, however, researchers in the field are still working to overcome some pretty significant hurdles. One of them, perhaps the most significant, is figuring out how to bioprint vascularized tissues, or tissues with blood vessel systems.

 

Blood vessels, of course, help to give life to organs and tissues, so vascularization is a crucial part of implanting organic material and having it stay alive inside the body. In recent months though, researchers from a number of places seem to have been making breakthroughs in the field.

 

For instance, a team of scientists from the University of California San Diego recently announced they had successfully 3D printed a blood vessel network using an ultra-fast bioprinting system, and a team from China reportedly transplanted 3D printed blood vessels into a monkey to promote vascular tissue regeneration.

 

Even more recently, a collaborative project between researchers from Chile, Italy, Saudi Arabia, Korea, and the United States has resulted in a simple 3D bioprinted vascularized liver tissue. The research study, entitled “Bioprinted 3D vascularized tissue model for drug toxicity analysis,” was published in the journal Biomicrofluidics just days ago.

 

Bioprinted using a special “sacrificial” bio-ink, the vascularized liver tissue model can be used for more accurate drug toxicity testing. The researchers even say their method for creating the innovative tissue could be adapted for use with different types of cells, which could open the doors for patient-specific drug screening.

 

“Most drug test models use a two-dimensional (2D) monolayer cell tissue, or a 3D tissue, but without this network,” explained Su Ryon Shin, an instructor and researcher at the Harvard Medical School and an author on the study. “Our bodies are actually composed of a 3D construct with a vascular network, not composed of [just] single cells.”

 

Because of the way the tissue incorporates sacrificial bio-ink (material that can be washed away), the researchers found they could print complex microchannel scaffolding into the tissue in a way that mimicked the architecture and functionality of natural human tissue. Compared to 2D monolayers of cell modules, the 3D structure demonstrated more accurate predictions for drug toxicity testing.