3D printing technology has raised the possibility for scientists to produce biological tissue that could be used to replace organs or other body parts. Until now though, one of the problems with 3D printing biological tissue is that the cells may die before oxygen-delivering blood vessels grow into the material.

In search of a solution, researchers at Harvard turned to algae and encapsulated it within a cellulose-based bio-ink. Afterward, both the algae-laden bio-ink and human-liver-derived cells were then injected into a 3D hydrogel matrix with honeycomb-shaped patterns, which is similar to the structures that make up the liver.

New Atlas reports that when exposed to light, the algae proceeded to produce oxygen to keep the cells alive while even producing liver-specific proteins. Meanwhile, the carbon dioxide released by the cells allowed the algae to thrive. When the cells had grown enough, the bio-ink with algae was removed by introducing an enzyme known as cellulase. This left empty microchannels where the bio-ink had been, which were subsequently filled with human vascular cells that formed into blood vessels.

Although there is more research to be done, the hope is that algae can help propel 3D printing technology to a point where human biological tissue could be produced for purposes of research and drug testing. In the future, the technology could even be used to replace actual human organs or other body parts.