Lung diseases kill millions of people around the world each year. Treatment options are limited, and animal models for studying these illnesses and experimental medications are inadequate. Now, writing in ACS Applied Bio Materials, researchers describe their success in creating a mucus-based bioink for 3D printing lung tissue. This advancement could one day help study and treat chronic lung conditions.

While some people with lung diseases receive transplants, donor organs remain in short supply. As an alternative, medications and other treatments can be used to manage symptoms, but no cure is available for disorders such as chronic obstructive pulmonary disease and cystic fibrosis.

Meanwhile, bioengineers are exploring the production of lung tissue in the lab, either as a more accurate model to study human lungs or as a potential material to use in implants. One technique involves 3D printing structures that mimic human tissue, but designing a suitable bioink to support cell growth remains challenging.

Hyaluronic acid—a natural polymer found in connective and other tissues—was added to increase the bioink’s viscosity and enhance cell growth and adhesion to MuMA. After the ink was printed in test patterns including round and square grids, it was exposed to blue light to crosslink the MuMA molecules. The crosslink bonds stabilized the printed structure in the form of a porous gel that readily absorbed water to support cell survival.