Researchers 3D print lung tissue with mucus-based bioink

According to the American Chemical Society (ACS), researchers have had success in creating a mucus-based bio ink for 3D printing lung tissue, as described in their paper ‘3D Bioprinting with Visible Light Cross-Linkable Mucin-Hyaluronic Acid Composite Bioink for Lung Tissue Engineering’, which is published in ACS Applied Bio Materials 2024. The advance could one day help study and treat chronic lung conditions.

Some people with lung diseases get transplants, but there aren’t enough donor organs to go around. Instead, doctors use medications and treatments to manage symptoms, but there’s no cure for diseases like chronic obstructive pulmonary disease (COPD) and cystic fibrosis. Researchers are always looking for better drugs, often testing them on rodents. However, these animal tests don’t always match the complexities of human lung diseases and may not predict how safe or effective new drugs will be.

Bioengineers are trying to create lung tissue in the lab for better research models and potential implants, with one method being the 3D printing of structures that mimic human tissue. However, finding the right bioink to support cell growth is tricky. Ashok Raichur and his team aimed to solve this problem.

The researchers started with mucin, a component of mucus that hasn’t yet been widely used in bioprinting. Parts of mucin’s structure are similar to a protein that promotes cell growth. The team modified mucin to create methacrylated mucin (MuMA) and mixed it with lung cells, then added hyaluronic acid, a natural substance in connective tissues, to make the bioink thicker and better for cell growth and adhesion.

After printing test patterns with the ink, they exposed it to blue light to link the MuMA molecules – creating a stable, porous gel that absorbed water and helped the cells survive.

The interconnected pores allowed nutrients and oxygen to diffuse – encouraging cell growth and lung tissue formation. The printed structures were nontoxic and slowly broke down in the body, which means they could potentially be used as implants where the printed scaffold would be replaced by new lung tissue over time. This bioink could also help create 3D lung models to study lung diseases and test treatments.