Scientists from Penn State University have recently demonstrated that it is possible to 3D print breathable tissue using an unexpected ingredient: seaweed.

Combining sodium alginate, which is a byproduct of seaweed, with human stem cells, scientists were able to 3D print strands of tissue that contain small pores within the fabric of the tissue.

To create the 3D strands, scientists exposed the tissue to a chemical cocktail. Once exposed, the cocktail turned the stem cells into specific tissue such as simulated bone or cartilage. Thanks to the tiny pores, the chemical cocktail could flow freely, reaching each stem cell. Those strands then joined together to form patches of tissue. The tissue was able to self-assemble once the 3D-printed strands are placed beside or on top of each other.

"One of the problems with fabrication of tissues is that we can't make them large in size," said Ibrahim Ozbolat, associate professor of engineering science and mechanics. "Cells die if nutrients and oxygen can't get inside."

According to the scientists, the tissue strands created by Penn State scientists maintain 25% porosity and 85% pore connectivity for an estimated three weeks.

Such a process, according to the team, makes the production of artificial tissue much easier than other current methods for producing artificial tissue.

"These patches can be implanted in bone or cartilage, depending on which cells they are," Ozbolat said. "They can be used for osteoarthritis, patches for plastic surgery such as the cartilage in the nasal septum, knee restoration and other bone or cartilage defects."

Currently, the team is only able to produce small patches, which limits tissue applications. Yet, the team is investigating whether the seaweed-derived tissue could also one day be used to create fat, muscle or other types of tissue.

The research appears in the journal Biofabrication.