A crucial element to keeping tissues and organs healthy is oxygen, whether they’re in the body or bioprinted in a lab. Typically, the oxygen is delivered to tissues via blood, which is carried in vessels, delivering the vital element and nutrients. In the case of bioprinting, however, vasculature inside a transplanted bioprinted tissue can take days to develop. To overcome this challenge, a team from the Terasaki Institute for Biomedical Innovation (TIBI) in Los Angeles developed a bioink that actually generates oxygen to keep cells alive.
The bioink is capable of creating oxygen and delivering it to cells embedded in 3D printed tissue for the period of time before blood vessels penetrate the tissue. The material can therefore be used to bioprint tissue implants with a superior ability to generate new tissue cells.
“By delivering oxygen to the implanted cells, we would be able to improve the tissue functionality and integration to the host tissue,” explained Samad Ahadian, PhD, lead investigator of the TIBI team. “A similar approach can be used to make functional tissues with improved survival for drug screening applications and pathophysiological studies within a long period of time.”
A study recently published in the journal Advanced Healthcare Materials, the research group details the testing process for the 3D bioprinting material, which enabled it to optimize the bioink’s chemical and physical properties. The resulting material is able to generate and deliver oxygen to the cells in the tissue until blood vessels can properly form. At this point, the blood vessels take over the oxygen delivery, allowing the cells in the tissue to continue to grow and regenerate. In their tests, the researchers worked with two types of cell, cardiac and muscle, and both worked well with the oxygen-generating bioink.
“In this study, a gelatin methacryloyl (GelMA) bioink that is optimized in terms of pH and viscosity is developed,” the abstract reads. “The improved rheological properties lead to the production of a robust bioink suitable for 3D bioprinting and controlled O2 release.”
The creation of such a bioink could have implications in a wide range of medical applications, including for treating heart attacks. Because a heart attack is caused by a lack of oxygen to the vital organ, the oxygenated bioprinted tissue could help to increase the survival of the affected cardiac cells and help to support the growth of cardiac blood vessels.