Researchers at the Terasaki Institute for Biomedical Innovation in Los Angeles, California have developed an oxygen-releasing bioink that may be useful in 3D printing bioengineered cell constructs. This can help live cells to survive in limited oxygen environments, such as those that exist inside of 3D printed devices, in the first days after implantation.
Developing cell-encapsulating constructs, consisting of regenerative cells in a supportive biomaterial matrix, holds great promise in the fields of tissue engineering and regenerative medicine. Such creations could be translated into off-the-shelf organ transplants or skin grafts, with huge implications for patients who require such treatments.
3D printing has emerged as a technique with huge potential in creating custom and elaborate cell constructs with precise geometry. Suspending regenerative cells in a so-called “bioink,” that is then printed, forms the basis of this technique.
However, a major bottleneck in translating such constructs, 3D printed or otherwise, into a clinical reality is the low oxygen environment cells within the construct experience when implanted into the body. Diseased tissue may suffer from poor blood flow, and without any blood vessels within the implant, the cells experience hypoxic conditions and quickly die, limiting the usefulness of the approach.
To address this, researchers have attempted to engineer blood vessels within constructs, to allow blood to rapidly permeate them, with mixed success. An alternative is to allow surrounding blood vessels to naturally grow into the construct, but this can take some time, and the encapsulated cells tend to be dead by then.
The Terasaki Institute researchers have adopted a different approach, and created an oxygen-releasing bioink that can keep encapsulated cells alive until the body’s own blood vessels can provide a blood supply. The ink consists of a gelatin methacryloyl ink that contains calcium peroxide, a substance which can release oxygen over extended periods. The calcium peroxide has an added benefit of also releasing calcium hydroxide, which reduces the viscosity of the bioink, making it easier to print.
“By delivering oxygen to the implanted cells, we would be able to improve the tissue functionality and integration to the host tissue,” said Samad Ahadian, a researcher involved in the study published in journal Advanced Healthcare Materials. “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.”
Study in Advanced Healthcare Materials: 3D Bioprinting of Oxygenated Cell‐Laden Gelatin Methacryloyl Constructs