Although we're hearing more and more about 3D-bioprinted body parts, at least one challenge remains: getting oxygen to the cells in the printed tissue. A new type of "bioink," however, is claimed to be capable of doing just that.
The basic idea with bioprinted organs, etc is that a few days after they've been implanted into the body, blood vessels from the surrounding natural tissue will grow into them. These will permanently supply the cells in the implant with oxygen, allowing them to thrive and even reproduce. Unfortunately, though, the blood vessels sometimes just don't grow in fast enough.
Some researchers have instead looked at bioprinting tissue with such vessels already present within it. An international group of scientists, though, are taking another approach. They've developed a bioink hydrogel – which is the 3D bioprinting medium – that combines calcium peroxide (CPO) with a substance known as gelatin methacrylol.
When mixed with water, CPO produces oxygen. A simple mixture of it and water, however, would lack the structure needed for bioprinting. That's where the gelatin methacrylol comes in. Its pH and viscosity are optimized to support the CPO, allowing it to generate oxygen on a sustained basis, while also offering the physical matrix necessary for the printing of implants.
In lab tests, the hydrogel was able to keep both muscle and cardiac cells oxygenated for the amount of time that it would take blood vessels to grow in and take over the task.
"By delivering oxygen to the implanted cells, we would be able to improve the tissue functionality and integration to the host tissue," says Dr. Samad Ahadian of the Los Angeles-based Terasaki Institute. "A similar approach can be used to make functional tissues with improved survival for drug screening applications and pathophysiological studies."
The research is described in a paper that was recently published in the journal Advanced Healthcare Materials.
Source: Terasaki Institute