The new stem cell-containing bio ink enables 3D printing of living tissue, which is called as bio-printing.

The new bio-ink features two different polymer components, including polymer extracted from seaweed and sacrificial synthetic polymer used in the medical industry.

Synthetic polymer makes the bio-ink to change from liquid to solid when the temperature is increased, while the seaweed polymer offers structural support when the cell nutrients are introduced.

Scientists can differentiate the stem cells into osteoblasts and chondrocytes, helping them to develop 3D printed tissue structures over five weeks.

The study’s lead researcher Dr Adam Perriman said: "Designing the new bio-ink was extremely challenging. You need a material that is printable, strong enough to maintain its shape when immersed in nutrients, and that is not harmful to the cells.

"The special bio-ink formulation was extruded from a retrofitted benchtop 3D printer, as a liquid that transformed to a gel at 37°C, which allowed construction of complex living 3D architectures."

Image: Bioprinting is a rapidly emerging technique for the building of living 3D tissue constructs. Photo: courtesy of University of Bristol.