3D-printing technique produces soft structures for tissue regeneration

Researchers from the Imperial College London have developed a 3D-printing technique, paired with cryogenics, capable of recreating biological structures for tissue regeneration and producing replica organs. Findings are published in Scientific Reports.

The key difference with this technique is the use of solid carbon dioxide, or dry ice, in cooling the hydrogel ink as it is printed. After thawing, the gel becomes as soft as human body tissue, allowing the structure to stand under its own weight.

"Cryogenics is the novel aspect of this technology—it uses the phase change between liquid and solid to trigger polymerisation and create super soft objects that can hold their shape. This means that the technology has a wide variety of possible uses,” stated Antonio Elia Forte, one of the researchers.

By matching the softness of human tissue, the structures could be used to form scaffolds for tissue regeneration without bodily rejection. Additionally, the softness of the structures allows for the eventual seeding of neuronal cells for the regeneration of organs like the brain and spinal cord. Another use for this technique in the recreation of body parts or organs would provide surgeons with a supply of organs for medical training.

In testing the 3D-printed structures, researchers seeded them with dermal fibroblast cells and could produce connective tissues in the skin.

"At the moment we have created structures a few centimeters in size, but ideally we'd like to create a replica of a whole organ using this technique,” concluded Zhengchu Tan, a researcher with the Department of Mechanical Engineering at Imperial.