Researchers have developed a new method for creating 3D structures using cryogenics (freezing) and 3D printing techniques. This builds on previous research but is the first to create structures that are soft enough to mimic the mechanical properties of organs such as the brain and lungs.

A new 3D printing technique allows researchers to replicate biological structures.
(Credit: Imperial College London)

Being able to match the structure and softness of body tissues means that these structures could be used in medical procedures to form scaffolds that can act as a template for tissue regeneration, where damaged tissues are encouraged to regrow.

The use of scaffolds is becoming more common and varied in its applications, but this new technique is special in that it creates super-soft scaffolds that are like the softest tissues in the human body and could help to promote this regeneration. In particular, there might be future potential in seeding neuronal cells; those involved in the brain and spinal cord.

The technique uses solid carbon dioxide (dry ice) to rapidly cool a hydrogel ink as it is extruded from a 3D printer. After being thawed, the gel formed is as soft as body tissues, but doesn’t collapse under its own weight.