3D Printing Technique Replicates Biological Structures

A 3D printing technique that replicates biological structures could be used for tissue regeneration and replica organs.

Imperial College London researchers have developed the method using cryogenics and 3D printing techniques. Their technique creates structures that are soft enough to mimic the mechanical properties of organs such as the brain and lungs.

Structure of a single unit (a). How eight units fit together (b). Two views of a printed (c) and set eight-unit structure (d). Courtesy of 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.

Regenerating damaged tissue by "seeding" porous scaffolds with cells and encouraging them to grow allows the body to heal without the issues that normally affect tissue-replacing transplant procedures, such as rejection by the body.

While the use of scaffolds is becoming more common, the Imperial College technique is different in that it creates super soft scaffolds that are like the softest tissues in the human body and could help to promote regeneration. In particular, there might be future potential in seeding neuronal cells 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, which has been a problem for similar techniques in the past.

Researchers tested the 3D-printed structures by seeding them with dermal fibroblast cells, which generate connective tissue in the skin, and found that there was successful attachment and survival. This success could lead to further possibilities around the successful growth of stem cells.

The technique also could be used to create replica body parts or even whole organs. These could be incredibly useful to scientists, allowing them to carry out experiments not possible on live subjects. They could even be used to help with medical training, replacing the need for animal bodies to practice surgery on.

"At the moment we have created structures a few centimetres in size, but ideally we'd like to create a replica of a whole organ using this technique,” said researcher Zhengchu Tan.

The technique is published in the journal Scientific Reports (doi:10.1038/s41598-017-16668-9).