Scientists have taken a leap forward toward the goal of growing artificial human organ replacements thanks to a new application of 3D printing technology. The new method has successfully created material that is soft and spongy like human brain and lung tissue.
Using a 3D printer, researchers create shapes similar to human organs using a synthetic composite hydrogel. Once these organ “scaffolds” are completed, they are “populated” with living cells which grow on the spongy material to fill out a complete organ.
There’s still a lot of bugs to be worked out of the process, however. For example, developers of the technique have yet to work out a way to prevent underlying layers from collapsing when additional layers are added. Because 3D printers work by spraying on layer after layer, each additional layer puts more pressure on the lower sections.
But there’s considerable reason for optimism. A fix has been developed that involves cooling down the lower layers with a cryogenic freezing technique. This makes them more stable and able to accept additional layers of material. After printing is completed, the frozen layers can be thawed slowly. The key is to maintain the integrity of the shape desired once fully warmed.
So far, brain-shaped 3D-printed organs have been populated with skin cells which are added over a layer of collagen applied to the hydrogel. The method is not yet ready for real brain cells, although smaller brain parts have been successfully populated using genuine neurons. Making a whole brain “scaffold” with the 3D print method has yet to be perfected.
This cutting-edge 3D bioprinting research is being conducted by the Department of Mechanical Engineering at Imperial College London in cooperation with the Tissue Engineering and Biophotonics Division of King’s College London.
It’s unclear when cryogenic bioprinting will be ready for actual human transplant. However, the ability to produce soft-tissue structures with this technique is a significant accomplishment.