1. CT scans can function like a CAD design
Instead of trying to create an organ or tissue model from the ground up, researchers and engineers can use a CT scan or MRI to create a 3D model to print. For example, the University of Louisville, when creating a 3D printed model of a young boy’s heart so doctors could use it for his surgery, the researchers used the CT scan from his doctor to make the 3D design model. Websites like Instructables even have tutorials to describe how to turn a CT scan into a 3D bioprinting model.
2. There are multiple types of printers
Bioprinters: Organovo made the first commercially used bioprinter, called NovoGen MMX, which is the world’s first production 3D bioprinter. The printer has two robotic print heads. One places human cells and the other places a hydrogel, scaffold, or other type of support.
“Inkjet” inspired printers: Experiments with bioprinting at Wake Forest University were inspired by traditional inkjet printers. The printer allows multiple cell types and components to be used for printing. In early forms of the technology, cells were placed in the actual walls of ink cartridges and the printers were programmed to place the cells in a particular order. Today, the university has adapted that technology so that skin cells can be placed in an ink cartridge and printed directly on a wound.
Six-axis printer: At the University of Louisville’s Cardiovascular Innovation Institute, Dr. Stuart Williams is using a robot/printer that, instead of building the tissue from the ground up, as traditional 3D printers do, can build multiple parts of the heart tissue he is making at the same time and move them around accordingly.
“We’ve built a six-axis printer that can print layers but come back and start printing a new layer on the outside [of the heart],” Williams said. “The valves are in one spot, and we use robot to bring the valves in and puts them in parts of the heart.”
3. Cells are used like “ink”
Organovo thoroughly explains the 3D bioprinting process in this video. Basically, once a tissue design is selected, the company makes “bio-ink” from the cells. Using a NovoGen MMX bioprinter, the cells are layered between water-based layers until the tissue is built. That hydrogel in between layers is sometimes used to fill spaces in the tissue or as supports to the 3D printed tissue. Collagen is another material used to fuse the cells together. This layer-by-layer approach is very similar to the normal 3D printing process, where products are built from the ground up.