3D Bioprinting is a form of additive manufacturing that uses cells and other biocompatible materials as “inks”, also known as bioinks, to print living structures layer-by-layer which mimic the behavior of natural living systems.
Bioprinted structures, such as an organ-on-a-chip, can be used to study functions of a human body outside the body (in vitro), in 3D. The geometry of a 3D bioprinted structure is more similar to that of a naturally occurring biological system than an in vitro study performed in 2D, and can be more biologically relevant. It’s used most commonly in the fields of tissue engineering and bioengineering, and materials science. 3D bioprinting is also increasingly used for pharmaceutical development and drug validation, and in the future will be used for medical applications – 3D printed skin grafts, bones, implants, biomedical devices, and even full 3d printed organs are all being actively researched.
How does 3d bioprinting work?
3D bioprinting starts with a model of a structure, which is recreated layer-by-layer out of a bioink either mixed with living cells, or seeded with cells after the print is complete. These starting models can come from anywhere – a CT or MRI scan, a computer generated design (CAD) program, or a file downloaded from the internet.
That 3D model file is then fed into a slicer – a specialized kind of computer program which analyzes the geometry of the model and generates a series of thin layers, or slices, which form the shape of the original model when stacked vertically. Cura and slic3r are examples of slicers commonly used in 3D printing. Allevi also has a specialized slicer, optimized specifically for bioprinting, built into our Allevi Bioprint software.
Once a model is sliced, the slices are transformed into path data, stored as a gcode file, which can be sent to a 3D bioprinter for printing. The bioprinter follows instructions in the gcode file in order, including instructions to control for temperature of the extruders, extrusion pressure, bed plate temperature, crosslinking intensity and frequency, and, of course, the 3D movement path generated by the slicer. Once all of the gcode commands are completed, the print is done and can be cultured or seeded with cells as part of a biostudy.
Why is 3d bioprinting important?
Over 120,000 people in the US alone are on waiting lists for organs, and others experience chronic problems due to the long-term damaging effects of post-transplant immunosuppression. There’s a large and growing need for an alternative to the organ transplant waiting list. The scientific community has already succeeded in bringing together multidisciplinary teams of researchers, physicians, and engineers to take on the biggest challenges to human health, and 3D bioprinting is an exciting new tool with the potential to eliminate the organ transplant waiting list.
For pharmaceutical development, 3D bioprinting offers a means of testing drugs faster, at a lower cost, and with better biological relevance to humans than animal testing.
In the biomedical devices field, 3D bioprinting has enabled new developments such as sugar stents to help surgeons join veins with fewer complications, and systems for improved drug delivery, among others.