3D bioprinting represents a group of early-stage technologies. These fields of research examine the use of biological materials in printing functional implants and test devices that simulate, stimulate, or replicate real tissues, for either patient implants or research tools. While these technologies are at a very early stage, they show promise of paradigm shifts in medical interventions that have dramatic and far-reaching implications. This article will discuss: What is 3D bioprinting?, its history, how it works, and its types.

What Is Meant by 3D Bioprinting?

3D bioprinting is the use of biological and bio-functional materials in additive manufacturing. Highly specialist printers are used to create 3D structures made of these biological materials. Some examples are: living cells, bio-active framework or scaffold materials, and biomolecules. The process uses typical 3D printing methods to deposit the biological material in layers, resulting in biological mimic, framework, and substitute constructions for diverse medical purposes.

The purpose of this 3D bioprinting is the manufacture of highly functional, complex tissue constructs and eventually organs. These are used for medical purposes such as patient implantation, drug testing, and pathology modeling. This technology is currently operating at fairly primitive levels. In terms of functioning tissues, however, research progress suggests it will revolutionize healthcare by enabling the custom manufacture of organs that are functionally similar to (or better than) the natural tissues they replicate.

When Did 3D Bioprinting Begin?

There is no single moment when the technologies and research that have resulted in 3D bioprinting suddenly broke through into patient solutions. However, several significant events stand out as seminal in defining the foundations of this technology. Gabor Forgacs observed that cells could be organized into “new” spatial structures and that they would combine and retain the structure indefinitely. This understanding was later key to the 3D construction of biological structures, as it taught that they could be induced to retain a shape.

Biocompatible materials began to be used in regenerative healthcare solutions around 2000. This led directly to the construction of spatial scaffolds, developed at Wake Forest University. Scaffolds were colonized with cultured patient cells, and implanted without rejection or immunosuppression drugs. These proved to be long-term stable. In 2002, bio-extrusion technology was reported by Landers, and commercialized as “3D-Bioplotter”. Wilson and Boland used a modified HP inkjet printer as a bioprinter in 2003 and then in 2004 developed cell-loaded bioprinting with a commercial SLA printer constructing scaffolds.

How Does 3D Bioprinting Work?

The process of 3D bioprinting generally consists of these steps:

1. Create a 3D design of the tissues or organs that will be printed. Tools such as BioPrint Pro from Allevi 3D are developing fast.
2. Select the ideal bio-ink. The material used in 3D printing contains materials such as: proteins and growth factors in biocompatible, photocured resins. These are off-the-shelf materials, ready to print inappropriate SLA bioprinter equipment. Before printing, they must be infused with cultured patient cells which will be stimulated to “grow” the organ.
3. The bioprinter builds the model as designed, processing it through standard slicer software. Bio-inks are formulated for various production methods, such as extrusion, inkjet, and SLA printing. The deposited bio-ink fuses to form a porous structure, ready for cell maturation.
4. The printed structure is cured to a more stable, cross-linked form by a variety of processes, suited to particular bio-ink types.
5. After cross-linking, the printed material is incubated in a bioreactor. The printed tissue/organ will be treated as a living thing in this process, to optimize its development.

For more information, see our guide on How 3D Printers Work.

What Is the Importance of 3D Bioprinting?

The increasing use of bioprinting in all areas of patient care, drug development, and research is a result of the development of an increasingly powerful tool kit. This is the early stage of what is likely to become the manufacture of full replacement tissues and organs. The ability to custom-build new organs for surgical implants is on the verge of revolutionizing the entire medical sector. It allows patient treatments with the patient's tissues induced to deliver new, perfect, and “real” transplants with little or no rejection risk. Figure 1 is an example of a bioprinted organ: