Big Step Forward Made In The Quest For 3D Printed Organs

An exciting new development in 3D printing has brought the possibility of on-demand printed organs for transplant one big step closer to reality. We've already seen the way 3D printing is beginning to revolutionize healthcare with, for example, the production of lightweight printed casts, but this latest development has truly lifesaving potential.

Three dimensional printing was first developed in the late 1980s and was applied in the biomedical industry soon after in the production of bioscaffolds used for growing various tissues. In recent years, rapid growth has been seen in all areas of 3D printing thanks largely to the manufacture and sale of relatively inexpensive 3D printers. These days, anyone with a grand or two to spare can begin experimentation with this novel technology and many have done so, even outside the traditional realms of science and engineering.

Cube 3D Printer: Cube Commercial Home-use 3D PrinterCube 3D Printer: Cube Commercial Home-use 3D Printer

With the increased availability of 3D printers, the field of bioprinting -- defined as the layer-by-layer positioning of biological materials, biochemicals or living cells -- has taken off. A number of bodily tissues have been successfully printed offering in many cases a safer, less painful or less expensive alternative to traditional procedures like skin and bone grafts. Thus far, researchers have demonstrated the printing and transplant of such diverse tissues as multilayered skin, bone, vascular grafts, tracheal splints, heart tissue and cartilaginous structures. However, the ability to print and transplant functional organs remains a sort of Holy Grail in the field.

The major stumbling block is the development of a suitable bio-ink. Such an ink must meet a number of criteria beyond the standard printing requirements like an appropriate viscosity and surface tension. Bio-inks must also exhibit properties like non-toxicity and biocompatibility, self-healing, responsiveness to particular physiological stimuli, and permeability to nutrients. Now scientists report the development of such an ink using a mixture of two solutions containing DNA and peptides.

 3D Printed DNA Gel: 3D Printed Organ-like Gel; Image credit: Dr. Will Shu, Heriot Watt University3D Printed DNA Gel: 3D Printed Organ-like Gel; Image credit: Dr. Will Shu, Heriot Watt University

Upon mixing, the two solutions react spontaneously to form a water-based gel with sufficient rigidity to mimic the structure of an organ. This innovation, keeping the two active materials separate until the last minute, is akin to certain commercially available adhesives or drain cleaners. This allows the use of a solution-based processing technique like 3D printing to generate a solid product like an organ. Aside from their mechanical stability, the gels were also biocompatible, biodegradable and self-healing. Furthermore, slight modifications to the DNA strands used in the inks allowed the researchers specific control over the mechanical properties of the final product.

While this is already an impressive demonstration of the "first time in situ multilayer 3D bioprinting has been demonstrated", the scientists then took their experiment one step further by incorporating live cells into the process. Importantly, they found that this ink system allowed the cells to survive the printing process. Moreover, the gel matrix was found to be permeable to the nutrients required to sustain cell life paving the way to 3D printed organs. Indeed, one of the project leaders Will Shu explains that, "our eventual aim is to 3D print organs for transplant, as well as producing alternatives to the testing of drugs on animals".