Additive manufacturing technologies are now so advanced they can create structures on a nanoscale. But how close are we to seeing 3D printed organs in the market? Professor Hala Zreiqat and Dr Peter Newman explain.

From cures for cancer to fusion power and driverless cars, almost every technology seems to be perpetually five to 10 years away. For researchers, “five to 10 years away” means we’ve been working on it for quite a while and it seems feasible, we just haven’t got there yet.

We understand people’s scepticism when we say “in five to 10 years we’ll be 3D printing organs”. Sceptical? Don’t believe us? Consider this: Over the last decade, there has been a paradigm shift in stem cell research.

Since the mid-1800s, researchers have been growing cells in sheets layered on top of glass and plastic dishes. This method is the cornerstone of biological research and its impact has been immeasurable – it’s responsible for the development of vaccines for polio, measles and smallpox, as well as the insulin that’s used daily by millions of diabetics worldwide.

That’s why it’s surprising that stem cell biologists have stopped using this method. Why? It’s simple: A sheet of cells layered over a dish doesn’t behave anything like the organs from which they’re derived.

The change in method is the paradigm shift we’re talking about, the one that means 3D-printed organs are knocking at the door.

Biologists have stopped growing cells in sheets layered over petri dishes and have started studying suspensions of three-dimensional organ-like cell masses, otherwise known organoids. If given the right biochemical cocktail, stem cells will proliferate into supercellular networks that spontaneously organise into three-dimensional structures that mimic the physiology of real organs.

The progress is staggering and multifaceted. Organoids promise to cut down on the need for animal testing and offer improved models to understanding disease progression. However, the study of organoids has offered unprecedented insights into the development of organs.

Producing organoids at a scale large enough to confer therapeutic benefit to humans remains a significant challenge. Large structures require supporting scaffold structures, such as the meshwork of collagens that stitch together the cells of your organs. However, recreating scaffold structures with sufficient detail to support the growth of large-scale cell structure has proven problematic.

Enter 3D printing.

The increase in life expectancy in Australia has improved dramatically in the last century with the expected age at death of 84.6 years for men and 87.3 years for women. This will lead to a significant increase in the need for organs to replace the damaged ones.

While biologists have been busy revolutionising cell culture methods, engineers have developed 3D printers that can focus light so tight, it can polymerise features similar in size to that of a single collagen molecule. This technology is known as multi-photon 3D printing and is the brainchild of Professor Martin Wegener.

As a pioneering user of this technology he’s demonstrated materials that can bend light around objects, effectively making them disappear. Yes, you read that correctly. He’s made an invisibility cloak.

Over the next five to 10 years we aim to use multiphoton printing to build synthetic scaffolds mimicking the meshwork of collagens that hold organs together. These will be sufficiently complex scaffolds which will support the growth of organoids large enough for clinical applications. This much at least seems feasible, but trust us, we’ve worked on it for a while.

Maybe it will be more than five, or even 10 years, before you’re stopping by the hospital to pick up a new heart, but you can bet that during this time we’ll be 3D printing organs.

Professor Hala Zreiqat is the Director of the Australian Research Centre for Innovative BioEngineering and the Head of the Tissue Engineering and Biomaterials Research Unit at the University of Sydney. Dr Peter Newman a research fellow at the ARC Training Centre for Innovative Bioengineering at the University of Sydney.