Can we 3D print human tissue?

This post first appeared on GE LookAhead.

It all started 15 years ago with an old inkjet printer: Thomas Boland realised that its nozzles, about 25 microns in diameter, were approximately the same size as a typical human cell.

Today Mr Boland is chief science advisor and co-founder of TeVido BioDevices, a Texas company that develops live-tissue printing techniques. Its current mission: incorporating the fat cells of breast cancer patients to precisely print and reconstruct their nipples following mastectomies. What Mr Boland and others in the burgeoning field of bio-printing want is the stuff of sci-fi dreams. They endeavour to print live, viable, functioning organs on demand. Scientists believe it might happen in the next decade, but accomplishing it is easier said than done.

The actual printing is relatively straightforward: cells are mixed with a hydrogel that suspends the cellular “bio-inks.” Together, the cells and gels are printed in precise layers and patterns. After the printed tissue matures, the hydrogel is removed. Getting these printed tissues to stay alive, however, is difficult. In the body, cells receive life-sustaining nutrients from the vascular system. Such conditions are not easily met in the lab, and thus far, the vasculature problem remains an important obstacle for bio-printing. “When they [printed organs] fail, it’s almost always because they don’t vascularise very well. It’s a really big issue, but I don’t think it’s something that, for the most part, people are addressing” notes Dr Stephen Minger,  Director of Blue Skies Innovations Ltd and a Senior Consultant for GE Healthcare in an interview forMaterials World.

Still, progress is being made. Researchers at Harvard University, for example, have managed to 3D print tissues equipped with hollow structures that can act as blood vessels. And bio-printing companies are attracting interest. Organovo — the world’s first publicly-traded, 3D bio-printing company — uses hepatocytes, endothelial cells and hepatic stellates to bio-print liver tissue. At 3mm long and surviving only about 40 days, Organovo’s tiny slices are nowhere near fully-functional organs. Still, such bio-printed livers have the potential to shorten protracted, expensive government approval processes for living-tissue toxicology assays. In fact, Merck & Co. inked a deal with Organovo back in April with the aim of performing such testing. If those kinds of deals succeed, there may be money for more complex research.

Organovo has another high-profile partnership with Paris-based cosmetics giant L’Oréal to research bio-printing human skin tissue. Skin tissue, printed in relatively simple layers, is considered easier to scale than an architecturally-sophisticated heart or pancreas, so it’s a good place to prove functionality and market potential. Although not directly related to medicine, the L’Oréal deal might eventually prove helpful for skin and burn treatments. And if successful, such bio-printing could also eliminate controversial animal testing in the beauty industry.

The spirit of bio-printing — combining 3D printing with medicine — also extends to other areas of the medical frontier. In summer, the US Food and Drug Administration approved the use of a 3D-printed pill. The 3D printing of drugs enables researchers to control porosity, creating pills that break down immediately in the mouth. They can also create layers and change the shape of a pill to, say, a pyramid, giving them better control over absorption rates; or, in an upgraded nod to the compounding pharmacies of days past, they could increase the potency by packing more of the active ingredient into a smaller, single dose.

Developments of this kind suggest the possibility of a day where we’ll be downloading the bio-printing prescriptions for our own drugs, our own tissues, even our own microbes — or perhaps bio-engineering them ourselves. But first the research needs to be funded; this is perhaps the industry’s biggest current hurdle. TeVido successfully turned to Indiegogo to raise $35,000, but that’s a drop in the proverbial research bucket. As TeVido’s founder, Laura Bosworth, recently told journalist Andrew Leonard, it’s much easier to raise money “for an app that lets you order a taxi” than for potentially life-saving organ technology. Too bad they can’t bio-print dollars.

Publication does not imply endorsement of views by the World Economic Forum.

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Author: Holly Hickman writes for GE Look Ahead.

Image: A figurine is printed by Aurora’s 3D printer F1 during the 2014 Computex exhibition. REUTERS/Pichi Chuang.