Every human being is unique. That’s one reason three-dimensional printing, which enables the creation of products tailored to individual preferences and needs, is a natural fit for the medical field. The technology has already spurred a great leap forward in the way prosthetic limbs, and artificial bones and joints are made, for example. A surgical first was achieved last July in New York when doctors used a 3D replica of an infant’s heart, created from an MRI scan, to guide them through an operation on the child’s actual heart to overcome a congenital defect.
But applications for 3D printing, the process of making a physical object from a digital model by adding successive layers of material, don’t stop at creating inanimate objects. Perhaps the most lucrative—and life-saving—use may lie in reproducing living soft tissue, a field known as bioprinting. Organovo, a startup in San Diego, has already gone public with a market capitalization of half a billion dollars on the strength of its method for printing living cells. (So far, the company’s cell cultures are reported to be small, about the size of a postage stamp, and not fully functional.) A handful of other companies and even the U.S. military are developing their own methods of bioprinting, which could be a US$8.4 billion industry as soon as 2025, according to technology advisory firm Lux Research. Still more promising early-stage technologies, though, are coming out of Canada.
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In September, University of Toronto graduate students Arianna McAllister and Lian Leng were awarded the 2014 James Dyson Award for Canada for the PrintAlive Bioprinter. (They will go on to compete for the worldwide prize sponsored by the British billionaire inventor.) PrintAlive specializes in printing skin from a patient’s own cells, which one day could enable burn victims to avoid painful skin grafts from other parts of their bodies. PrintAlive is also notable for being faster, more compact and cheaper than other bioprinters currently in development that function more like ink-jet printers.
The industry’s holy grail, however, is the production of functioning organs. That’s conceivably within our grasp, says Dr. Sam Wadsworth, one of four principals in Aspect Biosystems, a company incubated at the University of British Columbia. Aspect has developed a bioprinter that, like PrintAlive, eschews ink-jet printing technology, which can end up killing cells.
Based on a 3D image such as an MRI scan, Aspect’s machine builds relatively complex organic structures out of a “hydrogel” embedded within cells taken from the body and grown in a cell culture. “We get a really high rate of survival, optimized specifically for printing living cells,” Wadsworth says. The company is currently working with a major pharmaceutical firm to print lung airways for use in testing medications to combat airway fibrosis, a condition that kills 100,000 Americans a year.
“At the moment, [the illness] is a bit of a death sentence,” says Wadsworth, a cell biologist at St. Paul’s Hospital in Vancouver. Animal testing has proven to be a poor predictor of how humans will respond to treatment. “There are around 200 different ways of curing a mouse from this disease, but none of them have shown any efficacy in humans.”
By printing multiple lung airways—or any other afflicted organ—from a human patient and testing drugs on them, pharma companies can bypass the ethically challenged practice of testing on animals and proceed to human clinical trials with greater confidence the drugs will actually work, according to Wadsworth. Clinical trials represent a large part of the US$40 billion or so the pharmaceutical industry spends every year on research and development, so any way to expedite the process would save big money, too.
Aspect has adopted Organovo’s business model in that it aims to sell the tissues as opposed to the printers, at least at first. “The market for tissues is huge, and that’s just from the pharmaceutical industry,” Wadsworth says. Further down the road, he foresees a business making living tissues for hospitals and clinics directly for the purposes of personalized medicine. Instead of giving a cancer patient a cocktail of 15 drugs as is done now, doctors could print 15 tumours from a biopsy and determine which one is most effective before issuing a prescription to the patient.
The company’s “moon shot,” which Wadsworth estimates is 10 to 15 years out, would be printing entire replacement organs from a patient’s own cells. While mindful of the negative connotations that might arise from manufacturing body parts and implanting them, cyborg style, in humans, he doubts someone on a waiting list for a new kidney and requiring daily dialysis would have such qualms. “The families of patients in this situation will see what we’re doing in a positive light,” he says.