Until bioprinters are reality, 3D printing can still save lives

A two-year-old girl born with a hole in her heart had a life-saving operation in London last month thanks to a 3D printer. Perhaps equally astounding is that she’s not the first.

Mina Khan was born with a hole in the wall between two chambers of her heart, a condition that left her exhausted and unable to gain weight or even grow hair. The deformity was so severe doctors said it likely couldn’t be repaired – but by creating an exact 3D replica of her heart using MRI and computerized tomography scans, surgeons at St. Thomas’ Hospital in London were able to design a bespoke patch, practice and perfect how to stitch it into place, and ultimately perform the surgery successfully on the girl’s actual heart.

“The 3D printing meant we could create a model of her heart and then see the inside of it with a replica of the hole as it looked when the heart was pumping,” Professor David Anderson, who led the operating team, recently told the Sunday Times. This meant that even though Mina had a “very complex” hole in her heart that posed a “huge intellectual challenge,” the team was able to enter the operating room with a “much better idea of what we would find.”

Mina isn’t the first tiny tot to benefit from these “practice” organs fashioned from a 3D printer. Just last year in New York, surgeons performed a similar surgery on a 2-week-old infant, whose congenital heart defect left several holes in his heart.

“It made a huge difference because the baby went from needing 3 or 4 surgeries to needing just one,” the head surgeon said at the time. “For people like us in congenital heart surgery, who deal with complex 3D structures, it’s a huge advancement because now we don’t have any more surprises. We go to the operating room, confident that we know exactly what the anatomy is like, so our outcomes are obviously going to be better for the benefit of the patients.”

3D-printed models of organs are just the tip of the iceberg. For a few years now scientists have been hard at work building 3D-printed organs for actual transplant. So far, the key drawback has been lifespan because of the need for 3D-printed veins and arteries that nourish the transplanted organs and keep them alive beyond, say, the current benchmark of 40 days, as achieved by California startup Organovo. Organs are, let’s face it, a step beyond prosthetics.

But scientists at Harvard, Stanford, MIT, and the University of Sydney made a major breakthrough last year when they bioprinted a network of tiny fibers coated with human endothelial cells, enabling them to remove the original print and leave just the capillaries in their place.

The developments may seem like strictly good news given some 18 people die every day in the U.S. because of a shortage of donated transplant organs, but the emerging field of 3D-printed organs and tissue is growing so rapidly it’s leaving several ethical and logistical questions unanswered in its wake.

“These initiatives are well-intentioned, but raise a number of questions that remain unanswered,” one researcher at Gartner said in a report last year about the “inflection point” of 3D printing. “What happens when complex ‘enhanced’ organs involving nonhuman cells are made? Who will control the ability to produce them? Who will ensure the quality of the resulting organs?”

Still, researchers are pushing ahead. One small kidney printed in China lasted a whopping four months (caveat: in a lab), while a 2-year-old girl in the US received a working windpipe grown using her own stem cells.

In fact, stem cells and biopsied tissues form the basis of this first experimental crop of printed organs – these cells are fed into 3D printers that arrange them by cell type, just as they are organized in our bodies. If all goes well, these cells signal to one another and begin to fuse into a coherent system.

Still, many researchers say that 3D-printed organ transplants are at least a few years out, and regulatory hurdles are likely to push that timeline back at least another few years.

Cambrian Genomics wants to make it 10,000 times cheaper to synthesize DNA with a laser-based system. Photo courtesy of Cambrian Genomics.

Cambrian Genomics wants to make it 10,000 times cheaper to synthesize DNA with a laser-based system. Photo courtesy of Cambrian Genomics.

Jennifer Lewis, professor of biologically inspired engineering at Harvard, said at EmTech last year that the holy grail, bioprinting functioning human organs, is a “really long moon shot.” But she also acknowledges that the vasculature printing breakthrough has prompted colleagues at Harvard and beyond to move forward quickly with their eyes on very complex organ parts – including kidney components (kidneys because they comprise 80 percent of the current waiting list demand).

To do so, researchers are having to devise 3D printing inks and nozzles to allow them to print different types of cells that help connect other cells. One ink enabled the Harvard group to construct tunnels inside tissue, which the researchers lined with blood vessel cells – an approach they’re also using to build blood-filtering tubes inside kidneys.

Meanwhile, a two-year-old boy in Kentucky last year became one of a growing list of kids born with devastating congenital defects whose life has been saved by a 3D printer. Like Mina Khan, Roland Lian Cung Bawi’s defective heart was rendered using a 3D printer by University of Louisville engineers and physicians, and he is alive and well a full year after his February 2014 surgery.

“A lot of it really has to do with the imaging capability being much better,” Timothy Gornet, part of the self-described “nerd herd” that built the model at the University of Louisville, told me. “It’s much harder to get a picture of a moving organ like a heart than, say, a bone … Most surgeons tend to be very tactile, are used to touching and feeling, so while you can get a good idea of what’s going on [with digital imaging], it’s hard to grasp exactly where everything is, especially when you think of the size heart of an infant.

“I’ve been in the 3D printing business since the late ‘80s, and almost everything we work on is stuff and things – parts for aircrafts, snowboards, inanimate objects. But when you can really do something in your job and actually touch someone’s life, change how they live their life, it’s one of the most rewarding projects I’ve ever worked no.”

As for little Roland, living with a fully functional heart is not a bad way to celebrate two of his first Valentine’s Days.