The Shape of Things to Come

This coming transformation in health care is part of a broader upheaval in manufacturing that’s already in full flower: 3-D printing. Think of it as the next industrial revolution, changing how things of all sorts are produced as dramatically as the advent of 19th-century factories and 20th-century automation did.

Though it’s called “printing,” forget about office machines shooting ink onto a flat page. 3-D printers build up objects of plastic, metal and other materials one layer at a time (which is why it’s also called “additive manufacturing”). The process can create intricate shapes directly from digital design files, bypassing the need for complicated molds or machining tools and techniques.

University of Maryland researchers are using the world’s most advanced 3-D printers, including ones that use lasers to solidify polymer resins into medical devices tinier than the diameter of a human hair. Other printers at UMD can fabricate precise replicas of human anatomy from materials already infused with living human cells, a process called bioprinting.

“Additive manufacturing literally changes the way people can design and create things,” says Jim Zahniser, assistant dean of engineering information technology for the A. James Clark School of Engineering and founder of Terrapin Works, which coordinates 3-D printing on campus. “You can build amazingly complex objects replicating very intricate structures in the body you could not make any other way.”

Physicians, scientists and engineers are working to better understand how human systems function and how to replicate functions as basic as oxygen and nutrient delivery throughout a synthesized body part, says John Fisher, professor and chair of the Fischell Department of Bioengineering.

“The printing technology is very capable—it’s already there,” he says. “That’s actually the easy part. It’s the biology that’s hard.”

Even as they pursue the ultimate goal of human replacement parts, UMD researchers are already proving the usefulness of 3-D printing in surgical rehearsal, drug testing and providing nearly instant custom medical equipment.

VIRTUAL ORGANS

Drug testing is slow, expensive and frustrating for patients desperate for effective new treatments. When it goes wrong, the results can be disastrous, even deadly. Part of the problem stems from traditional lab methods.

“Let’s say you’re testing a new drug and you put it in a petri dish with some cells,” says Ryan Sochol, assistant professor of mechanical engineering. “A petri dish is an incredibly inaccurate model of the human body.”

The biomedical movement known as “organ on a chip” aims for a more meticulous simulation by testing drug effects on cells grown inside the tiny rectangular channels of microfluidic chips. Delicate pumps circulate drugs and other fluids through the simulated organ structures, rather than simply mixing things up in a dish.

But for Sochol, this improvement over the petri dish can be improved upon even further with 3-D printing. Using the world’s highest-resolution printer, he can build models that closely mimic not just the functions but the tortuous shapes of microscopic structures in the liver, kidneys and elsewhere. More accurate shapes should produce more realistic results and greater drug safety, he says.

Sochol is also working with fellow Clark School researchers, including professors William Bentley and Kimberly Stroka, to help them incorporate 3-D printing into their experiments with models of the digestive system and the blood-brain barrier, respectively.
“To mimic the architecture of the body, the kind of nanoscale 3-D printing we have access to at Maryland is the only way to recreate these structures,” he says.

A flexible, 3-D- printed model of a child’s heart helped doctors at Children’s National Medical Center prepare for a complicated surgery.

PRACTICE CUTS

Imagine you’re a patient about to undergo surgery to fix a complex heart abnormality, or the parent of conjoined twins whose tiny, intertwined organs doctors are about to separate.

Do you want this to be the surgeons’ first tangible exposure to the organs? Or would you rather the doctors be able to first hold accurate representations of the affected body parts, spin them around for closer examination, and even disassemble them to look inside?

Axel Krieger, assistant professor of mechanical engineering, specializes in 3-D printing of body structures for surgical rehearsal. He spent several years in charge of 3-D printing at Children’s National Medical Center in Washington, D.C., and is now researching the fabrication of more functional, more accurate models at UMD.

“If the disease is really, really complex and very unique in terms of what surgeons encounter on a day-to-day basis, this can really give them a spatial understanding of where the disease is in reference to how they access it surgically,” he says.

The printed models have the potential to boost doctors’ confidence and improve communication between providers as they study and prepare for complicated surgeries, says Dr. Laura Olivieri, a pediatric cardiologist with whom Krieger has frequently worked.

“With these very rare heart defects that require very precise, individually tailored approaches, you want the people performing the surgery as informed as possible and armed with as much data as possible,” Olivieri says.

DEVICES ON DEMAND

The rise of 3-D printing will change the way medical equipment is manufactured and distributed, increasing convenience and affordability.

The technology has already made prosthetics more accessible. Even a basic hand or arm can cost upward of $10,000 and require multiple fitting visits to a specialist. Prosthetics can be impractical for children, who outgrow the devices in a few months, and for people who lack the cash or insurance coverage, or geographic access to a prosthetics lab.

But for less than $20 in material costs, it’s now possible to print out a custom-sized basic plastic hand that allows users to grasp objects. It requires only a consumer-level 3-D printer, and the device doesn’t require a prosthetics specialist to put together.

Terrapin Works is working with the nonprofit Enabling the Future to provide free prosthetic hands to children, and UMD engineering students are helping to improve the foundation’s downloadable designs and print files, says Maria Esquela, a volunteer with Enabling the Future.

“You send the file to print… and you’re hours away from having a custom prosthetic,” she says. “The speed, compared to traditional methods, is really precious to the youth receiving them, because they’re going to outgrow these before they need their next pair of shoes.”

Printing can also help create advanced, high-end prosthetics; the nonprofit is working on designs for a myolectric arm—one controlled by electrical signals generated by muscles—that will cost about $300 to make and offer similar functionality to devices that now cost $40,000.

Another advantage to the technology: It can encourage quick, inexpensive biomedical innovation and entrepreneurship, as a team of UMD undergrads recently learned. When they needed an EEG headset for a portable system to detect Alzheimer’s disease in people without symptoms, they didn’t plunk down $10,000 at a medical supply shop. Instead, they downloaded a free file from the neurotechnology company Openbci.

The DIY approach resulted in a brain-scanning tool that’s smaller and easier to carry to senior centers, as well as in about $8,500 in savings, says Dhruv Patel ’20, a leader of the Synapto team. It won first place and $20,000 in a National Institutes of Health biomedical design competition last summer.

“When we’re facing this kind of public health crisis, we need something that’s easily transported and easily manufactured,” Patel says.

Students in Terrapin Works turned a computer design file into a 3-D-printed prosthetic hand.

PRINTING THE BODY

One of medicine’s holy grails is wholesale replacement of body tissues and parts damaged by accident or disease. Known as tissue engineering, it has already seen limited success in the lab with the replacement and regeneration of relatively simple tissues in isolation, like skin, bone and cartilage.

The body isn’t simple, however, and to fulfill its promise, tissue engineering must be able to generate body parts in all their intricacy—with bones connected to tendons, blood vessels and nerves, or organs composed of many types of tissues.

For such a difficult assignment, 3-D printing is the tool of choice, says Fisher, who directs the National Institutes of Health-sponsored Center for Engineering Complex Tissues. Fisher is working with bioprinting, fabricating increasingly elaborate structures with cell populations growing inside them.

He’s collaborating with researchers at Rice University and the Wake Forest Institute for Regenerative Medicine, as well as with Dr. Curt Civin, director of the Center for Stem Cell Biology & Regenerative Medicine at the University of Maryland School of Medicine in Baltimore. It’s part of the MPowering the State partnership to combine the strengths of UMD and the University of Maryland, Baltimore.

“I can build things out of a single material and a single cell population and have control over exterior geometry and interior architecture, which is one step,” Fisher says. “The next step is that I start building things with multiple cell populations adjacent to one another in whatever position I would like. I start asking questions about how those populations interact based on their locations, which 3-D printing gives you the ability to do in a very precise way.”

While the reality of fabricating new body parts and organs is still years in the future, the concept is no longer limited to the sick bay in “Star Trek.”

“There are people in the field who’ve made suggestions that involve laying someone down on a table with a big printer above them and printing directly in the body,” Fisher says. “I think we’re a ways away from that … Right now we’re building model tissues to help us understand biology better. But something like that is the ultimate goal.”