Industry Watch

The future of organ modeling and bioprinting

Life in 3D: The future of organ modeling and bioprinting

It’s not science fiction; it’s forward-thinking, far-reaching — Promethean even. And it’s inevitable. Humanity will likely, at some point, master the basic building blocks of life. Life-saving organs may be transplanted from printers not donors, potentially reducing both the risk of rejection and long donor waiting lists. We’re not quite there yet, but those who take the opposing bet do so at their own peril. They’re betting against some of Minnesota’s brightest researchers.

Building a better prostate
In addition to biopsies and imaging, which help identify and visualize internal tissues and structures, physicians regularly rely on organ models to game out surgical interventions. 

Organ models aren’t revolutionary. Crude wooden versions predate modern anesthesia; today, surgeons use hard, plastic models to get a rough sense of what to expect when they open patients up. “Rough” is the operative word: These models only approximate actual patient anatomies, and they respond nothing like actual tissue.

A research team led by Michael McAlpine, Benjamin Mayhugh Associate Professor of Mechanical Engineering at the University of Minnesota, is perfecting something better: 3D-printed silicone organ models that combine anatomical accuracy and mechanical fidelity.

Working off MRI scans, McAlpine’s team used a specially designed 3D printer last year to produce three prostate models “tuned exactly to the feel of each patient’s prostate,” says McAlpine. In other words, each artificial prostate looked like the corresponding patient’s actual prostate and displayed equivalent responses to surgical maneuvers. The team outfitted the models with electronic sensors that delivered helpful feedback — a potential game-changer for surgical trainees inclined to cut too deep or miss marks. 

McAlpine’s soft-organ model process has a patent pending. But it’s still early going: The prostate is simple enough to require just one type of silicone ink. The next step, he says, is to prove that 3D-printed soft-organ models work with more complicated internal structures, including those with tumors and other abnormalities. 

The technology “would be a huge benefit for doctors to practice before surgery or train medical residents,” says McAlpine.

Soft-organ models could also help medtech companies designing organ implants. “You need something that behaves like tissue itself,” during testing, says McAlpine.

Cells made to order
Pediatrics professor and University of Minnesota Bioprinting Facility director Angela Panoskaltsis-Mortari is on the forefront of the still-nascent field of bioprinting, which (literally) aims to inject life into inert 3D inks using pluripotent stem cells — the undifferentiated building blocks of human tissues. In a 2015 project, Panoskaltsis-Mortari attempted to grow a viable esophagus for transplant into a live pig. 

Bioprinting remains expensive, time-consuming and error-prone. Complex, transplant-ready human organs are still years off, though Hennepin County Medical Center recently repaired a patient’s skull using a 3D-printed composite of titanium and calcium phosphate. But momentum is building: Panoskaltsis-Mortari inaugurated a bioprinting course at the U of M last fall, and Century College is rolling out a bioprinting certificate program next year.

Shocking tattoos 
A more recent McAlpine project could have similarly far-reaching benefits. Earlier this year, a research team led by McAlpine published a study on 3D-printed bio-electronics — essentially, conductive tattoos on the backs of human hands. 

“We’re already good at printing electronics,” says McAlpine. “Why not integrate them into the body?”

McAlpine’s process requires detailed pre-imaging to ensure that the ink nozzle doesn’t pierce the skin, electronic ink that cures at room temperature to avoid tissue damage, and a complex motion-control system that uses cameras to track real-time hand movements during printing to reduce printing error and prevent injury. Unlike bioprinting, it’s cheap: The printer costs under $400, says McAlpine. And it has a range of uses, from deadly serious to downright frivolous.

“We imagine soldiers using [this technology] in the field to conduct chemical hazard analyses or capture solar energy,” says McAlpine. “Or, your kid could print some colorful LEDs on their skin for Halloween.” 

With costs already so low and prices for other conductive materials (such as solar panels) falling fast, 3D-printed electronics will likely become commoditized in the near future. To the extent that there’s money to be made in this space, says McAlpine, it’s in the software and algorithms supporting the printing process — like hand imaging and motion control. 

That’s probably not what entrepreneurs hoping to squirrel away the next world-changing technology want to hear. But it’s great news for end-users, whomever they turn out to be.