University of Minnesota researcher has one of the first 'bioprinters' using living tissue

Prof. Angela Panoskaltsis-Mortari stood silently a few feet from the machine as it whirred alive for the first time. The device deposited coat atop delicate coat of pink goo through a small syringe until it had transformed a computerized image into a physical object.

Then she exhaled. Instead of wax or plastic, this 3-D printer uses "living" ink.

"It's like science fiction," said Panoskaltsis-Mortari, a pediatrics and medicine professor at the University of Minnesota.

Her lab was one of 20 worldwide selected recently to receive bioprinters from a fledgling company called BioBots, and it places her at the vanguard of research that could transform transplant medicine, burn therapy, drug testing and other fields of health care.

At labs across the country, researchers have used bioprinters like hers to produce transplantable ears, bone and muscle.

Panoskaltsis-Mortari plans to use her month-old printer to produce a biocompatible piece of esophagus; she and her colleagues hope to transplant it into a pig by the end of the year.

"The idea is that if you can generate the [right] types of cells," she said, "then all you have to do is print them in the right pattern."

Eventually, she said, medical researchers hope to "print" entire organs, such as lungs or hearts, for human transplant. On average, about 21 Americans die each day waiting for a transplant. That goal is at least a decade off, she said, but it raises tantalizing possibilities.

"There's no limit; if you know how to generate the individual parts, then theoretically there's a way to put them together … and put them somewhere in the body," she said.

Her bioprinter is the first at the U, and she hopes it can eventually anchor a campuswide lab for all the computer engineers, biophysicists, material scientists, mathematicians and biomedical researchers who are clamoring to use it.

Treating burns, diabetes

Before it's inserted into the printer, the bio-ink is a fluorescent pink gel. Once a syringe lays it down in successive layers, it dries to become smooth and pale — like hot glue — but slippery and decidedly organic to the touch.

For now, Panoskaltsis-Mortari purchases her bio-ink. But bioprinted components could be completely personalized, using a patient's specific dimensions and customizing the ink using cells from their own bodies.

U surgeons have been using simpler 3-D printers on simpler tasks for some time. At the U's Visible Heart Laboratory on a recent afternoon, five chirping printers were spitting out plastic models of the human heart. Some will be used to teach students and physicians, others to help heart surgeons customize patient care.

Robroy MacIver, a pediatric cardiothoracic surgeon at the school's Children's Hospital, uses the one-in-a-million models — tailored specifically to each of his patients — to help parents visualize complicated issues like aortic diagnoses or ventricular septal defects.

But bioprinting promises entirely new landscapes.

Using cells from any part of the adult body, Panoskaltsis-Mortari said, researchers can create what are called induced pluripotent stem cells. Those, in turn, can provide a basically endless supply of cells for patients. When fed into a bioprinter, the possibilities are endless.

"You could make skin cells for burn patients. You could produce pancreatic cells for insulin," she said. "You can make whatever cells you want."

Yet surgeons and researchers must clear significant hurdles before they begin printing out hearts with the push of a button. Complex, solid organs like lungs would be difficult to integrate into existing networks of vessels and nerves. Growing cells for bio-ink remains expensive.

"It has tremendous potential, but it's not as easy as it looks," said Wendy Dean, medical adviser to the Armed Forces Institute of Regenerative Medicine. Her office oversees work on technology that would scan and print skin cells directly into burn wounds suffered in combat or training, using ink made from patients' bodies. It's also studying reconstructive nose and ear cartilage and facial muscles and bones.

"The whole field holds so much potential for changing the paradigm of medicine," Dean said.

While producing entire organs remains a distant goal, researchers are already harnessing the technology for other uses. The pioneering Wake Forest Institute for Regenerative Medicine, for example, is bioprinting human "organoids" to test drugs, eliminating the need for animal testing.

"Instead of studying a random mix in a petri dish, you can actually put cells together … approximate[ly] how they are normally in the body," Panoskaltsis-Mortari said. "Even if we never print an organ that we can use for transplant, people are already using 3-D bioprinting."

Marion Renault • marion.renault@startribune.com