Researchers make progress on printing 3-D hearts for humans

LOUISVILLE, Ky. — Researcher Stuart Williams is not talking about a far-off, sciencefiction effort when he describes how scientists will create new, functioning human hearts — using cells and a 3-D printer.

The project is among the most ambitious in the growing field of three-dimensional printing that some say could revolutionize medicine.

“We think we can do it in 10 years — that we can build, from a patient’s own cells, a total ‘bioficial’ heart,” said Williams, executive and scientific director of the Cardiovascular Innovation Institute. The institute is a collaboration between the University of Louisville and the Jewish Heritage Fund for Excellence.

Known for creating products as diverse as car parts and action figures, 3-D printing also is being used to create models of human bones and organs, medical devices, personalized prosthetics and now, human tissues. Williams describes the process as taking a three-dimensional structure “and essentially cloning it, using a printer.”

“Bioprinting is pretty much done everywhere,” said Dr. Anthony Atala, director of the Wake Forest Institute for Regenerative Medicine in North Carolina, where scientists recently won an award for innovations in bioprinting. “Our ultimate goal is increasing the number of patients who get organs.”

Custom parts

Earlier this month, officials announced that a baby’s life had been saved when a 3-D printed device from the University of Michigan — a specially designed splint — restored his breathing. The case was recently featured in the New England Journal of Medicine.

In Kentucky, Williams and his colleagues created and implanted parts of hearts in mice as part of their heart-printing research.

And University of Kentucky scientists used the technology to grow new ulna bones in rabbits and make models of human parts for teaching and surgery planning.

Eventually, scientists across the globe hope printing tissues and organs from patients’ cells can eliminate the danger of rejection and the shortage of transplant organs.

Bill Gregory of the UK Center for Visualization and Virtual Environments expressed the optimism of many scientists, saying that, in the future, “You’ll be able to custom-make parts and get them when you need them.”

Work began in 1990s

While interest in 3-D printing has “all of a sudden exploded,” Williams said that he and other scientists have been studying medical applications of the technology since the 1990s.

It involves taking a three-dimensional digital image of a structure, then replicating the structure by depositing material in layers. Materials can be plastic, liquid or cells in a biologically safe glue. Different researchers use different custom-made glues and printers.

Williams, who worked at the University of Arizona before coming to Louisville in 2007, said his team there received money from the U.S. Department of Defense to use 3-D printing to create a lymph node — with the idea it could be implanted in the event of bioterrorism.

To create the node — which they did in 2001 — they built a 3-D printer called the BioAssembly Tool, or BAT, for about $400,000.

Williams brought the BioAssembly Tool to Louisville, where his main interest is creating blood vessels, cardiac structures and ultimately hearts to fight cardiovascular disease.

In 2007, the Cardiovascular Innovation Institute received a $2 million grant from the National Institutes of Health to

‘‘ We think we can do it in 10 years — that we can build, from a patient’s own cells, a total ‘bioficial’ heart.”

Executive and scientific director of the Cardiovascular Innovation Institute develop the printing technology, which researchers used at the time to organize tissue grown in the lab to build networks of small blood vessels using mice and rats. Their work has continued since.

Tissues are created using cells derived from an individual’s fat and extracted with a machine. They go into the BioAssembly Tool, and the living cells are mixed with a glue that eventually dissolves inside the body like surgical sutures.

The printer rebuilds the structure, which then can be implanted. Williams said they are still working on whether the fat-derived cells will be coaxed into becoming cardiovascular cells in the lab or inside the body.

He said building a heart involves creating five parts — valves, coronary vessels, microcirculation, contractile cells and the organ’s electrical system. Six months ago, researchers created and implanted a portion of a heart and blood vessels in mice.

The ultimate goal is to extract a patient’s fat through liposuction, isolate cells with a machine, mix them with the glue and “print” a heart — all within an hour.

Williams said the total bioficial heart could cost about $100,000 in today’s dollars, not counting $150,000 or so in hospital and surgery costs. That’s less than the typical heart transplant and doesn’t require ongoing costs for anti-rejection drugs.

Williams said some of his peers laugh at his 10-year timetable, but he’s not discouraged.

“I love it when they laugh,” he said. “It provides me with a challenge.”