Louisville Researcher, Stuart Williams, Ph.D., is Closing in on Printing 3-D Hearts
Stuart Williams of the Cardiovascular Innovation Institute talks about the medical applications of 3-D printing and his hopes to create a “bioficial” heart.
Louisville researcher Stuart Williams is not talking about a far-off, science-fiction effort when he describes how local scientists will create new, functioning human hearts — using cells and a 3-D printer.
“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, a collaboration between the University of Louisville and the Jewish Heritage Fund for Excellence.
The project is among the most ambitious in the ever-growing field of three-dimensional printing that some experts say could revolutionize medicine.
Known for creating products as diverse as car parts and action figures, 3-D printing is also 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.”
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.
Locally, Williams and his colleagues recently created and implanted parts of hearts in mice as part of their heart-printing research. And University of Kentucky scientists have used the technology to grow new ulna bones in rabbits and make numerous 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 persistent shortage of transplant organs. Atala said that may be years away, and scientists face a number of challenges, such as replicating the complexity of blood vessels.
But 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
Williams said that, while interest in 3-D printing has “all of a sudden exploded,” 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 U of L in 2007, said his team there received funds 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. They started with a direct-write printer, adding parts from the hardware store and from custom shops.
In 2003, Williams won an R&D 100 Award for his work on the BAT, which has resulted in $30 million worth of bioprinting work.
Williams has brought the BAT to Louisville, where his main interest is creating blood vessels, cardiac structures and, ultimately, hearts — to fight cardiovascular disease, which accounts for about three in 10 deaths in Kentucky.
“This was what killed my dad,” he said. “My dad was in congestive heart failure.”
In 2007, the Cardiovascular Innovation Institute received a $2 million grant from the National Institutes of Health to develop the printing technology, which they 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 BAT, and the living cells are mixed with a glue that will eventually dissolve inside the body like surgical sutures.
The printer rebuilds the structure, which can then 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, Williams said, they 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.
If the bioficial heart was proven and federally approved, he said, insurance would most likely cover it if it was considered medically necessary for the patient.
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.”
Scientists in Lexington also are tapping into the possibilities of 3-D printing.
Gregory said his UK center printed ulnas for rabbits around 2005, using “bone-seeding” material that coaxed new bone to grow within rabbits.
A more common application of 3-D printing at UK is to create surgical models from CT or MRI images, using liquid, small beads or powder, Gregory said.
Models allow surgeons to practice on a person’s precise anatomy before an operation — or teach medical students or residents — using printed replicas of structures such as jaws, eye sockets or cheekbones. Gregory said doctors also develop custom implants for reconstruction.
Dr. Larry Cunningham, chief of oral maxillofacial surgery at UK, said models give doctors “something you can hold in your hand,” instead of trying to visualize a structure from a two-dimensional image
“The advantage to the patient is I’m better prepared,” Cunningham said. “I can be faster, with less down time — which is important because OR time can cost $100 a minute.”
The cost of 3-D printers has come down. Gregory said people can buy decent “hobby printers” for a couple thousand dollars, and sophisticated lab versions cost around $20,000, with custom-made printers costing much more.
The increasingly accessible technology has spawned new companies and products.
San Francisco-based Bespoke Innovations, for example, creates custom prosthetic, saying on its website: “The advent of 3-D printing has allowed us to build something based on the unique shape of a particular user, modify it with our designs, and turn it into something physical that can be worn.”
Meanwhile, scientists across the world are working on the next step — creating an array of real human parts.
In February, doctors at Weill Cornell Medical College and biomedical engineers at Cornell University in New York announced they had used 3-D printing and injectable gels made of cells to build a facsimile of a human ear that looks and acts like a real one.
And in the case of the baby in Michigan, university officials said the splint was created from a CT scan of the patient’s trachea and bronchus, integrating a computer model with 3-D printing. The baby, who used to stop breathing every day when his collapsed bronchus blocked the flow of air, was off a ventilator three weeks after the surgery, and officials say he hasn’t had breathing trouble since.
Wake Forest scientists, like their peers in Louisville, are working on organs. Officials at Wake Forest say their scientists were the first in the world to engineer a lab-grown organ, and they hope to scale up the process by printing organs with a custom printer. Institute scientists there have also designed a bioprinter to print skin cells onto burn wounds.
So far, Williams said, he knows of no instance where a tissue or organ created through 3-D printing has been implanted in a human. But he said the race is on.
“I think this will have an incredible effect on trauma patients … on the armed forces. You can imagine printing a jaw, printing muscle cells, printing the skin,” he said. “Ultimately I see it being used to print replacement kidneys, to print livers, and to print hearts — and all from your own cells.”