Experts hail tissue-printing work of South Carolina scientists

The tissue-printing work of Charleston and Clemson scientists holds great promise for treating illness and growing organs for transplant, according to tissue engineers and other scientists across the country.

Dr. Vladimir Mironov of the Medical University of South Carolina and Thomas Boland of Clemson University have modified commonplace desktop printers to produce three-dimensional living tissue. They have printed alternate layers of cell clumps and a super gel to build three-dimensional structures. The cells quickly grow and meet, then the gel can be washed away, leaving only living material behind.

“It’s a very significant contribution to the field of tissue engineering,” said Dr. Anthony Atala, a surgeon and the director of tissue engineering at Children’s Hospital at Harvard Medical School.

The tissue printing is faster, better and easier than other methods of growing cells, Atala said. “It’s like the difference between a typewriter and a computer.”

Atala envisions himself and many other scientists using tissue printing.
“It’s a very ingenious approach. And what’s nice is it is simple,” he said. “It’s an extremely important advance in creating organs. … The work done by the group is based on sound science.”

Mironov and Boland are among a handful of people trying to solve an incredibly important problem in tissue engineering, namely developing a three-dimensional network of blood vessels before cells or tissues are transplanted, said Dr. Bruce Klitzman, senior director of the Kenan Plastic Surgery Research Laboratories at Duke University Medical Center.

Blood flow, to supply nutrients and remove waste, demands three-dimensional tissue rather than the two-dimensional living cells that have been grown in the past, he said. “That is difficult to extend to three dimensions.”

Klitzman described the solution as significant.

The “work is critically important in testing the hypothesis of whether we can grow and develop organs by placing cells in critical spots for a whole organ,” said Dr. Peter C. Johnson, the chief executive officer of TissueInformatics, a Pittsburgh company that builds analytical tissue software.

“The general approach could be applied to all tissue types and therefore is fundamental to tissue engineering,” Johnson said.

The work was well-received when Mironov gave presentations at two major scientific meetings recently, said Dr. Kelvin Brockbank, senior vice president of the Chicago-based Organ Recovery Systems and head of the company’s Charleston Research Center.

“It’s definitely sound (science),” said Brockbank, adding that Mironov and Boland have put together several technologies never combined previously.

Now, Brockbank said, he can envision taking cells from a patient, creating a construct in a lab, then putting the organ or other tissue product into the patient.

Because the transplant or implant would be grown from the patient’s own cells, there would be no rejection, no need for expensive immune-suppressant drugs and no use of expensive medications that can have side effects or prove toxic, Brockbank said.

Step one may be the printing of blood vessels, which could be used in heart bypass or other surgery. Next muscle cells might be added, he said.

Then a simple heart might be printed, something like today’s left ventricular assist device but composed of human tissue rather than the current mechanical device that uses batteries, Brockbank said. The mechanical pump-type devise that helps maintain a heart’s pumping ability could correct many cases of heart disease, said Brockbank, who has worked with a company that makes the devices.

Johnson foresees diverse uses, such as fabrication of meat substitutes and development of foods.

Atala looks to medical treatments, including cell therapy and gene delivery, envisioned as ways to cure and even prevent disease by correcting ills at the gene and cell levels.

Tissue printing could lead to developing a beating heart in a laboratory, creating bio-artificial pancreases for transplant into diabetics, nourishing muscle grown to save limbs and easing facial reconstruction, according to Klitzman.

In plastic surgery today, he must transplant muscle from inside a patient’s body, from a patient’s back to his arm or leg, for example, to prevent amputation and save a limb. Printing blood vessels would allow muscle to be grown and nourished outside the body then transplanted, even to the face in cases of facial paralysis, he said.

Efforts are under way to develop bio-artificial pancreases that would restore lost function in diabetics. Not enough pancreases are donated, and the organs are difficult to transplant. Most experts are looking for an off-the-shelf alternative, and Mironov’s approach to making a capillary system would help, Klitzman said.

Experts say they don’t know how rapidly tissue printing will progress.

In five or 10 years, Brockbank said, “There is a significant chance this will make a major contribution to engineering tissues and later organs.”

State, federal and private investment are needed to advance the project, Mironov said.

Brockbank forecasts a bright economic future for the work in part because the National Institutes of Health is giving a big push to regenerative medicine and tissue engineering. He expects the federal government to take tissue printing to the next level of research, and then private companies to invest in potential products.