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In downtown Winston-Salem, researchers are using a modified Hewlett-Packard inkjet printer to "print" human cells, one layer at a time, to build tissues and organs.

This unlikely process has produced tiny, two-chambered hearts within 40 minutes. When stimulated with electrical impulses similar to those that regulate the human heart, those hearts started beating within four to six hours and beat on their own for five to seven days.

A more sophisticated printer, guided by electronic images, has created the entire top of a thighbone.

And in a project sponsored by the military, the technology is being modified to print skin directly on burns.

The phrase "Physician, heal thyself" is at least as old as Luke's Gospel. These researchers, at Wake Forest University Baptist Medical Center's Institute for Regenerative Medicine, are seeking new ways for the body to do just that.

They search for ways to use a patient's own cells to grow new tissue and even whole organs. Researchers are working with 22 cell types and tissues, aiming to treat conditions such as burns and muscular dystrophy.

The roughly 100 full-time scientists from a variety of disciplines, plus about 60 collaborating researchers from other Wake Forest Baptist departments, hope the work can help people's bodies heal and reduce demand for scarce transplant organs.

Researchers already have grown heart valves and muscle tissue, although none has been implanted in patients yet.

It all started with a bladder

Lab-grown bladder implantations performed as long ago as 1999 by the institute's director, Dr. Anthony Atala, have succeeded and suggest that the approach will work with other tissues. The bladders were the first lab-grown organs to be implanted in humans.

Similar work is ongoing elsewhere, and some early successes have been reported. On Wednesday, four European doctors writing on the Web site of the medical journal The Lancet reported that they had successfully transplanted a trachea, lined with cells engineered from stem cells in the patient's own bone marrow, to replace her left bronchus.

That tube, which connects the lung to the windpipe, had been damaged by tuberculosis. The engineered cells enabled the woman to get the transplant without her body attempting to reject it. The procedure was the first to use stem cells in transplanting an airway.

Atala, at Harvard when he performed the bladder transplants, came to Wake Forest along with a small group of scientists in 2004, when the institute was founded.

The institute hopes to form partnerships that will speed discoveries to the marketplace. As part of that effort, Atala leads the scientific advisory board of Tengion, a Winston-Salem company that makes bladders, and the institute is talking with pharmaceutical maker Pfizer about a possible partnership.

The Tengion bladders are now in clinical trials involving children with spina bifida. They're also being studied in adults with spinal-cord injuries and urge incontinence, in which urine leaks because of inappropriate bladder contractions.

Before coming to the institute, some of its researchers engineered cartilage and urethras, the tube that transports urine out of the body.

The work has attracted national attention - and money. The institute will lead a consortium that has won a $42.5 million federal grant, announced in April, for five projects to benefit wounded and disfigured armed services members. The findings would be used to help civilians, too.

The institute does not disclose its budget, but it's big: The military grant is being matched by $150 million in funds and pledges for the consortium. Sources include the National Institutes of Health and foundations.

Repairing the wounds of war

One key aspect of that work will be engineering skin for burn victims, says Dr. James Yoo, an associate professor at the institute.

Many such patients cannot receive skin grafts from their own bodies, a common burn treatment, because they have too little healthy skin left. But burns must be covered because skin prevents infections and helps the body regulate such functions as temperature.

The institute is developing what Yoo calls "mobile bioprinting technology," the equipment and expertise to print new skin for placement over burned or otherwise injured skin. Making the technology mobile would mean wounded service members could be treated without having to be flown to burn units.

Skin engineering and printing also may help reduce scarring and allow the body's own skin to regenerate, says Benjamin Harrison, an assistant professor at the institute.

It's just another part of you

To grow tissues, the institute begins with a patient's own cells, thus eliminating the possibility that the body will reject the tissue or organ it later receives.

The institute also can work with stem cells, which can grow into any type of tissue. In recent years, controversy has arisen over using stem cells found in blastocysts, human embryos just days old. Because many people have objected to using embryonic stem cells, federal funding for using them in research is banned.

But about two years ago, Atala and colleagues reported that stem cells from amniotic fluid could be used, thus bypassing the controversy. President-elect Barack Obama's Senate Web site includes his statement supporting federal funding for embryonic stem-cell research.

The construction of the cell

Growing tissues works like this:

First, staff members ensure they're getting the type of cells they want by finding the cells' molecular "fingerprints." Then they reproduce those cells in an incubator that mimics the body's natural environment.

The cells are then tested to ensure they react properly to stimuli and chemicals - that muscle cells contract and relax properly, for example.

The cells are tested genetically to ensure they are identical to the original cells.

The researchers then create a scaffold, or a mold shaped like the organ, made of materials such as collagens that are found naturally in the body. The cells are placed on these scaffolds and then placed in a incubator where they continue to multiply.

The engineered tissue or organ would then be implanted into a patient, where the scaffolding dissolves within months as the new tissue integrates with the body.

A cure for diabetes, too

Another project for which the institute has received a federal grant is its effort to engineer cells that might cure Type 1 diabetes.

In that disorder, which can be fatal if untreated, the body's immune system destroys beta cells, which produce insulin. Patients must inject themselves with insulin several times a day or use an insulin pump.

Insulin regulates blood-sugar levels. It also prevents the eye, nerve, blood-vessel and kidney damage people with diabetes often face.

The beta cells are found in portions of the pancreas called islets. Since 1966, doctors have treated Type 1 diabetes by transplanting an entire pancreas. Since 1990, they also have been transplanting islets alone.

But there aren't enough donors. Also, both approaches require patients to take drugs to keep their bodies from rejecting the foreign tissue.

The institute is trying to grow stem cells into islets of beta cells both in the lab and within the bodies of animals, says Dr. Shay Soker, head of cellular and molecular research at the institute and leader of the 12 staffers working on the projects. Soker says researchers hope to achieve these goals within five years.

This work is one of just five programs that have been designated as "quantum programs" by the National Institutes of Health. If successful, they would represent quantum leaps in health care. That designation carries a $3.2 million, three-year grant for the institute and its academic partners.

Partnership also is important within the institute because it involves so many specialties, Harrison says.

"You've got basic scientists, chemists, physicists, all working together," he says. "You don't see that in too many other fields."

The institute's cutting-edge work is an attraction, too, Yoo says. A urologist by training, he joined Atala's lab for a two-year fellowship - 15 years ago.

"The work was just fascinating - it was, you know, outrageous," he says. "I thought, 'This could be the future.'"

Contact Lex Alexander at 373-7088 or lex.alexander@news-record.com