Labs Try To Grow Breast Implants

While lawyers battle over the dangers of silicone breast implants, scientists are exploring a startling procedure that uses a woman’s own cells to create tissue inside the breasts - in effect, a “grow-your-own” alternative.

The experimentation is years behind other substitutes for silicone that use vegetable fats and oils, but supporters note that this technique doesn’t permanently leave foreign substances in the body.

“We’ve been trying to outsmart the body’s immune system. These fellows have come up with a concept that works with it,” said James Martin, research director at Carolinas Medical Center. The experiments were begun last fall at the Charlotte, N.C.-based hospital and at the University of Michigan in Ann Arbor.

Silicone has been blamed by hundreds of thousands of women for serious immune system diseases. In 1992, the Food and Drug Administration banned purely cosmetic silicone implants; the procedure is still available for cancer and other medical reasons.

If early work on laboratory animals succeeds, the researchers, within three to five years, will remove a tissue sample from somewhere in a woman’s body, use it to grow additional cells in the lab, then implant the cells in the woman’s breast. There they should multiply and mature into real breast tissue.

The only comparable procedure now in existence involves removing a woman’s abdominal tissue to reconstruct breasts, an operation that is complicated, risky and often causes scarring, said Dr. Michael Miller, an associate professor of plastic surgery at the University of Texas Anderson Cancer Center in Houston.

The researchers’ aim is to help women who have undergone mastectomies after breast cancer. But the method also could be used for cosmetic breast enlargements.

This year, the scientists are trying the treatment in laboratory rats. Next year, they plan to try it on pigs.

A number of questions remain before it can be tried in humans, though the scientists got a tentative endorsement last month from the FDA.

The Charlotte and Ann Arbor labs have licensed sales rights to a small biotechnology company, Dallas-based Reprogenesis, which is paying for some of the research.

Miller called the breast implant work “a very exciting area of research.”

“Tissue engineering will affect the way we do reconstructive surgery in the next century, without question,” he said.

Tissue engineering was pioneered about 12 years ago by two surgeons at Childrens Hospital in Boston, Drs. Robert Langer and Joseph Vacanti.

One key discovery, Langer said, is that many body cells can be manipulated to form different kinds of tissues.

“You can take certain cell types, put the right ones together and give them the right cues and they tend to reorganize and form structures,” he said.

One way to give cells such cues is to erect a “scaffold,” and make the cells attach themselves to it, said David Mooney, an assistant chemical engineering professor at the University of Michigan.

Here’s how it would work for breasts:

A tissue sample with cells similar to breasts - high in fat - is removed from the thigh or abdomen. The tissue is treated with enzymes to break it down into basic cells. These cells are collected in a laboratory dish along with a solution of nutrients, where they multiply quickly.

Once there’s enough of them, the cell solution is sprayed over, or dipped in, a spongelike scaffold made of a biodegradable plastic and formed in the shape of a breast implant.

The cells stick to the scaffold, which will then be implanted.

Inside the body, the cells continue to multiply, but now they start acquiring characteristics of most breast tissue - except for mammary glands that produce milk.

Capillaries start to grow into the scaffolding to feed food and oxygen to the cells. Within weeks, the scaffold dissolves through normal body metabolism, leaving only breast cells behind.

Scientists believe the cells will fill the space left for them by the scaffolding and then somehow know to stop growing.