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But now, researchers say these incredibly pliable cells may someday help provide patients with breast and facial implants that are both safer and more durable over the long term.
Using the person's own stem cells, plastic surgeons would create and shape implants from natural body tissue, instead of turning to the synthetic implants used in plastic surgery today.
Synthetic materials used
"Currently, the materials used in reconstructive surgery - such as after breast cancer - are synthetic, like silicon or saline implants," said lead researcher Jeremy Mao, an associate professor and director of the Tissue Engineering Laboratory at the University of Illinois at Chicago. In addition, synthetic implants using collagen are employed in facial reconstructive surgery, wrinkle removal and lip augmentation, he added.
Patients and their surgeons continue to voice concern about the materials used in currently available breast implants, which have been known to rupture and leak. In facial plastic surgery, too, materials are less than ideal - for example, studies show that silicon used in lip and facial reconstruction and cosmetic surgery tends to lose its size and shape over time.
Better shape than synthetics
The advantage of this new, stem cell-based method is that, when used for wrinkle removal and breast augmentation, the implants will retain their size and shape better than synthetics, according to a presentation researchers made Feb. 17 at the American Association for the Advancement of Science annual meeting in Washington, D.C. The data will also appear in the April issue of Tissue Engineering.
To get around some of these common problems, Mao's team speculated they could grow tissue using the patient's own stem cells.
"We took [human] adult bone marrow stem cells and differentiated them into soft tissue," Mao said. The researchers then put the stem cells into hydrogel, and moulded the hydrogel into the desired shape, he said.
Hydrogel is a substance that can be moulded into any shape or size, mimicking the natural environment in which fat cells grow in the body. In the Chicago study, hydrogel moulds containing stem cells were placed under the skin of eight mice. Four weeks later, the researchers removed and examined the implants.
"We found that the fatty tissue we created held its shape," Mao said. "This approach, down the road, will be useful for soft tissue reconstruction procedures."
Part of the patient's own body tissue
Mao noted that when the tissue is implanted, it will essentially become part of the patient's own body tissue, and since the stem cells started as that patient's own, there should be no risk of tissue rejection. In later experiments, Mao's team has shown that, once implanted in animals, this new tissue develops the blood vessels necessary for its continued survival.
Mao hopes to begin human trials in the foreseeable future.
This approach is promising but still has a long way to go, according to Dr Jeffrey Salomon, an assistant clinical professor of plastic surgery at Yale University School of Medicine.
"At least 12 to16 ounces (360 to 480 ml) minimum volume of fat cells is required to reconstruct a breast," he said. "Obtaining that volume is not a major problem either from cell cultures or a person's own tissues. What is a problem is having a blood supply to accompany that tissue volume so that it remains alive and doesn't shrink," Salomon added.
"Presently, only vascularised tissue harvested from the patient offers that alternative," Salomon said. "Perhaps in the future, stem cells can offer a bioengineered tissue containing more than one type of tissue, one of which will account for blood vessels and capillaries to provide the nutritional support to the other tissue, fat, muscle or bone." – (HealthDayNews)
