Fat injections add more than volume to hands

"The way that fat acts in the back of hands is, it doesn't just make the hands fatter. It actually makes the skin better so that it disguises the veins and tendons and acts to fill out the area when one has big depressions. But the more important thing it does is it gives a younger-looking hand without making it fat," says Sydney R. Coleman, M.D., a plastic surgeon in private practice in New York City.

Until recently, researchers knew little about how fat injections accomplished such changes. As they learn more about stem cells, however, they find that it appears these cells play a significant role in rejuvenation.

In bone marrow, stem cells function to manufacture red and white blood cells, as well as platelets.

"But we're finding out that they do a lot of other things," Dr. Coleman says. "Some of the recent research even shows that bone marrow stem cells help repair skin when the skin is damaged. There's a lot of very interesting research in the tissue engineering literature right now about that."

Fat cells can change Among the latest discoveries is the finding that fat cells containing lipids can actually change to become bone-forming cells (Justesen J et al. Tissue Eng. 2004 Mar-Apr;10(3-4):381-391).

"We've known for a long time that calcium deposits can be formed in soft tissue - that's how we look for breast cancers and similar problems. But now we're finding out that there's a whole lot going on that we didn't know about" with stem cells, Dr. Coleman says.