In Spider-Man's latest adventure, scientists delve into the field of regenerative medicine as they work to re-grow a human limb. Koudy Williams, D.V.M., a self-described "Spider-Man geek" and real-life regenerative medicine researcher, says the plot of the latest comic book and movie isn't as far-fetched as some people might think.

"We're working on long-term projects to regenerate fingers and limbs," says Williams, a professor at Wake Forest Baptist Medical Center's Institute for Regenerative Medicine. "But we have safer ways to do it than the researchers in Spider-Man."

Several of the science themes in Spider-Man's latest adventure -- from working to harness the body's natural regenerative powers to making use of natural materials such as the silk in spiderwebs -- are happening today in regenerative medicine laboratories, Williams said. Regenerative medicine is a relatively new field of science that works to replace or repair damaged or diseased tissues and organs.

In the latest adventure, a scientist attempts to re-grow his missing arm by combining human genes and genes from a salamander, which has a natural ability to re-grow its limbs. When the experiment goes awry, the scientist becomes a lizard villain.

"When I was watching the movie, I said to myself, 'We do that -- sort of,'" said Williams. "We do study the regenerative abilities of salamanders and other animals and we try to harness the body's innate ability to regenerate itself. But we would never combine human and animal genes -- we have much safer methods."

Williams said real-life researchers take three approaches in their efforts to repair and replace organs. One is to build, or engineer, replacement organs in the lab using a patient's own cells and an organ-shaped mold or scaffold to support cells as they grow. Bladders, urine tubes and sections of windpipes have all been built in this way and implanted in humans. A second method is to inject healing cells into a diseased organ. The third approach -- most like the science portrayed in Spider-Man -- is to use drug-like molecules to promote healing from within.

"The body has the capacity to heal naturally," says Williams. "When there's an injury, cells release substances known as chemokines that attract other cells to promote healing. That's how a broken bone repairs itself and the outer layer of the eye re-grows if it is scratched. In regenerative medicine, our aim is to boost this natural healing power.

"The body knows what it needs to heal. We work to see if we can improve on it. This is most like what scientists in the Spider-Man movie were doing. Our projects include evaluating the use of natural materials to speed up nerve regeneration, heal diseased kidneys and improve one of the current options for heart valve replacement."

Just like in the Spider-Man comic book and movie, researchers at the Wake Forest Institute for Regenerative Medicine and colleagues at other institutions have a long-term project to re-grow fingers and limbs to help wounded military personnel. "We're years away from being able to bioengineer an arm, or even a finger," Williams said. "But we're working on the component parts, including muscle, bone, fat, skin and tendons, and part of our work will be to use the body for the regeneration process."

Williams calls Spider-Man a "science genius" for determining the best substance for the web-like substance he shoots out from a device he made. "He figured out something that would carry his weight and be elastic so he could swing from rooftop to rooftop."

In the lab, scientists use natural materials such as silk -- found in spiderwebs -- as scaffolds for organs and tissues that they are engineering. Like Spider-Man, they must select materials that match their use -- looking for materials that are compatible with the body, promote cell growth and degrade into the body once the engineered tissue has integrated with existing tissue.

Also similar to Spider-Man, Wake Forest Baptist scientists developed a device that shoots out a spider-web-looking material. In this case, the material is caught on a spinning rod to create a tubular structure that can be used to engineer blood vessels.

Williams, who owned the first Spider-Man comic book -- and wishes he still had it -- said he got interested in science through Spider-Man, a super-hero who wins awards for his research. When Williams had difficulties with reading in grade school, his teacher encouraged his parents to let him read anything he wanted. He chose comic books and Spider-Man was the first one he bought.

"As a child, I always wanted to be Spider-Man. But now I have the next-best thing. I'm a researcher who uses some of the same technology as Spider-Man."