Biodegradable polymers that are safe to use in the human body are already used in drug delivery, tissue engineering, and more. Whether impregnated with medicine or serving as a scaffold for growing cells, such polymers are eventually absorbed by the body when their work is done.

Until now, however, none of these polymers has had the defining property of a rubberband: the ability to stretch then snap back to an original shape. The dominant material in todays market is hard and brittle.

"If you think about it, though, many of the organs in the body are elastic," said Robert Langer, MITs Germeshausen Professor of Chemical and Biomedical Engineering. For example, the tiny air sacs in lungs expand more than seven times when you inhale. "So if researchers engineer replacements for these organs some day, they certainly want them to mimic the original tissues."

Hence the query Langer received eight years ago from Dr. Joseph P. Vacanti, head of surgical transplantation at Massachusetts General Hospital. Vacanti, who has collaborated with Langer for years, asked the MIT engineer if he could make an elastic polymer for use in tissue engineering.

Biorubber, announced in the June issue of the journal Nature Biotechnology, is the result. Langers coauthors are Yadong Wang, a research associate in chemical engineering; Guillermo A. Ameer, a chemical engineering postdoctoral associate now at Northwestern University; and Barbara J. Sheppard, a comparative pathologist in the Division of Comparative Medicine now at the Wyeth Genetics Institute.

"This work is extremely important and represents the culmination of several years of effort specifically aimed at new materials that could have applications in the field of tiss
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Contact: Elizabeth Thomson
thomson@mit.edu
617-258-5402
Massachusetts Institute of Technology
31-May-2002