![dek](https://content.time.com/time/time100/2007/walkup/images/langer_robert.jpg)
Robert Langer
AGE: 58
OCCUPATION: Polymer chemist at the Massachusetts Institute of Technology
NUMBER OF TIME COVERS: 0
PREVIOUS APPEARANCES ON THE TIME 100: 0
PRO: One of MIT's most distinguished professors, who specializes in developing new polymers for chronic drug delivery. He has some 550 patents to his name. His work has helped spawn the young field of tissue engineering and has contributed greatly to developing a wide range of controlled drug-delivery systems for diseases ranging from cancer to heart disease.
CON: Technological innovation is always a group effort.