Robert Langer, ScD—Engineering Medicine

Abstract

CANCER RESEARCH ISN’T A TRADItional career track for a chemical engineer. But Robert Langer, ScD, isn’t an ordinary chemical engineer. After completing his doctoral degree in 1974, he turned down offers from the petroleum industry to take a postdoctoral position with cancer researcher Judah Folkman, MD, at Children’s Hospital, in Boston. Langer’s task in Folkman’s laboratory was to isolate the first angiogenesis inhibitor (Langer et al. Science. 1976; 193:70-72). One crucial aspect of this challenge was to come up with a plastic, or polymer, delivery system that would slowly release these large protein molecules to tissues in a controlled manner. At the time the general consensus was that only substances of a much smaller size could move through plastic. But Langer invented a device that allowed the slow release of large, medically important molecules from a 3-dimensional polymer matrix (Langer and Folkman. Nature. 1976;263:797800). The principles he followed formed the foundation for drug delivery systems in use today. Today, as professor of chemical and biomedical engineering at the Massachusetts Institute of Technology, in Cambridge, Langer continues his work on controlled drug delivery. He and his colleagues are working to develop effective long-term delivery systems for insulin, vaccines, anticancer drugs, and gene therapy agents and devising release systems, such as novel drug delivery microchips, that can be controlled electrically, magnetically, ultrasonically, or enzymatically. Langer also has been instrumental in the emergence of the field of tissue engineering. Working with Jay Vacanti, MD, professor of surgery at Harvard Medical School, in Boston, he builds biodegradable polymer scaffolds onto which various types of cells can be seeded and treated with growth factors to develop into 3-dimensional structures, such as skin, cartilage, and blood vessels.