Robert S. Langer

Macromolecular theory was born out of the study of biomaterials like cellulose, silk, and rubber. It is only fitting that one of the most active research frontiers in polymer science is that of biologically compatible synthetic materials. At the cutting edge of this field is Robert S. Langer.

The son of a liquor store owner in Albany, New York, Langer (b. 1948) earned his bachelor’s degree from Cornell University in chemical engineering and went on to receive a Ph.D. in that field from the Massachusetts Institute of Technology. Writing his dissertation on a biochemical topic, “The Enzymatic Regeneration of ATP,” he entered the then-new fields of biochemical and biomedical engineering. Graduating in the middle of the oil crisis of the mid-1970s, Langer might easily have taken a job with one of the big oil companies, but he held out for a position in a medical setting. His letters of application were turned down by several puzzled medical researchers, not knowing what to do with an engineer in their midst, but Judah Folkman of Boston’s Children’s Hospital and Harvard Medical School offered him a postdoctoral position.

Folkman was researching how to inhibit the growth of blood vessels supplying blood to cancerous tumors, and thus limit their growth and metastasis. Langer helped in the isolation of the first angiogenesis inhibitor, which turned out to be a macromolecule. Delivering such molecules to the body is exceedingly difficult since they are broken down by digestion and are blocked by tissues in the body if they are injected or inhaled. Langer thought the answer lay in encapsulating the angiogenesis inhibitor in a noninflammatory synthetic polymer wafer that could be implanted in the tumor and would control the release of the angiogenesis inhibitor. Since known synthetic polymers blocked the passage of the inhibitor, he had to invent a very complex porous polymer that enabled the controlled release of this very large molecule. At first his ideas met with much skepticism and ridicule; his grant applications were regularly turned down, and he even worried that his appointment in 1977 to MIT as an assistant professor would not be renewed.

Langer succeeded in making the necessary polymer and, with the assistance of an ever-growing laboratory of researchers at MIT, went on to invent many more polymers with specific biomedical uses. Among them was a drug-delivery system for the treatment of brain cancer (developed with Henry Brem of the Johns Hopkins University Medical School) that delivers chemotherapy directly to a tumor site and has far fewer side effects than conventional chemotherapy. Over the years, the wafers or chips that his teams have designed have become increasingly more sophisticated. Some can carry several drugs at a time and/or respond to stimuli external to the body, such as ultrasound signals, or chemical stimuli within the body—even using the latter to home in on a tumor. Langer is also renowned for developing synthetic polymers that serve as the scaffolding on which new skin, muscle, bone, or entire organs can grow so that victims of serious accidents or birth defects can generate missing tissue.

In his MIT laboratory he fosters an entrepreneurial attitude among his postdoctoral students by urging patenting of inventions, forging links with industry, and forming start-up companies. For the excellence of his research and his dedication to making results available for the medical care of the public, he has received many honors, including election to all three American academies—the Institute of Medicine, the National Academy of Sciences, and the National Academy of Engineering. In 2008 he received the Millennium Technology Prize, the largest prize for technological innovation and comparable to the Nobel prizes in the sciences.

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