Biomedical Engineering: Drug Deliveryman

Langer has also pioneered remote-control systems in which the rate at which the drug is released can be varied using ultrasound, electric pulses and even magnetic fields. This team has recently developed the prototype of an implantable "pharmacy-on-a-chip" that they hope someday will not only monitor a patient's blood chemistry but also prescribe a carefully measured dose of the proper medicine precisely when it's needed.

Langer's approach to the design of biomaterials has paved the way for the emergence of the new field of tissue engineering. Working closely with Harvard's Joseph Vacanti, Langer is using tailor-made polymers to build tiny scaffolds that can then be seeded with skin, cartilage, liver or other cells. The idea is to provide a temporary structure that cells can colonize and upon which they can eventually grow into a functioning organ--at which point the scaffold dissolves away. Langer foresees the day when scientists will be able to grow a new liver or pancreas for patients waiting for scarce donor organs. Skin grown using Langer's principles has been approved by the FDA, and cartilage for rib cages is in clinical trials.

Langer, who in lives in the Boston suburbs with his wife and three children and throws an annual barbecue for his lab group at his beach house on Cape Cod, is something of an amateur magician. Folkman, Langer's original mentor, remains one of his biggest fans. "He's a true genius," says Folkman. "He sees answers to problems in such unique ways you can't trace the steps he took." In other words, he's very good at pulling rabbits out of hats.