Since then, biomaterials have enabled the slow release of ever-larger bioengineered proteins into the body, with release times ranging from one day to more than three years. Products like Lupron Depot permit controlled release of medicines that would normally deteriorate in minutes to be released slowly over four months. Researchers are also working on ways to deliver growth hormones and methods to provide a constant release of insulin for diabetics. Using an oscillating magnetic field, a wristwatch-like device could, for example, release a dose of insulin just before a diabetic's meal. The magnetic field would release the drug by squeezing drug-containing pores at a microscopic level.
Trials using such a device on mice are underway.
With Dr. Henry Brem, an oncologist at Johns Hopkins University, Langer explored more focused drug delivery for types of brain cancer. Treatment usually involves chemotherapy, which can have terrible side effects for the liver and other organs. For a more targeted release of the drug BCNU, doctors inserted a dime-sized polymer wafer containing BCNU in the surgical cavity at the tumor. As the polymer eroded, it released the drug over time directly to the tumor without the impediment of the blood-brain barrier. In this study, physicians have used the polymer wafers to treat thousands of brain cancer victims, with significant improvements.