Artificial Pancreas Developed as a Ph.D. Project. A microscopic device that, when implanted, delivers ongoing, regular doses of insulin.

Tissue Engineering: Boston University

When Tejal Desai walked into professor Mauro Ferrari's office at the University of California, Berkeley, she looked so young he mistook her for an overeager high schooler and almost threw her out. Undeterred, Desai told him she'd studied biomedical engineering as an undergrad at Brown and was seeking a challenging Ph.D. project. Ferrari assigned her a whopper: Build an implantable device that will eliminate the daily insulin injections diabetics give themselves to control blood sugar levels. Desai's colleagues warned her the task was too hard, that she'd never graduate.

But after four years of coaxing cells to grow on chemically modified silicon surfaces, Desai had it: a microscopic device that, when implanted in diabetic rats, delivered ongoing, regular doses of insulin. The device functioned like a tiny tea strainer: A hollow bit of silicon perforated with tiny holes, it was filled with pancreas cells doing what pancreas cells do naturally—produce insulin. The holes were large enough for the insulin to diffuse out, but small enough that the pancreas cells stayed inside, and the rat's immune agents—which would normally mark the cells as foreign and attack them—could not enter. "Nobody expects you to cure diabetes before you graduate," recalls Ferrari. "And then Tejal did!" (For rats, anyway.)

Desai's implant is being developed by a private company for human use,

Courtesy of Boston University