Contact Us

Staff

Rising biomedical engineering star joins ENG

By David J. Craig

In the rapidly evolving field of biomedical engineering, there is no hotter area of research than the development of biological microelectromechanical devices (bioMEMS). These tiny silicon chips, which are smaller than half the width of a human hair, are designed to be implanted in a patient's body and slowly release drugs for treating heart disease, diabetes, and other conditions. BioMEMS also can deliver stem cells, which replicate rapidly, generating cells that make up muscles, organs, blood, and other tissues.

	Tejal Desai, an associate professor of biomedical engineering at the College of Engineering, was hired in January to help lead BU's new thrust in the study of subcellular bioengineering. Photo by Kalman Zabarsky

In January, BU added to its faculty one of the brightest young engineers working on bioMEMS, Tejal Desai, as an associate professor of biomedical engineering at the College of Engineering. Desai is one of the first faculty members recruited in an effort to build a top-tier program in subcellular bioengineering. The University's thrust in micro- and nano-biosystems, which are the interface of biology and engineering at a very small scale, was made possible by a $14 million grant BU received last year from the Whitaker Foundation of Arlington, Va. The award will be spread over five years and matched by $18 million from BU.

Desai, 29, received a Ph.D. in bioengineering from the University of California at Berkeley in 1998 and subsequently was an assistant professor of bioengineering at the University of Illinois at Chicago. She has published more than 30 papers and chaired and organized several conferences about bioMEMS, microfabricated biomaterials, and microscale tissue engineering. Last year she was selected as one of MIT Technology Review's top 100 Young Innovators.

She is best known for her work designing a new bioMEMS for treating diabetes. The two-millimeter-by-two-millimeter microcapsules, currently being tested in rats, are filled with insulin-producing cells from the pancreas of healthy animals and implanted in the abdomens of diabetic animals. They are punctured with holes large enough to let oxygen and other nutrients flow in, keeping the foreign pancreatic cells alive, and let insulin flow out. The holes are too small, however, for antibodies and white blood cells to enter and attack the foreign cells. The body's immune system is thus kept at bay.

"We're trying to achieve a self-regulating system so that patients with diabetes don't have to prick their finger several times a day to monitor their glucose level and then inject themselves with insulin in response to what they're eating," says Desai. "The pancreatic cells in the bioMEMS have a sensing mechanism that monitors the body's blood-sugar level and releases insulin accordingly."

Other methods of delivering insulin with tiny implantable devices have been tested in humans, but, Desai says, the bioMEMS she designed advances the technology because the holes -- which are between 10 and 20 nanometers wide -- in its semipermeable surface do not let in antibodies and therefore make it more efficient than other microencapsulation devices. The technology is 5 to 10 years away from being tested in humans.

Desai also is developing a new bioMEMS that would be ingested and travel through a patient's digestive track, releasing medication to treat ailments such as intestinal or colon cancer. "It is an oral delivery system that would be intelligent in the sense that it would target a particular part of the body with the peptides and pharmaceutical agents it releases," she says.

"Dr. Desai has been identified as a future leader in the field of cellular and tissue engineering driven by bioMEMS and nanotechnology, which clearly is a major-impact area in the future of medicine and biomedical engineering," says Kenneth Lutchen, an ENG professor and biomedical engineering department chairman. "She certainly is someone to lead us into that aspect of the Whitaker grant."

This fall, ENG's biomedical engineering department will offer two new graduate courses for students interested in studying bioMEMS nanotechnology. Joe Tien, an ENG assistant professor of biomedical engineering, who specializes in bioMEMS, was hired last year, and according to Lutchen, the department plans to hire three more faculty members working in the area of subcellular engineering.

"What drew me to BU was that the biomedical engineering department is very forward-looking in planning facilities aimed at nanosystems and small biosystems," says Desai. "It will be very unique to be able to go from studying basic science to prototype development to the actual testing of a technology all in a single laboratory."

1 February 2002
Boston University
Office of University Relations