August 11, 1999 Contact: Rachel Snyder (312)996-3457, rsnyder@uic.edu

DIABETIC NEEDLES ON THEIR WAY OUT

If Tejal Desai's wafer-thin membranes work the way she anticipates, diabetics from Portland to Poughkeepsie may be able to one day toss their needles. Desai, a University of Illinois at Chicago professor of bioengineering, has just been named one of Technology Review's 100 Young Innovators for a tiny biocapsule she developed that delivers transplanted insulin-secreting cells into the body.

The goal of Desai's biocapsule research is to offer a vehicle for delivery of cells to specific parts of the body. The biocapsule is a biocompatible device inserted into the body which essentially mirrors the function of a normal pancreas.

Such an approach diffuses the problems inherent in similar therapies. For example, a serious drawback to organ transplantation is the use of chronic and toxic drugs that destroy the immune system to block organ rejection. The biocapsules, on the other hand, can protect transplanted cells from rejection by the body's immune system using a membrane that blocks out harmful immune molecules.

What makes Desai's approach unique is microfabrication, which is also used to make computer chips. "The advantages in this technique," Desai says, "are that you can control the dimensions of the capsule, as well as the architectures and the cell-surface interactions on a microlevel. We use chemical modification techniques to control the surface that a cell would see and mimic that in the lab."

The microfabricated biocapsule consists of two membranes that encapsulate insulin-producing cells. Insulin is then secreted out of pores so small that antibodies can't get in. Because the pores are so tiny, the body's immune system cannot reach the insulin-producing cells.

Such "engineering camouflage," Desai says, could overcome the problem of organ donor shortages-perhaps the biggest obstacle in transplants today.

So far, preliminary tests have been positive, Desai says, confirming that they have been able to deliver insulin to mice. Human testing, however, is still several years away.

Desai's biocapsule, once approved for general use, could replace even the insulin pump-an effective new treatment for diabetes which allows insulin users convenience and flexibility while maintaining consistent blood sugar levels without using needles. One drawback, however, is that the pump is worn outside one's clothing, like a pager, and can be cumbersome, unlike the biocapsule which is internal.

Technology Review's list is limited to those under 35 who show significant potential to shape technology in the coming years.

With 25,000 students, the University of Illinois at Chicago is the largest and most diverse university in the Chicago area. UIC is home to the largest medical school in the United States and is one of the 88 leading research universities in the country. Located just west of Chicago's Loop, UIC is a vital part of the educational, technological and cultural fabric of the area.

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