Monitoring blood sugar levels is a prickly, twice-daily routine for many of the nearly 21 million diabetes sufferers in the United States.

But the process could become automatic--and painless--with a new implantable device that a Carolina chemistry and biochemistry professor is helping to develop with researchers at Columbia University in New York.

Qian Wang and doctoral student Siqi Li are developing a biocompatible, nano-scale polymer that's capable of detecting and measuring glucose levels in blood. The goal is to put the polymer--a gel-like substance whose primary sensing ingredient is boronic acid--in an implantable chamber smaller than a coin. A special membrane would allow blood to continuously pass through the monitor while keeping the polymer sensor material inside.

"We've been working to develop a polymer that is highly sensitive to glucose detection," Wang said. "The idea is for the device to send a signal when blood sugar levels reach a serious level. Perhaps it would send the signal to a wrist watch-like device on the user or perhaps to a central computer if the individual wasn't able to care for himself."

In the lab, Wang's and Li's sensor does an admirable job of detecting glucose but responds weakly to fructose levels. That's a good thing, Wang said, because fructose is a natural sugar from fruits that diabetics don't need to monitor. Other sensors already on the market don't differentiate between fructose and glucose, which compromises their accuracy.

Unlike conventional twice-a-day blood testing, the proposed device would continuously monitor blood glucose levels so the user could correlate blood sugar swings with diet and make changes as needed, Wang said. In addition, the system could be integrated with an insulin pump for automated medication based on the user's glucose levels.

The device has several hurdles to overcome before it can be tested in human trials, not the least of which is biocompatibility issues with the polymer. Still, Wang hopes that animal studies could begin in one to two years. If ultimately successful, the device could go a long ways toward making glucose monitoring a painless and automatic process.

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