Drug Delivery by Chip May Be Coming

Monday, May 20th 2002, 12:00 am
By: News On 6

CAMBRIDGE, Mass. (AP) _ John Santini is building implantable microchips that he hopes someday will replace needles and complicated drug regimens.

He isn't there yet, but three years after attracting attention by demonstrating an early version of the device in a laboratory beaker, he insists that his company, MicroCHIPS, is making progress and will have a product out in five years.

The company has made the device work in a lab rat, and because it's a device, not a drug, Santini says that means it would almost certainly work in a person as well.

The chip _ fingernail-sized, attached to a battery and wrapped in titanium _ would be inserted just under the skin, likely in the abdomen. It contains hundreds of tiny reservoirs which would be filled by a drug, or several drugs. Software would instruct the chip when and how much of each drug to release, automatically and precisely.

On Monday, the company plans to announce a second round of venture financing _ $16 million Santini claims will carry it into clinical trials. The other good news: Santini, 29, has been named one of the top 100 innovators under 35 by the Massachusetts Institute of Technology's Technology Review magazine. The winner will be announced Thursday.

Santini's is a field that requires a mind for biochemistry, electronics and engineering. But for him, the inspiration also came partly from the heart.

Diagnosed at age 12 with lupus, an immune system disease, he spent several years in and out of hospitals. He's in remission now, but he learned that for patients drug delivery can be as important as the drugs themselves.

``I learned early on that if you can find better ways to deliver these drugs, (reduce) these side effects, it improves quality of life,'' he said.

Before his senior year at the University of Michigan, Santini spent a summer at MIT and hooked up with nanotechnology and drug delivery experts Robert S. Langer and Michael Cima.

They wanted to build a microchip that could solve many of the problems of drug delivery. Their first attempt left room for improvement.

``It was a really ugly looking device,'' says Santini, sitting in his office surrounded by sports paraphernalia of his beloved Detroit teams. ``It was a glass slide with holes drilled in it and lots of apoxy gooped on it. It didn't work, but it gave us a lot of confidence it could.''

Santini came to MIT for graduate school, worked with Langer and Cima, and became president of MicroCHIPS. Now 21 employees are tweaking the device, preparing it for clinical trials in about two years.

The chip works like this: each of the tiny, drug-filled reservoirs is sealed with gold, which is virtually corrosion-proof.

But if surrounded by chloride _ found in the body's natural saltiness _ the gold dissolves when a single-volt current from the device's battery is run through it. The gold harmlessly slips into the body and the drug is released; by subbing a fluorescent die into the reservoirs one can watch the process through a microscope.

Santini says it will be safe; the chip faces backward in the body and about the only thing that could shatter it and release all the drugs would be a bullet.

The technology could make drugs not only easier to manage, but more effective. That's because research is veering toward smaller proteins that focus on particular tasks and draw less attention from the immune system. But those molecules are also more fragile.

``This stuff ... has to be the wave of the future,'' says Doug Munch, a pharmaceutical and drug delivery consultant in Basking Ridge, N.J., ``because of the control that may be required for future high-tech drugs may exceed what you can achieve by giving these orally and having them chopped up in the GI (gastro-intestinal) tract.''

Chips also have the advantage of what economists call a ``precommitment device'' _ locking patients into a drug regimen they may be tempted to slip out of. That could be especially useful for a disease like Hepatitis C, where the symptoms can be less unpleasant than the toxic effects of the treatment.

Obvious candidates are patients suffering from diabetes, which can require daily injections, and HIV/AIDS, which requires a complicated daily regimen of several medications.

But uses for those diseases are far down the road, Santini says, because insulin and HIV drugs cannot yet be made in sufficient concentration to fit in the reservoirs. For now, the most likely early uses are for delivering steroids, hormones, cancer drugs and pain killers.

Santini said he isn't worried about rivals. MicroCHIPS has partnered with one pharmaceutical company, whom he declined to identify. There could be a threat if such companies decide to push their own research in the field. Last year, for instance, Johnson & Johnson merged with drug-delivery company ALZA.

Another company, ChipRX, is focusing on devices equipped with sensors that respond to the environment _ sensing, for instance, a rise in blood sugar and triggering a release of insulin.

Some say pre-programming a drug release, like microCHIPS is doing, is useful, but creating a device that thinks for itself is moreso.

``There are two big problems out there, and if their stuff works, they'll have knocked off one of them,'' said Howard J. Chizeck, chairman of the electrical engineering department at the University of Washington in Seattle and an expert in the field. ``The huge markets and the tremendous opportunities that are there, like diabetes, they need a sensor that can stay in the body.''

Santini says the company plans eventually to work on incorporating sensors.

``The holy grail of drug delivery has been to integrate biosensors with drug delivery systems so they can respond automatically to changes in the body,'' he said. ``We will definitely be heading that way.''