Implanted Chips to Deliver Drugs

Online staff -- Electronic News, 3/14/2006

A new study has demonstrated that drugs can be delivered to patients over a period of time by using an implanted microchip device.

The study was conducted by researchers at Bedford, Mass.-based start up, MicroChips, and relied on the implanted chips and wireless technology to control the release of drugs in the body over a period of time.

"This research is an important step toward development of novel drug delivery systems in which small devices filled with potent, therapeutic drugs are used to release medicines into the body as needed," said John Santini, president, in a statement.
 
The chip uses a wireless signaling and system of reservoirs that allow precise, efficient delivery of solids, liquids or gels.  MicroChips said the device, about the size of a postage stamp, is not expected to replace all pills or other forms of drug delivery. Rather, it will deliver proteins, small molecules and other drugs that are highly potent, have limited stability, and must be delivered in precise doses at specific times.

Santini, along with Massachusetts Institute of Technology Professors Robert Langer and Michael J. Cima, began work on the concept of so-called "intelligent drug delivery devices" more than a decade ago.

The scientists began the current research by developing microchips made of silicon, each the size of a postage stamp and containing 100 tiny "wells" or "reservoirs." According to James Prescott, director of analytical chemistry at MicroChips and co-lead author of the study, "We filled the reservoirs with a model polypeptide drug known to be poorly absorbed when taken orally. Each reservoir was capped with an electrically-erodable membrane made of platinum and titanium. Filled chips were then sealed and connected to a titanium case containing electronic hardware, power, and wireless connectivity. We also combined custom software with "off-the shelf" electronic components and a handheld wireless communication device for use in sending data back and forth."

The current study, which used a microprocessor and a power source, demonstrates the feasibility of what Santini calls "active" reservoir control. According to Santini, while one important use of reservoirs is to contain drugs for release, reservoirs can also be used to selectively expose biosensors in order to monitor and provide feedback on conditions in a patient's body. Biosensors may one day be interactively paired with drug delivery.

MicroChips is also working on another type of reservoir technology, which Santini terms "passive." Passive reservoir systems use specially-designed, layered polymers which, when implanted, regulate drug release over time without microprocessors or power sources, Santini said.

"Reservoir drug delivery systems should be especially useful if applied to congestive heart failure, diabetes, osteoporosis and orthopedics," Santini said.
MicroChips plans to partner with pharmaceutical and medical device companies to identify "difficult-to-deliver" molecules that would be compatible with reservoir technology and to develop novel biosensors.

"Reservoir technology is unique in that it can provide the basis for a stand-alone, intelligent medical device unlike anything available on the market or it can provide market differentiation for an existing product when incorporated as a new feature," Santini said.

The company hopes to begin human safety trials for passive reservoir systems for drug delivery within three years and for active "sensing" systems in three to five years.