An experimental drug-delivery method is based on this implanted microchip.
Circa the early 1990s at MIT, drug-delivery researcher and MicroChips Inc. (Bedford, MA; www.mchips.com) cofounder Bob Langer saw a TV documentary on how Intel mass-produced microchips. And the wheels began to turn.
“He wondered if there was a way of using the same sort of mass production technology and the intelligence that a microchip affords,” says John Santini, PhD, president of MicroChips. “And could you put that together with drug delivery to gain a much more controlled method of giving drugs to the body. That was the genesis of the work.”
Now the company has developed ‘intelligent’ drug-delivery devices. The systems consist of an implanted microchip device that features such components as a microprocessor and a power source. Wireless technology enables the controlled release of drugs. Changes to a program or to a drug dosage can be instituted in real-time using the wireless transmission mechanism.
“The device enables control over both the timing and the rate of delivery,” Santini says. “The timing we can precisely control down to the second; I have control over when that drug starts coming out because I have control over when I open that reservoir.” The rate of release can also be controlled, to an extent, depending on how the drug is formulated.
The key to the controlled drug-delivery method is in the use of these reservoirs, according to Santini. Reservoirs in the silicon microchip hold the drug, prevent leakage, and protect the drug from the body until it is needed, he says.
They also offer flexibility. Whereas such devices as drug pumps require drugs to be in liquid form, the use of a reservoir permits the use of drugs in solid, liquid, or gel form. Furthermore, reservoirs act independently of one another, so more than one can coexist without negative consequences.
This technology will not likely move into the clinical trial stage for humans for several years. However, a six-month trial of the drug-delivery system proved effective in canines. “This was a big deal in that this kind of highly controlled drug-delivery out of these discrete reservoirs had not been done before,” Santini says.
Despite the potential for this drug-delivery method, it is only suited for specific types of drugs, namely those that are potent, have poor stability, and are difficult to deliver, according to Santini. Potential applications include use with drugs for growth factors and hormones. Diseases such as osteoporosis and congestive heart failure might also be treated.
“We are moving toward a future where drug therapy is going to be much more intelligent than it is today; it’s not going to be a one-size-fits-all pill,” Santini says. “I don’t want to go to the extent of saying that drugs will be customized for the patient, but the way in which we give drugs in terms of their dose and timing may be customized to the patient.”