Researchers have developed an "on/off" switch for implantable drug delivery systems that uses an external magnet to trigger the internal release of the medicine. The half-inch implant stores the drug inside a nanoengineered membrane containing magnetitie. An external magnetic field causes the membrane's pores to open up. Children's Hospital Boston physician Daniel Kohane and his colleagues published their experiments in the scientific journal Nano Letters. From Children's Hospital Boston:
"A device of this kind would allow patients or their physicians to determine exactly when drugs are delivered, and in what quantities," says Kohane, who directs the Laboratory for Biomaterials and Drug Delivery in the Department of Anesthesiology at Children's.In animal experiments, the membranes remained functional over multiple cycles. The size of the dose was controllable by the duration of the "on" pulse, and the rate of release remained steady, even 45 days after implantation.
Testing indicated that drug delivery could be turned on with only a 1 to 2 minute time lag before drug release, and turned off with a 5 to 10 minute time lag.
Using magnetism to turn drugs on and off
