"A device that will deliver this compound into the fluid filled chambers is exactly what we need to deliver these drugs," says Edge, whose lab is working on ways to regenerate inner ear hair cells. The device will be remotely controlled and could deliver a variety of drugs, in a preprogrammed sequence, without damaging the delicate environment of the inner ear.

The device being developed at Draper Laboratory is no larger than an AA battery. It consists of a microfluidics pump, a drug reservoir, and a small tube. The pump and drug reservoir are surgically implanted in the temporal bone of the ear, with the tube injecting drugs into the cochlea.

The Draper-MEEI team tested a prototype on guinea pigs, and demonstrated the first instance of precise and timed delivery of drugs to the cochlea, with no damage to the animal's hearing apparatus. The team is working on miniaturizing the device so it can be implanted into the human ear. "We're hoping to have the system ready for clinical trials in less than five years--that's the goal," says Jeffrey Borenstein, a researcher at Draper Laboratory.

One potential application of timed drug delivery would be stem-cell-induced growth of hair cells in the inner ear. "A potential scenario would be that it would deliver one drug for a couple of days, and then another," says Edge. "The first drug [would] help prime the cell types and help them divide and the other [would] help them differentiate."

Recent advances in microfluidics technology have been combined with miniaturized electronics and to make this tiny pump a reality. The work was supported by the National Institute on Deafness and Other Communication Disorders.

While the team is working on better prototypes, researchers like Edge are racing to develop the compounds that will regenerate or stop the death of hair cells. "In a perfect world, they both would be ready at the same time," says Edge.