Remote control drug delivery

The wireless device, which is no bigger than the width of a human hair, could one day be used to treat pain, depression, epilepsy and other neurological disorders in people by targeting therapies to specific brain circuits, the researchers said.

The technology - initially demonstrated in mice - has been dubbed “a major step forward” in pharmacology, building on work in optogenetics - a branch of scientific technology that causes individual brain cells to be sensitive to light and then activates those targeted populations of cells with flashes of light.

“This approach potentially could deliver therapies that are much more targeted but have fewer side effects

Professor Michael R. Bruchas

“In the future, it should be possible to manufacture therapeutic drugs that could be activated with light,” said co-principal investigator Michael R. Bruchas, associate professor of anesthesiology and neurobiology at Washington University.

“With one of these tiny devices implanted, we could theoretically deliver a drug to a specific brain region and activate that drug with light as needed,” Bruchas said.

“This approach potentially could deliver therapies that are much more targeted but have fewer side effects.”

The Washington team’s device was built with four chambers to carry drugs directly into the brain. By activating brain cells with drugs and with light, the scientists are getting an unprecedented look at the inner workings of the brain, the researchers said.

“This is the kind of revolutionary tool development that neuroscientists need to map out brain circuit activity,” said James Gnadt, programme director at the National Institute of Neurological Disorders and Stroke at the National Institutes of Health (NIH).

Likewise, research graduate Jordan G. McCall said it is now “literally” possible to deliver drugs with the push of a button.

“We’ve designed [the device] to exploit infrared technology, similar to that used in a TV remote,” McCall said.

“If we want to influence an animal’s behaviour with light or with a particular drug, we can simply point the remote at the animal and press a button,” he added.

Meanwhile, a secondary part of the study showed that by delivering drugs to juts one side of a mouse’s brain, neurons could stimulated, causing the mouse to move in a circle.

What’s more, in other mice, shining a light directly onto brain cells expressing a light-sensitive protein prompted the release of dopamine, a neurotransmitter that rewarded the mice by making them feel good, the researchers said.

“We’ve successfully produced and demonstrated an implantable, cellular-scale microfluidic and micro-optical interface to biology, with application opportunities not only in the brain but in other parts of the nervous system and other organs as well,” said the study’s other co-principal investigator, John A. Rogers, professor of materials science and engineering at the University of Illinois.

In the future, the researchers hope to incorporate a design much like a printer’s ink cartridge so that drugs can continue to be delivered to specific cells in the brain, or elsewhere in the body, for as long as required without the need to replace the entire device.

A full account of the study has been published in the journal Cell.