Soon, taking brain medication may be as easy as a sniff

Scientists, including those of Indian origin, have developed an aerosol nasal spray that can non-invasively deliver drugs to the brain.

The novel approach is based on aerosol science and engineering principles that allow the generation of monodisperse nanoparticles, which can deposit on upper regions of the nasal cavity via diffusion, researchers said.

"This would be a nanoparticle nasal spray, and the delivery system could allow a therapeutic dose of medicine to reach the brain within 30 minutes to one hour," said Ramesh Raliya, research scientist at Washington University in the US.

Researchers developed an aerosol consisting of gold nanoparticles of controlled size, shape and surface charge.

The nanoparticles were tagged with fluorescent markers, allowing the researchers to track their movement.

They then exposed locusts antennae to the aerosol, and observed the nanoparticles travel from the antennas up through the olfactory nerves.

Due to their tiny size, the nanoparticles passed through the brain-blood barrier, reaching the brain and suffusing it in a matter of minutes, researchers said.

The team tested the concept in locusts because the blood-brain barriers in the insects and humans have anatomical similarities, and the researchers consider going through the nasal regions to neural pathways as the optimal way to access the brain.

To determine whether or not the foreign nanoparticles disrupted normal brain function, researchers examined the physiological response of olfactory neurons in the locusts before and after the nanoparticle delivery.

Several hours after the nanoparticle uptake, no noticeable change in the electrophysiological responses was detected.

"The shortest and possibly the easiest path to the brain is through your nose. Your nose, the olfactory bulb and then olfactory cortex: two relays and you've reached the cortex," said Barani Raman, associate professor at Washington University.

"The same is true for invertebrate olfactory circuitry, although the latter is a relatively simpler system, with supraesophageal ganglion instead of an olfactory bulb and cortex," Raman said.

"The blood-brain barrier protects the brain from foreign substances in the blood that may injure the brain," Raliya said.

"But when we need to deliver something there, getting through that barrier is difficult and invasive. Our non- invasive technique can deliver drugs via nanoparticles, so there’s less risk and better response times," he said.

The study was published in the journal Scientific Reports.