Drug delivery to the brain could 1 day be as simple as a sniff, according to engineers at Washington University that developed a new nanoparticle-based delivery technique.
“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,” research scientist Ramesh Raliya said in prepared remarks.
“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.”
The team’s approach is based on aerosol science and engineering that allowed a generation of monodisperse nanoparticles to deposit on upper regions of the nasal cavity via diffusion. They developed an aerosol that is composed of gold nanoparticles of controlled size, shape and surface charge.
The nanoparticles were tagged with fluorescent markers so that the team could track the particles’ movements.
Then the team exposed locusts’ antennae to the aerosol and watched as the nanoparticles traveled from the antennas up through the olfactory nerves. The nanoparticles passed through the blood-brain barrier thanks to their tiny size and reached the brain in a matter of minutes, according to the team.
The researchers used locusts because the barriers in insects’ and humans’ brains are anatomically similar, they said. They added that the nose is an easy way to quickly access the brain.
“The shortest and possibly the easiest path to the brain is through your nose,” Barani Raman, associate professor of biomedical engineering, explained. “Your nose, the olfactory bulb and then olfactory cortex: two relays and you’ve reached the cortex. 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.”
The team examined whether or not the foreign particles disrupted normal brain function and observed no noticeable change in the locusts’ electrophysiological responses.
“This is only a beginning of a cool set of studies that can be performed to make nanoparticle-based drug delivery approaches more principled,” Raman said.
The next phase of research will involve fusing gold nanoparticles with various drugs and using ultrasound to target more precise doses to certain regions of the brain, the team reported.
“We want to drug target delivery within the brain using this non-invasive approach,” Raliya said. “In the case of a brain tumor, we hope to use focused ultrasound so we can guide the particles to collect at that particular point.”
