Ultrasound pulses could replace daily injections for diabetics


November 21, 2013

Focused waves of ultrasound have been used to release insulin from reservoirs in the skin

Focused waves of ultrasound have been used to release insulin from reservoirs in the skin

There could be hope for diabetics who are tired of giving themselves insulin injections on a daily basis. Researchers at North Carolina State University and the University of North Carolina at Chapel Hill are developing a system in which a single injection of nanoparticles could deliver insulin internally for days at a time – with a little help from pulses of ultrasound.

The biocompatible and biodegradable nanoparticles are made of poly(lactic-co-glycolic acid), and contain a payload of insulin. Each particle has either a positively-charged chitosan coating, or a negatively-charged alginate coating. When the two types of particles are mixed together, these oppositely-charged coatings cause them to be drawn to each other by electrostatic force.

This holds true even when they're injected into the subcutaneous layer of the skin, where they all join together to form what's described as a "nano-network." Since the nanoparticles are porous, the insulin begins to seep out of them once they're in the body. The electrostatic force still keeps the insulin close, however, causing it to form into a reservoir adjacent to the network.

When it's time to get a dose of that insulin into the bloodstream, a hand-held device is used to externally deliver focused waves of ultrasound to the nano-network. The scientists believe that this excites microscopic gas bubbles in the body tissue, disrupting the network and thus slackening the electrostatic force that ordinarily keeps the insulin reservoir from dispersing. In any case, the insulin is indeed able to enter the bloodstream, and is pushed along by the force of the ultrasound waves.

Once the ultrasound is turned off, the nano-network re-forms and more insulin leaks out to form another reservoir. In tests on diabetic lab mice, one injection of the nanoparticles was enough to regulate blood glucose levels for as much as 10 days. When a nano-network is depleted, another batch of particles can be injected – the old network will be absorbed by the body within a few weeks.

The scientists are now working towards applying the technology to humans. Dr. Zhen Gu is leading the research, which was recently described in a paper published in the journal Advanced Healthcare Materials.

Source: North Carolina State University

About the Author
Ben Coxworth An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away. All articles by Ben Coxworth

If I am going to store insulin inside my body I want it to be released to automatically maintain my blood sugar level. The shot is not the painful or difficult part.


I believe this would be a not so bad thing but what about overdosing and under dosing. There's always a risk of something to go wrong in cases like these, why risk this on a diabetic? I believe this should be something heavily studied and tested before ever out "out there."

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