Science-- there's something for everyone

Sunday, June 24, 2012

Injections without needles

Here’s an innovation I think we can all get behind: needless injections. Andrew Taberner of the University of Auckland and Catherine Hogan and Ian Hunter from MIT have developed a controllable jet injection device that could replace standard needles for delivering drugs. Medicines would be delivered through the skin in the form of a high-pressured jet with no stabbing. The tiny hole created by the injection would quickly and painlessly heal.

Jet injection systems aren’t new. They were used to deliver vaccines as far back as the ‘60’s. I should note that this was before the notion was popularized by the original Star Trek series. Conventional jet injectors rely on a variety of energy sources, often chemical reactions or compressed springs or gases, to achieve the power necessary for high pressure drug delivery. Unfortunately, this means that doctors cannot control the injection speed once it’s begun.

In contrast, Hunter and his team used a Lorentz-force motor (essentially a magnet covered with a coil of wire). When current is applied to the device, this creates a force that plunges a piston and delivers the drug. By altering the amount of current, researchers can control the velocity and pressure of the drug delivery in real time.  For example, they can use greater force to penetrate the skin, and then less force to dissipate the drug once it’s passed through that barrier.

If I’m breaching a baby’s skin to deliver vaccine, I won’t need as much pressure as I would need to breach my skin. We can tailor the pressure profile to be able to do that, and that’s the beauty of this device.

Needleless injection system

MIT-engineered device injects drug without needles, delivering a high-velocity jet of liquid that breaches the skin at the speed of sound.
Image courtesy of the MIT BioInstrumentation Lab.

Thus far, the device has only been tested on gels and animals, not humans. Due to concerns about infection, the World Health Organization no longer recommends conventional jet injectors for the delivery of vaccines. This new injector would have to have a better safety record to win over the medical establishment. I for one, am rooting for it to do so!

You can see an explanation by Hunter and Hogan below: