Technology that allows for needle-free glucose monitoring

The researchers turned their attentions to needle-free jet injection, an emerging but well-developed technique in which a drug is delivered directly with a high-speed narrow jet of fluid.

In a study published in the Journal of Diabetes Science and Technology, led by ABI researchers Jiali Xu and James McKeage, researchers demonstrated for the first time that a jet injector could also be used to collect blood samples from humans – that is, release enough blood for glucose sampling, sans needles.

People with diabetes typically need to measure their blood glucose concentration several times each day, by pricking their fingers with a needle to release a drop of blood which is measured by a glucose meter, which indicates how much insulin is required for the person to maintain their blood sugar.

Fingertips are the preferred site for blood sampling because they have a high density of blood vessels. But the fingertips are also sensitive, and pain, skin damage, bruising and risk of infection from regular ‘pricking’ has spurred increasing efforts to develop needle-free methods of blood testing for people with diabetes.

Jet injection is appealing for a number of reasons – including the obvious, that many find having a needle stuck into them extremely unpleasant.
Jet injection has been the subject of years of research by the ABI Bioinstrumentation Lab at the ABI, University of Auckland, which includes developing jet injectors for delivering drugs such as insulin, nicotine, and as local anaesthetic for dental treatment.

He was pleased, but not surprised. “Diesel mechanics have known for years that you should never put your finger in front of a fuel injector, because it will inject fuel into your finger. They found this out the hard way. But we’re taking advantage of what diesel mechanics discovered accidentally years ago, with a very small amount of harmless liquid, to deliberately release blood.”

The team is now investigating if they can use jet injection not only to release blood, but to suck back, to extract fluid. This would allow for the design of an even smaller nozzle.

They have the technology, having developed the world’s first jet injection device that uses electric motors to pressurise the drug – this allows for more precise control than the more common spring-actuated jet injector.

Moreover, “our technology has the capability to both deliver and withdraw fluid. No other jet projection technology has that capacity,” says Dr Taberner.

Research into needle-free injections is a long game, as is the potential commercialisation of the technology he says, but he believes Ms Xu’s research will contribute to the ultimate aim, of the development of a single lancet-free reversible technology that will allow for both blood sampling and insulin delivery based on the glucose measurement in one device.

“I hope that this research will contribute to that, and the improvement in human healthcare, especially in the management of diabetes,” says Ms Xu.