The idea is that the electronic skin patch - which senses raised glucose and delivers a drug dose in response - will remove the need for diabetics to prick their finger.
Image credit: Hui Won Yun, Seoul National University
The sweat-based diabetes monitoring and feedback therapy patch is the brainchild of scientists from the US and Korea, who write about it in the journal Nature Nanotechnology.
The idea is that the wearable device will remove the need for finger-pricking - a painful and unpleasant procedure that not many diabetic patients comply with.
The stretchable patch sits on the skin and detects the level of glucose in the wearer's sweat. If the level goes above a programmed amount, it triggers heaters embedded in the patch to dissolve the coating on microneedles so they release an appropriate amount of drug through the skin.
In their paper, Dae-Hyeong Kim, of Seoul National University and the Institute for Basic Science (IBS) in South Korea, and colleagues explain how they showed the patch can be heat-activated to deliver the diabetes drug metformin through the skin of diabetic mice.
They say the components need to be scaled up before the patch is ready for human trials.
Graphene 'doped' with gold
Graphene is a revolutionary new, 2D nanomaterial made of extremely thin flakes of carbon that are only one atom thick. Many scientists are interested in using it to create wearable electronics because it is soft, thin, flexible, conducts electricity and can be made transparent.
To improve the material's electrochemical ability so it can be used to sense biomolecules, ions and changes in acidity, the authors "doped" the graphene with gold nanoparticles and combined it with a gold mesh. Doping the graphene with gold means adding gold particles to change the electrical properties without altering the basic structure of the material.
The patch contains an array of sensors that detect not only glucose, but other properties of sweat, such as temperature, humidity and pH, so as to eliminate the effect these can have on glucose and thus arrive at a reliable measurement.
On-board electronics determine whether the glucose level is too high, then trigger the microneedles to dissolve their coating and release the metformin through the skin.
In an accompanying article, Richard Guy, a professor of pharmaceutical chemistry at the University of Bath in the UK, notes:
"[...] although the holy grail of diabetes management - a non-invasive feedback system combining glucose monitoring and responsive drug delivery - is not yet at hand, Kim and co-workers have certainly moved the field closer to this coveted prize."
Meanwhile, Medical News Today recently learned that treating patients with a rare, genetic form of diabetes with drugs for controlling type 2 diabetes could be harmful. The disease - called maturity-onset diabetes of the young (MODY1) - has some of the symptoms of type 2 diabetes, but the underlying mechanism is different, say the researchers behind the finding.