DIABETES patients may soon have an alternative to conventional monitoring and medication involving painful, repetitive blood drawing and injections with the development by researchers in South Korea of a “smart” glucose monitor that can also dispense insulin.
The device, which measures blood glucose levels in sweat, was developed by a research team at the Center for Nanoparticle Research at the Institute for Basic Science in Daejon, South Korea.
In a post on the Institute’s website, lead researcher Dr. Lee Hyunjae explained that reluctance to comply with conventional treatment can aggravate diabetes symptoms and lead to severe complications. The non-invasive method of measuring blood glucose levels through sweat is a promising alternative, but existing enzyme-based systems are prone to errors and may lead to drug overdoses.
The new system is an improvement of an earlier device developed by Lee’s team, using different materials to improve its sensitivity and allow it to function reliably using as little as one microliter (one millionth of a liter).
“It was quite a challenge to find the optimal size of the sensors. If the size is too small, the signal becomes too small or the surface functionalization becomes difficult to handle,” Lee said.
The device is contained in a waterproof sweatband with a layer that collects sweat. When the system detects elevated glucose levels, an internal heater activates one or two microneedles, which contain two different “temperature responsive phase change nanoparticles” (PCNs) that deliver the medicine. The temperature is raised according to the glucose level detected; one PCN is activated at 40 degrees Centigrade, and both are activated at 45°C, thus providing the appropriate amount of medication.
The device produced by Lee’s team is fitted with three microheaters and pairs of microneedles, allowing up to six levels of medication, the team’s research report, which was published in Nature Nanotechnology, explained.
“The previous systems could not prevent natural diffusion of the drugs from the drug reservoir, and relied heavily upon elevation of temperature to enhance the rate of drug diffusion. Our system uses PCNs to prevent drug release by using the melting properties of phase change materials above critical temperature, enabling stepwise drug delivery. Furthermore, different drugs can also be loaded in phase change nanoparticles for stepwise and multiple drug delivery,” Lee said.
“This convenient and accurate system is also compatible for mass-production as it uses the metal electrode that can be easily fabricated via a conventional semiconductor fabrication process,” he added. “Although there is still room for improvement before applying our system into the clinical application, this approach can surely contribute to improve the quality of life of diabetic patient by managing blood glucose more easily.”