Nav: Home

Convenient and easy to use glucose monitoring and maintenance

March 12, 2017

A research group from the Center for Nanoparticle Research within the Institute for Basic Science (IBS) has developed a convenient and accurate sweat-based glucose monitoring and maintenance device. The research group has furthered its previous study* (Nat. Nanotech. 11, 566, 2016) to enhance the efficiency of the sweat collection and sensing & therapy process. This sweat-based system allows rapid glucose measurement incorporating small and sensitive sensors and also comes in a disposable strip sensor to the convenience of users. This accurate glucose analysis allows to prescribe a multistep and precisely controlled dosage of drug.

* The previous study reported a wearable graphene-based patch that allows diabetes monitoring and feedback therapy by using human sweat. The device's pH and temperature monitoring functions enable systematic corrections of sweat glucose measurements.

The conventional treatment protocol causes a huge stress to diabetics since it requires painful and repetitive blood-withdrawal and insulin shots. Patients become reluctant to take the periodic tests and treatments, aggravating the diabetes symptoms and suffer severe diabetic complications. A recent alternative approach, sweat-based monitoring offers a painless blood glucose monitoring method, enabling more convenient control of blood glucose levels. However, many challenges still exist for the practical application of the existing system: tedious blood collection procedure; error-prone, enzyme-based glucose sensing that may lead to overtreatment of drugs, etc.

Useful, Efficient Glucose Monitoring to the Convenient of Patients

To address such issues, the research group presented an easy-to-use and multistage module to ensure an accurate glucose monitoring and therapy. To speed up the sweat collection, the researchers redevised the system to work under a small amount of sweat. They used electrochemically active, porous metal electrodes (replacing the graphene materials of the previous study) to enhance the sensitivity of the system. Also the porous structure allows to form strong linkage among enzymes, resulting in increased reliability of the sensors under mechanical friction and deformation. (Figs. 1a, 1b)

Notably, the device features more sensors of a smaller size than the previous study. This miniaturized sensor design allows for reliable sweat analysis even with 1 μl of sweat. The first author of the study, Dr. LEE Hyunjae explains, "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." Also, in the glucose and pH sensors, the reference and counter electrodes are designed to be packed as closely as possible to minimize the required amount of sweat (Fig. 2).

For more accurate reading and feedback therapy, the patch system incorporates an additional sweat uptake layer and a waterproof band. Because the sweat uptake layer consists of water-soluble and porous carbohydrate network, it can efficiently absorb the sweat exuding from the skin. Furthermore, the waterproof band behind the silicone patch facilitates the sweat collection and keeps the patch intact even under physical deformation of the skin. (Fig. 3)

Precise, Timely Drug Delivery to Prevent Overtreatment

The system also enables precise and timely drug delivery. Drugs for the feedback therapy are loaded on two different temperature-responsive phase change nanoparticles (PCNs). These nanoparticles are embedded in the microneedles, which are additionally coated with phase change materials (PCMs). Once the system detects a high glucose level, the integrated heater modulates thermal actuation to activate either PCN1 alone or both PCNs. When the temperature reaches 40°C, only the drugs contained in PCN1 are released, whereas at 45°C, the drugs in both PCN1 and PCN2 are released. (Figs. 4a, 4b)

Dr. Lee underscores the role of the additional PCM spray coating that prevents the dissolution before the controlled melting of the PCM. "The previous systems cannot prevent natural diffusion of the drugs from drug reservoir, and rely heavily upon elevation of temperature to enhance the rate of drug diffusion. Our system uses PCMs 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." (Fig. 4c)

The thermos-responsive microneedles controlled by three multichannel heaters can deliver the drug up to 6 steps of drug dosages (Fig. 5) in response to the measured sweat glucose level. The researchers confirmed that as more drug is delivered to the diabetic mice, the blood glucose level is suppressed more.

Disposable, Sweat-based Strip Sensor

This study also features a disposable, sweat-based strip sensor (Fig. 6). The strip sensor is more convenient for the sweat analysis than the patch system since it is small enough to be used easily and can operate by absorbing generated sweat on the skin. Also, the strip-type sensor can analyze the sweat glucose levels after connecting to ZIF connector.

Dr. Lee says, "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." "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," he says. One of the corresponding authors of the study, KIM Dae-Hyeong adds, "The fundamental mechanism underlying this system can be applied in the diagnosis and clinical treatments of various diseases not to mention diabetes."
-end-


Institute for Basic Science

Related Glucose Articles:

What drives inflammation in type 2 diabetes? Not glucose, says new research
Research led by Barbara Nikolajczyk, Ph.D., disproved the conventional wisdom that glucose was the primary driver of chronic inflammation in type 2 diabetes.
ALS patients may benefit from more glucose
A new study led by scientists at the UA has uncovered a potential new way to treat patients with ALS, a debilitating neurodegenerative disease.
Artificial muscles powered by glucose
Artificial muscles made from polymers can now be powered by energy from glucose and oxygen, just like biological muscles.
Efficiently producing fatty acids and biofuels from glucose
Researchers have presented a new strategy for efficiently producing fatty acids and biofuels that can transform glucose and oleaginous microorganisms into microbial diesel fuel, with one-step direct fermentative production.
Protein released from fat after exercise improves glucose
Exercise training causes dramatic changes to fat. Additionally, this 'trained' fat releases beneficial factors into the bloodstream.
WSU researchers create 3D-printed glucose biosensors
A 3D-printed glucose biosensor for use in wearable monitors has been created by Washington State University researchers.
Gut protein mutations shield against spikes in glucose
Why is it that, despite consuming the same number of calories, sodium and sugar, some people face little risk of diabetes or obesity while others are at higher risk?
Glucose binding molecule could transform the treatment of diabetes
Scientists from the University of Bristol have designed a new synthetic glucose binding molecule platform that brings us one step closer to the development of the world's first glucose-responsive insulin which, say researchers, will transform the treatment of diabetes.
Nutrients may reduce blood glucose levels
One amino acid, alanine, may produce a short-term lowering of glucose levels by altering energy metabolism in the cell.
Cancer hijacks the microbiome to glut itself on glucose
A University of Colorado Cancer Center study published today in the journal Cancer Cell shows that leukemia actively undercuts the ability of normal cells to consume glucose, thus leaving more glucose available to feed its own growth.
More Glucose News and Glucose Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.