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Breakthroughs in diabetes care

By Chukwuma Muanya
11 November 2021   |   3:38 am
Scientists have recorded major breakthroughs in diabetes diagnosis and care with discovery of a new wearable, noninvasive, low-cost sensor, glucose-monitoring device that can detect ‘sugar’ in sweat.

Scientists blamed unhealthy lifestyle choices, such as a lack of exercise and smoking, for the “striking differences” for type 2 diabetes

•First-of-its-kind wearable, noninvasive glucose monitoring device prototype
•Pioneering new once-a-week injection could put type 2 diabetes patients in ‘remission’
•High prices, low availability still major barrier for patients’ access to new, old medicines

Scientists have recorded major breakthroughs in diabetes diagnosis and care with discovery of a new wearable, noninvasive, low-cost sensor, glucose-monitoring device that can detect ‘sugar’ in sweat.

Before now, noninvasive glucose monitoring devices were not currently commercially available, so people with diabetes must collect blood samples or use sensors embedded under the skin to measure their blood sugar levels.

But with the discovery by Pennsylvania State researchers, less intrusive glucose monitoring could become the norm.
Led by Huanyu “Larry” Cheng, Dorothy Quiggle Career Development Professor in Pennsylvania State’s Department of Engineering Science and Mechanics, the researchers published the details of the noninvasive, low-cost sensor that can detect glucose in sweat in Biosensors and Bioelectronics. The paper, available online, will be published in the journal’s December print issue.

The researchers constructed the device first with laser-induced graphene (LIG), a material consisting of atom-thick carbon layers in various shapes. With high electrical conductivity and a convenient fabrication time of just seconds, LIG appeared to be an ideal framework for the sensing device — but there was a significant caveat.

“The challenge here is that LIG is not sensitive to glucose at all,” Cheng said. “So, we needed to deposit a glucose-sensitive material onto the LIG.”

The team chose nickel because of its robust glucose sensitivity, according to Cheng, and combined it with gold to lower potential risks of an allergic reaction. The researchers hypothesised that the LIG outfitted with the nickel-gold alloy would be able to detect low concentrations of glucose in sweat on the skin’s surface.

A material with high glucose sensitivity was a priority. Sweat exhibits remarkably low glucose concentrations compared to blood — but according to Cheng, there is a strong correlation between glucose levels in sweat and blood. While the concentration of glucose in sweat is about 100 times less than the concentration in blood, the team’s device is sensitive enough to accurately measure the glucose in sweat and reflect the concentration in blood.

The nickel-gold alloy’s sensitivity allowed Cheng’s team to exclude enzymes, which are often used to measure glucose in more invasive, commercially available devices or in noninvasive monitors proposed by other researchers. These enzymes, however, can degrade quickly with time and changing temperatures.

“An enzymatic sensor has to be kept at a certain temperature and pH, and the enzyme can’t be stored in the long term,” Cheng said. “A non-enzymatic glucose sensor, on the other hand, is advantageous in terms of stable performance and glucose sensitivity regardless of these changes.”

Non-enzymatic sensors require alkaline solution, which can damage the skin and typically limits device wearability. To curb this issue, Cheng and his team attached a microfluidic chamber to the LIG alloy. This chamber is smaller than previously developed configurations to promote wearability and porous to allow for a range of movement, such as stretching or crushing. It is connected to a collection inlet that passes sweat into the solution without allowing the solution to touch the skin. The basic solution interacts with the glucose molecules to produce a compound that reacts with the alloy. This reaction triggers an electrical signal, indicating the concentration of glucose in the sweat.

With a smaller alkaline solution chamber, the entire device is roughly the size of a quarter and is flexible enough to maintain a secure attachment to the human body, Cheng said.

In a proof-of-concept test, the researchers used a skin-safe adhesive to attach the reusable device to a person’s arm one hour and three hours after a meal. The subject performed a brief workout — just enough to produce sweat — right before each measurement time. A few minutes after collecting the sweat, the researchers found that the detected glucose concentration dropped from the first measurement to the next. The glucose measurements from the device were verified by measurements made with a commercially available glucose monitor.

Cheng and the team plan to improve upon their prototype for future applications, including addressing how patients or clinicians may use the sensor for incremental glucose measurements or continuous monitoring to determine treatment actions, such as administering insulin. They also intend to refine and expand this platform for more comfortable monitoring of other biomarkers that can be found in the sweat or interstitial fluids that fill the space between cells in the body.

Also, a once-a-week jab can put type 2 diabetes patients ‘into remission’ – slashing blood sugar to normal levels, cutting cholesterol and blood pressure, and helping patients lose a stone and a half or more.

The results of a pivotal trial into the drug, announced at the European Association for the Study of Diabetes annual conference last month, found that it vastly outperformed current treatment regimes, offering hope to those with the incurable condition.

The new medicine, tirzepatide, is so effective it may offer patients a viable alternative to weight-loss surgery, which is at present the most effective method of treating patients who need to lose large amounts of weight and bring their type 2 diabetes into remission.

The cost of surgery can range from £4,000 to £15,000 privately, depending on the type of procedure, and fewer than 7,000 such operations are carried out on the British National Health Service (NHS) each year.

Tirzepatide is not yet licensed, but it would be expected to offer the NHS a saving on the cost of surgery, say experts.
Tirzepatide is a new type of drug that combines an existing form of medication called glucagon-like peptide-1 (GLP-1) receptor agonists, and a new, similar drug, known as a glucose-dependent insulinotropic peptide, or GIP.

Meanwhile, the World Health Organisation (WHO) has published the new edition of its Model Lists of Essential Medicines and Essential Medicines for Children, which include new treatments for various cancers, insulin analogues and new oral medicines for diabetes, new medicines to assist people who want to stop smoking, and new antimicrobials to treat serious bacterial and fungal infections.

The listings aim to address global health priorities, identifying the medicines that provide the greatest benefits, and which should be available and affordable for all. However, high prices for both new, patented medicines and older medicines, like insulin, continue to keep some essential medicines out of reach for many patients.

WHO Director-General, Dr. Tedros Adhanom Ghebreyesus, said: “Diabetes is on the rise globally, and rising faster in low- and middle-income countries.

Too many people who need insulin encounter financial hardship in accessing it or go without it and lose their lives. Including insulin analogues in the Essential Medicines List, coupled with efforts to ensure affordable access to all insulin products and expand use of biosimilars, is a vital step towards ensuring everyone who needs this life-saving product can access it.”

Insulin was discovered as a treatment for diabetes 100 years ago and human insulin has been on WHO’s List of Essential Medicines since it was first published in 1977. Unfortunately, limited insulin supply and high prices in several low- and middle-income countries are currently a significant barrier to treatment. For example, in Ghana’s capital, Accra, the amount of insulin needed for a month would cost a worker the equivalent of 5.5 days of pay per month. Insulin production is concentrated in a small number of manufacturing facilities, and three manufacturers control most of the global market, with the lack of competition resulting in high prices that are prohibitive for many people and health systems.

The move to list long-acting insulin analogues (insulin degludec, detemir and glargine) and their biosimilars, along with human insulin, is intended to increase access to diabetes treatment by expanding the choice of treatment. Inclusion in the List means that biosimilar insulin analogues can be eligible for WHO’s prequalification programme; WHO prequalification can result in more quality-assured biosimilars entering the international market, creating competition to bring prices down and giving countries a greater choice of products.

Long-acting insulin analogues offer some extra clinical benefits for patients through their prolonged duration of action, which ensures that blood glucose levels can be controlled over longer periods of time without needing a booster dose. They offer particular benefit for patients who experience dangerously low blood glucose levels with human insulin. The greater flexibility in timing and dosing of insulin analogues has been shown to improve quality of life for patients living with diabetes. However, human insulin remains a staple in the treatment of diabetes and access to this life-saving medicine must continue to be supported through better availability and affordability.

The list also includes Sodium-Glucose Co-transporter-2 (SGLT2) inhibitors empagliflozin, canagliflozin and dapagliflozin as second line therapy in adults with type 2 diabetes. These orally administered medicines have been shown to offer several benefits, including a lower risk of death, kidney failure and cardiovascular events. Because SGLT2 inhibitors are still patented and high-priced, their inclusion in the list comes with the recommendation that WHO work with the Medicines Patent Pool to promote access through potential licencing agreements with the patent-holders to allow generic manufacturing and supply in low- and middle-income countries.

Improving access to diabetes medicines including insulin and SGLT2 inhibitors is one of the workstreams of the Global Diabetes Compact, launched by WHO in April 2021, and a key topic under discussion with manufacturers of diabetes medicines and health technologies.

Also, cancers are among the leading causes of illness and death worldwide, accounting for nearly 10 million deaths in 2020, with seven out of 10 occurring in low- and middle-income countries. New breakthroughs have been made in cancer treatment in the last years, such as medicines that target specific molecular characteristics of the tumour, some of which offer much better outcomes than “traditional” chemotherapy for many types of cancer. Four new medicines for cancer treatment were added to the Model Lists: Enzalutamide, as an alternative to abiraterone, for prostate cancer; Everolimus, for subependymal giant cell astrocytoma (SEGA), a type of brain tumour in children; Ibrutinib, a targeted medicine for chronic lymphocytic leukaemia; and Rasburicase, for tumour lysis syndrome, a serious complication of some cancer treatments.

The listing for imatinib was extended to include targeted treatment of leukaemia. New childhood cancer indications were added for 16 medicines already listed, including for low-grade glioma, the most common form of brain tumour in children.

A group of antibodies that enhance the immune response to tumour cells, called PD-1 / PD-L1 immune-checkpoint inhibitors, were not recommended for listing for the treatment of a number of lung cancers, despite being effective, mainly because of their exceedingly high price and concerns that they are difficult to manage in low-resourced health systems. Other cancer medicines were not recommended for listing due to uncertain additional clinical benefit compared with already listed medicines, high price, and management issues in low-resource settings. These included osimertinib for lung cancer, daratumumab for multiple myeloma, and three types of treatment (CDK4/6 inhibitors, fulvestrant and pertuzumab) for breast cancer.

Meanwhile, there are other developments for infectious diseases. New medicines listed include cefiderocol, a ‘Reserve’ group antibiotic effective against multi-drug resistant bacteria, echinocandin antifungals for severe fungal infections and monoclonal antibodies for rabies prevention – the first monoclonal antibodies against an infectious disease to be included on the Model Lists. The updated lists also see new formulations of medicines for common bacterial infections, hepatitis C, HIV and tuberculosis, to better meet dosing and administration needs of both children and adults. An additional 81 antibiotics were classified as Access, Watch or Reserve under the AWaRe framework, to support antimicrobial stewardship and surveillance of antibiotic use worldwide.

Also, on smoking cessation, two non-nicotine-based medicines – bupropion and varenicline – join nicotine-replacement therapy on the Model List, providing alternative treatment options for people who want to stop smoking. Listing aims to support the race to reach WHO’s ‘ Commit to Quit’ campaign goal that would see 100 million people worldwide quitting smoking over the coming year.

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