Author: Maria Flores
Editors: Sophia Chen and Hwi-On Lee
Artist: Jenny Luo
For millions of Americans living with type 1 diabetes, Continuous Glucose Monitors (CGMs) are life-changing equipment. A CGM contains a small hydrogel sensor that bases its readings on the intensity of boronic acid-based fluorescence. These hydrogels can detect the monomers and polymers of glucose present in blood. With these readings, physicians inject the appropriate amount of insulin to regulate glucose levels. Despite their impressive impact on endocrinology, CGMs have a clear downside: they are short-lasting. Hydrogel glucose sensors typically degrade after implementation and, in return, cause inaccurate readings.
A group of researchers from the University of Tokyo have addressed this issue by engineering a long-lasting hydrogel, a critical component of CGMs. First, the researchers examined the components of hydrogels, starting with boronic acids. The boronic acids cleaved, or severed, in vivo, which is a scientific term referring to work performed within a whole, living organism. Believing that reactive oxygen species may be responsible for the cleavage, they immersed their hydrogels in hydrogen peroxide — a representative of the reactive oxygen species found in all living organisms. Immediately after, the boron-carbon bonds disappeared. These results indicated a relationship between the degradation of hydrogel sensors and the presence of reactive oxygen species in our bodies. To counteract this, researchers thought to slow the degradation process by using two antioxidants: superoxide dismutase and catalase. The reaction rate between the hydrogen peroxide and the two antioxidants was higher than that between the hydrogen peroxide and aryl boronic acid. Therefore, the antioxidant enzymes would attach themselves to the glucose-responsive fluorescent dye before the aryl boronic acid, blocking the process of degradation. This innovative approach slowed down degradation, ensuring prolonged functionality.
This breakthrough not only enhances CGM longevity but also offers substantial cost savings for patients, potentially eliminating the need for frequent replacements that can cost hundreds of dollars monthly. Most at-home CGM sensors last 10 to 14 days before requiring the purchase of a replacement sensor. For those without insurance, the cost of replacing CGMS can range from approximately $160 per month to $500 per month.
In addition to saving patients the visits to replace CGMs, experimenters found that the hydrogel glucose sensors with antioxidants could more accurately trace blood glucose. They found that hydrogel sensors with antioxidant enzymes were better at detecting concentrations within the hypoglycemic range, which includes dangerously high levels of glucose in the blood. These levels, when not treated appropriately, can lead to a diabetic coma and other health problems. These developments are not only limited to the future of CGMs but can apply to a new generation of artificial pancreas. CGMs are used in a hybrid closed-loop system that automatically inserts insulin when necessary. Advancements in these medicinal treatments would run independently, slashing costs for those with diabetes completely.
The groundbreaking solution to CGM degradation has furthered the advancement of bioengineering while simultaneously benefiting millions of Americans. Through the use of antioxidants, researchers at the University of Tokyo have revolutionized the field of diabetes management. As the technology matures, it stands as a beacon of hope for patients by potentially reducing the financial burdens associated with diabetic care. Holding the potential to address a recurring theme in all medical fields, this innovation can be the first step toward addressing the pervasive issue of accessibility to treatment.
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