A stick-on patch that can automatically control blood glucose levels is being developed by scientists in the US. The patch is embedded with over a hundred microneedles which contain tiny sacs of insulin and glucose-sensing enzymes. These tiny needles detect blood glucose levels and release the correct amount of insulin in response.
When the patch is placed on the skin, the blood flowing through the capillaries just beneath the surface flows around the microneedles. Rising blood glucose levels trigger the activity of an enzyme contained in the microneedle sacs. This active enzyme uses up oxygen, triggering a second chemical reaction that causes the sacs to disintegrate and release the insulin they contain. The glucose-sensing enzymes become more or less active depending on the amount of glucose in the blood, ensuring that the appropriate amount of insulin is released.
The patch can be placed anywhere on the body and is the size of a postage stamp, while the microneedles are 100 times finer than a human hair and are reportedly painless. When scientists used the patch on mice with diabetes, their blood sugar normalised within half an hour, and stayed that way for several days. The patch was able to maintain normal blood glucose levels even after large amounts of glucose that were given to the mice, without causing hypos.
The patch would need to be replaced regularly as insulin stores get used up, probably once a week. Although this technology shows great promise, it hasn’t been tested in humans yet. Some fine-tuning is still needed by the researchers to make sure that the patch will still be safe and effective in people of different weights and insulin sensitivity.
If successful, the patch could remove the need for regular insulin injections and manual blood glucose testing, making life a lot easier for people living with type 1 diabetes.
Read journal abstract: Microneedle-array patches loaded with hypoxia-sensitive vesicles provide fast glucose-responsive insulin delivery. – PubMed – NCBI