Diabetes management continues to get more complicated with the advancement of tools like AID systems, high-tech pumps, and more accurate CGMs, one subsection of researchers is pursuing a decidedly different approach.
The insulin patch, which consists of a small wearable patch filled with tiny microneedles that painlessly and continuously injecting insulin throughout the day, requires no tech and is cheap to manufacture.
Similar to an umbrella whose simple function shields you from bad weather.
And now, thanks to research funded by the National Natural Science Foundation of China and published in Science Advances, we are closer than ever to an insulin patch capable of not only replacing the need for insulin pumps and injections, but that shows promise to even further reduce glucose fluctuations before and after meals.
How Insulin Patches Work
Insulin patches consist of an integrated microneedle patch (IMP) prefilled with insulin. Similar to the Nicorette patch in size and wearability, the insulin IMP is placed on the skin, allowing hundreds of tiny needles to penetrate the subdermal layer and release insulin on an as-needed basis.
Each needle array is constructed of a matrix material that reacts to the acidic nature of glucose in the blood and automatically releases insulin in response to rising blood sugar levels.
Not only does this process allow for an insulin dosing pattern that more accurately mimics the function of a working pancreas, but it also erases the need for frequent blood sugar monitoring and manual needle injections.
However, up to this point, these IMP systems have been unable to effectively stabilize basal blood sugar rates and post-meal glucose spikes with equal magnitude.
Now, researchers out of China have created a patch capable of normalizing fasting glucose levels as well as effectively reducing post-meal blood sugar fluctuations.
Controlled Release Kinetics
This technology consists of multiple different matrix materials to build three separate needle arrays on each patch.
The researchers experimented with various materials to create their final product, including both native and cross-linked polymers.
Each type of polymer reacts to glucose blood markers in a different way.
- Swelling of the matrix cell allows for slow sustained insulin release
- Shrinking of the cell matrix enables rapid insulin release.
By utilizing multiple materials on the same patch, the researchers were able to account for the need for continuous insulin dosing to create stable basal blood sugar levels as well as the rapid-release of insulin to combat blood sugar spikes after meals.
Three Insulins per Patch — Fast, Intermediate, and Long Acting
The use of various matrix materials was not enough to completely replicate the natural pattern of insulin release of a healthy pancreas. To achieve this, the researchers had to incorporate three different types of insulin into their arrays.
- Cells with the slowest release matrix were filled with long-acting insulin to mimic the basal insulin dosing and to stabilize blood sugars in response to hormonal changes seen in the body throughout the day.
- Cells with the rapid release matrix material were filled with short-acting insulin to mimic the higher, single insulin dose taken with meals and to prevent post-meal glucose spikes.
- Finally, the third array, composed of matrix material that releases at a moderate pace, was filled with intermediate-acting insulin to further customize insulin release in response to fluctuating blood glucose levels.
A Low-Tech Solution
Contrary to the immense complexity of artificial pancreas systems which need to analyze current glucose readings, past trends, insulin-on-board, time-of-day, etc., these glucose responsive patches are simple and will likely be safer.
Tissue and animal studies have shown promising results for this new patch’s ability to effectively control glucose throughout the day, including after meals.
In addition to demonstrating a unique ability to reduce overall glucose fluctuations, the patch also appears to reduce the occurrence of hypoglycemic episodes, as insulin release is automatically slowed in response to falling glucose levels.
If this patch technology continues to show success in animal trials and, eventually, human trials, it could provide a great solution to managing blood sugar levels and reducing diabetes management burden that is both affordable and effective.