To prick a finger to extract a drop of blood and, thus, to measure the level of glucose concentrated in it: it is the uncomfortable ritual that hundreds of millions of people with diabetes face every day. It is a necessary practice to have the disease controlled and some patients have to repeat it up to ten times in 24 hours. In recent years, new technologies have allowed the development of alternative methods, but none have yet completely replaced the traditional system. Now, researchers at the University of Bath (United Kingdom) have developed a patch that extracts glucose concentrated in the interstitial fluid from the hair follicles. Thus, measurements are obtained that are proportional to those observed in the blood and do not need to use needles, according to these scientists.
The most common current method of controlling blood glucose levels is uncomfortable and hurts, the researchers say. The alternatives exist, but they are not always applicable, they say. An example is a sensor with microneedles. There are also flash systems , sensors that allow non-invasive and continuous measurement of glucose by collecting interstitial fluid through the skin.
All have some drawback: either they are little used, or they cost too much, or they do not allow to reflect with full accuracy the concentration of glucose in the blood detected with the traditional method. And that’s why sometimes it’s still necessary to compare the results with those obtained by punctures.
The new technique discovered by researchers at the University of Bath, published in the journal Nature nanotechnology , allows, however, to use a cheap, comfortable method that does not hurt to monitor the level of sugars in the blood, they maintain. It is a patch applicable to some part of the body, for example the wrist, equipped with graphene sensors that capture with the technique of electroosmosis, that is, with a small electrical charge, the glucose present in the interstitial fluid under the skin through each follicle. In this way, the area in which each sensor acts is clearly delimited.
This method allows control of glucose levels for six hours at intervals of 10-15 minutes, according to the scientists responsible for the investigation. The observed data can be transferred via wireless connection , for example, by bluetooth to a device that allows the visualization of the results.
A valid system for people at risk
British scientists remember that diabetes patients are on the rise. According to the World Health Organization, they have gone from 108 million in 1980 to 422 million in 2014. Richard Guy, one of the researchers at the head of the eight-person team that has conducted the study, says that the method used is for all types of patients with diabetes. “We believe that it can also be applied to those individuals who are at risk of suffering from type 2 diabetes but who have not yet received an unambiguous diagnosis,” he adds. This would represent a novelty with respect to existing methods.
Guy explains that the cost of the patch still can not be established exactly, but he believes that it will be an important saving. According to his estimates, with this device a patient could spend less than 1.50 euros in a day, while each puncture is worth 30 cents and allows a single measurement and only once. The most common non-invasive method, the flash system, is worth 60 euros every 14 days. In Spain, Social Security covers the materials that are used for the traditional method, but the flash system is only covered in some autonomous communities.
The researchers responsible for the study, who have worked on the project for five years, have experienced the measuring instrument in pig skin samples and also in two healthy people who volunteered. “In the experiments carried out so far in vivo in humans we have not detected contraindications,” says Guy.
Anna Novials, president of the Spanish Diabetes Society (SED) and researcher at the Hospital Clínico de Barcelona, considers the technique discovered “promising”, because she believes that non-bloody methods of measurement mean improvements for patients. Novials believes that the device “needs many more studies” to determine its effectiveness and points to several factors to determine the development of the patch: “We will have to see if the method responds to the glucose variations of diabetics, depending on the treatments, of the response to meals, physical activity, even environmental factors, humidity and heat, “he says.
Richard Guy highlights, among the possible steps to further develop the patch, the need to improve the technology that allows measurements. The scientist also considers it important to test the system in different contexts, for example in subjects under physical exertion or in patients with different blood glucose levels, as well as to optimize the benefits so that the same patch can cover a period of 24 hours.