Brazilian and U.S. scientists have developed prescription glasses equipped with a biosensor that can measure blood glucose levels through a person's tears. They can lead to less invasive testing for diabetics.
Glucose levels need to be checked frequently to monitor diabetes. It is a disease that now affects 380 million worldwide. Today, biosensors can solve the problem.
According to the World Health Organization (WHO)diabetes has risen alarmingly in recent decades. The biggest increase is in low and middle income countries, and could affect 580 million people by 2035.
Many people use a handheld blood glucose meter to monitor their diabetes by looking at their blood glucose levels. They prick their fingers, obtain a blood sample and submit it to a device for analysis. The process, which can be repeated several times a day, can be painful and carries a risk of infection. The new (different and encouraging) methods have not yet taken off.
The biosensors developed by the USA-Brazil team are able to identify an enzyme called glucose oxidase (widely used to detect free glucose in body fluids) from tears, eliminating the need to prick your fingers. But that's not all: they can also measure blood sugar, vitamin and alcohol levels.
Biosensors are able to measure biological or chemical reactions and generate a signal proportional to the concentration of a particular substance. They are increasingly being designed and used to accelerate laboratory test results, monitor health conditions, diagnose and prevent disease.
Monitor diabetes through tears
The project was born from researchers from São Carlos Physics Institute of the University of Sao Paulo, together with scientists from the Department of Nanoengineering of the University of California, San Diego. The teams immobilized the enzyme on an electrode coupled to a circuit with a constant flow of electrons, then installed the device on the nosepiece of the glasses. The user can produce tears on command (if he has good acting skills ... joke) or by exposing the eyes to a substance that stimulates the lacrimal gland.
When the tears come in contact with glucose oxidase, they alter the flow of electrons, producing a signal that is recorded and processed by the device installed in the bar of the glasses, which sends the results in real time to a computer or smartphone.
Laís Canniatti Brazaca, physician and researcher at the São Carlos Institute of Chemistry and one of the authors of the study published in the journal Biosensors and Bioelectronics, He declares: "The concentrations of various metabolites in the tears reflect the concomitant blood levels, making them a breeding ground for biosensors capable of non-invasively monitoring diabetes, and also observing other physiological parameters."
In addition to being painless, the biosensor could "reduce the risk of infection in people who use glycosometers frequently," Brazaca added.
The scientist said the device could also measure the levels of vitamins and alcohol in the blood “Simply by changing the electrode positioned on the nose pads of the glasses”.
A single drop of blood
Using the same approach, a team of researchers of the State University of San Paolo has developed biosensors capable of detecting and quantifying biomarker proteins for the clinical diagnosis of neglected diseases and chronic degenerative diseases, such as certain types of cancer.
For Paulo Roberto Bueno, materials engineer at the Chemical Institute of the State University of Sao Paulo, "The idea is to conduct the test using only a drop of blood on the device.". A bit like the dream (unfortunately it turned out to be) of Elizabeth Holmes and her Theranos.
This simple approach could improve diagnosis of disease by medical professionals or by patients themselves at home. With the help of artificial intelligence software they could keep their vital signs under control.
The researchers plan to market the new device within three years. In the case of biosensors mounted on glasses to monitor diabetes, the device is not yet expected to reach the market.
Biosensors: it takes time, unless ...
Cleverton Pirich, a biochemist at Paraná Federal University in Brazil, said the benefits of biosensors for improving the quality of life and human health have been known for some time. However, there is still a way to go to produce and market them on a large scale, at least in countries like Brazil.