Scientists have developed sticky biosensors to prevent patients suffering from chronic illnesses from continually going to the clinic to check their different physiological markers. However, these must often be changed. To overcome these limitations, German bioengineers have developed permanent tattoos that change color depending on albumin, glucose and pH levels. If it has not been the subject of human clinical trials, this biomedical technology is extremely promising.
Tattoos have not yet been tested on humans, but on pigskin pieces, while scientists have changed the concentrations of important biomarkers. This is a crucial first step that can lead to real tattoos, allowing patients and doctors in real time to check for chronic illnesses such as diabetes and kidney disease. The study was published in the journal Angewandte Chemie International Edition.
The team, led by & # 39; the chemical engineer Ali Yetisen from & # 39; At the Technical University of Munich, the concentrations could precisely be estimated based on pictures of tattoos that are not included in a smartphone. Although not all of the dyes have yet been reversed, it can be a personalized medical transformation technology – based on decorative modification practices of human bodies for thousands of years.
" Body modification by injecting pigments into the dermis is a measure of more than 4000 years Write the researchers. " Here, a functional aesthetic technology has been developed by combining artistic biosensors and colorimetric biosensors. ".
Dynamically control albumin, glucose and pH of blood
The three biomarkers were chosen to give them a physiological problem. Albumin is a protein found in the blood plasma. Low concentrations can indicate kidney or liver problems, while high concentrations can indicate heart problems.
Glucose should be closely monitored for diabetes management, which affects the ability of the body to metabolize sugars. And blood pH changes – low pH acidosis, high alkalosis can be caused by a whole series of blood gas problems.
The team made another dye to detect changes in each of these biomarkers in one intermediate fluid. The albumin sensor is a yellow dye that becomes green in the presence of albumin. The more albumin there is, the more green it becomes (though it appears more or less blue on the images).
On the same subject: How do tattoos remain permanent?
The glucose sensor benefits from the enzymatic reactions of glucosa oxidase and peroxidase; The changing concentration of glucose produces a structural change in the pigment of yellow to dark green. And the pH sensor consisted of methyl red dyes, blue bromothymol and phenolphthalein. At a pH between 5 and 9 – the pH of normal human blood oscillate at 7.4 – the sensor differs from yellow to blue.
Non-reversible human colors and tests: a promise, but still long work
When the levels of these biomarkers were changed to the intermediate fluid in pieces of pork skin (that is, an ordinary medium on which tattoo artists can practice), the colors also changed. However, it is necessary to remember that this technology is not yet tested on humans.
In addition, only the color of a pH sensor was reversed; a non-reversible color offers only one reading, which is far from satisfying. The researchers said the other colors could be reversed with synthetic receptors, but they did not yet test them. The next step will probably be to test tattoos on live animals to determine if the inks cause uncommon effects.
" Sensor applications can be expanded to detect electrolytes, proteins, pathogenic microorganisms, gases and dehydration status. Skin sensors developed to apply in medical diagnostics to control a wide range of metabolic biomarkers Conclude the researchers.
Source: Angewandte Chemie International Edition