In order to prevent patients with chronic diseases continuously going to the clinic to check their various physiological markers, scientists have developed adhesive biosensors. However, they need to be changed frequently. In order to overcome these limitations, German bioengineers have developed permanent tattoos that alter the color of albumin, glucose and pH. If it has not been the subject of clinical trials in humans, this biomedical technology is extremely promising.
Tattoos on humans have not yet been tested, but on pieces of pork, and scientists have changed the concentration of key biomarkers. This is a key first step that could lead to true tattoos that allow patients and physicians to monitor chronic diseases such as diabetes and kidney disease in real time. The study was published in the magazine Angewandte Chemie International Edition.
The team, led by chemical engineer Ali Yetisen of the Technical University of Munich, then could accurately assess the concentration on the basis of photographs of tattoos taken on a smartphone. Although all colors are not yet reversible, this can be a personalized technology for medical transformation, based on the practice of decorative changes in the human body for thousands of years.
" Changing the body by injecting pigments into the dermis is usually over 4000 years old Write to researchers. " Functional aesthetic technology was developed by combining artificial biosensors and colorimetric biosensors. pH, glucose and albumin ".
Dynamically adjust the pH of the albumin, glucose and blood
Three biomarkers were selected because they often indicate a physiological problem. Albumin is a blood plasma protein. Low concentrations may indicate problems with the kidneys or liver, and high concentrations may indicate heart problems.
For the treatment of diabetes, glucose must be carefully monitored, which affects the ability of the body for the metabolism of sugars. Changes in the pH level in the blood – acidosis due to low pH, high alkalosis – can cause a whole range of problems with gases in the blood.
The team created another dye that is capable of detecting changes in each of these biomarkers in an interstitial fluid. The albumin sensor is a yellow color that becomes green in the presence of an albumine. The more albumin is, the greener becomes (although it looks more or less blue on the pictures).
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The glucose sensor utilizes the enzymatic reactions of glucose oxidase and peroxidase; the changing concentration of glucose causes a structural change in the pigment from yellow to dark green. The pH sensor was composed of methyl red dyes, blue bromotymer and phenolphthalein. At pH between 5 and 9 – the pH of normal human blood fluctuates around 7,4 – the sensor changes from yellow to blue.
Inverted colors and tests on humans: promising, but still long work
When the levels of these biomarkers changed in the interstitial fluid in pieces of pork skin (which is the usual medium in which tattoos can be practiced), the colors also changed. However, one should be aware that this technology has not yet been tested on humans.
In addition, only the color of the pH sensor was reversible; an irresistible color offers only one reading, which is far from satisfactory. Researchers say other colors may be reversible with synthetic receptors but have not yet been tested. The next step is likely to test tattoos on live animals to determine if ink produces unwanted effects.
" The use of sensors can be extended to detect electrolytes, proteins, pathogenic microorganisms, gases and dehydration status. Developing skin sensors could have an application in medical diagnostics to monitor a wide range of metabolic biomarkers Finish the researchers.
Sources: Angewandte Chemie International Edition