If tattoos can accurately be used in the diagnostic process, might clinical laboratories soon offer these types of diagnostic tattoos at their patient service centers?
Could color-changing tattoos help diagnose illnesses? Researchers at the ATLAS Institute at the University of Colorado Boulder think so. They are working on prototypes of permanent tattoos that can detect chemical changes in the body and smart tattoo ink that would take the concept of wearable medical devices to a whole new level.
Called “dynamic” or “smart” tattoos, these color-changing tattoos have a biomedical purpose. They alert individuals to potential health issues due to changes in the biochemistry in their body. The technology has already been used in animal studies to detect sodium, glucose, electrolytes, and pH levels. Pathologists and clinical lab manager will recognize the value of a relatively non-invasive way to measure and track changes in these types of biomarkers.
The ATLAS Institute published its findings in ACS Nano, a publication of the American Chemical Society, titled, “Solar Freckles: Long-Term Photochromic Tattoos for Intradermal Ultraviolet Radiometry.”
“We developed a photochromic tattoo that serves as an intradermal ultraviolet (UV) radiometer that provides naked-eye feedback about UV exposure in real time. These small tattoos, or ‘solar freckles’, comprise dermally implanted colorimetric UV sensors in the form of nano encapsulated leuco dyes that become more blue in color with increasing UV irradiance,” the ATLAS scientists wrote.
Studies analyzing the efficacy of dynamic tattoos have provided strong evidence that they can be engineered to change color and sense and convey medical information. This field is called “dynamic tattoos” and in recent years various proof-of-concept studies have demonstrated that tattoos can be used to “pick up changes in sodium, glucose, electrolytes or pH levels in animal models,” Labroots reported.
“We demonstrate the tattoos’ functionality for both quantitative and naked-eye UV sensing in porcine skin ex vivo, as well as in human skin in vivo. Solar freckles offer an alternative and complementary approach to self-monitoring UV exposure for the sake of skin cancer prevention,” the researchers explained in their ACS Nano article.
“Activated solar freckles provide a visual reminder to protect the skin, and their color disappears rapidly upon removal of UV exposure or application of topical sunscreen. The sensors are implanted in a minimally invasive procedure that lasts only a few seconds yet remain functional for months to years,” they added.
“These semipermanent tattoos provide an early proof-of-concept for long-term intradermal sensing nanomaterials that provide users with biomedically relevant information in the form of an observable color change,” the ATLAS researchers concluded.
Nanotechnology Gives Dynamic Tattoos Functionality
“When you think about what a tattoo is, it’s just a bunch of particles that sit in your skin,” Carson Bruns, PhD, Assistant Professor, Laboratory for Emergent Nanomaterials, ATLAS Institute, Mechanical Engineering, told Technology.org. “Our thought is: What if we use nanotechnology to give these particles some function?”
The invisible tattoos Bruns and the ATLAS team created turn blue in the presence of harmful levels of ultraviolet radiation to inform wearers that their skin needs protection and to apply or reapply sunscreen.
The tattoo ink used for these tattoos contains a UV-activated dye inside of a plastic nano capsule that is less than a thousandth of a millimeter in size, or several sizes smaller than the width of a human hair. The capsules protect the dyes from wear and tear while allowing them to sense and respond to biochemical changes in the body. These tattoos are implanted into the skin using tattoo machines, much like getting a regular tattoo.
“I call them solar freckles because they’re like invisible freckles that are powered by sunshine,” Bruns told Inked, adding, “Millions of cases of preventable skin cancer are treated every year. I hope that the UV-sensitive tattoo will help us reduce the number of those cases by reminding people when their skin is exposed to unsafe levels of UV light.”
Dynamic Tattoos May Help People Lead Healthier Lives
One downside to these tattoos is that they only last a few months before they begin to degrade, requiring the wearer to get a “booster” tattoo.
The researchers hope that someday similar tattoo technologies will be applied to a wide variety of preventative and diagnostic applications. The goal is to enable people to detect health issues and allow them to lead healthier lives.
“We want to make tattoos that will allow you to, for example, sense things that you can’t currently sense,” Bruns told Inked. “Sometimes I joke that we want to make tattoos that give you superpowers.”
The ATLAS scientists imagine a future where tattoos can detect things like blood alcohol levels or high/low blood sugar levels or other changes in a person’s biochemistry.
“More generally, I hope that smart tattoos will help people stay healthy and more informed about their body, while also giving people new ways to express themselves creatively,” Bruns said.
Using Dynamic Tattoo to Detect Cancer
In 2018, a team of biologists created a tattoo comprised of engineered skin cells and an implantable sensor which could detect elevated blood calcium levels that are present in many types of cancers. These cancer-detecting tattoos were tested on living mice and would darken to notify researchers of potential problems.
Scientists at the Department of Biosystems Science and Engineering at the Swiss Federal Institute of Technology Zurich (ETHZ), Switzerland, developed a biomedical tattoo that uses bio sensitive ink and changes color based on variations in the body’s interstitial fluid. It recognizes four widespread cancers:
- lung, and
“Nowadays, people generally go to the doctor only when the tumor begins to cause problems. Unfortunately, by that point it is often too late,” Martin Fussenegger, PhD, Professor of Biotechnology and Bioengineering at the Department of Biosystems Science and Engineering (D-BSSE) of the ETH Zurich in Basel as well as at the University of Basel, told Medical News Today.
“For example, if breast cancer is detected early, the chance of recovery is 98%,” he continued. “However, if the tumor is diagnosed too late, only one in four women has a good chance of recovery.”
Fussenegger and his team hope their specialized biomedical tattoo may help detect the presence of cancer cells early and significantly improve patient outcomes. They published the results of their research in the journal Science Translational Medicine, titled, “Synthetic Biology-Based Cellular Biomedical Tattoo for Detection of Hypercalcemia Associated with Cancer.”
Though it appears that dynamic tattoos may be a functional and decorative way to track health, rigorous research and safety testing on human subjects will be required before clinical laboratories can set up diagnostic tattoo parlors in their offices.
Nevertheless, this concept demonstrates how different technologies under development may provide clinical laboratories with innovative and unusual diagnostic tools in the future.