Scientists have developed painless tattoos that can be self-administered.
Instead of sitting in a tattoo chair for hours, imagine being tattooed painlessly with microscopic needles. Researchers at the Georgia Institute of Technology (Georgia Tech) have developed an inexpensive, painless and bloodless tattoo that can be administered on their own. They have many applications, from medical alerts to tracking neutered animals to cosmetics.
“We’ve made the needle painless, but we’re still putting tattoo ink into the skin,” said Mark Prausnitz, lead researcher on the paper. “This could be a way not only to make medical tattooing more accessible, but also to create new opportunities for cosmetic tattooing due to the ease of management.”
Prausnitz presented his research in the journal iScience on September 14, with former Georgia Tech postdoctoral fellow Song Lee. Prausnitz is a Regents Professor and J. He is the Erskine Love Jr. Chair in the School of Chemical and Biomolecular Engineering.
Tattoos are used in medicine for many purposes. These include covering scars, directing repeat cancer radiation therapy, or restoring nipples after breast surgery. Tattoos can also be used instead of bracelets as a medical warning to convey serious medical conditions such as epilepsy, diabetes or allergies.
Various cosmetic products that use microneedles are already on the market – mostly for anti-aging. However, the development of microneedle technology for tattooing is relatively new. Prausnitz is a veteran in this area. For years he studied microneedle patches to painlessly deliver drugs and vaccines to the skin without the need for hypodermic needles.
“We saw this as an opportunity to use our work on microneedle technology to make tattooing more accessible,” Prausnitz said. “We thought that while some people are willing to accept the pain and time required to get a tattoo, others prefer a tattoo that is simply pressed on the skin and doesn’t hurt.”
Changing the tattoo
Tattoos are generally used to pierce the skin repeatedly using large needles to get a good image. It is a time consuming and painful process. The Georgia Tech team developed microneedles that are smaller than a grain of sand and embedded in a soluble matrix with tattoo ink.
“Because the microneedles are made of tattoo ink, they will deposit the ink well into the skin,” said Lee, the leader of the study.
In this way, the microneedles are pressed into the skin only once and then dissolve. After a few minutes, they leave the color in the skin without blood.
Although most microneedle patches for pharmaceuticals or cosmetics have dozens or hundreds of microneedles arranged in a square or circle, a microneedle patch tattoo prints a design that can include letters, numbers, symbols, and images. By arranging the microneedles in a certain pattern, each microneedle acts as a pixel to create a tattoo image in any shape or pattern.
The researchers start a mold that contains microneedles in a pattern that creates an image. They fill the microneedles in the mold with tattoo ink and add plaster support for convenient handling. The result is applied to the skin for a few minutes, during which the microneedles dissolve and the tattoo ink is released. Tattoo inks of different colors can be incorporated into the microneedles, including black-light ink that can only be seen when viewed under ultraviolet light.
Prausnitz’s lab has been researching microneedles for vaccine delivery for years and found that they could be similar for tattoos. With support from the Consortium on Contraception in Cats and Dogs, Prausnitz’s team began working on tattoos to identify spayed and inbred pets, but realized the technology would also work for humans.
The tattoos are also designed with privacy in mind. The developers have created surfaces that are sensitive to environmental conditions such as light or temperature changes where the tattoo is only visible under ultraviolet light or high temperatures. This gives privacy to patients, revealing the tattoo when needed.
The study shows that the tattoo can last at least one year and can be permanent. This also makes them a viable cosmetic option for those who want to get beautiful tattoos without the risk of infection or pain associated with traditional tattoos. Microneedle tattoos can be installed as an alternative to temporary tattoo ink to address short-term needs in medical and cosmetic applications.
Microneedle plaster tattoos can also be used to hide information on animal skin. Instead of ear cropping or ear tagging on animals, a painless and discreet tattoo can be applied to indicate sterilization status.
“The goal isn’t to replace all tattoos,” Prausnitz said, “they’re often just works of art created by tattoo artists.” “Our goal is to create new opportunities for patients, pets and people looking for an easily treatable, painless tattoo.”
Reference: “Microneedle Patch Tattoo” by Song Li, Youngeun Kim, Jeong Woo Lee and Mark R. Prausnitz, 14 Sep 2022; iScience.
Prausnitz founded a company, Micron Biomedical, to develop the microneedle patch technology, bring it further into clinical trials, promote it, and ultimately make it available to patients.
Prausnitz and several other Georgia Tech researchers are the inventors of the microneedle patch technology used in this study and have a patent interest in Micron Biomedical. Micron Biomedical is entitled to royalties from future sales of products related to the research. These potential conflicts of interest are disclosed and monitored by the Georgia Institute of Technology.