Tattoos that "Mark the Spot" for Surgery, Then Disappear
Tattoos aren’t just for body art. They have medical applications, too. Doctors use them on cancer patients to mark an area for future treatment, such as biopsies or radiation treatments. Currently, doctors use carbon graphite, India ink, or fluorescent dye for the tattoo ink. But this can cause inflammation and discomfort at the site of the tattoo. Plus, the tattoos are permanent, so patients who don’t want to live with a lingering reminder of their bout with a deadly disease will need laser or surgical removal after their surgery.
Kai Chen, Gary S. Chuang, Hsian-Rong Tseng, and colleagues have developed a safer, more patient-friendly option. In the journal ACS Nano, the researchers report on a new ink that glows only under certain light conditions and then disappears altogether after a period of time.
The investigators created a time-limited pigment by cross-linking fluorescent supramolecular nanoparticles. Under ambient lighting, the nanoparticles are invisible, which would avoid unwanted markings in a patient’s skin. The pigment glows under light shining at a wavelength of 465 nanometers, so doctors would be able to use an in vivo optical imaging system to see the dye. Testing in mice showed that tattoos created with these nanoparticles didn’t cause inflammation and lasted for three months. This would be long enough to mark a spot from biopsy through treatment for a non-melanoma patient.
The authors acknowledge funding from the National Institutes of Health and the Department of Radiology at the University of Southern California.
Read more about the research: Cross-Linked Fluorescent Supramolecular Nanoparticles as Finite Tattoo Pigments with Controllable Intradermal Retention Times, ACS Nano, 2016, Article ASAP.