Study finds ordinary tattoo ink is a useful tool for detecting cancer

The ink used to apply your last tattoo may also be a useful tool for detecting hidden cancers, according to a new study from the University of Southern California. The trick is being able to distinguish the cancer cells from the normal cells nearby, something that can be achieved using nanoparticles paired with tattoo ink or food dye, the study explains.

The research was conducted by USC's Viteri Department of Biomedical Engineering, where researchers developed the new type of imaging contrast made by pairing ordinary food dye or tattoo ink with nanoparticles. Such contrasts are injected into patients before imaging, making it easier for doctors to determine where cancer is located.

As such, the detection is only as good as the imaging contrast used; the newly developed option is described as offering more sensitive imaging contrast for picking up these cells compared to traditional options. The study refers to these as 'optical inks' — the nanoparticles used are designed to target cancer cells specifically.

Of note, the coloring agents that could be used in the image contrast already have FDA approval, which may make it easier to eventually bring these optical inks into practice. Food dyes, of course, are already used in foods sold at stores around the world; the body can easily process them. In addition, the researchers developed a nanoparticle that can carry the pigments and stick around in the tumor regions for longer than commonly used small molecule dyes.

Study lead Cristina Zavaleta explained:

With small molecules, you may be able to see them accumulate in tumor areas initially, but you'd have to be quick before they end up leaving the tumor area to be excreted. Our nanoparticles happen to be small enough to seep through, but at the same time big enough to be retained in the tumor, and that's what we call the enhanced permeability and retention effect ... If you encapsulate a bunch of dyes in a nanoparticle, you're going to be able to see it better because it is going to be brighter. It's like using a packet of dyes rather than just one single dye.