Scientists have developed an invisible tattoo that turns black in the presence of prostate and several other cancers in animal models. This biomedical tool, which responds to the high calcium levels in these cancers, has the potential to serve as an early warning sign of disease.
The animal study, “Synthetic biology-based cellular biomedical tattoo for detection of hypercalcemia associated with cancer,” was published in the journal Science Translational Medicine.
The early diagnosis of cancer makes it more likely the patient will beat the illness and recover. So early detection is an important public health strategy.
However, many cancers progress without symptoms, which delays diagnosis and worsens the prognosis of patients.
In addition to other diseases, some types of cancer, including breast, colon, lung, and prostate cancer, cause blood calcium levels to increase — a condition called hypercalcemia.
With that in mind, researchers used synthetic biology and cell engineering to develop a sensing tattoo that detects high blood calcium levels in mice and on pig skin.
Their biomedical implant was made up of cells that turned dark, like a mole — it produced melanin, a pigment that gives skin and hair its color — in response to continuously increased blood calcium levels.
In animal models, the tattoo was able to recognize prostate, breast, colon, and lung cancer at very early stages. And while the tattoo became clearly visible, the animals remained asymptomatic throughout the 38-day experimental period.
This early warning sign precedes a conventional diagnostic method for cancer.
“An implant carrier should then see a doctor for further evaluation after the mole appears,” Martin Fussenegger, a professor in the Department of Biosystems Science and Engineering at ETH Zurich in Basel, and senior author of the study, said in a press release.
“The mole does not mean that the person is likely to die soon,” Fussenegger said. The dark skin tattoo indicates an abnormally high level of calcium, which requires an accurate diagnosis and, if necessary, treatment.
People tend to consult a doctor when their tumor is already at an advanced state, often making it difficult to treat.
Besides its potential as an early cancer detector, other benefits of this implant is that “it is intended primarily for self-monitoring, making it very cost effective,” Fussenegger said.
This prototype sensor system has a fairly short life span. “Encapsulated living cells last for about a year, according to other studies. After that, they must be inactivated and replaced,” Fussenegger said.
A great amount of testing is still needed, but “this biomedical tattoo strategy could also potentially be used to noninvasively monitor response to treatment,” the scientists wrote.