Engineered Cells Turn Living Skin Tissue Into a Long-Lasting, Power-Free "Living Sensor Display"

Researchers from the University of Tokyo, Tokyo City University, the RIKEN Center for Biosystems Dynamics Research (BDR), and Canon Medical Systems have come up with a novel way to monitor biomarkers in living subjects — by turning their skin into a display.

"Conventional approaches [to biomarker monitoring] are often invasive or provide only snapshots in time," explains corresponding author Hiroyuki Fujita of the team's aims with the research project. "Our goal was to explore a biologically integrated system that enables continuous sensing and intuitive interpretation, even at home."

Dubbed a "Living Sensor Display," the team's creation is based on keratinocyte stem cells (KSCs), which are sensitive to stimulation from their environment. Specially-engineered KSCs are created that are sensitive to a particular target biomarker signal, then implanted in living skin — expressing fluorescent proteins in response to the presence of the marker and turning the skin into a functional display readable at-a-glance.

In testing on a murine model, the team's Living Sensor Display was able to accurately detect inflammatory responses induced by TNF-α and lipopolysaccharides — and lasted for hundreds of days of active use. "Unlike conventional devices that require power sources or periodic replacement, this system is biologically maintained by the body itself," explains co-author Shoji Takeuchi. "In our experiments, the sensor functionality was preserved for over 200 days, as the engineered stem cells continuously regenerated the epidermis."

The researchers say that the same strategy could be applied to monitoring other physiological or metabolic cues, and could be extended beyond human healthcare to use-cases including animal research and veterinary medicine to assist with health monitoring of animals unable to communicate their symptoms.

The team's work has been published in the journal Nature Communications under open-access terms.