Biohybrid Skin Graft: A Fluorescent Window for Internal Health Monitoring

Biohybrid Skin Graft: A Fluorescent Window for Internal Health Monitoring

Wearable health devices such as smartwatches are now commonplace and enable continuous monitoring of physiological signals on the surface of the skin. Recently, a research team in Japan developed a biohybrid approach that works inside the body, turning artificial skin into a visible indicator of internal biological states.

A joint research group led by Tokyo City University and the University of Tokyo, in collaboration with RIKEN and Canon Medical Systems Co., has presented oneliving sensor display: an artificial skin graft that responds to certain biomarkers, such as: B. inflammation, fluoresces. Reported inNature communicationThe system utilizes the body's natural skin regeneration to support long-term monitoring of biomarkers, provides visual display without blood sampling post-implantation, and enables intuitive assessment through observation.

More than superficial

Monitoring internal biomarkers – proteins that indicate inflammation, stress or disease – typically relies on blood samples or externally attached sensors that only work for limited periods of time.

“Conventional approaches are often invasive or only provide snapshots of time,” said Distinguished Professor Hiroyuki Fujita of Tokyo City University (Professor Emeritus of the University of Tokyo). “Our goal was to research a biologically integrated system that enables continuous perception and intuitive interpretation even at home.”

To achieve this, the researchers used epidermal stem cells, which naturally nourish and renew the skin throughout its life. By genetically engineering these cells to respond to inflammatory signals—specifically, activation of the NF-κB pathway—the team created skin tissue that increased expression of green fluorescent protein (EGFP) in response to inflammatory signals.

If the sensor is part of the body

When transplanted into mice, the manipulated skin grafted and functionally integrated into the host tissue. When inflammation was induced, the transplanted area emitted green fluorescence and converted internal molecular signals into an external optical signal.

Since the sensor consists of living epidermal stem cells, it is maintained by the skin's natural cell metabolism.

Unlike traditional devices that require power sources or regular replacement, this system is biologically maintained by the body itself. In our experiments, the sensor’s functionality was maintained for over 200 days as the manipulated stem cells continuously regenerated the epidermis.”

Professor Shoji Takeuchi, University of Tokyo

Towards visible, long-term biomarker monitoring

This study demonstrates a proof of concept for long-term, biologically integrated sensing without batteries, wiring, or active user operation. Although this work focused on inflammatory signaling, the underlying strategy is adaptable. By modifying the molecular targets, similarly engineered skin constructs could be developed that respond to different physiological or metabolic signals.

The researchers note that this technology could have applications beyond human healthcare, including in animal research and veterinary medicine, where visual indicators of health status can aid early detection of disease in animals that are unable to communicate symptoms.

Although this work is still at an early preclinical stage, it offers a biologically based approach to linking living tissues with sensing functions and blurs the line between biological systems and technical devices.

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