Detecting melanoma before it becomes visible is a major challenge in dermatology. Now, scientists at the Université du Québec’s National Institute of Sciences (INRS), in collaboration with researchers at the Université de Montréal, have developed a promising solution.
The system, called SMEAR-ULM, is a high-tech system that can detect skin cancer in its early stages by measuring small temperature changes on the skin’s surface. The research team, led by INRS professor Jinyang Liang, has published their findings in the journal Nature Sensors..
The study was carried out in close collaboration with multiple research teams, including those led by Professor Fiorenzo Vetrone from INRS, David Brambilla, professor of pharmacology at UdeM, and Sylvain Meloche, professor of medicine.
The potential implications of this study are significant, the researchers say.
Cases are on the rise
The incidence of melanoma continues to increase in Canada, and early diagnosis is important to improve survival rates. Current diagnostic approaches rely on visual inspection followed by biopsy, which is an invasive and sometimes unnecessary procedure.
By enabling rapid, direct, and non-invasive assessment of suspicious skin lesions, this technology has the potential to reduce unnecessary biopsies, improve early diagnostic accuracy, and support clinical decision-making.
“Our goal is to provide a minimally invasive tool to detect very small but aggressive melanomas,” said Liang, senior author of the study and an expert in ultrafast imaging and biophotonics at INRS.
“Due to their small size,[melanomas]are typically excluded from clinical visual examinations, leaving the threat unmonitored. We want to detect them so we can intervene as soon as possible.”
“Although this study was conducted in mice, this animal model recapitulates the genetic changes observed in human melanoma and could therefore potentially benefit patients,” added Melosh, a researcher at UdeM’s Institute of Immunology and Cancer and co-lead author of the study.
This approach also redefines the role of temperature in cancer detection. Tumors are known to generate more heat because they are more metabolically active, but this signal has traditionally been considered too imprecise to be used as a diagnostic marker. SMEAR-ULM changes this by converting subtle thermal changes into highly sensitive and measurable signals.
temporary “tattoo”
At the heart of the system is a painless patch of microneedles that deposits specialized nanoparticles just under the skin. These nanoparticles form temporary “intelligent tattoos” that act like a series of microscopic thermometers.
When irradiated with near-infrared light, nanoparticles emit visible light. Importantly, the lifetime of this luminescence, or how long it lasts, depends directly on the local temperature. Cancer cells consume more oxygen and nutrients than healthy cells, so they produce additional heat, which can be detected through this light signal.
SMEAR-ULM uses an ultra-fast imaging system to capture all this information in one fast snapshot, producing detailed thermal maps with sub-millimeter spatial resolution and sub-1 degree temperature sensitivity.
We obtain all the information needed for an instantaneous temperature map in one shot, making our method fast and robust for continuous monitoring of abnormal thermal responses in small melanomas, even in complex interiors. alive conditions. “
Yingming Lai, lead author of the study, INRS graduate student
Only 4 days old
Using this approach, researchers were able to detect micromelanoma as early as four days after birth. At this stage, it is usually too small to be identified using traditional imaging techniques.
Conversely, traditional thermal imaging methods rely on infrared technology, which suffers from limited spatial resolution and high noise levels. As a result, only tumors larger than 5 millimeters are detected, usually lesions that are already visible to the naked eye.
Similarly, existing microneedle-based sensing approaches require repeated measurements, which limits their use in living organisms.
SMEAR-ULM technology overcomes these limitations by combining microneedle encoding, rare earth-doped nanoparticles, and ultrafast optical imaging into a system capable of real-time, single-shot thermal mapping in vivo.
Researchers say this breakthrough effectively converts skin temperature from a secondary indicator to an accurate diagnostic biomarker for early-stage melanoma.
Beyond skin cancer detection, the platform could be adapted to map other physiological parameters such as pH and ion concentration, opening new possibilities for biomedical imaging and diagnostics.
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Reference magazines:
Lai, Y. others. (2026). Single-shot microneedle encoded upconversion lifetime mapping for real-time in vivo thermodermoscopy. nature sensor. DOI: 10.1038/s44460-026-00078-4. https://www.nature.com/articles/s44460-026-00078-4
