As part of the Eurostars project AirToxMonitor, researchers from the Adolphe Merkle Institute’s BioNanomaterials group have validated a cutting-edge device developed by external partners NanoLockin and Vitrocell that could transform how scientists monitor diesel exhaust particles (DEPs) as they interact with lung cells —a crucial step in understanding the health risks posed by air pollution.

DEPs, emitted from vehicle engines, are especially concerning because their tiny size allows them to penetrate deep into the lungs, potentially triggering inflammation, respiratory diseases, or even cancer. The innovative system the AMI researchers evaluated, the Cloud Alpha/CalorQuanti system, merges two sophisticated technologies to deliver both accuracy and ease of use.

At its core is the Cloud Alpha 6, an advanced exposure system developed by German company VITROCELL that automates the process of delivering airborne particles to lung cell cultures.  Unlike traditional methods where cells are submerged in liquid, the Cloud Alpha 6 exposes cells at the air/liquid interface (ALI), closely replicating real-life inhalation and ensuring that airborne substances interact directly with lung cells. This approach yields more physiologically relevant results, which should make toxicity studies more applicable to human health. The Cloud Alpha 6 can measure deposited mass down to 170 nanograms per square centimeter per second, and all this data is captured and visualized in real time.

The other central element of the project is the CalorQuanti sensor, developed in collaboration with NanoLockin, a company launched by the BioNanomaterials group in 2018. This miniaturized device uses lock-in thermography: pulsed laser light is shone onto particles deposited on lung cells, and the resulting tiny temperature changes are detected and correlated with the amount of particle deposition.

Altogether, the new system allows scientists to track particles in real time, without disturbing the living cells — a significant improvement over traditional, often destructive, methods.

“The system ensures uniform particle deposition on lung cells, enabling real-time monitoring with remarkably low detection limits for diesel exhaust particles, as our results show,” said AMI researcher Dr. Ruiwen He.

“By adjusting settings to balance sensitivity and minimize cell damage, this device offers precise, non-destructive tracking of particle aerosol exposure at the air-liquid interface. This is important because it bridges lab simulations and real-world field studies, advancing our ability to assess how combustion-related pollutants affect human health.”

With the system, scientists can monitor how much pollution reaches lung cells in real time, track the effects over time on the same living cells, and generate data that is more relevant for setting public health and occupational safety standards. It paves the way for more precise studies of air pollution’s health impacts and more effective policies for cleaner air and safer workplaces.

This AirToxMonitor project has received funding from the European Union’s Horizon 2020 research and innovation programme under the grant agreement No 955756. Eurostars is the largest international funding programme for SMEs wishing to collaborate on R&D projects that create innovative products, processes, or services for commercialisation.

Reference: He, R.; Schaub, O.; Geers, C.; Moreno-Echeverri, A. M.; Gunasingam, G.; Balog, S.; Schultheiß, M.; Gutmann, B.; Krebs, T.; Petri-Fink, A.; Rothen-Rutishauser, B. An Online Measurement Approach to Monitor the Deposition of Diesel Exhaust Particles on Lung Cells In Vitro. Environ. Sci. Technol. 2025. https://doi.org/10.1021/acs.est.4c08426.