Invisible pollutants at the nanoscale are quietly entering bodies and ecosystems, yet standard toxicology tools still treat living organisms like a black box. A new perspective article in the journal New Contaminants describes how cutting edge bioimaging is turning that black box into a transparent map, revealing where these particles go and how they may harm health.
Lighting up hidden nano pollution
Emerging nanoscale contaminants such as engineered nanomaterials and nanoplastics are now found in water, soil, food and even the air we breathe, but their tiny size and complex behavior make them hard to track with traditional methods. Conventional toxicology usually looks only at endpoints, like tissue damage, and often misses the step by step journey and subtle early effects of these particles inside living organisms.
The new paper highlights advanced bioimaging tools that can follow nanoscale contaminants in real time, from the moment they enter cells to their accumulation in organs and eventual clearance from the body. These methods range from high resolution electron microscopy to whole body imaging, with fluorescence imaging emerging as a central bridge between cellular details and organism level effects.
A new class of "switch on" probes
A key focus of the article is a special group of fluorescent probes called aggregation induced emission luminogens, or AIEgens, which become brighter instead of dimmer when they clump together. This unusual property directly addresses a major limitation of traditional dyes, which often lose their signal when particles aggregate, exactly when scientists most need to see them.
"AIE technology allows us to watch the entire life cycle of nanoscale pollutants in living systems, from their first contact with cells to long term storage in organs, without losing sight of them over time," says lead author Dr Neng Yan of China University of Geosciences. Because AIEgens are highly photostable and compatible with biological systems, they can support long term time lapse imaging that captures slow, chronic effects relevant to real world environmental exposures.
From cell level events to whole body maps
Using AIE labeled particles, scientists can distinguish how nanoplastics or metal based nanoparticles enter cells, for example via rapid clathrin mediated endocytosis or slower macropinocytosis, and follow them as they move through endosomes and lysosomes. Sudden changes in fluorescence patterns can even reveal critical events such as lysosomal membrane rupture, which is linked to toxicity.
At the tissue and organ level, AIE based imaging can be combined with tissue clearing and light sheet microscopy to build three dimensional "cartographies" of where contaminants accumulate, including in sensitive regions like the brain. In live animals, near infrared AIE probes in the NIR I and NIR II windows allow deeper imaging with less background, enabling researchers to quantify how quickly particles cross barriers, circulate through blood vessels and are eventually eliminated.
Toward predictive toxicology for the nano age
The authors note that important challenges remain, including avoiding disturbance of particle behavior by labels, balancing resolution with penetration depth and handling the huge volumes of imaging data. They argue that the next leap will come from combining smarter multimodal probes, integrated imaging workflows and artificial intelligence driven analytics that can turn images into predictive models of toxicity.
"By visualizing where nanoscale contaminants go and how they interact with cells over time, we can move from simply observing damage to forecasting risk and designing safer materials before they are released into the environment," says co author Prof Jianbo Shi of the Chinese Academy of Sciences. The perspective concludes that such imaging powered, predictive toxicology frameworks will be essential to ensure that the benefits of nanotechnology are realized without compromising environmental and human health.
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Journal reference: Yan N, Parodi A, Dang F, Shi J. 2025. Shedding light on the invisible: aggregation-induced emission-based bioimaging for assessing the environmental impact of emerging nanoscale pollutants. New Contaminants 1: e019
https://www.maxapress.com/article/doi/10.48130/newcontam-0025-0017
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About the Journal:
New Contaminants is an open-access journal focusing on research related to emerging pollutants and their remediation.
