In a groundbreaking study by researchers at University College London (UCL), scientists have achieved an unprecedented level of detail in examining microplastics embedded within the tissues of living organisms.
The research, published in the journal Advanced Science, demonstrates that it is now possible to detect microplastics located deep within the tissues of live mice using non-invasive techniques. Previously, such analysis could only be performed post-mortem.
A collaborative effort involving researchers from UCL, Kingston University, and the University of Birmingham identified common microplastic substances, including polypropylene (frequently found in food containers and disposable coffee cups) and polyethylene (commonly used in single-use plastic bags).
Their breakthrough lies in a novel technique called photoacoustic imaging. This method involves directing pulses of laser light into tissues. Microplastics, possessing a distinct light absorption profile, absorb this light. This absorption generates minuscule, high-frequency sound waves, which are subsequently captured by ultrasonic detectors. The data gathered then forms a detailed map, clearly illustrating the precise location of microplastics within the organism.
This advancement holds significant potential for understanding the pathways of microplastic dissemination throughout the human body and their subsequent impact on health.
“Microplastics are a global concern, present in our food, drinks, clothing, and everyday household items, affecting everyone on Earth. There’s a growing apprehension regarding their effects on human health, which has been challenging to study within living tissues. Most existing methods rely on biopsies or post-mortem tissue analysis, limiting researchers’ ability to observe changes over time,” stated lead author of the study, Steven Patrick. “We anticipate that our new approach to microplastic detection will pave the way for novel research into where these particles accumulate in the body, how long they persist, and whether they contribute to diseases affecting the brain, blood vessels, and other organs.”
This high-resolution method is capable of identifying individual microplastic particles as small as a human hair. Furthermore, it allows for the tracking of particle movement and accumulation within the body over periods of months, rather than days—a timeframe more relevant to long-term human exposure.
Previously, researchers typically had to chemically tag microplastics before tracking them within animals. This process could potentially alter the particles’ behavior and restrict realistic study conditions. The new method developed at UCL, however, detects the inherent optical signature of common plastics themselves. This allows researchers to non-invasively map and track microplastics situated deep within living tissues for several months, with microscopic precision.
“By demonstrating that microplastics can be visualized within living tissue without modification or destruction, this work establishes a crucial foundation for future research. As the photoacoustic signal directly correlates with microplastic quantity, our method can overcome the limitations of current indirect assessment techniques for microplastic accumulation. We anticipate this will ultimately assist researchers in linking everyday microplastic exposure to long-term health consequences in a manner that more accurately reflects real-world scenarios,” explained co-author Olumide Ogunlade.
During their experiments, mice were administered a controlled quantity of microplastics (approximately half a milligram per experiment, comparable to half a grain of salt) via injection. This allowed the researchers to meticulously track the particles’ journey through living tissues over time. It is worth noting that, similar to humans, the animals likely already possessed a low baseline level of microplastics from their diet and drinking water.
“The versatility of this method enables us to investigate the behavior of other types of plastics within the body. A particular focus is on surgical implants, such as hernia meshes, due to their common occurrences of mechanical failure, adverse effects, and the need for replacement. We are continuing our research to enhance patient outcomes and the safety of these devices,” concluded co-author Joseph Bear.
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