New technology to image microplastics in living organisms
Microplastics—tiny particles of plastic—have become a serious global health concern. Humans encounter microplastics almost daily, as these particles are found in the air, dust, trash, fabrics, cosmetics, cleaning products, seafood, and more. These particles have been detected throughout the human body, including in blood, saliva, liver, kidneys, and placenta. Researchers are still investigating whether microplastics also exist in lung tissues, where they could lead to various lung diseases. Additionally, studies show that microplastics may damage DNA and alter gene activity, potentially leading to cancer. There are further concerns about microplastics found in human breast milk, an infant’s first stool, and their impact on the reproductive system.
Given these concerns, identifying and measuring microplastics in living organisms is becoming increasingly important. However, due to their tiny size, microplastics in biological samples are often challenging to detect with conventional techniques, such as microscopy. Another method, vibrational spectroscopy (a way of detecting molecules using laser light), has also been used to image microplastics. But this approach struggles with interference or background noise, making it difficult to create clear images in living organisms.
Recently, scientists have developed a new technique that could make it easier to detect and study microplastics in living organisms. This method builds on a technology that maps tiny particles in biological samples, called Mass Spectrometry Imaging (MSI). Regular mass spectrometry works by identifying molecules based on their unique "mass-to-charge ratio" after being turned into charged particles (ions) with a laser. MSI takes this further by combining the detailed imaging of microscopy with the molecular analysis of mass spectrometry, creating a map that shows both the structure and the chemical makeup of molecules in a sample.
In a recent study, researchers from Nankai University and the University of Massachusetts used MSI along with an advanced technique called matrix-assisted laser desorption/ionization (MALDI) and specialized equipment to pinpoint and measure tiny microplastics inside living organisms. This method allowed them to detect plastics like PMMA, GMA, and PVC—materials commonly found in packaging, coatings, and everyday products—without disrupting the organism's natural processes.
While this technique is promising, there are still hurdles to overcome. Researchers are working on reducing interference from chemicals used in sample preparation, speeding up the imaging process, and improving the accuracy of their measurements.
Once these challenges are addressed, this technique could revolutionize our understanding of how microplastics accumulate, move, and transform within living organisms. Such insights would enhance our knowledge of the potential health and environmental impacts of microplastics.
While this technique offers hope in addressing the global microplastic health crisis, questions remain about whether it can be applied to detect microplastics in human cells for clinical diagnosis, and how challenging that might be. Nonetheless, it represents an exciting advancement in microplastic research.
References:
Li, Y.; Sha, X.; Wang, Y.; Zhao, Y.; Zhang, J.; Wang, P.; Chen, X.; Xing, B.; Wang, L., In situ imaging of microplastics in living organisms based on mass spectrometry technology. Eco-Environment & Health 2024, 3 (4), 412-417. https://doi.org/10.1016/j.eehl.2024.05.007