A single speck of polyethylene, no wider than a human hair, glides silently through the bloodstream of a mouse in a London lab—its journey now visible in real time, thanks to a breakthrough imaging technique developed by scientists at Kingston University, University College London, and the University of Birmingham. For the first time, researchers have mapped microplastics deep within living tissue over months, not just days, using a noninvasive method that could revolutionize how we study the invisible plastic burden inside our bodies. This advancement, detailed in Advanced Science, offers a powerful new lens on a global health concern: the long-term impact of microplastics, which infiltrate our food, water, and air, yet have remained largely hidden from real-time observation.
Until now, studying microplastics in living organisms meant either dissecting tissue or chemically tagging particles—methods that alter their behavior or offer only snapshots in time. But the team’s use of photoacoustic imaging changes that. By pulsing laser light into tissue, they exploit the unique optical fingerprints of plastics like polypropylene and polyethylene, which absorb light and emit high-frequency sound waves. These signals are captured by ultrasound detectors, generating high-resolution maps of microplastic movement and accumulation—down to the microscopic level and across timescales that mirror real human exposure.
The implications are profound. Led by Dr. Stephen Patrick of UCL Medicine and first author Dr. Joseph Bear of Kingston University, the study tracked particles over months, revealing how they settle and persist in living systems. One image from the research, so striking it was shortlisted for the Wellcome Photography Prize 2025, captures this unseen world in haunting clarity. Dr. Olumide Ogunlade, the study’s lead physicist now at the University of Birmingham, emphasized the method’s precision: 'Since the photoacoustic signal is directly related to the amount of microplastic, our method could overcome the limitations of existing indirect methods of estimating microplastic accumulation.'
Beyond environmental health, the technology opens doors in medicine. The team is already applying it to study surgical implants like hernia meshes, where plastic degradation can lead to mechanical failure and patient harm. By visualizing how these materials break down in vivo, researchers aim to improve device safety and patient outcomes.
This is more than a technical leap—it’s a shift in how we confront the plastic age. As microplastics become an inescapable part of human biology, this new window into their behavior offers hope: that we can finally see, understand, and ultimately mitigate their impact on our bodies and our future.