About This Project

Polyethylene terephthalate (PET) microplastics have been detected in human blood and tissues, and linked to inflammation, hormone disruption, and metabolic dysfunction. We hypothesize that engineered PETase and MHETase enzymes will effectively degrade PET microplastics under physiologically relevant conditions without producing harmful byproducts. This validation study is the first step toward developing the first FDA-approved therapeutic to safely remove microplastics from our bodies.

Ask the Scientists

What is the context of this research?

It is estimated that humans may consume 74,000–121,000 microplastic particles per year through ingestion and inhalation combined (1). Among them, PET (polyethylene terephthalate) is widespread, used in bottles, textiles, and packaging (2). PET microplastics have been detected in human blood (3), and evidence of presence has also been reported in the placenta (4). Evidence suggests these particles may contribute to chronic inflammation (5), hormone disruption (6), and metabolic dysfunction (7). Scientists have already engineered enzymes such as PETase and MHETase that can efficiently depolymerize PET in environmental conditions (8). Based on this, it is theoretically possible that engineered versions of these enzymes could also act on PET microplastics in human biological fluids. What remains unknown, and what this study will test, is whether they remain active, stable under human-like conditions while demonstrating a safety profile suitable for therapeutic development.

What is the significance of this project?

This project represents the first step toward removing microplastics from the human body. If enzyme therapy could degrade PET microplastics within the human body, it would be a paradigm shift: rather than just reducing environmental plastic, we could remove plastics from our bodies. That could potentially mitigate inflammation, oxidative stress, endocrine disruption, or metabolic disease risk, which microplastics are associated with (8, 9, 10). A recent study showed an engineered PETase could degrade PET in human serum without harming cells (11). This is evidence that enzymes may function safely in human biological fluids. However, this early work tested a single enzyme under limited conditions. Our study will expand on this by systematically evaluating multiple engineered enzymes (PETase and MHETase), enzyme stability, dose-response safety, and breakdown products to determine whether this approach is truly viable for therapeutic development and human application.

What are the goals of the project?

In this first validation study, we’ll ask a simple question: can specially engineered enzymes safely break down PET microplastics in a blood-like fluid and remain friendly to human cells? We’ll add the enzymes (PETase and MHETase) to human serum containing PET, track how much plastic is broken down and how long the enzymes keep working, and check cell health in standard human cell models. We’ll also confirm that the breakdown byproducts are well-tolerated and non-toxic to human cells. With clear “go/no-go” criteria set in advance, the results will show if this approach is feasible, safe, and provide the evidence to move toward a first-of-its-kind therapeutic to reduce internal plastic burden in humans.