A new collaborative study led by Imptox researchers from the University of Vienna designs test materials to better understand how nanoplastics interact with the human body.

Micro- and nanoplastics (MNPs) are increasingly being detected in every corner of the planet - from remote mountain peaks and ocean depths to food items, drinking water, and even within human tissues. These particles typically form through the degradation of larger plastic materials - such as packaging, textiles, or industrial waste - broken down over time by sunlight, mechanical forces, or chemical processes. Despite their ubiquity, significant uncertainties remain regarding their potential impacts on human health.

Among MNPs, nanoplastics - defined as particles smaller than one micrometer or a thousandth of a millimeter - pose particular scientific challenges. Their extremely small size allows them not only to evade standard detection methods, but also to easily cross biological barriers and enter deep into human organs, cells, and potentially even subcellular compartments. This raises critical concerns about their interactions with biological systems and their possible contribution to adverse health outcomes.

Given this context, it may seem counterintuitive that researchers are intentionally producing more of them in the lab! However, this approach is essential for one key reason: real-world MNP samples are highly heterogeneous. They vary widely in size, shape, polymer type, and surface chemistry, and are often associated with other environmental contaminants. Studying their effects under such uncontrolled conditions is similar to identifying the cause of a food allergy from a mystery stew.

To overcome this, scientists developed model nanoplastics - well-defined particles manufactured under controlled conditions - to enable reproducible and meaningful toxicological studies.

Designing with Purpose

Imptox researchers from the University of Vienna and the University of Belgrade, in collaboration with colleagues from PlasticsFatE and Polyrisk (fellow CUSP projects), have taken an important step forward in this area. Their new study, published in Environmental Science: Nano, introduces a new approach for producing nanoplastics from two commonly used materials: polyethylene terephthalate (PET) and polypropylene (PP) - the same plastics often found in food packaging and beverage bottles.

The team, led by Prof. Lea Ann Dailey (UniVie) used a quality-by-design approach, a concept borrowed from industry. Quality-by-design means thinking ahead. Before making the nanoplastics, the team defined exactly what properties the particles needed to have - like size, purity, and easy handling for use in lab tests. Then they built their process around meeting those standards.

The result? High-quality, standardized nanoplastics that are ready to use in cell cultures and animal studies. These materials were made consistently and in sufficiently large quantities, paving the way for more reliable experiments on how nanoplastics might affect health.

Laying the Groundwork for Global Comparisons

These model particles could eventually become reference materials, helping to standardize nanoplastics research across laboratories and institutions. If adopted by the International Organization for Standardization (ISO), they would allow scientists worldwide to compare results more easily - an essential step for advancing the field and shaping future regulatory decisions.

As researchers continue to investigate how MNPs may contribute to allergies, asthma, and other health outcomes, having reliable and reproducible tools is crucial. In the global challenge of plastic pollution, even the smallest particles matter. Thanks to thoughtful design and international collaboration, scientists are finally gaining the tools they need to study them.

Reference: Wimmer, L., Nguyen Hoang, M. V., Schwarzinger, J., Jovanović, V. B., Anđelković, B., Cirkovic Velickovic, T., Meisel, T., Waniek, T., Weimann, C., Altmann, K., & Dailey, L. A. (2025). A quality-by-design inspired approach to develop PET and PP nanoplastic test materials for use in in vitro and in vivo biological assays. Environmental Science: Nano. https://doi.org/10.1039/D4EN01186D