Abstract

Nanoplastic particles are at least two orders of magnitude smaller than eukaryotic cells, and therefore their environmental and health effects are likely to stem from their molecular level interplay with living organisms. The underlying interactions with biomolecular systems are, however, difficult to characterize experimentally, due to the complexity of polymer systems and the biological matrix they are embedded in. To overcome these obstacles, we employed molecular modeling, which helped us understanding the changes nanoplastics induce in the molecular structure of biomolecules in solution.

Modeling nanoplastics has its own challenges, in particular creating reasonable starting geometries for these polymer assemblies. We established an involved, rigorous workflow to generate nanoplastic models for molecular simulations through the self-assembly of polymer macromolecules [1]. To avoid such a series of simulations every time before simulating a system that contains nanoplastics, we created an online library, where the best obtained structures are freely available, aiding future modeling studies in the field. The self-assembly of the macromolecules composing the nanoplastics is strongly influenced by the solvent, as we found that the density of these particles varies significantly in different media. A similar protocol was used to predict the adsorption of antibiotics on nanoplastics through the example of tetracycline, and was found that this process can have a severe impact through the known Trojan horse effect, and also via hindering the absorption of drugs into the body during treatment [2].

Furthermore, we investigated examples of proteins, lipids, and nucleic acids in contact with polymer systems. Interactions of polyethylene particles with lipid bilayers showed significant perturbations in the membrane structure. Polystyrene was found prone to crossing membranes that resemble the blood-brain barrier. We found that the molecules adsorbed onto the surface of these plastics, i.e. the corona, have a decisive effect in this process. Interactions of polymers with proteins [3] and DNA [4] both triggered significant changes in the conformation and self-assembly of these biomolecules, which may also have severe biological impact. In future studies molecular modeling will be employed to more complex systems, which will enable us to connect the predictions from our calculations with direct toxic effects induced by these pollutants.

References

[1] B. Szabó et al., J. Phys. Chem. B. 130, 881 (2026).

[2] L. Dick et al., Sci. Rep. 14, 25853 (2024).

[3] O. Hollóczki, S. Gehrke, Sci. Rep. 9, 16013 (2019).

[4] M. Varenicja, O. Hollóczki, Nano Lett. 25, 15890 (2025).