Prof. Dr Oldamur Hollóczki
Department of Physical Chemistry, University of Debrecen, Egyetem tér 1., 4032 Debrecen, Hungary
Through the fragmentation of plastic waste, micro- and nanoplastics (MNPs) are formed and distributed through our environment. While these particles have been observed in food, various organisms, and even in human tissues, their impact is still unclear, partly due to the variety of MNPs in composition, size, shape, compounds at their surface (i.e. corona), and partly due to the limitations of analytical techniques to observe them. Molecular modeling offers a structural insight into the interactions of MNPs with biomolecular systems, leading to a deeper understanding of the environmental and health effects of these pollutants [1].
Molecular dynamics simulations have revealed the fundamental interactions between MNPs and lipid bilayers [2]. In the passing of the MNP through a membrane, the role of the corona was shown. Depending on the composition of the corona, the thermodynamics of the sorption into the bilayer
(e.g. a blood-brain barrier model) can be varied significantly. Thereby it is feasible that with the right compounds adsorbed onto the surface of the particle, the passive transmembrane transport through the blood-brain barrier can be thermodynamically and kinetically possible. In agreement, only two
hours after mice are fed with food containing environmentally relevant concentration of MNPs, plastic particles appear in their brain tissue just after two hours [2].
When interacting with biomolecules, the composition of the MNP is decisive. Simulations and quantum chemical calculations showed that MNPs can alter the secondary structure of proteins [3,4]. Depending on the plastic compound, the relative energy between α-helix and β-sheet structures of the same protein can be shifted significantly. While polyethylene was found to stabilize the helix, nylon-6,6 was prone to change the peptide into a β-sheet [2, 3]. Since neurodegenerative diseases may be related to changes in secondary structures of certain proteins, these findings show that further research in the field is essential.
Keywords: nanoplastics, Toxicity, biomolecular structure, pollution, molecular dynamics, quantum chemistry
References:
[1] E. S. Gruber, V. Stadlbauer, V. Pichler, K. Resch-Fauster, A. Todorovic, T. C. Meisel, S. Trawoeger, O. Hollóczki, S. D. Turner, W. Wadsak, A. D. Vethaak, L. Kenner. Expo. Health 15 (2023), 33.
[2] V. Kopatz, K. Wen, T. Kovács, A. S. Keimowitz, V. Pichler, J. Widder, D. A. Vethaak, O. Hollóczki, L. Kenner. Nanomaterials, 13 (2023), 1404.
[3] O. Hollóczki and S. Gehrke. Sci. Rep. 9 (2019), 16013.
[4] O. Hollóczki. Int. J. Quantum Chem. 121 (2021), e26372.
Recording:
Virtual Winter School on Computational Chemistry