A Comparative Study on the Interaction Between Protein and PET Micro/Nanoplastics: Structural and Surface Characteristics of Particles and Impacts on Lung Carcinoma Cells (A549) and Staphylococcus aureus

Abstract

The interaction between particles and proteins is a key factor determining the toxicity responses of particles. Therefore, this study aimed to examine the interaction between the emerging pollutant polyethylene terephthalate micro/nanoplastics from water bottles with bovine serum albumin. The physicochemical characteristics of micro/nanoplastics were investigated using nuclear magnetic resonance, x‐ray diffraction, Fourier transform infrared, dynamic light scattering, and x‐ray energy dispersive spectroscopy after exposure to various concentrations and durations of protein. Furthermore, the impact of protein‐treated micro/nanoplastics on biological activities was examined using the mitochondrial activity and membrane integrity of A549 cells and the activity and biofilm production of Staphylococcus aureus. The structural characteristics of micro/nanoplastics revealed an interaction with protein. For instance, the assignment of protein‐related new proton signals (e.g., CH2, methylene protons of CH2O), changes in available protons s (e.g., CH and CH3), crystallinity, functional groups, elemental ratios, zeta potentials (−11.3 ± 1.3 to −12.4 ± 1.7 to 25.5 ± 2.3 mV), and particle size (395 ± 76 to 496 ± 60 to 866 ± 82 nm) of micro/nanoplastics were significantly observed after protein treatment. In addition, the loading (0.012–0.027 mM) and releasing (0.008–0.013 mM) of protein also showed similar responses with structural characteristics. Moreover, the cell‐based responses were changed regarding the structural and surface characteristics of micro/nanoplastics and the loading efficiencies of protein. For example, insignificant mitochondrial activity (2%–10%) and significant membrane integrity (12%–28%) of A549 cells increased compared with control, and reductions in bacterial activity (5%–40%) in many cases and biofilm production specifically at low dose of all treatment stages (13%–46% reduction) were observed.