Cellular Process of Polystyrene Nanoparticles Entry into Wheat Roots

Abstract

Nanoscale plastic particles are widely found in the terrestrial environment and being increasingly studied in recent years. However, the knowledge of their translocation and accumulation mechanism controlled by nanoplastic characterizations in plant tissues is limited, especially in plant cells. Here, 20 mg L–1 polystyrene nanoparticles (PS NPs) with different sizes and amino/carboxy groups were employed to investigate the internalization process in wheat roots and cells. From the results, we found that the uptake of small-size PS NPs in the root tissues was increased compared to that of large-size ones, but no PS NPs were observed in the vascular cylinder. Similar results were observed in their cellular uptake process. Besides, the cell wall could block the entry of large-size PS NPs while the cell membrane could not. The −NH2 group on the PS NPs surface could benefit their tissular/cellular translocation compared to the −COOH group. The internalization of PS NPs was controlled by both particle size and surface functional group, and the size should be the primary factor. Our findings offer important information for understanding the PS NPs behaviors in plant tissues, especially at the cellular level, and assessing their potential risk to food safety, quality, and agricultural sustainability.

Distinguishing the nanoplastic–cell membrane interface by polymer type and aging properties: translocation, transformation and perturbation

“…Micro(nano)plastics continuously disintegrate into smaller particles until fully degraded in the environment, and size was expected as a primary aging property determining the cellular process of nanoplastics. 68,69 In our simulations, smaller nanoplastics of 5 nm equal to the membrane thickness rapidly translocate into the membrane. In the finite simulation period, only PE and PET nanoplastics remain intact, whereas PS, PP and PVC nanoplastics are all dissolved to a higher extent than larger nanoplastics (Fig.…”

“…Previous experiments demonstrated distinct accumulation of differentially charged nanoplastics in plant tissues, 19 and the cellular processes of nanoplastics were also influenced by the surface charge. 68,77 Our simulations reveal that cationic nanoplastics attract more lipids to enhance uptake.…”

“…In contrast with anionic nanoplastics, cationic nanoplastics cause more severe membrane perturbation due to favorable electrostatic interactions with the membrane containing negatively charged lipids, in accordance with experimental results. 68,76…”

“…Again, cationic nanoplastics show higher extents of cell membrane interactions, supporting previous experiments explaining the higher capacity of cell entry and cytotoxicity for cationic nanoplastics. 68,76 4 Discussion…”

“…In contrast with anionic nanoplastics, cationic nanoplastics cause more severe membrane perturbation due to favorable electrostatic interactions with the membrane containing negatively charged lipids, in accordance with experimental results. 68,76 Although our simulations provide molecular-level insights into the nanoplastic's fate and toxicity to mammalian cells, it is worth putting a caveat on these results. Firstly, membrane complexity has been improved by incorporating 63 different lipid species asymmetrically distributed across two leaflets (Fig.…”