title: Real-Time Visualization of Perylene Nanoclusters in Water and Their Partitioning to Graphene Surface and Macrophage Cells.
abstract: Hydrophobic organic chemicals (HOCs) are of special ecotoxicological concern because they can be directly incorporated and bioconcentrated in living organisms. However, the effects of self-clustering of HOCs on their environmental behavior and toxicology have not yet received enough attention. With the use of a recently developed technique, single-molecule fluorescence microscopy, the motion and distribution of perylene nanoclusters (PNCs) formed in water at very low concentration (1 μM) were visualized with high temporal and spatial resolution. The liquid-solid interface process of PNCs adsorbing onto graphene was also recorded. Instead of the traditional view of HOC adsorption as a single molecule, our study revealed the characteristic of irreversible adsorption of perylene onto the carbonaceous surface in the form of nanoclusters, exhibiting random sequential "car-parking" events. More interestingly, the transport of PNCs across the cell membrane was also captured in real time, demonstrating that they entered macrophage cells by endocytosis. Supplementing the well-recognized routine of passive diffusion through a membrane lipid bilayer, the uptake of HOCs in the form of nanoclusters by endocytosis is proposed to be an additional but important mechanism for their uptake into living cells. The distribution of HOCs in environmental systems in the form of nanoclusters, exemplified by PNCs in this study, may have significant implications for understanding their environmental fate and potential toxicological effects.
authors.affiliation: †State Key Laboratory of Environment Simulation, School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Beijing 100875, China.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Guo
authors.affiliation: †State Key Laboratory of Environment Simulation, School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Beijing 100875, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Jin
authors.affiliation: †State Key Laboratory of Environment Simulation, School of Environment, Beijing Normal University, No. 19 Xinjiekouwai Street, Beijing 100875, China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Lv
authors.affiliation: ‡Biodynamic Optical Imaging Center, School of Life Science, Peking University, No. 5 Yiheyuan Road, Beijing 100871, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Pu
authors.affiliation: ‡Biodynamic Optical Imaging Center, School of Life Science, Peking University, No. 5 Yiheyuan Road, Beijing 100871, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Bai
mesh_terms: D000327:Adsorption; D000818:Animals; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D003199:Computer Systems; D005453:Fluorescence; D006108:Graphite / Q000737:chemistry*; D007700:Kinetics; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry*; D010569:Perylene / Q000032:analysis*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D014874:Water Pollutants, Chemical; D014867:Water; D010569:Perylene; D006108:Graphite