• Nano-sized plastics may enter and permea

    From ScienceDaily@1:317/3 to All on Thu Feb 17 21:30:42 2022
    Nano-sized plastics may enter and permeate cell membranes

    Date:
    February 17, 2022
    Source:
    University of Eastern Finland
    Summary:
    Researchers have used molecular modelling methods to investigate the
    movement of nano-sized plastics in membrane structures. The results
    indicate that for some microplastics, passive transport through
    the cell membrane may be a significant gateway into the cell.



    FULL STORY ========================================================================== Researchers at the University of Eastern Finland have used molecular
    modelling methods to investigate the movement of nano-sized plastics in membrane structures. The results indicate that for some microplastics,
    passive transport through the cell membrane may be a significant gateway
    into the cell.


    ==========================================================================
    The occurrence of microplastics in nature has been studied extensively,
    also at the University of Eastern Finland. However, little is known about
    the health effects of microplastics, and understanding of their transport
    into the human body is also lacking. Any adverse health effects possibly associated with plastics may be caused by the plastic compound itself,
    or by the environmental toxins it carries. Many known fat-soluble
    environmental toxins and heavy metals are known to be able to attach
    to the surface of small plastic particles. This is why it is important
    to investigate the transport mechanisms of microplastics into the human
    body. However, not enough research methods have been developed for the
    study of this transport. Another key challenge in microplastics research
    is the lack of standardised methods.

    With the help of molecular modelling, researchers at the University
    of Eastern Finland's School of Pharmacy analysed the behaviour and
    transport of nano-sized microplastics in bilayer membranes which mimic
    cell membranes. The researchers performed simple molecular dynamics
    simulations using well-known and widely used polyethylene (PE) and
    polyethylene terephthalate (PET) particles.

    The cell membrane permeability of pulverised PE and PET plastics was also examined using the Parallel Artificial Membrane Permeability Assay method, PAMPA. The method is usually used to investigate passive absorption of medicines, but it hasn't been used to study microplastics before. The
    PAMPA method was used to investigate the amount of matter permeating
    the membrane.

    The amount of plastic permeating the artificial membrane was measured
    by NMR spectroscopy at certain intervals.

    In both experiments, the movement of molecules was controlled only by concentration differences on different sides of the membrane, and by
    occasional movement induced by heat. In other words, the methods provided information on the passive permeation of molecules through the membranes.

    In the computer simulations, PE particles were found to prefer the
    centre of the lipid membrane as their location. In the PAMPA experiments,
    PE plastic partially permeated the membrane, but membrane permeability
    slowed down significantly over time, probably due to the accumulation
    of plastic in the membrane. In the simulations, the preferred location
    of PET particles was, to a certain degree, the surface part of the
    membrane, and in the experiments, they permeated the membrane fairly
    well. According to this study, the properties of the membrane structures
    were not significantly affected by individual plastics.

    The study provides a starting point for the further development
    of computer simulations and experimental methods for the needs of
    microplastics research.

    Significantly more information is still needed on the active transport
    of microplastics, such as their binding to transporter proteins, possible phagocytosis, and toxic effects on cells.

    The study was funded by the Olvi Foundation and the Doctoral School of
    the University of Eastern Finland. High-performance computing resources
    of CSC - - IT Centre for Science were used in the simulations.

    ========================================================================== Story Source: Materials provided by University_of_Eastern_Finland. Note: Content may be edited for style and length.


    ========================================================================== Journal Reference:
    1. Joni Ja"rvenpa"a", Milla Perkkio", Riikka Laitinen, Maija Lahtela-
    Kakkonen. PE and PET oligomers' interplay with membrane bilayers.

    Scientific Reports, 2022; 12 (1) DOI: 10.1038/s41598-022-06217-4 ==========================================================================

    Link to news story: https://www.sciencedaily.com/releases/2022/02/220217141218.htm

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