Materials Physics, Department of Physics and Astronomy, Ångström Laboratory, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (SLU), Box 7050, SE-750 07 Uppsala, Sweden.
J Colloid Interface Sci. 2018 Feb 1;511:474-481. doi: 10.1016/j.jcis.2017.09.102. Epub 2017 Sep 28.
The interactions between perfluoroalkyl substances (PFASs) and a phospholipid bilayer (1,2-dimyristoyl-sn-glycero-3-phosphocholine) were investigated at the molecular level using neutron reflectometry. Representative PFASs with different chain length and functional groups were selected in this study including: perfluorobutane sulfonate (PFBS), perfluorohexanoate (PFHxA), perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA), perfluorooctane sulfonate (PFOS), and perfluorooctane sulfonamide (FOSA). All PFASs were found to interact with the bilayer by incorporation, indicating PFAS ability to accumulate once ingested or taken up by organisms. The interactions were observed to increase with chain length and vary with the functional group as SONH(FOSA)>SOO(PFOS)>COO(PFNA). The PFAS hydrophobicity, which is strongly correlated with perfluorocarbon chain length, was found to strongly influence the interactions. Longer chain PFASs showed higher tendency to penetrate into the bilayer compared to the short-chain compounds. The incorporated PFASs could for all substances but one (PFNA) be removed from the lipid membrane by gentle rinsing with water (2mLmin). Although short-chain PFASs have been suggested to be the potentially less bioaccumulative alternative, we found that in high enough concentrations they can also disturb the bilayer. The roughness and disorder of the bilayer was observed to increase as the concentration of PFASs increased (in particular for the high concentrations of short-chain substances i.e. PFHxA and PFBS), which can be an indication of aggregation of PFASs in the bilayer.
采用中子反射技术在分子水平上研究了全氟烷基物质（PFAS）与磷脂双层（1,2-二肉豆蔻酰-sn-甘油-3-磷酸胆碱）之间的相互作用。在本研究中选择了具有不同链长和官能团的代表性 PFAS，包括：全氟丁烷磺酸（PFBS）、全氟己酸（PFHxA）、全氟己烷磺酸（PFHxS）、全氟壬酸（PFNA）、全氟辛烷磺酸（PFOS）和全氟辛烷磺酰胺（FOSA）。所有 PFAS 均被发现通过掺入与双层相互作用，表明 PFAS 一旦被摄入或被生物体吸收，就有积累的能力。观察到相互作用随链长而增加，并随官能团而变化，即 SONH（FOSA）>SOO（PFOS）>COO（PFNA）。与全氟碳链长度密切相关的 PFAS 疏水性被发现强烈影响相互作用。与短链化合物相比，长链 PFAS 更倾向于穿透双层。除一种物质（PFNA）外，所有物质的掺入 PFAS 都可以通过用温和的水（2mLmin）冲洗从脂质膜中去除。尽管短链 PFAS 被认为是潜在的生物累积性较低的替代品，但我们发现，在足够高的浓度下，它们也会干扰双层。随着 PFAS 浓度的增加（特别是对于短链物质的高浓度，即 PFHxA 和 PFBS），观察到双层的粗糙度和无序性增加，这可能表明 PFAS 在双层中聚集。
