Bioaccumulation of perfluoroalkyl and polyfluoroalkyl substances (PFASs) is an important indicator of their hazard. Partitioning to membrane phospholipids is one of the pathways for their bioaccumulation. However, the molecular mechanism on PFASs uptake into membrane phospholipids is not yet to be fully understood. In this work, we used molecular dynamics (MD) simulations to study the uptake processes of PFOS and its alternatives (6:2 Cl-PFESA and OBS) into DPPC bilayers, and to evaluate their interaction with DPPC bilayers and their effect on properties of DPPC bilayers. The result of free energy changes shows that a barrier of 2–3 kcal mol⁻¹ exists when these adsorbed PFASs on the surface are absorbed into DPPC bilayers. After incorporating into DPPC bilayers, three DPPC molecules interact with and thus stabilize a PFOS (or 6:2 Cl-PFESA or OBS) molecule. And another role of the three DPPC molecules is to shield these PFASs from exposure to water environment. These PFASs have the similar condensing effect on the model membrane. The molecular-level study is beneficial for understanding the bioaccumulation and toxicity of PFOS and its alternatives.

全氟烷基和多氟烷基物质（PFAS）的生物蓄积是其危害的重要指标。膜磷脂的分配是其生物蓄积的途径之一。但是，尚未完全了解PFASs吸收到膜磷脂中的分子机制。在这项工作中，我们使用分子动力学（MD）模拟研究了全氟辛烷磺酸及其替代物（6：2 Cl-PFESA和OBS）进入DPPC双层的吸收过程，并评估了它们与DPPC双层的相互作用以及它们对DPPC双层膜性能的影响。 DPPC双层。自由能变化的结果表明，势垒为2-3 kcal mol ^-1当这些表面吸附的PFAS被吸收到DPPC双层中时，存在。掺入DPPC双层后，三个DPPC分子与PFOS（或6：2 Cl-PFESA或OBS）分子相互作用，从而使其稳定。三个DPPC分子的另一个作用是保护这些PFAS免受暴露于水环境中。这些PFAS对模型膜具有类似的冷凝作用。分子水平的研究有助于理解全氟辛烷磺酸及其替代物的生物蓄积性和毒性。