Effect of PFAS partitioning on diffusiophoretic migration of phospholipid vesicles

The exceptional amphiphilicity of per- and polyfluoroalkyl substances (PFAS) enables them to penetrate through biological plasma membranes. While the partitioning of PFAS into phospholipid bilayers and its consequent effects on membrane properties have been extensively studied, their influence on the vesicular transport remains largely unexplored. Here, we investigate how PFAS partitioning impacts the diffusiophoretic transport of phospholipid vesicles. Our hypothesis is that insertion of ionic PFAS compounds would alter the surface charge of vesicles, thereby modulating their diffusiophoretic mobility. To test this, we use a microfluidic assay to quantify vesicle migration in the presence of PFAS, along with quartz crystal microbalance experiments to quantify PFAS-lipid interactions. Comparing the experimental results with theoretical predictions, we find that the change in the zeta potential due to the PFAS insertion follows a simple Langmuir isotherm. Notably, we observe an anomalous boomerang-like diffusiophoretic motion of vesicles upon exposure to certain PFAS species. Our study suggests that PFAS partitioning can lead to abnormal transport of membrane-bound biological colloids.