Recent studies have shown that the interactions between condensates and biological membranes is of functional importance. Here, we study how the interaction between complex coacervates and liposomes as model systems can lead to membrane deformation and endocytosis. Depending on the interaction strength between coacervates and liposomes, the wetting behavior ranged from non-wetting, to partial wetting (adhesion), engulfment (endocytosis), and finally complete wetting. Endocytosis of coacervates was found to be a general phenomenon: coacervates made from a wide range of components could be taken up by liposomes. A simple theory that takes into account surface energies and coacervate sizes can explain the observed coacervate-liposome interactions. Our findings can help to better understand condensate-membrane interactions in cellular systems and provide new avenues for intracellular delivery using coacervates.
Supplementary methods, tables, figures and theory.