We propose a strategy to adjust the size of multiliposomal complexes made of small unilamellar anionic liposomes (lipid bilayer vesicles prepared from zwitterionic lipid 1,2-dioleoyl-sn-glycero-3phosphocholine DOPC and ionic lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine POPS with a typical diameter of 50 nm) with cationic polymers due to electrostatic attraction. Hereby, the use of quaternized poly(dimethylaminoethyl methacrylate), qPDMAEMA, allows the construction of multicompartmental carriers. Variation of the architecture and composition of various qPDMAEMA samples demonstrates the effect of introducing poly(ethylene oxide) PEO moieties and/or branching on the size of the hierarchical assemblies: both the PEO block (as seen for block copolymers and miktoarm stars) and the branching (as seen for star-shaped homopolymers and miktoarm stars) lead to smaller complexes compared to complexes with a linear qPDMAEMA homopolymer. Besides the use of cryogenic transmission electron microscopy (cryo-TEM), the formation of multicompartmental carriers composed of differently loaded liposomes is verified by two-color fluorescence cross-correlation spectroscopy (FCCS). (C) 2017 Elsevier Ltd. All rights reserved.