Cylindrical polyelectrolyte brushes from poly(styrenesulfonate) were synthesized by polymer analogous hydrolysis from the corresponding dodecyl and ethyl ester brushes. These brushes were characterized in solution (GPC-MALLS, static and dynamic light scattering, SANS, and H-1 NMR), and on solid interfaces (AFM and TEM). It was shown that the cylindrical brushes may form extended aggregates in solution. The aggregation behavior and the size and shape of the aggregates depend on the side chain length and the degree of saponification. For samples with identical backbone and side chain length, but varying degrees of ester hydrolysis, marked differences in the aggregation behavior were observed. Cylindrical end-functionalized polyelectrolyte brushes from poly(styrenesulfonate) were synthesized by a combination of anionic polymerization yielding an end-functionalized ATRP macroinitiator with a positively charged head group, atom transfer radical polymerization, and polymer analogous hydrolysis. The brushes and their precursors were characterized in solution by MALDI-TOF MS, H-1 NMR, GPC-MALLS, static and dynamic light scattering, and cryo-TEM. These brushes were found to form complexes with negatively charged latex particles. They may be discussed as models to mimic proteoglycan in the proteoglycan-hyaluronic acid complex.