In this proposal, we focus on the effect of hydrostatic pressure on the co-assembly behavior of strongly pH-responsive polyelectrolyte - surfactant complexes. The studied system is based on diluted solutions of chitosan, a cationic polysaccharide and oppositely charge ethoxylated fatty acids, whose behavior is strongly dependent on the degree of ionization of the surfactant. By applying an external pressure on the system, the effective pKa of the surfactant is systematically changed, and therefore its degree of charging. Accordingly, already small variations in external pressure are expected to have a deep impact on the resulting self-assembled colloids, as the strong pressure-dependence of the surfactant ionization is used as a lever to amplify the pressure effects on the self-assembly process.