Polystyrene-block-polyvinylpyridine (PS-b-P4VP) polypseudorotaxanes with cucurbit[7]urils (CB[7]) were prepd. from water sol. PS-b-P4VPH+ polymer and CB[7] in aq. soln. at room temp. At acidic and neutral pH, the pyridinium block of PS-b-P4VP is protonated (PS-b-P4VPH+) pushing CB[7] to preferably host the P4VP block. At basic pH (pH 8), P4VP is not charged and thus is not able to strongly complex CB[7]. This phenomenon was verified further by monitoring the release of pyrene, a hydrophobic cargo model, from a PS-b-P4VPH+/CB[7] micellar membrane. Release study of UV active pyrene from the membrane at different pH values revealed that the system is only operational under basic conditions and that the host-guest interaction of CB[7] with P4VPH+ significantly slows down cargo release.