Switch on/off microcapsules for controllable photosensitive drug release in a ‘release-cease-recommence’ mode

Microcapsules as carriers with special ‘release-cease-recommence’ capabilities were fabricated through a layer-by-layer (LbL) assembly that was driven by a host–guest interaction between adamantane (AD) and β-cyclodextrin (β-CD), as well as a UV-sensitive one between azobenzene (Azo) and β-CD. These two kinds of interactions enabled the microcapsules to switch reversibly between ‘off’ and ‘on’ states triggered by UV rays. The controllable transformation of the two states allowed the contents to release or halt and thus attain a ‘release-cease-recommence’ mode.