OEGylated cyclodextrin-threaded polyrotaxanes (PRXs) capped with UV-cleavable stoppers were synthesized, and their thermoresponsive and degradable behavior were investigated. These PRXs in aqueous solutions exhibit fast thermally induced phase transitions and small hysteresis as well as tunable phase transition temperatures, which are quite distinct from previous methylated PRXs. Based on the mechanically interlocked architecture, PRXs are stable in solutions but can be completely degraded into hydrophilic components upon UV cleavage of stoppers. As a consequence, the thermoresponsive behavior of PRXs was switched off. Furthermore, micrometer-scale globular aggregates were formed from thermoresponsive PRXs above their phase transition temperatures but disaggregated quickly upon cooling or UV irradiation. This phenomenon was utilized to take these PRXs as unique carriers for guests with dually controlled release by both temperature and light. The present work provides efficient synthesis of a new class of thermoresponsive interlocked polymers with on-demand degradation, and the findings illustrate the prominent effect of PRX architecture on the remarkable thermoresponsive and degradable behavior.

The present work provides a versatile access for "smart" cyclodextrins (CDs) that are responsive to temperature, redox, and metal ions. These CDs are modified with oligoethylene glycols through thiol-ene click chemistry, which are inherently thermoresponsive in aqueous solutions. At the same time, their thermoresponsiveness is tunable through oxidation or metal ion chelation of thioether moieties. Significantly, these stimuli-responsive CDs retained strong inclusion abilities to guest dyes, and the inclusion complexation can be tuned by thermally induced phase transitions, oxidation, as well as metal chelation. The stimuli-responsive complexation with dyes allows to fabricate colorimetric/fluorescent sensors for temperature or for soft metal ions, such as Ag and Hg. With multiple responsiveness integrated in one material, these monodisperse CDs have formed a new class of stimuli-responsive macrocycles, which can reversibly encapsulate and release guest species through multiple switches.

Monodisperse thermoresponsive cyclodextrins appended with benzenesulfonamides were demonstrated to reversibly regulate the enzymatic activity of carbonic anhydrase, which was found to be dependent on both scaffold effect and thermoresponsiveness.