New kinds of thermosensitive and supramolecular structured hydrogels were synthesized via copolymerization of N-isopropylacrylamide (NIPA) with photocurable and biodegradable polypseudorotaxanes as cross-linkers under UV irradiation. The polypseudorotaxanes were prepared by supramolecular self-assemblies of R-cyclodextrins threaded onto amphiphilic LA-PEG-LA copolymers end-capped with methacryloyl groups. The structure of the hydrogels was characterized in detail with FTIR, 1 H NMR, XRD, DSC, and TGA techniques. The analytical results have demonstrated that the channel-type crystalline structure of inclusion complexes (ICs) remains in as-obtained hydrogels. Their swelling behavior was measured gravimetrically in the temperature range from 22 to 67 °C. It was observed that the crosslinked hydrogel made of only the macromer guest shows also thermosensitive. However, this stimuliresponsive property disappears when R-CDs are threaded onto the polymeric backbone and reappears when PNIPA blocks are introduced. The theromsensitivity of these hydrogels could be modulated by changing the PNIPA content as well as the R-CD to macromer ratio.

A kind of novel three-dimensional crosslinked networks based on the self-assemly of a-CDs with thiolated four-arm PEG was prepared by thiol-disulfide interchange reaction using a three-step oxidation. The supramolecular structure of the resulting hydrogels was characterized via FTIR, 1 H NMR, XRD, DSC and TGA measurements. The results demonstrated that the channel-type crystalline structure of inclusion complexes is still maintained after the multi-step oxidation. According to the swelling and degradation tests, the swelling behaviors and degradation properties can be readily regulated by tuning the feed compositions of a-CDs and PEG-thiolated prepolymer. Furthermore, the threading a-CDs clearly protects disulfide bonds from an attack of a reduced form of glutathione as a result of prolonging the degradation time of the hydrogels in water.

A novel gelation process is demonstrated in self‐assemblies of amphiphilic star‐shaped macromers of poly(L‐lactide)‐b‐poly(ethylene glycol) bearing methacryloyl terminals with α‐cyclodextrins. A physical hydrogel is first formed by inclusion complexation, and subsequently it is changed when a chemically crosslinked hydrogel under UV irradiation; a photoinitiator is added in advance, and this leads to a great improvement in the strength of the hydrogel. The effects of the degree of polymerization of the lactide oligomers as well as the amounts of α‐cyclodextrins added on the gelation time are described in detail. The analytical results show that most of the α‐cyclodextrins added are still threaded and immobilized onto the network chains after photopolymerization. A study of the gel content and equilibrium swelling behaviors of the crosslinked hydrogel has been performed.

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