Preparation of thermosensitive and supramolecular structured hydrogel by copolymerization of photocurable polypseudorotaxanes based on α-cyclodextrins with N-isopropylacrylamide and its characterization

The macromer of PLA-PEG-PLA terminated with methacryloyl moieties was prepared by one-pot procedure in high yield, both the ring-opening polymerization of L-lactide and end-capped reaction with methacrylic anhydride were carried out in toluene under nitrogen atmosphere at 120°C. Then the polypseudorotaxanes were obtained through supramolecular self-assemblies between α-CDs and the macromer. Afterwards, the resultant polypseudorotaxanes were suspended in aqueous solution of N-isopropylacrylamide (NIPA) in the presence of a photo-initiator. While exposed to UV irradiation, the suspension mixtures could be photopolymerized rapidly to give rise to the thermosensitive and supramolecular structured hydrogels. Their thermosensitivity was confirmed by the swelling ratio changes under different temperatures. The polypseudorotaxanes and hydrogels were characterized by FTIR, XRD and TG techniques. The studies on their potential use as biomedical materials are ongoing.