Enzyme-catalyzed preparation of supramolecular structured hydrogel of polypseudorotaxanes derived from the self-assembly of α-CDs with 3-arm p-hydroxyphenylpropionate terminated PEG

A kind of novel 3-D cross-linked supramolecular structured hydrogels has been fabricated via enzymatic oxidative coupling of polypseudorotaxanes (PPRs) derived from the self-assembly of α-cyclodextrins (α-CDs) with 3-arm p-hydroxyphenylpropionate terminated PEG (3-HPPP) as a macromer by using horseradish peroxidase (HRP)/H₂O₂ catalytic system. The enzymatic cross-linking of the macomer or PPRs made with a smaller amount of α-CDs was found to be much faster than that by ordinary chemical pathways, showing the promise to be used as the surgical adhesive and sealant which are needed to rapidly function in vivo. The gelation time was highly extended and the gel content was considerably decreased by increasing the α-CDs to macromer feeding molar ratio. Thereby these hydrogels exhibited a decreasing trend in dynamical mechanical properties with increasing the amount of α-CDs in regard to the blank hydrogel made without α-CD addition.