Slide-Ring Hydrogel Networks via Host–Guest Complexation with Cucurbit[8]uril

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Slide-ring hydrogels are a promising class of materials with exceptional toughness, but most rely on pseudopolyrotaxane architectures of cyclodextrin (CD) and poly(ethylene glycol) (PEG) with complicated synthesis and limited tunability. Here, we successfully incorporate cucurbit[8]uril (CB[8]) macrocycles into host–guest slide-ring hydrogels, creating a novel architecture that overcomes these limitations and offers exceptional control over network structure. Using azobenzene guest-modified telechelic macromers that form CB[8]–guest homoternary complexes, this platform enables precise regulation of cross-link density, variation of the axle and axle length, and introduction of an energy dissipation mechanism. The resulting slide-ring hydrogels exhibit exceptional tensile performance combined with improved toughness, overcoming the typical stiffness–toughness trade-off in this class of materials. Hydrogels prepared by using a PEG backbone achieved an elastic modulus of up to 45 kPa, a maximum elongation of 3241%, and a work of rupture (toughness) of 7227 kJ/m 3 . More strikingly, exchanging the PEG polymer for a Pluronic F127 backbone enabled an increased elastic modulus (182 kPa) and toughness (15608 kJ/m 3 ), with a comparable maximum elongation (2815%). Both systems surpassed conventional CD-based gels, offering a versatile platform for designing highly tunable, tough hydrogels for advanced applications.