Cyclodextrin-linked PVP/PEG supramolecular hydrogels

Herein, we developed supramolecular hydrogels by using cyclodextrin (CD) molecules as crosslinking domains to hold poly(ethylene glycol) (PEG) and poly(N-vinylpyrrolidone) (PVP) chains in a network structure. The presence of PVP surrounding α-CD-PEG inclusion complexes through hydrogen bonds resulted in water-insoluble gels. Feed ratios of the reaction components and the molecular weight of the PEG chains were found considerably essential to adjust the properties of the final networks. With the increase of PEG concentration both the elastic and viscous modulus and the tensile capacity of the gels decreased. When the molecular weight of the PEG chains was used as ≥10 kDa, stable gels resistant to swelling forces were obtained. The synergistic effect of physical and chemical crosslinking by adding poly(ethylene glycol) dimethacrylate (PEGDMA) to the system was also investigated at varying concentrations resulted in stable networks with self-healing properties.