Polymer-Supramolecular Polymer Double-Network Hydrogel

Mechanical properties of hydrogels are critical for their applications as articular cartilage regeneration scaffolds, because they provide not only the mechanical support, but also the mechanical cues essential to maintain the phenotype of cartilage-forming cells. Inspired by the microscopic architecture of natural cartilage, here the engineering of a novel double-network hydrogel with interconnected polymer-supramolecular polymer double-network (PS-DN gel) for cartilage regeneration is reported. The polymer network is made of polyacrylamide and the supramolecular polymer network comprises of a kind of self-assembled peptide fibers. Upon mechanical loading, the peptide fibers serve as sacrificial bonds to efficiently dissipate energy. They can quickly reform when mechanical load is released thanks to the fast and accurate peptide self-assembly. These entail the PS-DN gel of high mechanical strength of approximate to 0.32-0.57 MPa, fracture energy of approximate to 300-2670 J m(-2), compressibility of approximate to 66%-90%, and fast recovery in seconds. The gel also shows significant energy dissipation, strain stiffening, and stress relaxation behaviors similar to articular cartilage. Moreover, the mechanical properties of the PS-DN gel can be tailored by adjusting the chemical components of the gel. Therefore, this novel biomaterial represents a promising candidate for the regeneration of cartilage and other load bearing tissues.