Bioinspired Hyperboloid Mechanical Metamaterial for Shock Absorption and Strain Regulation in Cartilage Remodeling.

Inspired by the shock-absorbing capabilities of natural insect elytra, a hyperboloid lattice metamaterial exhibiting unique compression-torsion coupling behavior is designed and fabricated. This structure efficiently converts dynamic loads into strain energy, enabling high-strain elastic deformation. The hyperboloid lattice is integrated with a classic reticulation framework and filled with GelMA hydrogel, creating a tailored osteochondral scaffold with mechanical properties that closely match those of joint tissue. Under dynamic mechanical culture, compression-torsion stimulation in the hyperboloid zone induced high-strain elastic deformation, promoting chondrogenic differentiation of stem cells, while the more rigid reticulation zone, experiencing minimal deformation, facilitated osteogenic differentiation of stem cells. In a rabbit osteochondral defect model, hyperboloid-based shock-absorption scaffolds significantly enhanced the integrative repair of both cartilage and subchondral bone via the NF-κB and calcium signaling pathways. The incorporation of the hyperboloid metamaterial, with its shock-absorbing and strain-regulating properties, demonstrates great potential for developing adaptable mechanical scaffolds for cartilage remodeling.